Towards a link between magnesium, exercise, and risk of type 2 diabetes mellitus

Placental Transcriptome Profiling in Subtypes of Diabetic Pregnancies Is Strongly Confounded by Fetal Sex

The placenta is a temporary organ with a unique structure and function to ensure healthy fetal development. Placental dysfunction is involved in pre-eclampsia (PE), fetal growth restriction, preterm birth, and gestational diabetes mellitus (GDM). A diabetic state affects maternal and fetal health and may lead to functional alterations of placental metabolism, inflammation, hypoxia, and weight, amplifying the fetal stress. The placental molecular adaptations to the diabetic environment and the adaptive spatio-temporal consequences to elevated glucose or insulin are largely unknown (2). We aimed to identify gene expression signatures related to the diabetic placental pathology of placentas from women with diabetes mellitus. Human placenta samples (n = 77) consisting of healthy controls, women with either gestational diabetes mellitus (GDM), type 1 or type 2 diabetes, and women with GDM, type 1 or type 2 diabetes and superimposed PE were collected. Interestingly, gene expression differences quantified by total RNA sequencing were mainly driven by fetal sex rather than clinical diagnosis. Association of the principal components with a full set of clinical patient data identified fetal sex as the single main explanatory variable. Accordingly, placentas complicated by type 1 and type 2 diabetes showed only few differentially expressed genes, while possible effects of GDM and diabetic pregnancy complicated by PE were not identifiable in this cohort. We conclude that fetal sex has a prominent effect on the placental transcriptome, dominating and confounding gene expression signatures resulting from diabetes mellitus in settings of well-controlled diabetic disease. Our results support the notion of placenta as a sexual dimorphic organ.

Magnesium dietary intake and physical activity in Type 2 diabetes by gender in White, African-American and Mexican American: NHANES 2011-2014

Aims

To analyse the causal relationships of nutrition intake and physical activity on haemoglobin A1c (HbA1C) in patients diagnosed with type 2 diabetes mellitus (T2DM) stratified by gender and ethnicity.

Materials and Methods

An historical cohort of patients with diagnosed T2DM (n = 2831) was extracted from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 public database, including but not limited to, measurements of physical activity, nutrition, body mass index (BMI) and HbA1c. Multivariate analyses and path analyses were employed to estimate the regression coefficients and path coefficients (ρ) of causal path models of physical activity and nutrition intake on HbA1c stratified by gender and three ethnicity groups (ie non-Hispanic white, non-Hispanic black and Mexican American).

Results

A significant causal path from increased physical activity to increased magnesium (Mg) intake to decreased HbA1c was found. In addition, increased physical activity significantly decreased BMI, which further decreased HbA1c. These results varied by gender and ethnicity but were directionally consistent. Physical activity decreased HbA1c through BMI for males and through Mg intake for females. Mexican American decreased HbA1c through Mg intake, while non-Hispanic black had an increased HbA1c due to its ethnicity and through increased BMI.

Conclusions

The beneficial effects of physical activity on decreased HbA1c were mediated through the increased Mg intake and decreased BMI. This aligned with recent investigations of the inverse causal association of Mg intake with insulin resistance and with decreased inflammation.