Gestational obesity/prediabetes and folic acid supplementation program fetal one-carbon metabolism and beta cell mass

Background: Folic acid supplementation is recommended for women of childbearing age to prevent birth defects. Women with pregestational obesity (BMI≥30kg/m²) and/or diabetes are recommended to take up to 12x the recommended dose of folic acid. Concerns have been raised that elevated folic acid during pregnancy may have negative impacts on the cardiometabolic health of the mother and child. The objective of my thesis was to determine the effects of folic acid supplementation in gestational obesity/prediabetes on maternal and fetal health. Methods: Female (C57BL/6J) mice were fed from weaning a control diet (10% kcal fat; control dams) or western diet (45% kcal fat; western dams; model of obesity/prediabetes). Diets contained supplemental (10mg/kg diet) or recommended level (2mg/kg diet) folic acid. Dams (n=11-14/diet) were fed for 13 weeks prior to breeding with control males. Tissue from dams and fetal offspring were collected at embryonic day (E)18.5. Results: Prior to breeding, western dams had greater body weight and adiposity accompanied by glucose intolerance and impaired β cell function. Folic acid supplementation reduced insulin sensitivity in control dams and improved insulin sensitivity in western dams. At E18.5, western dams had larger livers and key methyl donor, S-adenosylmethionine (SAM), and it’s demethylated product, S-adenosylhomocysteine (SAH), were lower in liver, compared to control dams. Male offspring from western dams had smaller livers and higher hepatic betaine and choline compared to offspring from control dams. Female offspring from western dams had smaller livers and higher hepatic betaine compared to those from control dams. Maternal folic acid supplementation increased hepatic SAM in female offspring, but not in male offspring. Maternal diet did not affect fetal pancreas size, but male offspring from folic acid supplemented dams had greater β cell mass and β cell density compared to those from non-supplemented dams; no effect of maternal diet on β cell mass was observed in female offspring. Conclusion: Folic acid supplementation does not exacerbate adiposity and glucose tolerance in dams with gestational obesity/prediabetes. However, maternal folic acid supplementation and gestational obesity/prediabetes has sex-specific effects on hepatic one-carbon metabolism and pancreatic β cell mass in fetal offspring.Medicine, Faculty ofObstetrics and Gynaecology, Department ofGraduat

A multicenter analytical performance evaluation of a multiplexed immunoarray for the simultaneous measurement of biomarkers of micronutrient deficiency, inflammation and malarial antigenemia.

A lack of comparative data across laboratories is often a barrier to the uptake and adoption of new technologies. Furthermore, data generated by different immunoassay methods may be incomparable due to a lack of harmonization. In this multicenter study, we describe validation experiments conducted in a single lab and cross-lab comparisons of assay results to assess the performance characteristics of the Q-plex™ 7-plex Human Micronutrient Array (7-plex), an immunoassay that simultaneously quantifies seven biomarkers associated with micronutrient (MN) deficiencies, inflammation and malarial antigenemia using plasma or serum; alpha-1-acid glycoprotein, C-reactive protein, ferritin, histidine-rich protein 2, retinol binding protein 4, soluble transferrin receptor, and thyroglobulin. Validations included repeated testing (n = 20 separately prepared experiments on 10 assay plates) in a single lab to assess precision and linearity. Seven independent laboratories tested 76 identical heparin plasma samples collected from a cohort of pregnant women in Niger using the same 7-plex assay to assess differences in results across laboratories. In the analytical validation experiments, intra- and inter-assay coefficients of variation were acceptable at <6% and <15% respectively and assay linearity was 96% to 99% with the exception of ferritin, which had marginal performance in some tests. Cross-laboratory comparisons showed generally good agreement between laboratories in all analyte results for the panel of 76 plasma specimens, with Lin's concordance correlation coefficient values averaging ≥0.8 for all analytes. Excluding plates that would fail routine quality control (QC) standards, the inter-assay variation was acceptable for all analytes except sTfR, which had an average inter-assay coefficient of variation of ≥20%. This initial cross-laboratory study demonstrates that the 7-plex test protocol can be implemented by users with some experience in immunoassay methods, but familiarity with the multiplexed protocol was not essential