Selenium status in pregnancy influences children's cognitive function at 1.5 years of age.

BACKGROUND & AIMS: Selenium deficiency has been shown to affect the neurological development in animals, but human research in this area is scarce. We aimed to assess the impact of selenium status during pregnancy on child development at 1.5 years of age. METHODS: This prospective cohort study was nested into a food and micronutrient supplementation trial (MINIMat) conducted in rural Bangladesh. Using inductively coupled plasma mass spectrometry, we measured selenium concentrations in erythrocyte fraction of blood collected from 750 mothers at gestational week 30, and calculated μg per g hemoglobin. A revised version of Bayley Scales of Infant Development was used to assess children's mental and psychomotor development. A Bangladeshi version of MacArthur's Communicative Development Inventory was used to assess language comprehension and expression. Linear regression analyses adjusted for multiple covariates were used to assess the associations. RESULTS: Maternal erythrocyte selenium concentrations varied considerably, from 0.19 to 0.87 μg/g hemoglobin (median 0.46 μg/g hemoglobin), and were associated with developmental measures. An increase in erythrocyte selenium by 0.50 μg/g hemoglobin was associated with an increase in children's language comprehension by 3.7 points (0.5 standard deviations; 95% confidence interval: 0.40, 7.1; p = 0.028). The same increase in erythrocyte selenium corresponded to an increase in the girls' psychomotor development by 12 points (0.9 standard deviation; 95% confidence interval: 4.3, 19; p = 0.002), but much less in boys. CONCLUSIONS: Low prenatal selenium status seems to be disadvantageous for children's psychomotor and language development. Further studies are needed to elucidate the underlying mechanisms of these effects

Blood Metal Levels and Amyotrophic Lateral Sclerosis Risk: A Prospective Cohort

International audienceObjective: Metals have been suggested as a risk factor for amyotrophic lateral sclerosis (ALS), but only retrospective studies are available to date. We compared metal levels in prospectively collected blood samples from ALS patients and controls, to explore whether metals are associated with ALS mortality. Methods: A nested ALS case–control study was conducted within the prospective EPIC (European Prospective Investigation into Cancer and Nutrition) cohort. Cases were identified through death certificates. We analyzed metal levels in erythrocyte samples obtained at recruitment, as a biomarker for metal exposure from any source. Arsenic, cadmium, copper, lead, manganese, mercury, selenium, and zinc concentrations were measured by inductively coupled plasma–mass spectrometry. To estimate ALS risk, we applied conditional logistic regression models. Results: The study population comprised 107 cases (65% female) and 319 controls matched for age, sex, and study center. Median time between blood collection and ALS death was 8 years (range = 1–15). Comparing the highest with the lowest tertile, cadmium (odds ratio [OR] = 2.04, 95% confidence interval [CI] = 1.08–3.87) and lead (OR = 1.89, 95% CI = 0.97–3.67) concentrations suggest associations with increased ALS risk. Zinc was associated with a decreased risk (OR = 0.50, 95% CI = 0.27–0.94). Associations for cadmium and lead remained when limiting analyses to noncurrent smokers. Interpretation: This is the first study to compare metal levels before disease onset, minimizing reverse causation. The observed associations suggest that cadmium, lead, and zinc may play a role in ALS etiology. Cadmium and lead possibly act as intermediates on the pathway from smoking to ALS. ANN NEUROL 20209999:n/a–n/a

Urinary iodine concentrations of pregnant women in rural Bangladesh : A longitudinal study

Iodine is an essential dietary element required for normal fetal growth and development. We aimed to explore intraindividual and interindividual variations in iodine intake in pregnant women and whether non-dietary factors might influence the intake. Iodine intake was assessed in 271 women, residing in Matlab, rural Bangladesh, by measuring their urinary iodine concentration (UIC) at gestational week (GW) 8, 14, 19, and 30 with inductively coupled plasma mass spectrometry. The women's UIC increased significantly during pregnancy (median 241 (GW8) and 300 μg/l (GW30)). About 6% of the women had insufficient iodine intake (UIC<150 μg/l) and 10% had excessive iodine intake (UIC≥500 μg/l) at all of their four sampling occasions. The women's UIC were dependent on their education, socio-economic status, and BMI, as well as the season of sampling and iodine concentrations in drinking water. Supplementation with a multi-micronutrient capsule, including 150 μg potassium iodine, increased the UIC in women with the lowest UIC (10th percentile) at GW30 but decreased the UIC in women with the highest UIC (90th percentile) at GW30. In conclusion, median UIC throughout pregnancy indicated adequate intake of iodine among pregnant women in Matlab, but, notably, consistently insufficient and excessive intake was also prevalent