Publications by authors named "K Michael Hambidge"

253 Publications

Improved first trimester maternal iodine status with preconception supplementation: The Women First Trial.

Matern Child Nutr 2021 May 25:e13204. Epub 2021 May 25.

Department of Pediatrics, Section of Nutrition, University of Colorado School of Medicine, Aurora, Colorado, USA.

Maternal iodine (I) status is critical in embryonic and foetal development. We examined the effect of preconception iodine supplementation on maternal iodine status and on birth outcomes. Non-pregnant women in Guatemala, India and Pakistan (n ~ 100 per arm per site) were randomized ≥ 3 months prior to conception to one of three intervention arms: a multimicronutrient-fortified lipid-based nutrient supplement containing 250-μg I per day started immediately after randomization (Arm 1), the same supplement started at ~12 weeks gestation (Arm 2) and no intervention supplement (Arm 3). Urinary I (μg/L) to creatinine (mg/dl) ratios (I/Cr) were determined at 12 weeks for Arm 1 versus Arm 2 (before supplement started) and 34 weeks for all arms. Generalized linear models were used to assess the relationship of I/Cr with arm and with newborn anthropometry. At 12 weeks gestation, adjusted mean I/Cr (μg/g) for all sites combined was significantly higher for Arm 1 versus Arm 2: (203 [95% CI: 189, 217] vs. 163 [95% CI: 152, 175], p < 0.0001). Overall adjusted prevalence of I/Cr < 150 μg/g was also lower in Arm 1 versus Arm 2: 32% (95% CI: 26%, 38%) versus 43% (95% CI: 37%, 49%) (p = 0.0052). At 34 weeks, adjusted mean I/Cr for Arm 1 (235, 95% CI: 220, 252) and Arm 2 (254, 95% CI: 238, 272) did not differ significantly but were significantly higher than Arm 3 (200, 95% CI: 184, 218) (p < 0.0001). Nominally significant positive associations were observed between I/Cr at 12 weeks and birth length and head circumference z-scores (p = 0.028 and p = 0.005, respectively). These findings support the importance of first trimester iodine status and suggest need for preconception supplementation beyond salt iodization alone.
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May 2021

Perceptions of women, their husbands and healthcare providers about anemia in rural Pakistan: Findings from a qualitative exploratory study.

PLoS One 2021 27;16(4):e0249360. Epub 2021 Apr 27.

Department of Community Health Sciences, Aga Khan University, Karachi, Pakistan.

Background: In Pakistan, there is a dearth of literature on the perceptions of anemia among women of reproductive age (WRA). This study was undertaken to explore the perceptions of women, their husbands, and healthcare providers about anemia, its possible causes, and how anemia impacts maternal and child health in Thatta, Pakistan.

Methods: A qualitative study was conducted in Thatta, Pakistan from September to December 2018. Using a pre-tested semi-structured interview (SSI), we collected data to understand their definitions of anemia through ten focus group discussions (FGDs) with women and their partners and ten primary informant interviews (KIIs) with healthcare providers. We identified six major themes: (I) Knowledge and awareness of anemia, (II) Causes and consequences of Anemia, (III) Dietary practices, (IV) Knowledge and practices regarding the use of iron-folic acid supplements, (V) Factors influencing prevention and control of anemia and (VI) Women's health behavior. We analyzed the data through thematic analysis using NVivo 10 software.

Results: Most community members were not aware of the term anemia but described anemia as a condition characterized by 'blood deficiency' in the body. All study participants perceived anemia as an important health problem tending to cause adverse outcomes among WRA and their children. Study participants perceived gutka (chewable tobacco) consumption as an important cause of anemia. Healthcare providers identified short inter-pregnancy intervals, lack of family planning, poor health-seeking behavior, and consumption of unhealthy food as causes of anemia in the district. Consumption of unhealthy food might not be related to related to a poorer knowledge of iron-deficient foods, but economic constraints. This was further endorsed by the healthcare providers who mentioned that most women were too poor to afford iron-rich foods. All men and women were generally well versed with the sources of good nutrition to be consumed by WRA to prevent anemia.

Conclusion: The findings suggest that the government should plan to develop strategies for poverty-stricken and vulnerable rural women and plan health awareness programs to improve dietary practices, compliance with supplements, and health-seeking behavior among women of reproductive age. There is a need to develop effective counseling strategies and context-specific health education sessions to improve the health-seeking behavior of women and men in the Thatta district of Pakistan. Besides, there is need to address social determinants of health such as poverty that pushes women of poorer socioeconomic strata to eat less nutritious foods and have more anaemia. Therefore, a comprehensive and robust strategic plan need to be adopted by government that focuses not only on the awareness programs, but also aim to reduce inequities that lead to pregnant women eat iron-poor foods, which, in turn, forces them to become anemic.
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September 2021

Gestational weight gain in 4 low- and middle-income countries and associations with birth outcomes: a secondary analysis of the Women First Trial.

Am J Clin Nutr 2021 08;114(2):804-812

Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.

Background: Adequate gestational weight gain (GWG) is essential for healthy fetal growth. However, in low- and middle-income countries, where malnutrition is prevalent, little information is available about GWG and how it might be modified by nutritional status and interventions.

Objective: We describe GWG and its associations with fetal growth and birth outcomes. We also examined the extent to which prepregnancy BMI, and preconception and early weight gain modify GWG, and its effects on fetal growth.

Methods: This was a secondary analysis of the Women First Trial, including 2331 women within the Democratic Republic of Congo (DRC), Guatemala, India, and Pakistan, evaluating weight gain from enrollment to ∼12 weeks of gestation and GWG velocity (kg/wk) between ∼12 and 32 weeks of gestation. Adequacy of GWG velocity was compared with 2009 Institute of Medicine recommendations, according to maternal BMI. Early weight gain (EWG), GWG velocity, and adequacy of GWG were related to birth outcomes using linear and Poisson models.

Results: GWG velocity (mean ± SD) varied by site: 0.22 ± 0.15 kg/wk in DRC, 0.30 ± 0.23 in Pakistan, 0.31 ± 0.14 in Guatemala, and 0.39 ± 0.13 in India, (P <0.0001). An increase of 0.1 kg/wk in maternal GWG was associated with a 0.13 cm (95% CI: 0.07, 0.18, P <0.001) increase in birth length and a 0.032 kg (0.022, 0.042, P <0.001) increase in birth weight. Compared to women with inadequate GWG, women who had adequate GWG delivered newborns with a higher mean length and weight: 47.98 ± 2.04 cm compared with 47.40 ± 2.17 cm (P <0.001) and 2.864 ± 0.425 kg compared with 2.764 ± 0.418 kg (P <0.001). Baseline BMI, EWG, and GWG were all associated with birth length and weight.

Conclusions: These results underscore the importance of adequate maternal nutrition both before and during pregnancy as a potentially modifiable factor to improve fetal growth.
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August 2021

Zinc absorption and zinc status are reduced after either sleeve gastrectomy or Roux-en-Y gastric bypass in premenopausal women with severe obesity studied prospectively over 24 postoperative months.

Am J Clin Nutr 2021 07;114(1):322-329

Section of Nutrition, Department of Pediatrics, School of Medicine University of Colorado, Aurora, CO, USA.

Background: Roux-en-Y gastric bypass (RYGBP) is known to reduce zinc absorption; the effects of vertical sleeve gastrectomy (SG) and its long-term implications on zinc absorption have not yet been studied.

Objective: The aim was to evaluate the effects of SG and RYGBP on zinc absorption and zinc status in premenopausal women with severe obesity up to 24 mo after surgery.

Methods: Twenty-six premenopausal women undergoing SG [BMI (in kg/m2): 37.3 ± 3.2] and 32 undergoing RYGBP (BMI: 42.0 ± 4.2) were studied. A series of anthropometric, dietary, and zinc status parameters (plasma and hair zinc), and the size of the exchangeable zinc pool (EZP), as well as percentage zinc absorption from a standardized dose using a stable isotope methodology were evaluated in the patients before the surgical procedure and at 12 and 24 mo after SG or RYGBP. SG patients received 15 mg and RYGBP received 25 mg of supplemental Zn/d.

Results: In premenopausal women, zinc absorption was decreased by 71.9% and 52.0% in SG and RYGBP, respectively, 24 mo postsurgery, compared with initial values. According to 2-factor repeated-measures ANOVA, time effect was significant (P = <0.0001), but not time × group interaction (P = 0.470). Plasma zinc below the cutoff point of 70 µg/dL increased from 0 to 15.4% and 38.1% in SG and RYGBP, respectively. Mean EZP was significantly reduced 24 mo after surgery, although no time × group interactions were observed. Hair zinc did not change across time or between groups.

Conclusions: Both SG and RYGBP have profound effects on zinc absorption capacity, which are not compensated for after 24 mo. Although zinc absorption reduction was similar in both types of surgeries, plasma zinc was more affected in RYGBP than SG, despite greater zinc supplementation in RYGBP.This trial was registered at as ISRCTN31937503.
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July 2021

Preconceptional Lipid-Based Nutrient Supplementation in 2 Low-Resource Countries Results in Distinctly Different IGF-1/mTOR Placental Responses.

J Nutr 2021 03;151(3):556-569

Section of Neonatology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.

Background: Preconceptional maternal small-quantity lipid-based nutrient supplementation (SQLNS) improved intrauterine linear growth in low-resource countries as demonstrated by the Women First Preconception Maternal Nutrition Trial (WF). Fetal growth is dependent on nutrient availability and regulated by insulin-like growth factor 1 (IGF-1) through changes in placental transfer capacity, mediated by the mechanistic target of rapamycin (mTOR) pathway.

Objectives: Our objective was to evaluate the role of placental mTOR and IGF-1 signaling on fetal growth in women from 2 low-resource countries with high rates of stunting after they received preconceptional SQLNS.

Methods: We studied 48 women from preconception through delivery who were from Guatemala and Pakistan and received SQLNS or not, as part of the WF study. Placental samples were obtained at delivery (control, n = 24; SQLNS, n = 24). Placental protein or mRNA expression of eukaryotic translation initiation factor binding protein-1 (4E-BP1), ribosomal protein S6 (rpS6), AMP-activated protein kinase α (AMPKA), IGF-1, insulin-like growth factor receptor (IGF-1R), and pregnancy associated plasma protein (PAPP)-A, and DNA methylation of the IGF1 promoter were determined. Maternal serum IGF-1, insulin-like growth factor binding protein (IGFBP)-3, IGFBP-4, IGFBP-5, PAPP-A, PAPP-A2, and zinc were measured.

Results: Mean ± SEM maternal prepregnancy BMI differed between participants in Guatemala (26.5 ± 1.3) and Pakistan (19.8 ± 0.7) (P < 0.001). In Pakistani participants, SQLNS increased the placental rpS6(T37/46):rpS6 ratio (1.5-fold) and decreased the AMPKA(T172):AMPKA ratio. Placental IGF1 mRNA expression was positively correlated with birth length and birth weight z-scores. Placental PAPP-A (30-fold) and maternal serum zinc (1.2-fold) increased with SQLNS. In Guatemalan participants SQLNS did not influence placental mTOR signaling. Placental IGF-1R protein expression was positively associated with birth length and birth weight z-scores. SQLNS increased placental PAPP-A (40-fold) and maternal serum IGFBP-4 (1.6-fold).

Conclusions: In Pakistani pregnant women with poor nutritional status, preconceptional SQLNS activated placental mTOR and IGF-1 signaling and was associated with improved fetal growth. In contrast, in Guatemalan women SQLNS did not activate placental nutrient-sensing pathways. In populations experiencing childhood stunting, preconceptional SQLNS improves placental function and fetal growth only in the context of poor maternal nutrition. This trial was registered at as NCT01883193.
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March 2021