Longitudinal Assessment of Prenatal, Perinatal, and Early-Life Aflatoxin B1 Exposure in 828 Mother-Child Dyads from Bangladesh and Malawi.

BACKGROUND: In utero or early-life exposure to aflatoxin, which contaminates staple crops in disadvantaged settings, may compromise pregnancy and infant outcomes, but investigations into the extent, persistence, and determinants of aflatoxin exposure at these life stages have lacked longitudinal data collection and broad geographic representation. OBJECTIVES: Aflatoxin exposure and selected determinants thereof were characterized in mother-child dyads with serial plasma/serum samples in prenatal, perinatal, and early life in Malawi and Bangladesh. METHODS: Circulating aflatoxin B1 (AFB1)-lysine albumin adducts were measured in dyads from Bangladesh (n = 573; maternal first and third trimester, 3 mo postpartum, cord blood, infant 24 mo) and Malawi (n = 255; maternal second and third trimester, 6 mo postpartum, infant 6 and 18 mo) with isotope dilution mass spectrometry. We examined AFB1-lysine adduct magnitude, persistence, seasonality, and associations with infant feeding, and estimated daily AFB1 intake. RESULTS: Maternal AFB1-lysine was higher in Malawi (98% detectable; median: 0.469, IQR: 0.225-1.027 pg/µL) than in Bangladesh (59%; 0.030, nondetectable [nd]-0.077 pg/µL). Although estimated dietary exposure in Malawi was temporally stable (648 ng AFB1/day), estimated intake in Bangladesh was reduced by 94% between rainy and winter seasons (98 to 6 ng/day). AFB1-lysine was low in cord blood from Bangladesh (15% detectable; 0.045, 0.031-0.088 pg/µL among detectable) and in Malawian infants at 6 mo of age (0.072, nd-0.236 pg/µL), but reached maternal concentrations by 18 or 24 mo (Bangladesh: 0.034, nd-0.063 pg/µL; Malawi: 0.370, 0.195-0.964 pg/µL). In Malawian infants, exclusive breastfeeding at 3 mo was associated with 58% lower AFB1-lysine concentrations at 6 mo compared with other feeding modes (P = 0.010). CONCLUSIONS: Among pregnant women, aflatoxin exposure was persistently high in Malawi, while lower and seasonal in Bangladesh. Infants were partially protected from exposure in utero and with exclusive breastfeeding, but exposures reached adult levels by 18-24 mo of age. The Bangladesh and Malawi trials are registered at clinicaltrials.gov as NCT00860470 and NCT01239693.

Relative Contributions of Malaria, Inflammation, and Deficiencies of Iron and Vitamin A to the Burden of Anemia during Low and High Malaria Seasons in Rural Zambian Children.

OBJECTIVE: To estimate the burden of anemia attributable to malaria, inflammation, and deficiency of iron or vitamin A during low and high malaria seasons among Zambian children. STUDY DESIGN: From a cohort of children (n = 820), 4-8 years of age participating in a randomized controlled trial of pro-vitamin A, we estimated attributable fractions for anemia (hemoglobin of <110 or 115 g/L, by age) owing to current malaria or inflammation (C-reactive protein of >5 mg/L, or α-1 acid glycoprotein of >1 g/L, or both), and current or prior iron deficiency (ID; defined as low ferritin [<12 or 15 µg/L for age <5 or >5 years] or functional ID [soluble transferrin receptor of >8.3 mg/L] or both) and vitamin A deficiency (retinol of <0.7 µmol/L), during low and high malaria seasons, using multivariate logistic regression. Serum ferritin, soluble transferrin receptor, and retinol were adjusted for inflammation. RESULTS: The burden of anemia independently associated with current malaria, inflammation, ID, and vitamin A deficiency in the low malaria season were 12% (P < .001), 6% (P = .005), 14% (P = .001), and 2% (P = .07), respectively, and 32% (P < .001), 15% (P < .001), 10% (P = .06), and 2% (P = .06), respectively, in the high malaria season. In both seasons, functional ID was independently associated with more anemia (approximately 11%) than low ferritin (approximately 4%). Anemia and ID in the low malaria season, accounted for 20% (P < .001) and 4% (P = .095) of the anemia in the subsequent high malaria season. CONCLUSIONS: Anemia in this population is strongly linked to malaria, inflammation, and functional ID, and to a lesser extent, low iron stores. Integrated control strategies are needed.

Impact of biofortified maize consumption on serum carotenoid concentrations in Zambian children.

Biofortified maize, designed as an intervention strategy to prevent vitamin A deficiency, can provide upwards of 15 µg ß-carotene per g dry weight. Some varieties also have elevated concentrations of other carotenoids. We conducted a cluster randomized, controlled feeding trial in rural Zambia to test the impact of daily consumption of biofortified maize over a 6-month period on vitamin A status. Serum concentrations of retinol and carotenoids were assessed by high-performance liquid chromatography. Data on circulating carotenoids by intervention group in 679 children are reported here. As previously shown, consumption of this ß-carotene-rich maize significantly improved serum ß-carotene concentrations (0.273 vs. 0.147 µmol/L, p < 0.001, in this subset of children). Here we show significant increases in α-carotene, ß-cryptoxanthin, and zeaxanthin (p < 0.001). There was no impact on lutein or lycopene concentrations. Consumption of biofortified maize can have broader implications beyond the control of vitamin A deficiency (Trial registration: NCT01695148).

A cross-sectional study of the prevalence and risk factors for hypertension in rural Nepali women.

BACKGROUND: The prevalence of hypertension is increasing in much of the South Asian region, including Nepal. This paper reports the prevalence and risk factors of hypertension and pre-hypertension among adult women in a rural community of Nepal. METHODS: Cross-sectional data on socioeconomic status (SES), lifestyle factors and blood pressure (BP) were collected from a cohort of 15,934 women in rural Nepal in 2006-08. Among a subsample (n = 1679), anthropometry and biomarkers of cardiovascular risk were measured. RESULTS: The mean age of women was 34.2 years (range 16.4-71.2 years). More than three percent (3.3%) had hypertension and 14.4% had pre-hypertension. In an adjusted analysis, lower SES, especially lower household farm assets and storage of food for long term consumption, was associated with increased odds of hypertension (OR = 1.14 for mid-level SES and OR = 1.40 for low SES; p for trend < 0.01). Smoking, alcohol use and not working outside the home were also associated with higher risk. In a subsample, both systolic BP (SBP) and diastolic BP (DBP) were positively associated with high triglycerides (SBP ß = 4.1 mm Hg; DBP ß =3.6 mm Hg), high HbA1c (SBP ß = 14.0; DBP ß = 9.2), raised fasting glucose (SBP ß = 10.0; DBP ß = 6.9), high BMI (SBP ß = 6.7; DBP ß = 5.1) and high waist circumference (SBP ß = 6.2; DBP ß = 5.3) after adjusting for potential confounders (p for all <0.01). CONCLUSIONS: Although the prevalence of hypertension was low in this cohort, it was more prevalent among the poorer women and was strongly associated with other cardiovascular risks. These associations at a relatively young age may confer greater risk for cardiovascular disease among women in later life, indicating the need for interventions to reduce the progression from pre-hypertension to hypertension.