Publications by authors named "Steven B Heymsfield"

388 Publications

Stimulated Insulin Secretion Predicts Changes in Body Composition Following Weight Loss in Adults with High BMI.

J Nutr 2021 Sep 29. Epub 2021 Sep 29.

New Balance Foundation Obesity Prevention Center, Boston Children's Hospital, Boston, MA, USA.

Background: The aim of obesity treatment is to promote loss of fat relative to lean mass. However, body composition changes with calorie restriction differ among individuals.

Objectives: The goal of this study was to test the hypothesis that insulin secretion predicts body composition changes among young and middle-age adults with high BMI (in kg/m2) following major weight loss.

Methods: Exploratory analyses were conducted with pre-randomization data from 2 large feeding trials: the Framingham, Boston, Bloomington, Birmingham, and Baylor study (FB4; n = 82, 43.9% women, BMI ≥27) and the Framingham State Food Study [(FS)2; n = 161, 69.6% women, BMI ≥25]. Participants in the 2 trials consumed calorie-restricted moderate-carbohydrate or very-low-carbohydrate diets to produce 12-18% weight loss in ∼14 wk or 10-14% in ∼10 wk, respectively. We determined insulin concentration 30 min after a 75-g oral glucose load (insulin-30) as a measure of insulin secretion and HOMA-IR as a measure of insulin resistance at baseline. Body composition was determined by DXA at baseline and post-weight loss. Associations were analyzed using general linear models with adjustment for covariates.

Results: In FB4, higher insulin-30 was associated with a smaller decrease in fat mass (0.441 kg per 100 μIU/mL increment in baseline insulin-30; P = 0.005; -1.20-kg mean difference between the first compared with the fifth group of insulin-30) and a larger decrease in lean mass (-0.465 kg per 100 μIU/mL; P = 0.004; 1.27-kg difference). Participants with higher insulin-30 lost a smaller proportion of weight loss as fat (-3.37% per 100 μIU/mL; P = 0.003; 9.20% difference). Greater HOMA-IR was also significantly associated with adverse body composition changes. Results from (FS)2 were qualitatively similar but of a smaller magnitude.

Conclusions: Baseline insulin dynamics predict substantial individual differences in body composition following weight loss. These findings may inform understanding of the pathophysiological basis for weight regain and the design of more effective obesity treatment. Registered at clinicaltrials.gov as NCT03394664 and NCT02068885.
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http://dx.doi.org/10.1093/jn/nxab315DOI Listing
September 2021

A pose-independent method for accurate and precise body composition from 3D optical scans.

Obesity (Silver Spring) 2021 Sep 21. Epub 2021 Sep 21.

Graduate Program in Human Nutrition, University of Hawai'i Manoa, Honolulu, Hawaii, USA.

Objective: The aim of this study was to investigate whether digitally re-posing three-dimensional optical (3DO) whole-body scans to a standardized pose would improve body composition accuracy and precision regardless of the initial pose.

Methods: Healthy adults (n = 540), stratified by sex, BMI, and age, completed whole-body 3DO and dual-energy X-ray absorptiometry (DXA) scans in the Shape Up! Adults study. The 3DO mesh vertices were represented with standardized templates and a low-dimensional space by principal component analysis (stratified by sex). The total sample was split into a training (80%) and test (20%) set for both males and females. Stepwise linear regression was used to build prediction models for body composition and anthropometry outputs using 3DO principal components (PCs).

Results: The analysis included 472 participants after exclusions. After re-posing, three PCs described 95% of the shape variance in the male and female training sets. 3DO body composition accuracy compared with DXA was as follows: fat mass R = 0.91 male, 0.94 female; fat-free mass R = 0.95 male, 0.92 female; visceral fat mass R = 0.77 male, 0.79 female.

Conclusions: Re-posed 3DO body shape PCs produced more accurate and precise body composition models that may be used in clinical or nonclinical settings when DXA is unavailable or when frequent ionizing radiation exposure is unwanted.
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http://dx.doi.org/10.1002/oby.23256DOI Listing
September 2021

The carbohydrate-insulin model: a physiological perspective on the obesity pandemic.

Am J Clin Nutr 2021 Sep 13. Epub 2021 Sep 13.

New Balance Foundation Obesity Prevention Center, Boston Children's Hospital, Boston, MA, USA.

According to a commonly held view, the obesity pandemic is caused by overconsumption of modern, highly palatable, energy-dense processed foods, exacerbated by a sedentary lifestyle. However, obesity rates remain at historic highs, despite a persistent focus on eating less and moving more, as guided by the energy balance model (EBM). This public health failure may arise from a fundamental limitation of the EBM itself. Conceptualizing obesity as a disorder of energy balance restates a principle of physics without considering the biological mechanisms that promote weight gain. An alternative paradigm, the carbohydrate-insulin model (CIM), proposes a reversal of causal direction. According to the CIM, increasing fat deposition in the body-resulting from the hormonal responses to a high-glycemic-load diet-drives positive energy balance. The CIM provides a conceptual framework with testable hypotheses for how various modifiable factors influence energy balance and fat storage. Rigorous research is needed to compare the validity of these 2 models, which have substantially different implications for obesity management, and to generate new models that best encompass the evidence.
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http://dx.doi.org/10.1093/ajcn/nqab270DOI Listing
September 2021

Can increasing physical activity prevent aging-related loss of skeletal muscle?

Am J Clin Nutr 2021 Sep 2. Epub 2021 Sep 2.

Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA.

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http://dx.doi.org/10.1093/ajcn/nqab283DOI Listing
September 2021

Evaluation of Dietary Patterns and All-Cause Mortality: A Systematic Review.

JAMA Netw Open 2021 Aug 2;4(8):e2122277. Epub 2021 Aug 2.

Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge.

Importance: The 2020 Dietary Guidelines Advisory Committee conducted a systematic review of existing research on diet and health to inform the current Dietary Guidelines for Americans. The committee answered this public health question: what is the association between dietary patterns consumed and all-cause mortality (ACM)?

Objective: To ascertain the association between dietary patterns consumed and ACM.

Evidence Review: Guided by an analytical framework and predefined inclusion and exclusion criteria developed by the committee, the US Department of Agriculture's Nutrition Evidence Systematic Review (NESR) team searched PubMed, the Cochrane Central Register of Controlled Trials, and Embase and dual-screened the results to identify articles that were published between January 1, 2000, and October 4, 2019. These studies evaluated dietary patterns and ACM in participants aged 2 years and older. The NESR team extracted data from and assessed risk of bias in included studies. Committee members synthesized the evidence, developed conclusion statements, and graded the strength of the evidence supporting the conclusion statements.

Findings: A total of 1 randomized clinical trial and 152 observational studies were included in the review. Studies enrolled adults and older adults (aged 17-84 years at baseline) from 28 countries with high or very high Human Development Index; 53 studies originated from the US. Most studies were well designed, used rigorous methods, and had low or moderate risks of bias. Precision, directness, and generalizability were demonstrated across the body of evidence. Results across studies were highly consistent. Evidence suggested that dietary patterns in adults and older adults that involved higher consumption of vegetables, fruits, legumes, nuts, whole grains, unsaturated vegetable oils, fish, and lean meat or poultry (when meat was included) were associated with a decreased risk of ACM. These healthy patterns were also relatively low in red and processed meat, high-fat dairy, and refined carbohydrates or sweets. Some of these dietary patterns also included intake of alcoholic beverages in moderation. Results based on additional analyses with confounding factors generally confirmed the robustness of main findings.

Conclusions And Relevance: In this systematic review, consuming a nutrient-dense dietary pattern was associated with reduced risk of death from all causes.
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http://dx.doi.org/10.1001/jamanetworkopen.2021.22277DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8408672PMC
August 2021

Weight and body composition changes affect resting energy expenditure predictive equations during a 12-month weight-loss intervention.

Obesity (Silver Spring) 2021 Oct 25;29(10):1596-1605. Epub 2021 Aug 25.

Department of Medicine, Anschutz Health and Wellness Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.

Objective: Mathematical equations that predict resting energy expenditure (REE) are widely used to derive calorie prescriptions during weight-loss interventions. Although such equations are known to introduce group- and individual-level error into REE prediction, their validity has largely been assessed in weight-stable populations. Therefore, this study sought to characterize how weight change affects the validity of commonly used REE predictive models throughout a 12-month weight-loss intervention.

Methods: Changes in predictive error of four models (Mifflin-St-Jeor, Harris-Benedict, Owen, and World Health Organization/Food and Agriculture) were assessed at 1-, 6-, and 12-month time points in adults (n = 66, 76% female, aged 18-55 years, BMI = 27-45 kg/m ) enrolled in a randomized clinical weight-loss trial.

Results: All equations experienced significant negative shifts in bias (measured - predicted REE) toward overprediction from baseline to 1 month (p < 0.05). Three equations showed reversal of bias in the positive direction (toward underprediction) from baseline to 12 months (p < 0.05). Early changes in bias were correlated with decreased fat-free mass (p ≤ 0.01).

Conclusions: Changes in body composition and mass during a 12-month weight-loss intervention significantly affected REE predictive error in adults with overweight and obesity. Weight history should be considered when using mathematical models to predict REE during periods of weight fluctuation.
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http://dx.doi.org/10.1002/oby.23234DOI Listing
October 2021

Targeting visceral adiposity with pharmacotherapy.

Lancet Diabetes Endocrinol 2021 09 3;9(9):551-552. Epub 2021 Aug 3.

Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA. Electronic address:

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http://dx.doi.org/10.1016/S2213-8587(21)00204-7DOI Listing
September 2021

Errors in the implementation, analysis, and reporting of randomization within obesity and nutrition research: a guide to their avoidance.

Int J Obes (Lond) 2021 Nov 29;45(11):2335-2346. Epub 2021 Jul 29.

Department of Epidemiology and Biostatistics, Indiana University School of Public Health-Bloomington, Bloomington, IN, USA.

Randomization is an important tool used to establish causal inferences in studies designed to further our understanding of questions related to obesity and nutrition. To take advantage of the inferences afforded by randomization, scientific standards must be upheld during the planning, execution, analysis, and reporting of such studies. We discuss ten errors in randomized experiments from real-world examples from the literature and outline best practices for their avoidance. These ten errors include: representing nonrandom allocation as random, failing to adequately conceal allocation, not accounting for changing allocation ratios, replacing subjects in nonrandom ways, failing to account for non-independence, drawing inferences by comparing statistical significance from within-group comparisons instead of between-groups, pooling data and breaking the randomized design, failing to account for missing data, failing to report sufficient information to understand study methods, and failing to frame the causal question as testing the randomized assignment per se. We hope that these examples will aid researchers, reviewers, journal editors, and other readers to endeavor to a high standard of scientific rigor in randomized experiments within obesity and nutrition research.
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http://dx.doi.org/10.1038/s41366-021-00909-zDOI Listing
November 2021

Effects of testosterone undecanoate on performance during multi-stressor military operations: A trial protocol for the Optimizing Performance for Soldiers II study.

Contemp Clin Trials Commun 2021 Sep 3;23:100819. Epub 2021 Jul 3.

Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA.

Background: Previously, young males administered 200 mg/week of testosterone enanthate during 28 days of energy deficit (EDef) gained lean mass and lost less total mass than controls (Optimizing Performance for Soldiers I study, OPS I). Despite that benefit, physical performance deteriorated similarly in both groups. However, some experimental limitations may have precluded detection of performance benefits, as performance measures employed lacked military relevance, and the EDef employed did not elicit the magnitude of stress typically experienced by Soldiers conducting operations. Additionally, the testosterone administered required weekly injections, elicited supra-physiological concentrations, and marked suppression of endogenous testosterone upon cessation. Therefore, this follow-on study will address those limitations and examine testosterone's efficacy for preserving Solder performance during strenuous operations.

Methods: In OPS II, 32 males will participate in a randomized, placebo-controlled, double-blind trial. After baseline testing, participants will be administered either testosterone undecanoate (750 mg) or placebo before completing four consecutive, 5-day cycles simulating a multi-stressor, sustained military operation (SUSOPS). SUSOPS will consist of two low-stress days (1000 kcal/day exercise-induced EDef; 8 h/night sleep), followed by three high-stress days (3000 kcal/day and 4 h/night). A 23-day recovery period will follow SUSOPS. Military relevant physical performance is the primary outcome. Secondary outcomes include 4-comparment body composition, muscle and whole-body protein turnover, intramuscular mechanisms, biochemistries, and cognitive function/mood.

Conclusions: OPS II will determine if testosterone undecanoate safely enhances performance, while attenuating muscle and total mass loss, without impairing cognitive function, during and in recovery from SUSOPS.

Trial Registration: ClinicalTrials.gov Identifier: NCT04120363.
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http://dx.doi.org/10.1016/j.conctc.2021.100819DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8264529PMC
September 2021

Phase angle as a marker for muscle abnormalities and function in patients with colorectal cancer.

Clin Nutr 2021 07 17;40(7):4799-4806. Epub 2021 Jun 17.

Postgraduate Program in Health and Behavior, Catholic University of Pelotas, Pelotas, Rio Grande do Sul, Brazil. Electronic address:

Background And Aims: Considering the applicability of phase angle (PhA) as a marker of muscle mass and function, we aimed to investigate whether PhA is a predictor of muscle abnormalities and function in patients with cancer.

Methods: In a sample of patients with colorectal cancer (CRC), PhA was obtained from measurements of resistance and reactance from bioelectrical impedance analysis. Computerized tomography imaging at the third lumbar vertebra was used to evaluate muscle abnormalities by quantifying skeletal muscle index (SMI) and skeletal muscle radiodensity (SMD). Muscle function was assessed by handgrip strength (HGS) and gait speed (GS).

Results: This cross-sectional study included 190 participants (X±SD), mean age 60.5 ± 11.3 years; 57% men; 78% had cancer stages III to IV. PhA was highly correlated with SMI (r = 0.70) and moderately correlated with HGS (r = 0.54). PhA explained 48% of the SMI variability (R = 0.485), 21% of the SMD variability (R = 0.214), 26% of HGS (R = 0.261) and 9.8% of GS (R = 0.098). In the multivariate model adjusted for age, sex, body mass index, performance status, comorbidities and cancer stage, 1-degree decrease in PhA was associated with low SMI (Odds Ratio (OR) = 6.56, 95% CI: 2.90-14.86) and with low SMI and HGS combined (OR = 11.10, 95% CI: 2.61-47.25). In addition, Receiving Operating Characteristics curve analysis showed that PhA had a good diagnostic accuracy for detecting low SMI, low SMI and SMD combined, low SMD and HGS and low SMI and HGS combined (AUC = 0.81, 95% CI: 0.74-0.88; AUC = 0.88, 95% CI: 0.81-0.95; AUC = 0.80, 95% CI: 0.70-0.91; AUC = 0.82, 95% CI: 0.74-0.89; respectively).

Conclusions: PhA was a predictor of muscle abnormalities and function and had a good diagnostic accuracy for detecting low muscle mass, low muscle mass and radiodensity, low muscle radiodensity and strength, and low muscle mass and strength in patients with CRC.
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http://dx.doi.org/10.1016/j.clnu.2021.06.013DOI Listing
July 2021

Dietary supplements and alternative therapies for obesity: A Perspective from The Obesity Society's Clinical Committee.

Obesity (Silver Spring) 2021 07;29(7):1095-1098

Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA.

In this Perspective Statement from The Obesity Society, the Clinical Committee discusses the use of weight loss supplements in the United States and the lack of regulatory oversight and rigorous testing of their efficacy and safety. A number of products and services claiming to promote weight loss are directly marketed to individuals with obesity and those wanting to lose weight. These products are not regulated as "drugs" by the Federal Drug Administration but, rather, are treated as dietary supplements if ingredients are "generally regarded as safe," requiring little or no testing to show efficacy or safety. Health care providers should be aware of the lack of evidence and deficiencies in regulatory oversight of dietary supplements marketed for weight loss. Regulatory authorities should protect consumers by ensuring accurate and safe marketing claims and preventing promotion of unproven and potentially unsafe products and claims.
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http://dx.doi.org/10.1002/oby.23189DOI Listing
July 2021

A Systematic Review of Dietary Supplements and Alternative Therapies for Weight Loss.

Obesity (Silver Spring) 2021 07;29(7):1102-1113

Division of Endocrinology and Molecular Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.

Objective: Dietary supplements and alternative therapies are commercialized as a panacea for obesity/weight gain as a result of the minimal regulatory requirements in demonstrating efficacy. These products may indirectly undermine the value of guideline-driven obesity treatments. Included in this study is a systematic review of the literature of purported dietary supplements and alternative therapies for weight loss.

Methods: A systematic review was conducted to evaluate the efficacy of dietary supplements and alternative therapies for weight loss in participants aged ≥18 years. Searches of Medline (PubMed), Cochrane Library, Web of Science, CINAHL, and Embase (Ovid) were conducted. Risk of bias and results were summarized qualitatively.

Results: Of the 20,504 citations retrieved in the database search, 1,743 full-text articles were reviewed, 315 of which were randomized controlled trials evaluating the efficacy of 14 purported dietary supplements, therapies, or a combination thereof. Risk of bias and sufficiency of data varied widely. Few studies (n = 52 [16.5%]) were classified as low risk and sufficient to support efficacy. Of these, only 16 (31%) noted significant pre/post intergroup differences in weight (range: 0.3-4.93 kg).

Conclusions: Dietary supplements and alternative therapies for weight loss have a limited high-quality evidence base of efficacy. Practitioners and patients should be aware of the scientific evidence of claims before recommending use.
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http://dx.doi.org/10.1002/oby.23110DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8231729PMC
July 2021

Are metabolic adaptations to weight changes an artefact?

Am J Clin Nutr 2021 10;114(4):1386-1395

Institute of Human Nutrition and Food Science, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.

Background: Adaptive thermogenesis (AT) is currently defined as the fat-free mass (FFM)-independent change in resting energy expenditure (REE) in response to caloric restriction (CR) or overfeeding (OF). So far, the impact of changes in the anatomical and molecular composition of FFM on AT has not been addressed.

Objectives: To assess the impact of changes in FFM composition on AT.

Methods: FFM was assessed in 32 healthy young men during controlled 21-d CR and 14 d of subsequent OF. Anatomical (i.e., the organ/tissue level) and molecular (i.e., water, mineral, and protein content and thus body density) composition of FFM were characterized. REE was measured by indirect calorimetry.

Results: With CR, body weight and REE decreased by 4.2 ± 0.9 kg and 173 ± 107 kcal/d, respectively, with corresponding increases of 3.5 ± 1.2 kg and 194 ± 110 kcal/d during OF (P < 0.001 for all changes). Changes in FFM explained 56.7% and 66.7% of weight loss and weight gain, respectively. Weight changes were associated with changes in various anatomical (i.e., masses of skeletal muscle, liver, kidneys, and brain) and molecular components (total body water, protein, and bone minerals) of FFM. After adjustments for changes in FFM only, AT was 116 ± 127 (P < 0.001) and 27 ± 115 kcal/d (NS) with CR and OF, respectively. Adjustments for FFM and its anatomical and molecular composition reduced AT in response to CR to 83 ± 116 and 122 ± 123 kcal/d (P < 0.05 and P < 0.001) whereas during OF, AT became significant at 87 ± 146 kcal/d (anatomical; P < 0.05) and 86 ± 118 kcal/d (molecular; P < 0.001).

Conclusions: Adjusting changes in REE with under- and overfeeding for the corresponding changes in the anatomical and molecular composition of FFM decreased AT after CR and increased AT after OF, but overall adjusted AT was likely not large enough in magnitude to be able to prevent weight loss or resist weight gain.
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http://dx.doi.org/10.1093/ajcn/nqab184DOI Listing
October 2021

Multicomponent density models for body composition: Review of the dual energy X-ray absorptiometry volume approach.

Obes Rev 2021 08 7;22(8):e13274. Epub 2021 Jun 7.

Cancer Center, University of Hawaii Cancer Center, Honolulu, HI, USA.

Accurate and precise body composition estimates, notably of total body adiposity, are a vital component of in vivo physiology and metabolic studies. The reference against which other body composition approaches are usually validated or calibrated is the family of methods referred to as multicomponent "body density" models. These models quantify three to six components by combining measurements of body mass, body volume, total body water, and osseous mineral mass. Body mass is measured with calibrated scales, volume with underwater weighing or air-displacement plethysmography, total body water with isotope dilution, and osseous mineral mass by dual-energy X-ray absorptiometry. Body density is then calculated for use in model as body mass/volume. Studies over the past decade introduced a new approach to quantifying body volume that relies on dual-energy X-ray absorptiometry measurements, an advance that simplifies multicomponent density model development by eliminating the need for underwater weighing or air-displacement plethysmography systems when these technologies are unavailable and makes these methods more accessible to research and clinical programs. This review critically examines these new dual-energy X-ray approaches for quantifying body volume and density, explores their shortcomings, suggests alternative derivation approaches, and introduces ideas for potential future research studies.
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http://dx.doi.org/10.1111/obr.13274DOI Listing
August 2021

Digital anthropometric evaluation of young children: comparison to results acquired with conventional anthropometry.

Eur J Clin Nutr 2021 May 26. Epub 2021 May 26.

Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA.

Objective: Three-dimensional optical (3DO) imaging devices for acquiring anthropometric measurements are proliferating in healthcare facilities, although applicability in young children has not been evaluated; small body size and movement may limit device accuracy. The current study aim was to critically test three commercial 3DO devices in young children.

Methods: The number of successful scans and circumference measurements at six anatomic sites were quantified with the 3DO devices in 64 children, ages 5-8 years. Of the scans available for processing, 3DO and flexible tape-measure measurements made by a trained anthropometrist were compared.

Results: Sixty of 181 scans (33.1%) could not be processed for technical reasons. Of processed scans, mean 3DO-tape circumference differences tended to be small (~1-9%) and varied across systems; correlations and bias estimates also varied in strength across anatomic sites and systems (e.g., regression Rs, 0.54-0.97, all p < 0.01). Overall findings differed across devices; best results were for a multi-camera stationary system and less so for two rotating single- or dual-camera systems.

Conclusions: Available 3DO devices for quantifying anthropometric dimensions in adults vary in applicability in young children according to instrument design. These findings suggest the need for 3DO devices designed specifically for small and/or young children.
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http://dx.doi.org/10.1038/s41430-021-00938-xDOI Listing
May 2021

Body composition reference ranges in community-dwelling adults using dual-energy X-ray absorptiometry: the Australian Body Composition (ABC) Study.

J Cachexia Sarcopenia Muscle 2021 08 14;12(4):880-890. Epub 2021 May 14.

Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St Albans, Melbourne, Vic., Australia.

Background: Reference ranges for lean mass (LM) and fat mass (FM) are essential in identifying soft tissue disorders; however, no such reference ranges exist for the most commonly used Hologic dual-energy X-ray absorptiometry (DXA) machine in Australia.

Methods: Cross-sectional study of community-dwelling adults (aged 18-88 years) who underwent a Hologic DXA scan at one of three commercialized densitometry centres in Australia. Age-specific and sex-specific percentile curves were generated for LM [LM, appendicular lean mass (ALM), ALM adjusted for height squared (ALM/h ), and ALM adjusted for body mass index (ALM/BMI)] and FM [FM, FM adjusted for height squared (FM/h ), appendicular fat mass, and android and gynoid fat] parameters using the LMS statistical method. Cutpoints equivalent to T-scores of -1, -2, and -2.5 standard deviations below the young mean reference group (20-29 years) were also generated for LM parameters.

Results: A total of 15 479 community-dwelling adults (54% men) with a median age of 33 years (interquartile range: 28, 42) were included. LM, ALM, and ALM/h remained stable until age 50, after which these parameters started to decline in both sexes. Compared with age 50, median percentiles of LM, ALM, and ALM/h declined by -5.9 kg, -3.7 kg, and -0.86 kg/m in men and by -2.5 kg, -1.8 kg, and -0.10 kg/m in women at age 70, respectively. Adjusting ALM for BMI (rather than height squared) resulted in different trends, with ALM/BMI decreasing from as early as age 20. Compared with age 20, median percentiles of ALM/BMI at age 40 declined by -0.10 kg/kg/m in men and by -0.06 kg/kg/m in women; and at age 70, ALM/BMI declined by -0.25 kg/kg/m in men and by -0.20 kg/kg/m in women. Cutpoints equivalent to T-scores of -1, -2, and -2.5 standard deviations for ALM/BMI were 1.01, 0.86, and 0.77 kg/kg/m in men and 0.70, 0.59, and 0.53 kg/kg/m in women, respectively. All FM parameters progressively increased from age 20 and continued up until age 70.

Conclusions: We developed reference ranges for LM and FM parameters from Hologic DXA machines in a large cohort of Australian adults, which will assist researchers and clinicians in identifying soft tissue disorders such as obesity, sarcopenia, and cachexia.
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http://dx.doi.org/10.1002/jcsm.12712DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8350202PMC
August 2021

Diet Quality and Visceral Adiposity among a Multiethnic Population of Young, Middle, and Older Aged Adults.

Curr Dev Nutr 2020 Jun 26;4(6):nzaa090. Epub 2020 May 26.

University of Hawaii Cancer Center, Honolulu, HI.

Background: Visceral adiposity, more so than overall adiposity, is associated with chronic disease and mortality. There has been, to our knowledge, little research exploring the association between diet quality and visceral adipose tissue (VAT) among a mulitethnic population aged 18-80 y.

Objective: The primary objective of this cross-sectional analysis was to examine the association between diet quality [Healthy Eating Index-2010 (HEI-2010) scores] and VAT among a multiethnic population of young, middle, and older aged adults in the United States. Secondary objectives were to repeat these analyses with overall adiposity and blood-based biomarkers for type 2 diabetes and cardiovascular disease risk as outcome measures.

Methods: A total of 540 adults (dropped out:  = 4; age: 18-40 y,  = 220; 40-60 y,  = 183; 60-80 y,  = 133) were recruited across 3 sites (Honolulu County, San Francisco, and Baton Rouge) for the Shape Up! Adults study. Whole-body DXA, anthropometry, fasting blood draw, and questionnaires (food frequency, physical activity, and demographic characteristics) were completed. Linear regression was used to assess the associations between HEI-2010 tertiles and VAT and secondary outcome measures among all participants and age-specific strata, while adjusting for known confounders.

Results: VAT, BMI (kg/m), body fat percentage, total body fat, trunk fat, insulin, and insulin resistance were inversely related to diet quality (all values < 0.004). When stratified by age, diet quality was inversely associated with VAT among participants aged 60-80 y ( < 0.006) and VAT/subcutaneous adipose tissue (SAT) among participants aged 40-60 y ( < 0.008).

Conclusions: Higher-quality diet was associated with lower VAT, overall adiposity, and insulin resistance among this multiethnic population of young, middle, and older aged adults with ages ranging from 18 to 80 y. More specifically, adherence to a high-quality diet may minimize VAT accumulation in adults aged 60-80 y and preferentially promote storage of SAT compared with VAT in adults aged 40-60 y.This study was registered at clinicaltrials.gov as NCT03637855.
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http://dx.doi.org/10.1093/cdn/nzaa090DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8082229PMC
June 2020

Healthy weight and prevention of weight gain for cardiovascular disease prevention.

Int J Cardiol 2021 07 8;335:128-129. Epub 2021 Apr 8.

Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, United States of America.

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http://dx.doi.org/10.1016/j.ijcard.2021.04.011DOI Listing
July 2021

Validity of water compartments estimated using bioimpedance spectroscopy in athletes differing in hydration status.

Scand J Med Sci Sports 2021 Aug 13;31(8):1612-1620. Epub 2021 Apr 13.

Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal.

We aimed to validate bioelectrical impedance spectroscopy (BIS), compared with tracer dilution measurements, for assessing total body water (TBW), intracellular water (ICW), and extracellular water (ECW) in athletes differing in hydration status. A total of 201 athletes participated. Reference TBW and ECW were determined by deuterium and bromide dilution methods, respectively; ICW was calculated as TBW-ECW. Water compartments were estimated by BIS. Urine specific gravity (USG) classified athletes into well-hydrated (WH) (USG < 1.023), euhydrated (EH) (USG:1.024-1.026), and dehydrated (DH) (USG>1.027). No significant differences were found between BIS and the reference methods for WH, EH, and DH athletes for TBW, ICW nor ECW (p>0.05). Concordance of TBW and its compartments by method was significant (p < 0.001) with coefficients of determination ranging by hydration classification [EH:52-96%;DH:56-98%;WH:71-96%]. Bland-Altman analyses showed no trend for TBW and its compartments with the exception of ICW in the WH athletes. The 95% confidence BIS intervals for the WH group ranged from -3.08 to 2.68 kg for TBW, -4.28 to 4.14 kg for ICW, and -3.29 to 3.02 kg for ECW. For the EH athletes, the 95% confidence intervals ranged from -2.78 to 2.24 kg for TBW, -4.10 to 3.94 kg for ICW, and -3.44 to 3.06 kg for ECW. In DH group, TBW ranged between -1.99 and 2.01 kg, ICW between -3.78 and 6.34 kg, and ECW between -6.22 and 3.74 kg. These findings show that BIS is useful at a group level in assessing water compartments in athletes differing in hydration status. However, the usefulness of BIS is limited at an individual level, especially in dehydrated athletes.
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http://dx.doi.org/10.1111/sms.13966DOI Listing
August 2021

Resting Energy Expenditure Is Elevated in Asthma.

Nutrients 2021 Mar 25;13(4). Epub 2021 Mar 25.

Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.

Asthma physiology affects respiratory function and inflammation, factors that may contribute to elevated resting energy expenditure (REE) and altered body composition. We hypothesized that asthma would present with elevated REE compared to weight-matched healthy controls. Adults with asthma ( = 41) and healthy controls ( = 20) underwent indirect calorimetry to measure REE, dual-energy X-ray absorptiometry (DEXA) to measure body composition, and 3-day diet records. Clinical assessments included spirometry, fractional exhaled nitric oxide (FENO), and a complete blood count. Asthmatics had greater REE than controls amounting to an increase of ~100 kcals/day, even though body mass index (BMI) and body composition were similar between groups. Inclusion of asthma status and FENO in validated REE prediction equations led to improved estimates. Further, asthmatics had higher white blood cell (control vs. asthma (mean ± SD): 4.7 ± 1.1 vs. 5.9 ± 1.6, < 0.01) and neutrophil (2.8 ± 0.9 vs. 3.6 ± 1.4, = 0.02) counts that correlated with REE (both < 0.01). Interestingly, despite higher REE, asthmatics reported consuming fewer calories (25.1 ± 7.5 vs. 20.3 ± 6.0 kcals/kg/day, < 0.01) and carbohydrates than controls. REE is elevated in adults with mild asthma, suggesting there is an association between REE and the pathophysiology of asthma.
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http://dx.doi.org/10.3390/nu13041065DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8064324PMC
March 2021

Calf circumference: cutoff values from the NHANES 1999-2006.

Am J Clin Nutr 2021 06;113(6):1679-1687

Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA.

Background: Calf circumference (CC) is used in geriatric studies as a simple and practical skeletal muscle (SM) marker for diagnosing low SM and sarcopenia. Currently applied CC cutoff points were developed in samples including older participants; values representative of the full adult lifespan are lacking.

Objectives: We aimed to develop CC cutoff points and to identify relevant confounding factors from the large and diverse NHANES 1999-2006 population sample.

Methods: Demographic, anthropometric, and imaging data (DXA, appendicular lean mass) from the adult (age ≥18 y) NHANES sample were partitioned into subgroups according to sex, age, ethnicity, and race. Adults aged 18-39 y and BMI (in kg/m2) 18.5-24.9 were set as a reference population; CC cutoff points were derived at 1 and 2 SDs below the mean.

Results: The sample included 17,789 participants, 51.3% males and 48.7% females, with respective ages (mean ± SD) of 43.3 ± 16.1 y and 45.5 ± 16.9 y. CC was strongly correlated with appendicular lean mass, r = 0.84 and 0.86 for males and females (both P < 0.001), respectively. Significant differences in mean CC were present across sex, ethnic, self-reported race, and BMI groups. Adjusting CC for adiposity using BMI revealed a decrease in CC beginning after the second decade in males and third decade in females. Rounded CC cutoff values for moderately and severely low CC were 34 cm and 32 cm (males), and 33 cm and 31 cm (females), respectively. Our findings support the use of BMI-adjusted CC values for participants outside the normal-weight BMI range (18-24.9).

Conclusions: This study defined CC values in a diverse population sample along with a BMI-adjustment approach that helps to remove the confounding effects of adiposity and thereby improves CC as a useful clinical estimate of SM mass.
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http://dx.doi.org/10.1093/ajcn/nqab029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8433492PMC
June 2021

Digital anthropometric volumes: Toward the development and validation of a universal software.

Med Phys 2021 Jul 9;48(7):3654-3664. Epub 2021 Jul 9.

Pennington Biomedical Research Center, Baton Rouge, LA, 70808, USA.

Purpose: Anthropometry is a method for quantifying body size and shape often used to derive body composition and health risk prediction models. Recent technology advancements led to development of three-dimensional (3D) optical scanners that can overcome most of the limitations associated with manual anthropometric data collection. However, each of the currently available devices offers proprietary measurements that do not match conventional anthropometric definitions. The aim of the current study was to develop and then evaluate the precision and accuracy of new "universal" 3D optical analysis software that calculates digital anthropometric volumes using identical standard landmarks across scanners.

Methods: Dual-energy x-ray absorptiometry (DXA) and air displacement plethysmography (ADP) total body and regional volume and fat mass reference measurements and 3D optical scans from two proprietary devices were collected from 356 participants to evaluate the robustness of total body and regional volume and fat mass measurements calculated by the developed software. Linear regression modeling with threefold cross validation was used to evaluate total body and regional fat masses from 3D scans.

Results: Total body and regional volumes measured by DXA and ADP had strong associations with corresponding estimates from the commercial 3D optical scanners coupled with the universal software (e.g., R  = 0.98 for Styku and R  = 1.00 for SS20, for both DXA and ADP comparisons). Regional body volumes also had strong correlation between DXA and the 3DO scanners (e.g., for arm, leg and trunk, respective R s of 0.75, 0.86, and 0.97 for Styku and 0.79, 0.89, and 0.98 for SS20). Similarly, there were strong associations between DXA- measured total body and regional fat mass and 3D optical estimates calculated by the universal software (e.g., for total body, arm, leg and trunk, respective R s of 0.86, 0.72, 0.77, and 0.88 for Styku and 0.84, 0.76, 0.78, and 0.85 for SS20). Absolute differences in volumes and fat mass between the reference methods and the universal software values revealed underlying proprietary scanner differences that can be improved when designing future devices.

Conclusions: The current study suggests that, when compared against values calculated using DXA and ADP, the universal software was able to measure total and regional body volumes reliably from scans obtained by two different scanners. The universal software, with future refinements, combined with potential optical scanner design improvements, creates new opportunities for developing large multicenter anthropometric databases with uniformly defined body dimensions that can be used for modeling health risks.

Clinical Trial Registration Id: Shape Up! Adults Study, NCT0363785.
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http://dx.doi.org/10.1002/mp.14829DOI Listing
July 2021

Predictors of liver fat among children and adolescents from five different ethnic groups.

Obes Sci Pract 2021 Feb 9;7(1):53-62. Epub 2020 Oct 9.

University of Hawaii Cancer Center Honolulu Hawaii USA.

Objectives: As rates of obesity around the world have increased, so has the detection of high level of liver fat in children and adolescents. This may put them at risk for cardiovascular disease later in life. This analysis of a cross-sectional population-based study of children and adolescents evaluated demographic and lifestyle determinants of percent liver fat.

Methods: Healthy participants (123 girls and 99 boys aged 5-17 years) recruited by convenience sampling in three locations completed questionnaires, anthropometric measurements, and dual X-ray absorptiometry and magnetic resonance imaging (MRI) assessment. General linear models were applied to estimate the association of demographic, anthropometric, and dietary factors as well as physical activity with MRI-based percent liver fat.

Results: The strongest predictor of liver fat was body mass index (BMI; < 0.0001); overweight and obesity were associated with 0.5% and 1% higher liver fat levels. The respective adjusted mean percent values were 2.9 (95% CI 2.7, 3.1) and 3.4 (95% CI 3.2, 3.6) as compared to normal weight (2.4; 95% CI 2.3, 2.6). Mean percent liver fat was highest in Whites and African Americans, intermediate in Hispanic, and lowest among Asians and Native Hawaiians/Pacific Islanders ( < 0.0001). Age ( = 0.67), sex ( = 0.28), physical activity ( = 0.74), and diet quality ( = 0.70) were not significantly related with liver fat.

Conclusions: This study in multiethnic children and adolescents confirms the strong relationship of BMI with percent liver fat even in a population with low liver fat levels without detecting an association with age, sex, and dietary or physical activity patterns.
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http://dx.doi.org/10.1002/osp4.459DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7909587PMC
February 2021

Digital anthropometry for body circumference measurements: Toward the development of universal three-dimensional optical system analysis software.

Obes Sci Pract 2021 Feb 6;7(1):35-44. Epub 2020 Nov 6.

Metabolism-Body-Composition Pennington Biomedical Research Center LSU System Baton Rouge Louisiana USA.

Background/objective: Digital anthropometric (DA) assessments are increasingly being administered with three-dimensional (3D) optical devices in clinical settings that manage patients with obesity and related metabolic disorders. However, anatomic measurement sites are not standardized across manufacturers, precluding use of published reference values and pooling of data across research centers.

Subjects/methods: This study aimed to develop universal 3D analysis software by applying novel programming strategies capable of producing device-independent DA estimates that agree with conventional anthropometric (CA) measurements made at well-defined anatomic sites. A series of technical issues related to proprietary methods of 3D geometrical reconstruction and image analysis were addressed in developing major software components. To evaluate software accuracy, comparisons were made to CA circumference measurements made with a flexible tape at eleven standard anatomic sites in up to 35 adults scanned with three different commercial 3D optical devices.

Results: Overall, group mean CA and DA values across the three systems were in good agreement, with ∼2 cm systematic differences; CA and DA estimates were highly correlated (all -values <0.01); root-mean square errors were low (0.51-3.27 cm); and CA-DA bias tended to be small, but significant depending on anatomic site and device.

Conclusions: Availability of this software, with future refinements, has the potential to facilitate clinical applications and creation of large pooled uniform anthropometric databases.
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http://dx.doi.org/10.1002/osp4.467DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7909596PMC
February 2021

Resting Energy Expenditure: From Cellular to Whole-Body Level, a Mechanistic Historical Perspective.

Obesity (Silver Spring) 2021 03;29(3):500-511

Department of Human Nutrition and Food Science, Christian-Albrecht University of Kiel, Kiel, Germany.

The basis of heat generated by the human body has been a source of speculation and research for more than 2,000 years. Basal heat production, now usually referred to as resting energy expenditure (REE), is currently recognized as deriving from biochemical reactions at subcellular and cellular levels that are expressed in the energy expended by the body's 78 organs and tissues. These organs and tissues, and the 11 systems to which they belong, influence body size and shape. Connecting these subcellular-/cellular-level reactions to organs and tissues, and then on to body size and shape, provides a comprehensive understanding of individual differences in REE, a contemporary topic of interest in obesity research and clinical practice. This review critically examines these linkages, their association with widely used statistical and physiological REE prediction formulas, and often-unappreciated aspects of measuring basal heat production in humans.
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http://dx.doi.org/10.1002/oby.23090DOI Listing
March 2021

Total body and regional surface area: Quantification with low-cost three-dimensional optical imaging systems.

Am J Phys Anthropol 2021 08 5;175(4):865-875. Epub 2021 Feb 5.

Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA.

Objectives: Body surface area (SA) is a widely used physical measure incorporated into multiple thermophysiology and evolutionary biology models currently estimated in humans either with empirical prediction equations or costly whole-body laser imaging systems. The introduction of low-cost 3D scanners provides a new opportunity to quantify total body (TB) and regional SA, although a critical question prevails: can these devices acquire the quality of depth information and process this initial data to form a mesh that has the fidelity needed to generate accurate SA estimates?

Materials And Methods: This question was answered by comparing SA estimates calculated using images from four commercial 3D scanners in 108 adults to corresponding estimates acquired with a whole-body laser system. This was accomplished by processing initial mesh data from all devices, including the laser system, with the same universal software adapted specifically for repairing mesh gaps, identifying landmarks, and generating SA measurements.

Results: TB SA measured on all four 3D scanners was highly correlated with corresponding laser system estimates (R s, 0.98-0.99; all p < 0.001) with some small but significant mean differences (-0.19 to 0.06 m ); root-mean square errors (RMSEs) were small (0.02-0.03 m ); and significant bias was present for one device. Qualitatively similar results (e.g., R s, 0.78-0.95; mean Δs, -0.05 to 0.02 m ; RMSEs, 0.01-0.03 m ) were present for trunk, arm, and leg SA comparisons.

Discussion: The current study observations demonstrate that low-cost and practical 3D optical scanners are capable of accurately quantifying TB and regional SA, thus opening new opportunities for evaluating human phenotypes and related physiological characteristics.
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http://dx.doi.org/10.1002/ajpa.24243DOI Listing
August 2021

Effect of Bimagrumab vs Placebo on Body Fat Mass Among Adults With Type 2 Diabetes and Obesity: A Phase 2 Randomized Clinical Trial.

JAMA Netw Open 2021 01 4;4(1):e2033457. Epub 2021 Jan 4.

Translational Medicine, Novartis Institutes for BioMedical Research, Basel, Switzerland.

Importance: Antibody blockade of activin type II receptor (ActRII) signaling stimulates skeletal muscle growth. Previous clinical studies suggest that ActRII inhibition with the monoclonal antibody bimagrumab also promotes excess adipose tissue loss and improves insulin resistance.

Objective: To evaluate the efficacy and safety of bimagrumab on body composition and glycemic control in adults with type 2 diabetes and overweight and obesity.

Design, Setting, And Participants: This double-masked, placebo-controlled, 48-week, phase 2 randomized clinical trial was conducted among adults with type 2 diabetes, body mass index between 28 and 40, and glycated hemoglobin (HbA1c) levels between 6.5% and 10.0% at 9 US and UK sites. The trial was conducted from February 2017 to May 2019. Only participants who completed a full treatment regimen were included in analysis.

Interventions: Patients were randomized to intravenous infusion of bimagrumab (10 mg/kg up to 1200 mg in 5% dextrose solution) or placebo (5% dextrose solution) treatment every 4 weeks for 48 weeks; both groups received diet and exercise counseling.

Main Outcomes And Measures: The primary end point was least square mean change from baseline to week 48 in total body fat mass (FM); secondary and exploratory end points were lean mass (LM), waist circumference (WC), HbA1c level, and body weight (BW) changes from baseline to week 48.

Results: A total of 75 patients were randomized to bimagrumab (n = 37; 23 [62.2%] women) or placebo (n = 38; 12 [31.6%] women); 58 (77.3%) completed the 48-week study. Patients at baseline had a mean (SD) age of 60.4 (7.7) years; mean (SD) BMI of 32.9 (3.4); mean (SD) BW of 93.6 (14.9) kg; mean (SD) FM of 35.4 (7.5) kg; and mean (SD) HbA1c level of 7.8% (1.0%). Changes at week 48 for bimagrumab vs placebo were as follows: FM, -20.5% (-7.5 kg [80% CI, -8.3 to -6.6 kg]) vs -0.5% (-0.18 kg [80% CI, -0.99 to 0.63 kg]) (P < .001); LM, 3.6% (1.70 kg [80% CI, 1.1 to 2.3 kg]) vs -0.8% (-0.4 kg [80% CI, -1.0 to 0.1 kg]) (P < .001); WC, -9.0 cm (80% CI, -10.3 to -7.7 cm) vs 0.5 cm (80% CI, -0.8 to 1.7 cm) (P < .001); HbA1c level, -0.76 percentage points (80% CI, -1.05 to -0.48 percentage points) vs -0.04 percentage points (80% CI, -0.23 to 0.31 percentage points) (P = .005); and BW, -6.5% (-5.9 kg [80% CI, -7.1 to -4.7 kg]) vs -0.8% (-0.8 kg [80% CI, -1.9 to 0.3 kg]) (P < .001). Bimagrumab's safety and tolerability profile was consistent with prior studies.

Conclusions And Relevance: In this phase 2 randomized clinical trial, ActRII blockade with bimagrumab led to significant loss of FM, gain in LM, and metabolic improvements during 48 weeks in patients with overweight or obesity who had type 2 diabetes. ActRII pathway inhibition may provide a novel approach for the pharmacologic management of excess adiposity and accompanying metabolic disturbances.

Trial Registration: ClinicalTrials.gov number: NCT03005288.
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http://dx.doi.org/10.1001/jamanetworkopen.2020.33457DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7807292PMC
January 2021

New anthropometric and biochemical models for estimating appendicular skeletal muscle mass in male patients with cirrhosis.

Nutrition 2021 04 21;84:111083. Epub 2020 Nov 21.

Department of Gastroenterology, Surgical Division, Faculty of Medicine, University of São Paulo, São Paulo, Brazil.

Objectives: The use of easily accessible methods to estimate skeletal muscle mass (SMM) in patients with cirrhosis is often limited by the presence of edema and ascites, precluding a reliable diagnosis of sarcopenia. The aim of this study was to design predictive models using variables derived from anthropometric and/or biochemical measures to estimate SMM; and to validate their applicability in diagnosing sarcopenia in patients with cirrhosis.

Methods: Anthropometric and biochemical data were obtained from 124 male patients (18-76 y of age) with cirrhosis who also underwent dual-energy x-ray absorptiometry (DXA) and handgrip strength (HGS) assessments to identify low SMM and diagnose sarcopenia using reference cutoff values. Univariate analyses for variable selection were applied to generate predictive decision tree models for low SMM. Model accuracy for the prediction of low SMM and sarcopenia (when associated with HGS) was tested by comparison with reference cutoff values (appendicular SMM index, obtained by DXA) and clinical sarcopenia diagnoses. The prognostic value of the models for the prediction of sarcopenia and mortality at 104 wk of follow up was further tested using Kaplan-Meier graphics and Cox models.

Results: The models with anthropometric variables, alone and combined with biochemical variables, showed good accuracy (0.89 [0.83; 0.94] and 0.90 [0.84; 0.95], respectively) and sensitivity (0.72 [0.56; 0.85] and 0.74 [0.59; 0.86], respectively) and excellent specificity (0.96 [0.90; 0.99] and 0.97 [0.92; 0.99], respectively) in predicting SMM. Both models showed excellent accuracy (0.94 [0.89; 0.98], good sensitivity (0.68 [0.45; 0.86]), and excellent specificity (1.00 [0.96; 1.00]) in predicting sarcopenia. The models predicted mortality in patients with sarcopenia, with the likelihood of death sixfold greater relative to patients not predicted to have sarcopenia.

Conclusions: Our simple and inexpensive models provided a practical and safe approach to diagnosing sarcopenia patients with cirrhosis along with an estimate of their mortality risk when other reference methods are unavailable.
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http://dx.doi.org/10.1016/j.nut.2020.111083DOI Listing
April 2021

Muscle Echogenicity and Changes Related to Age and Body Mass Index.

JPEN J Parenter Enteral Nutr 2021 Sep 8;45(7):1591-1596. Epub 2020 Dec 8.

Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA.

Introduction: Muscle fibers are lost and replaced by fat- and fibrous-tissue infiltration during aging. This process decreases muscle quality and influences tissue appearance on ultrasound images over time. Increased muscle "echogenicity" represents changes caused by fat- and fibrous-tissue infiltration and can be quantified with recently developed software.

Objective: To investigate skeletal muscle quality through echogenicity, estimates according to participant's body mass index (BMI) and age were taken.

Methods: This was a cross-sectional study performed at the Pennington Biomedical Research Center, Baton Rouge, Louisiana with 117 participants (57 men and 60 women), with mean age (±SD) 38.9 ± 17.0 years and BMI 28.6 ± 6.2 kg/m². All participants were examined by ultrasound (LOGIQ GE Healthcare), using a 5.0-MHz linear transducer. Participants had muscle thickness measured by ultrasound at 4 anatomic locations (biceps and triceps brachial, femoral quadriceps, and calf triceps). Echogenicity was analyzed with specific software (Pixel Health) that evaluated the image in gray scale.

Results: According to BMI, 41% of participants were obese. There was a positive correlation between age and thigh-muscle echogenicity (r = 0.534, P < .0001) and a negative correlation between thigh-muscle echogenicity and thickness (r = -0.395, P <.0001). There was high muscle echogenicity in participants with overweight and obesity aged 50 years or older (P < .05).

Conclusion: Older age and higher BMI were associated with stronger echogenicity signals and smaller muscle thickness. People with overweight, obesity, and/or older than 50 years old have reduced muscle quality with smaller muscle thickness, as observed with ultrasound.
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http://dx.doi.org/10.1002/jpen.2030DOI Listing
September 2021

Total body water is the preferred method to use in forensic blood-alcohol calculations rather than ethanol's volume of distribution.

Forensic Sci Int 2020 Nov 2;316:110532. Epub 2020 Oct 2.

Clinical Pharmacology, Queen Mary University of London, London, EC1M 6BQ, UK; Analytical Services International, St George's-University of London, London, SW17 0RE, UK.

During the prosecution and defence of drink-driving cases, forensic practitioners are often required to engage in various blood-alcohol calculations, such as whether or not the statutory limit was exceeded (e.g. 80mg/100mL, 0.08g/100mL or 0.80g/L). For this purpose, most forensic scientists utilize the Widmark equation, or some modification thereof, to calculate a person's blood alcohol concentration (BAC) based on information about the amount of ethanol consumed and the pattern of drinking. This equation comes in two main forms; one of which incorporates the apparent volume of distribution of ethanol (V) and the other a person's total body water (TBW). In this study, we utilised two independent data sets, one involving the determination of V for ethanol in 173 men and 63 women, and the other TBW determined for 582 men and 884 women. Those subjects included in the TBW group represented various racial groups (Caucasians, African Americans, Hispanics, Asians and Puerto Ricans), with body mass index (BMI) ranging from 17 to 80kg/m. Both versions of the Widmark equation were evaluated in relation to their accuracy and precision in predicting TBW and/or V using the two most common anthropometric equations; those of Watson et al. and Forrest. Both anthropometric equations exhibited good accuracy (<4.3%) for the prediction of both TBW and V. However, the root mean square error was lower TBW was used for prediction (9.09-12.84%) rather than V (11.72-15.08%). Overall, this study has demonstrated (a) that blood-alcohol calculations are more reliable using TBW rather than V (b) that both equations (Watson et al. and Forrest) are applicable to ethnic groups other than Caucasians and (c) the Forrest equation predicts TBW in men and women with BMI from 17 to 35kg/m and that the Watson et al. equation works for those with more extreme BMI; females (17-80kg/m) and males (17-67kg/m).
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http://dx.doi.org/10.1016/j.forsciint.2020.110532DOI Listing
November 2020
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