Breast milk (BM) hormones have been hypothesised as a nutritional link between maternal and infant metabolic health. This study aimed to evaluate hormone concentrations in BM of women with and without gestational diabetes mellitus (GDM), and the relationship between maternal factors, BM hormones and infant growth. We studied ninety-six nulliparous women with (n 48) and without GDM and their exclusively breastfed term singletons. Women with GDM received dietary therapy or insulin injection for euglycaemia during pregnancy. Hormone concentrations in BM, maternal BMI and infant growth were longitudinally evaluated on postnatal days 3, 42 and 90. Mothers with GDM had decreased concentrations of adiponectin (P colostrum < 0·001; P mature-milk = 0·009) and ghrelin (P colostrum = 0·011; P mature-milk < 0·001) and increased concentration of insulin in BM (P colostrum = 0·047; P mature-milk = 0·021). Maternal BMI was positively associated with adiponectin (β = 0·06; 95 % CI 0·02, 0·1; P = 0·001), leptin (β = 0·16; 95 % CI 0·12, 0·2; P < 0·001) and insulin concentrations (β = 0·06; 95 % CI 0·02, 0·1; P < 0·001), and inversely associated with ghrelin concentration in BM (β = -0·08; 95 % CI -0·1, -0·06; P < 0·001). Among the four hormones, adiponectin was inversely associated with infant growth in both the GDM (β weight-for-height = -2·49; 95 % CI -3·83, -1·15; P < 0·001; β head-circumference = -0·39; 95 % CI -0·65, -0·13; P = 0·003) and healthy groups (β weight-for-height = -1·42; 95 % CI -2·38, -0·46; P = 0·003; β head-circumference = -0·15; 95 % CI -0·27, -0·03; P = 0·007). Maternal BMI and GDM are important determinants of BM hormone concentrations. Milk-borne adiponectin is determined by maternal metabolic status and plays an independent down-regulating role in early infant growth.

Aims/IntroductionThe present meta‐analysis was carried out to assess the association between exposure to the level of atmospheric particulate matter 2.5 (PM2.5; fine particulate matter with aerodynamic diameter less than 2.5 μm) and type 2 diabetes mellitus or gestational diabetes mellitus (GDM).Materials and MethodsWe searched the Medline, EMBASE, Cochrane and Web of Science databases to obtain articles according to the responding literature search strategies. Among a total of 279 identified articles, 55 were reviewed in depth, of which 10 articles (11 cohort studies) satisfied the inclusion criteria. Only cohort studies that disclosed the association between PM2.5 and type 2 diabetes mellitus or GDM were included in this article. A fixed‐effects model was selected if P > 0.1 and I 2 < 50%; otherwise, a random‐effects model would be used to calculate the total effect value. Subgroup analysis was further carried out according to the types of diabetes mellitus (type 2 diabetes mellitus and GDM). The relative risk was used to estimate the association between PM2.5 and diabetes mellitus.ResultsThe positive associations between PM2.5 and the incidence of type 2 diabetes mellitus were found in the long‐term exposure period (relative risk 1.25, 95% confidence interval 1.10–1.43), which showed that with every 10‐μg/m3 increase in PM2.5, the risk of type 2 diabetes mellitus would increase by 25% in the long‐term exposure. Although the significant associations were not identified between maternal exposure to PM2.5 and GDM in the first trimester, the second trimester and the entire pregnancy periods, we could conclude that maternal exposure to PM2.5 in the entire pregnancy period would be more likely to lead to developing GDM (relative risk 1.162, 95% confidence interval 0.806–1.675) than the other two periods.ConclusionsLong‐term exposure to PM2.5 would be more likely to lead to developing type 2 diabetes mellitus, but more studies would be required to confirm the association between PM2.5 and GDM. It might be a wise to take effective measures to reduce PM2.5 exposure in vulnerable populations, especially for pregnant women.

Women in early pregnancy with HNBP more likely develop total preeclampsia, early preeclampsia and severe preeclampsia, compared to those with optimal blood pressure. HNBP contribute more to early preeclampsia than severe preeclampsia. Our study provided robust epidemiological evidences for monitoring HNBP in early pregnancy to reduce the risks of preeclampsia.