Publications by authors named "Irene Fleur Kramer"

14 Publications

  • Page 1 of 1

Basal and Postprandial Myofibrillar Protein Synthesis Rates Do Not Differ between Lean and Obese Middle-Aged Men.

J Nutr 2019 09;149(9):1533-1542

Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, Netherlands.

Background: Excess lipid availability has been associated with the development of anabolic resistance. As such, obesity may be accompanied by impairments in muscle protein metabolism.

Objective: We hypothesized that basal and postprandial muscle protein synthesis rates are lower in obese than in lean men.

Methods: Twelve obese men [mean ± SEM age: 48 ± 2 y; BMI (in kg/m2): 37.0 ± 1.5; body fat: 32 ± 2%] and 12 age-matched lean controls (age: 43 ± 3 y; BMI: 23.4 ± 0.4; body fat: 21 ± 1%) received primed continuous L-[ring-2H5]-phenylalanine and L-[ring-3,5-2H2]-tyrosine infusions and ingested 25 g intrinsically L-[1-13C]-phenylalanine labeled whey protein. Repeated blood and muscle samples were obtained to assess protein digestion and amino acid absorption kinetics, and basal and postprandial myofibrillar protein synthesis rates.

Results: Exogenous phenylalanine appearance rates increased after protein ingestion in both groups (P < 0.001), with a total of 53 ± 1% and 53 ± 2% of dietary protein-derived phenylalanine appearing in the circulation over the 5-h postprandial period in lean and obese men, respectively (P = 0.82). After protein ingestion, whole-body protein synthesis and oxidation rates increased to a greater extent in lean men than in the obese (P-interaction < 0.05), resulting in a higher whole-body protein net balance in the lean than in the obese (7.1 ± 0.2 and 4.6 ± 0.4 µmol phenylalanine · h-1 · kg-1, respectively; P-interaction < 0.001). Myofibrillar protein synthesis rates increased from 0.030 ± 0.002 and 0.028 ± 0.003%/h in the postabsorptive period to 0.034 ± 0.002 and 0.035 ± 0.003%.h-1 in the 5-h postprandial period (P = 0.03) in lean and obese men, respectively, with no differences between groups (P-interaction = 0.58).

Conclusions: Basal, postabsorptive myofibrillar protein synthesis rates do not differ between lean and obese middle-aged men. Postprandial protein handling, including protein digestion and amino acid absorption, and the postprandial muscle protein synthetic response after the ingestion of 25 g whey protein are not impaired in obese men. This trial was registered at www.trialregister.nl as NTR4060.
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http://dx.doi.org/10.1093/jn/nxz104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6736155PMC
September 2019

Leucine coingestion augments the muscle protein synthetic response to the ingestion of 15 g of protein following resistance exercise in older men.

Am J Physiol Endocrinol Metab 2019 09 21;317(3):E473-E482. Epub 2019 May 21.

NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands.

Older adults have shown an attenuated postexercise increase in muscle protein synthesis rates following ingestion of smaller amounts of protein compared with younger adults. Consequently, it has been suggested that older adults require the ingestion of more protein to increase postexercise muscle protein synthesis rates compared with younger adults. We investigated whether coingestion of 1.5 g of free leucine with a single 15-g bolus of protein further augments the postprandial muscle protein synthetic response during recovery from resistance-type exercise in older men. Twenty-four healthy older men (67 ± 1 yr) were randomly assigned to ingest 15 g of milk protein concentrate (MPC80) with (15G+LEU; = 12) or without (15G; = 12) 1.5 g of free leucine after performing a single bout of resistance-type exercise. Postprandial protein digestion and amino acid absorption kinetics, whole body protein metabolism, and postprandial myofibrillar protein synthesis rates were assessed using primed, continuous infusions with l-[-H]phenylalanine, l-[-H]tyrosine, and l-[1-C]leucine combined with ingestion of intrinsically l-[1-C]phenylalanine-labeled milk protein. A total of 70 ± 1% (10.5 ±0.2 g) and 75 ± 2% (11.2 ± 0.3 g) of the protein-derived amino acids were released in the circulation during the 6-h postexercise recovery phase in 15G+LEU and 15G, respectively ( < 0.05). Postexercise myofibrillar protein synthesis rates were 16% (0.058 ± 0.003 vs. 0.049 ± 0.002%/h, < 0.05; based on l-[-H]phenylalanine) and 19% (0.071 ± 0.003 vs. 0.060 ± 0.003%/h, < 0.05; based on l-[1-C]leucine) greater in 15G+LEU compared with 15G. Leucine coingestion further augments the postexercise muscle protein synthetic response to the ingestion of a single 15-g bolus of protein in older men.
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http://dx.doi.org/10.1152/ajpendo.00073.2019DOI Listing
September 2019

Dose-Dependent Increases in Whole-Body Net Protein Balance and Dietary Protein-Derived Amino Acid Incorporation into Myofibrillar Protein During Recovery from Resistance Exercise in Older Men.

J Nutr 2019 02;149(2):221-230

NUTRIM School of Nutrition and Translational Research in Metabolism.

Background: Age-related decline in skeletal muscle mass is at least partly attributed to anabolic resistance to food intake. Resistance exercise sensitizes skeletal muscle tissue to the anabolic properties of amino acids.

Objective: The present study assessed protein digestion and amino acid absorption kinetics, whole-body protein balance, and the myofibrillar protein synthetic response to ingestion of different amounts of protein during recovery from resistance exercise in older men.

Methods: Forty-eight healthy older men [mean ± SEM age: 66 ± 1 y; body mass index (kg/m2): 25.4 ± 0.3] were randomly assigned to ingest 0, 15, 30, or 45 g milk protein concentrate after a single bout of resistance exercise consisting of 4 sets of 10 repetitions of leg press and leg extension and 2 sets of 10 repetitions of lateral pulldown and chest press performed at 75-80% 1-repetition maximum. Postprandial protein digestion and amino acid absorption kinetics, whole-body protein metabolism, and myofibrillar protein synthesis rates were assessed using primed, continuous infusions of l-[ring-2H5]-phenylalanine, l-[ring-2H2]-tyrosine, and l-[1-13C]-leucine combined with ingestion of intrinsically l-[1-13C]-phenylalanine and l-[1-13C]-leucine labeled protein.

Results: Whole-body net protein balance showed a dose-dependent increase after ingestion of 0, 15, 30, or 45 g of protein (0.015 ± 0.002, 0.108 ± 0.004, 0.162 ± 0.008, and 0.215 ± 0.009 μmol Phe · kg-1 · min-1, respectively; P < 0.001). Myofibrillar protein synthesis rates were higher after ingesting 30 (0.0951% ± 0.0062%/h, P = 0.07) or 45 g of protein (0.0970% ± 0.0062%/h, P < 0.05) than after 0 g (0.0746% ± 0.0051%/h). Incorporation of dietary protein-derived amino acids (l-[1-13C]-phenylalanine) into de novo myofibrillar protein showed a dose-dependent increase after ingestion of 15, 30, or 45 g protein (0.0171 ± 0.0017, 0.0296 ± 0.0030, and 0.0397 ± 0.0026 mole percentage excess, respectively; P < 0.05).

Conclusions: Dietary protein ingested during recovery from resistance exercise is rapidly digested and absorbed. Whole-body net protein balance and dietary protein-derived amino acid incorporation into myofibrillar protein show dose-dependent increases. Ingestion of ≥30 g protein increases postexercise myofibrillar protein synthesis rates in older men. This trial was registered at Nederlands Trial Register as NTR4492.
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http://dx.doi.org/10.1093/jn/nxy263DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6374151PMC
February 2019

Perioperative nutritional supplementation and skeletal muscle mass in older hip-fracture patients.

Nutr Rev 2019 04;77(4):254-266

Department of Surgery, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, The Netherlands.

Older people with hip fractures are often malnourished at the time of fracture, which can have substantial influence on mortality and clinical outcomes, as well as functional outcome and quality of life. A close relationship between protein intake and muscle maintenance has been demonstrated. Skeletal muscle weakness is an independent risk factor for falls and fall-related injuries in the elderly and is an independent marker of prognosis. However, the effect of perioperative nutritional interventions on outcomes in elderly hip-fracture patients remains controversial. In this narrative review, an overview is presented of the existing literature on nutritional status and sarcopenia in elderly hip-fracture patients, clinical outcomes, and the effects of nutritional intervention on outcome and rehabilitation in this patient group.
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http://dx.doi.org/10.1093/nutrit/nuy055DOI Listing
April 2019

One Week of Hospitalization Following Elective Hip Surgery Induces Substantial Muscle Atrophy in Older Patients.

J Am Med Dir Assoc 2019 01 11;20(1):35-42. Epub 2018 Aug 11.

Department of Human Biology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre+, The Netherlands. Electronic address:

Objectives: Short successive periods of skeletal muscle disuse have been suggested to substantially contribute to the observed loss of skeletal muscle mass over the life span. Hospitalization of older individuals due to acute illness, injury, or major surgery generally results in a mean hospital stay of 5 to 7 days, during which the level of physical activity is strongly reduced. We hypothesized that hospitalization following elective total hip arthroplasty is accompanied by substantial leg muscle atrophy in older men and women.

Design And Participants: Twenty-six older patients (75 ± 1 years) undergoing elective total hip arthroplasty participated in this observational study.

Measurements: On hospital admission and on the day of discharge, computed tomographic (CT) scans were performed to assess muscle cross-sectional area (CSA) of both legs. During surgery and on the day of hospital discharge, a skeletal muscle biopsy was taken from the m. vastus lateralis of the operated leg to assess muscle fiber type-specific CSA.

Results: An average of 5.6 ± 0.3 days of hospitalization resulted in a significant decline in quadriceps (-3.4% ± 1.0%) and thigh muscle CSA (-4.2% ± 1.1%) in the nonoperated leg (P < .05). Edema resulted in a 10.3% ± 1.7% increase in leg CSA in the operated leg (P < .05). At hospital admission, muscle fiber CSA was smaller in the type II vs type I fibers (3326 ± 253 μm vs 4075 ± 279 μm, respectively; P < .05). During hospitalization, type I and II muscle fiber CSA tended to increase, likely due to edema in the operated leg (P = .10).

Conclusions: Six days of hospitalization following elective total hip arthroplasty leads to substantial leg muscle atrophy in older patients. Effective intervention strategies are warranted to prevent the loss of muscle mass induced by short periods of muscle disuse during hospitalization.
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http://dx.doi.org/10.1016/j.jamda.2018.06.018DOI Listing
January 2019

Protein Ingestion before Sleep Increases Overnight Muscle Protein Synthesis Rates in Healthy Older Men: A Randomized Controlled Trial.

J Nutr 2017 12 30;147(12):2252-2261. Epub 2017 Aug 30.

NUTRIM, School of Nutrition and Translational Research in Metabolism, and

The loss of skeletal muscle mass with aging has been attributed to the blunted anabolic response to protein intake. Presleep protein ingestion has been suggested as an effective strategy to compensate for such anabolic resistance. We assessed the efficacy of presleep protein ingestion on dietary protein digestion and absorption kinetics and overnight muscle protein synthesis rates in older men. In a randomized, double-blind, parallel design, 48 older men (mean ± SEM age: 72 ± 1 y) ingested 40 g casein (PRO40), 20 g casein (PRO20), 20 g casein plus 1.5 g leucine (PRO20+LEU), or a placebo before sleep. Ingestion of intrinsically l-[1-C]-phenylalanine- and l-[1-C]-leucine-labeled protein was combined with intravenous l-[ring-H]-phenylalanine and l-[1-C]-leucine infusions during sleep. Muscle and blood samples were collected throughout overnight sleep. Exogenous phenylalanine appearance rates increased after protein ingestion, but to a greater extent in PRO40 than in PRO20 and PRO20+LEU ( < 0.05). Overnight myofibrillar protein synthesis rates (based on l-[ring-H]-phenylalanine) were 0.033% ± 0.002%/h, 0.037% ± 0.003%/h, 0.039% ± 0.002%/h, and 0.044% ± 0.003%/h in placebo, PRO20, PRO20+LEU, and PRO40, respectively, and were higher in PRO40 than in placebo ( = 0.02). Observations were similar based on l-[1-C]-leucine tracer (placebo: 0.047% ± 0.004%/h and PRO40: 0.058% ± 0.003%/h, = 0.08). More protein-derived amino acids (l-[1-C]-phenylalanine) were incorporated into myofibrillar protein in PRO40 than in PRO20 (0.033 ± 0.002 and 0.019 ± 0.002 MPE, respectively, < 0.001) and tended to be higher than in PRO20+LEU (0.025 ± 0.002 MPE, = 0.06). Protein ingested before sleep is properly digested and absorbed throughout the night, providing precursors for myofibrillar protein synthesis during sleep in healthy older men. Ingestion of 40 g protein before sleep increases myofibrillar protein synthesis rates during overnight sleep. These findings provide the scientific basis for a novel nutritional strategy to support muscle mass preservation in aging and disease. This trial was registered at www.trialregister.nl as NTR3885.
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http://dx.doi.org/10.3945/jn.117.254532DOI Listing
December 2017

Extensive Type II Muscle Fiber Atrophy in Elderly Female Hip Fracture Patients.

J Gerontol A Biol Sci Med Sci 2017 Oct;72(10):1369-1375

Department of Human Movement Sciences.

Background: Sarcopenia, or the loss of muscle mass and strength, is known to increase the risk for falls and (hip) fractures in older people. The objective of this study was to assess the skeletal muscle fiber characteristics in elderly female hip fracture patients.

Method: Percutaneous needle biopsies were collected from the vastus lateralis muscle in 15 healthy young women (20 ± 0.4 years), 15 healthy elderly women (79 ± 1.7 years), and 15 elderly women with a fall-related hip fracture (82 ± 1.5 years). Immunohistochemical analyses were performed to assess Type I and Type II muscle fiber size, and myonuclear and satellite cell content.

Results: Type II muscle fiber size was significantly different between all groups (p < .05), with smaller Type II muscle fibers in the hip fracture patients (2,609 ± 185 µm2) compared with healthy elderly group (3,723 ± 322 µm2) and the largest Type II muscle fibers in the healthy young group (4,755 ± 335 µm2). Furthermore, Type I muscle fiber size was significantly lower in the hip fracture patients (4,684 ± 211 µm2) compared with the healthy elderly group (5,842 ± 316 µm2, p = .02). The number of myonuclei per Type II muscle fiber was significantly lower in the healthy elderly and hip fracture group compared with the healthy young group (p = .011 and p = .002, respectively). Muscle fiber satellite cell content did not differ between groups.

Conclusion: Elderly female hip fracture patients show extensive Type II muscle fiber atrophy when compared with healthy young or age-matched healthy elderly controls. Type II muscle fiber atrophy is an important hallmark of sarcopenia and may predispose to falls and (hip) fractures in the older population.
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http://dx.doi.org/10.1093/gerona/glw253DOI Listing
October 2017

Both basal and post-prandial muscle protein synthesis rates, following the ingestion of a leucine-enriched whey protein supplement, are not impaired in sarcopenic older males.

Clin Nutr 2017 10 29;36(5):1440-1449. Epub 2016 Sep 29.

NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands.

Background: Studying the muscle protein synthetic response to food intake in elderly is important, as it aids the development of interventions to combat sarcopenia. Although sarcopenic elderly are the target group for many of these nutritional interventions, no studies have assessed basal or post-prandial muscle protein synthesis rates in this population.

Objective: To assess the basal and post-prandial muscle protein synthesis rates between healthy and sarcopenic older men.

Design: A total of 15 healthy (69 ± 1 y) and 15 sarcopenic (81 ± 1 y) older men ingested a leucine-enriched whey protein nutritional supplement containing 21 g of protein, 9 g of carbohydrate, and 3 g of fat. Stable isotope methodology combined with frequent collection of blood and muscle samples was applied to assess basal and post-prandial muscle protein fractional synthetic rates. Handgrip strength, muscle mass, and gait speed were assessed to identify sarcopenia, according to international criteria.

Results: Basal mixed muscle protein fractional synthetic rates (FSR) averaged 0.040 ± 0.005 and 0.032 ± 0.003%/h (mean ± SEM) in the sarcopenic and healthy group, respectively (P = 0.14). Following protein ingestion, FSR increased significantly to 0.055 ± 0.004 and 0.053 ± 0.004%/h in the post-prandial period in the sarcopenic (P = 0.003) and healthy groups (P < 0.001), respectively, with no differences between groups (P = 0.45). Furthermore, no differences were observed between groups in muscle protein synthesis rates during the early (0.058 ± 0.007 vs 0.060 ± 0.008%/h, sarcopenic vs healthy, respectively) and late (0.052 ± 0.004 vs 0.048 ± 0.003%/h) stages of the post-prandial period (P = 0.93 and P = 0.34, respectively).

Conclusions: Basal muscle protein synthesis rates are not lower in sarcopenic older men compared to healthy older men. The ingestion of 21 g of a leucine-enriched whey protein effectively increases muscle protein synthesis rates in both sarcopenic and healthy older men. Public trial registry number: NTR3047.
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http://dx.doi.org/10.1016/j.clnu.2016.09.023DOI Listing
October 2017

A single session of neuromuscular electrical stimulation does not augment postprandial muscle protein accretion.

Am J Physiol Endocrinol Metab 2016 Jul 7;311(1):E278-85. Epub 2016 Jun 7.

NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands

The loss of muscle mass and strength that occurs with aging, termed sarcopenia, has been (at least partly) attributed to an impaired muscle protein synthetic response to food intake. Previously, we showed that neuromuscular electrical stimulation (NMES) can stimulate fasting muscle protein synthesis rates and prevent muscle atrophy during disuse. We hypothesized that NMES prior to protein ingestion would increase postprandial muscle protein accretion. Eighteen healthy elderly (69 ± 1 yr) males participated in this study. After a 70-min unilateral NMES protocol was performed, subjects ingested 20 g of intrinsically l-[1-(13)C]phenylalanine-labeled casein. Plasma samples and muscle biopsies were collected to assess postprandial mixed muscle and myofibrillar protein accretion as well as associated myocellular signaling during a 4-h postprandial period in both the control (CON) and stimulated (NMES) leg. Protein ingestion resulted in rapid increases in both plasma phenylalanine concentrations and l-[1-(13)C]phenylalanine enrichments, which remained elevated during the entire 4-h postprandial period (P < 0.05). Mixed-muscle protein-bound l-[1-(13)C]phenylalanine enrichments increased significantly over time following protein ingestion, with no differences between the CON (0.0164 ± 0.0019 MPE) and NMES (0.0164 ± 0.0019 MPE) leg (P > 0.05). In agreement, no differences were observed in the postprandial rise in myofibrillar protein bound l-[1-(13)C]phenylalanine enrichments between the CON and NMES legs (0.0115 ± 0.0014 vs. 0.0133 ± 0.0013 MPE, respectively, P > 0.05). Significant increases in mTOR and P70S6K phosphorylation status were observed in the NMES-stimulated leg only (P < 0.05). We conclude that a single session of NMES prior to food intake does not augment postprandial muscle protein accretion in healthy older men.
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http://dx.doi.org/10.1152/ajpendo.00085.2016DOI Listing
July 2016

Co-ingesting milk fat with micellar casein does not affect postprandial protein handling in healthy older men.

Clin Nutr 2017 04 24;36(2):429-437. Epub 2015 Dec 24.

NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands; Top Institute Food & Nutrition (TIFN), Wageningen, The Netherlands. Electronic address:

Background & Aim: Dietary protein digestion and absorption plays an important role in modulating postprandial muscle protein synthesis. The impact of co-ingesting other macronutrients with dietary protein on protein digestion and absorption and the subsequent muscle protein synthetic response remains largely unexplored. This study investigated the impact of co-ingesting milk fat with micellar casein on dietary protein-derived amino acid appearance in the circulation and the subsequent postprandial muscle protein synthetic response in healthy older men.

Methods: Twenty-four healthy, older males (age: 65 ± 1 y, BMI: 25.7 ± 0.5 kg/m) received a primed continuous infusion of L-[ring-H]-phenylalanine and L-[1-C]-leucine and ingested 20 g intrinsically L-[1-C]-phenylalanine and L-[1-C]-leucine-labeled casein with (PRO + FAT; n = 12) or without (PRO; n = 12) 26.7 g milk fat. Plasma samples and muscle biopsies were collected in both the postabsorptive and postprandial state.

Results: Release of dietary protein-derived phenylalanine into the circulation increased following protein ingestion (P < 0.001) and tended to be higher in PRO compared with PRO + FAT (Time × Treatment P = 0.076). No differences were observed in dietary protein-derived plasma phenylalanine availability (52 ± 2 vs 52 ± 3% in PRO vs PRO + FAT, respectively; P = 0.868). Myofibrillar protein synthesis rates did not differ between treatments, calculated using either the L-[ring-H]-phenylalanine (0.036 ± 0.003 vs 0.036 ± 0.004 %/h after PRO vs PRO + FAT, respectively; P = 0.933) or L-[1-C]-leucine (0.051 ± 0.004 vs 0.046 ± 0.004 %/h, respectively; P = 0.480) tracer. In accordance, no differences were observed in myofibrillar protein-bound L-[1-C]-phenylalanine enrichments between treatments (0.018 ± 0.002 vs 0.014 ± 0.001 MPE, respectively; P = 0.173).

Conclusion: Co-ingesting milk fat with micellar casein does not impair protein-derived phenylalanine appearance in the circulation and does not modulate postprandial myofibrillar protein synthesis rates.

Clinical Trial Registration Number: NCT01680146 (http://www.clinicaltrials.gov/).
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http://dx.doi.org/10.1016/j.clnu.2015.12.011DOI Listing
April 2017

Impact of the Macronutrient Composition of a Nutritional Supplement on Muscle Protein Synthesis Rates in Older Men: A Randomized, Double Blind, Controlled Trial.

J Clin Endocrinol Metab 2015 Nov 26;100(11):4124-32. Epub 2015 Aug 26.

NUTRIM School for Nutrition and Translational Research in Metabolism (I.F.K., L.B.V., H.M.H., I.W.K.K., J.M.S., J.v.K., A.P.G., M.P., L.J.C.v.L.), Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands; Nutricia Research (S.V., Y.L.), Nutricia Advanced Medical Nutrition, 3584 CT Utrecht, The Netherlands; and Department of Surgery (I.F.K., M.P.), Division of Trauma Surgery, Maastricht University Medical Centre, 6200MD Maastricht, The Netherlands.

Context: An impaired muscle protein synthetic response to feeding likely contributes to muscle loss with aging. There are few data available on the effect of the macronutrient composition of clinical supplements on the postprandial muscle protein synthetic response in older subjects.

Objective: The objective of the study was to determine the impact of the macronutrient composition of a nutritional supplement on the postprandial muscle protein synthetic response in older men.

Methods: A total of 45 nonsarcopenic older men (aged 69 ± 1 y; body mass index 25.7 ± 0.3 kg/m(2)) were randomly assigned to ingest 21 g of leucine-enriched whey protein with carbohydrate (9 g) and fat (3 g) (Pro-En), an isonitrogenous amount of 21 g of leucine-enriched whey protein without carbohydrate and fat (Pro), or an isocaloric mixture (628 kJ) containing carbohydrate and fat only (En). Stable isotope tracer methodology was applied to assess the basal as well as the postprandial muscle protein synthesis rates in the three groups.

Results: Ingestion of protein in the Pro-En and Pro groups significantly increased muscle protein synthesis rates when compared with the basal rates (from 0.032 ± 0.003%/h to 0.05%/h 3 ± 0.004%/h and 0.040%/h ± 0.003%/h to 0.049%/h ± 0.003%/h, respectively; P < .05), whereas ingestion of carbohydrate and fat did not increase muscle protein synthesis rates in the En group (from 0.039%/h ± 0.004%/h to 0.040%/h ± 0.003%/h; P = .60). Despite the greater postprandial rise in circulating insulin concentration in the Pro-En group, no significant differences were observed in postprandial muscle protein synthesis rates between the Pro-En and Pro groups (P = .32). Postprandial muscle protein synthesis rates were higher in the Pro-En vs En group (P = .01).

Conclusion: The ingestion of a nutritional supplement containing 21 g of leucine-enriched whey protein significantly raises muscle protein synthesis rates in nonsarcopenic older men, but coingestion of carbohydrate and fat does not modulate the postprandial muscle protein synthetic response to protein ingestion in older men.
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http://dx.doi.org/10.1210/jc.2015-2352DOI Listing
November 2015

Snowboarders' ankle.

BMJ Case Rep 2014 Oct 29;2014. Epub 2014 Oct 29.

Department of Trauma Surgery, Maastricht University Medical Centre +, Maastricht, The Netherlands.

In this case study we report a fracture of the lateral process of the talus (LPF) in a snowboarder. The fracture is frequently overlooked initially, due to subtle clinical and radiological findings and a low incidence rate. However, LPF are associated with significant morbidity when missed. To address this, we report one case of a patient with a LPF and provide a review of the available literature.
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http://dx.doi.org/10.1136/bcr-2014-204220DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4216907PMC
October 2014

[Decompression illness: minor symptoms, major consequences].

Ned Tijdschr Geneeskd 2012 ;156(36):A4985

Universitair Medisch Centrum Utrecht, Afd. Cardiologie, Utrecht, the Netherlands.

Nowadays, diving is being performed ever more frequently; it is thus important to take diving injuries into consideration in patients presenting with even minor complaints after diving. Every dive is risky and could result in decompression illness, barotrauma and/or death. We report on two cases of decompression illness: a 30-year old man, an occupational diver, and a 46-year old man, an experienced diver, who were both clinically suspected of having decompression illness and were treated with hyperbaric oxygen in a recompression chamber. Both were eventually symptom-free after several treatments. Decompression illness is caused by a reduction in ambient pressure, which results in intra- or extravascular bubbles. Symptoms vary and are dependent on the site affected: from minor pain to neurological symptoms and death. If patients are suspected of having diving injuries, we recommend contacting a centre specialised in diving and hyperbaric medicine. Recompression in a hyperbaric chamber is the definitive treatment for decompression illness and should be performed as soon as possible.
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November 2012

Contributions to the understanding of the anabolic properties of different dietary proteins.

J Physiol 2012 Jun;590(12):2839-40

Department of Human Movement Sciences, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands.

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http://dx.doi.org/10.1113/jphysiol.2012.233684DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3448150PMC
June 2012
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