High folate and low vitamin B12 status during pregnancy is associated with gestational diabetes mellitus.

BACKGROUND & AIMS: B-vitamins and homocysteine may contribute to the development of gestational diabetes mellitus (GDM), but existing studies are inconsistent. We examined the cross-sectional associations of plasma folate, vitamins B6, B12, and homocysteine concentrations with GDM and glycemia in a sample of multi-ethnic Asian pregnant women. METHODS: Plasma concentrations of folate, vitamins B6, B12, homocysteine and glucose were measured at 26-weeks' gestation in 913 pregnant women. GDM was diagnosed using the 1999 World Health Organization criteria. Associations were examined with linear or logistic regression, adjusted for confounders and stratified by ethnicity. RESULTS: Higher plasma folate was associated with higher 2-h glucose and higher odds of GDM [0.15 (0.02, 0.23) per 1-SD increment in folate, OR 1.29 (1.00, 1.60)], mainly among Indian mothers. Higher plasma vitamin B12 and homocysteine were associated with lower fasting and 2-h glucose, and lower odds of GDM [-0.04 (-0.07, -0.01) per 1-SD increment in B12 and -0.09 (-0.18, -0.003) respectively, OR: 0.81 (0.68, 0.97); -0.05 (-0.08, -0.02) per 1-SD increment in homocysteine and -0.12 (-0.21, -0.02) respectively, OR: 0.76 (0.62, 0.92)]. The highest odds of GDM were observed among women with combined vitamin B12 insufficiency and high folate concentration [OR: 1.97 (1.05, 3.68)]. An association between higher vitamin B6 and higher 2-h glucose shifted towards null adjusting for other B-vitamins. CONCLUSIONS: Higher maternal folate coupled with vitamin B12 insufficiency was associated with higher GDM risk. This finding has potential implications for antenatal supplement recommendations but will require confirmation in future studies.

Inflammation mediates the association between fatty acid intake and depression in older men and women.

Antioxidants and fatty acids are associated with depression and inflammation, and inflammation appears to predict depression risk; hence, the associations between these nutrients and depression may be mediated by inflammation. We hypothesized that inflammatory markers interleukin (IL)-6 and C-reactive protein (CRP) mediate the associations between antioxidant and fatty acid intakes, and depression. Participants were from the Hunter Community Study, a longitudinal cohort of adults aged 55-85 years. Dietary intake was assessed using the Older Australian's Food Frequency Questionnaire. Fasting blood samples were drawn for analysis of nutrient and inflammatory biomarkers. Depressive symptoms were assessed using the 20-item Center for Epidemiologic Studies-Depression scale at baseline and at 5-year follow-up. Linear mixed models were used to investigate longitudinal associations between dietary intakes and depression, and mediation analyses were carried out to determine if IL-6 and/or CRP were the mediators. Analyses were conducted on men and women separately and adjusted for potential confounders. Fruit and monounsaturated fat intakes were negatively associated with depression, whereas total fat and saturated fat intakes were positively associated with depression in both sexes. Omega-3 polyunsaturated fat was inversely associated with depression in men only. IL-6 was a significant mediator of the association between fruits with low carotenoid content and depression in women. CRP significantly mediated the relationship between total fat, saturated fat, and monounsaturated fat intakes and depression in women, and saturated fat intake and depression in men. Our findings raise the possibility that the association between fatty acid intake and depression is partially mediated by inflammatory markers.