Age at Menarche and Risk of Gestational Diabetes Mellitus: A Prospective Cohort Study Among 27,482 Women

OBJECTIVE: To examine the association between age at menarche and risk of gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: A prospective cohort study of 42,109 eligible pregnancies from 27,482 women in the Nurses' Health Study II. RESULTS: The adjusted risk ratios for GDM across the age at menarche categories (≤11, 12, 13, and ≥14 years) were 1.34 (95% CI 1.14-1.58), 1.13 (0.97-1.31), 1.11 (0.95-1.29), and 1.00 (referent; P for trend = 0.0005), respectively. Analysis of the mediating effect indicated that 42.1% (P = 0.0007) of the association was mediated through prepregnancy BMI. CONCLUSIONS: These findings suggested that earlier menarche was significantly associated with an increased risk of GDM. This association was largely mediated through prepregnancy excessive body adiposity

Role of Leptin in Mood Disorder and Neurodegenerative Disease

The critical regulatory role of leptin in the neuroendocrine system has been widely reported. Significantly, leptin can improve learning and memory, affect hippocampal synaptic plasticity, exert neuroprotective efficacy and reduce the risk of several neuropsychiatric diseases. In terms of depression, leptin could modulate the levels of neurotransmitters, neurotrophic factors and reverse the dysfunction in the hypothalamic-pituitary-adrenal axis (HPA). At the same time, leptin affects neurological diseases during the regulation of metabolic homeostasis. With regards to neurodegenerative diseases, leptin can affect them via neuroprotection, mainly including Alzheimer’s disease and Parkinson’s disease. This review will summarize the mechanisms of leptin signaling within the neuroendocrine system with respect to these diseases and discuss the therapeutic potential of leptin

Longitudinal Plasma Metabolomics Profile in Pregnancy—A Study in an Ethnically Diverse U.S. Pregnancy Cohort

Amino acids, fatty acids, and acylcarnitine metabolites play a pivotal role in maternal and fetal health, but profiles of these metabolites over pregnancy are not completely established. We described longitudinal trajectories of targeted amino acids, fatty acids, and acylcarnitines in pregnancy. We quantified 102 metabolites and combinations (37 fatty acids, 37 amino acids, and 28 acylcarnitines) in plasma samples from pregnant women in the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singletons cohort (n = 214 women at 10-14 and 15-26 weeks, 107 at 26-31 weeks, and 103 at 33-39 weeks). We used linear mixed models to estimate metabolite trajectories and examined variation by body mass index (BMI), race/ethnicity, and fetal sex. After excluding largely undetected metabolites, we analyzed 77 metabolites and combinations. Levels of 13 of 15 acylcarnitines, 7 of 25 amino acids, and 18 of 37 fatty acids significantly declined over gestation, while 8 of 25 amino acids and 10 of 37 fatty acids significantly increased. Several trajectories appeared to differ by BMI, race/ethnicity, and fetal sex although no tests for interactions remained significant after multiple testing correction. Future studies merit longitudinal measurements to capture metabolite changes in pregnancy, and larger samples to examine modifying effects of maternal and fetal characteristics

Early Second-Trimester Serum MiRNA Profiling Predicts Gestational Diabetes Mellitus

BACKGROUND: Gestational diabetes mellitus (GDM) is one type of diabetes that presents during pregnancy and significantly increases the risk of a number of adverse consequences for the fetus and mother. The microRNAs (miRNA) have recently been demonstrated to abundantly and stably exist in serum and to be potentially disease-specific. However, no reported study investigates the associations between serum miRNA and GDM. METHODOLOGY/PRINCIPAL FINDINGS: We systematically used the TaqMan Low Density Array followed by individual quantitative reverse transcription polymerase chain reaction assays to screen miRNAs in serum collected at 16-19 gestational weeks. The expression levels of three miRNAs (miR-132, miR-29a and miR-222) were significantly decreased in GDM women with respect to the controls in similar gestational weeks in our discovery evaluation and internal validation, and two miRNAs (miR-29a and miR-222) were also consistently validated in two-centric external validation sample sets. In addition, the knockdown of miR-29a could increase Insulin-induced gene 1 (Insig1) expression level and subsequently the level of Phosphoenolpyruvate Carboxy Kinase2 (PCK2) in HepG2 cell lines. CONCLUSIONS/SIGNIFICANCE: Serum miRNAs are differentially expressed between GDM women and controls and could be candidate biomarkers for predicting GDM. The utility of miR-29a, miR-222 and miR-132 as serum-based non-invasive biomarkers warrants further evaluation and optimization

A prospective study of artificially sweetened beverage intake and cardiometabolic health among women at high risk

BackgroundArtificially sweetened beverages (ASBs) are commonly consumed and recommended for individuals at high risk for cardiometabolic diseases; however, the health effects of ASBs remain contradictory. Given that cross-sectional analyses are subject to reverse causation, prospective studies with long-term follow-up are needed to evaluate associations between ASBs and cardiometabolic health, especially among high-risk individuals.ObjectiveThe aim of this study was to examine associations of ASB intake and cardiometabolic health among high-risk women with prior gestational diabetes mellitus (GDM).MethodsWe included 607 women with GDM from the Danish National Birth Cohort (DNBC; 1996-2002) who completed a clinical exam 9-16 y after the DNBC pregnancy for the Diabetes & Women's Health (DWH) Study (2012-2014). We assessed ASB intake using FFQs completed during the DNBC pregnancy and at the DWH Study clinical exam. We examined cardiometabolic outcomes at the DWH clinical exam. We estimated percentage differences in continuous cardiometabolic markers and RRs for clinical endpoints in association with ASB intake both during pregnancy and at follow-up adjusted for prepregnancy BMI, diet, and lifestyle factors. Sensitivity analyses to account for reverse causation were performed.ResultsIn pregnancy and at follow-up, 30.4% and 36.4% of women regularly (≥2 servings/wk) consumed ASB, respectively. Consumption of ASBs, both during pregnancy and at follow-up, was associated with higher glycated hemoglobin (HbA1c), insulin, HOMA-IR, triglycerides, liver fat, and adiposity and with lower HDL at follow-up. After adjustment for covariates, particularly prepregnancy BMI, the majority of associations between ASB intake in pregnancy and outcomes at follow-up became null with the exception of HbA1c. ASB intake at follow-up (≥1 serving/d compared with <1 serving/mo) was associated with higher HbA1c (6.5%; 95% CI: 1.9, 11.3; P-trend = 0.007); however, associations were not upheld in sensitivity analyses for reverse causation.ConclusionsAmong Danish women with a history of GDM, ASB intake was not significantly associated with cardiometabolic profiles

NUMERICAL SIMULATION OF PRESSURE FLUCTUATION IN DRAFT TUBE OF LARGE FRANCIS TURBINE

ABSTRACT The pressure fluctuation caused by swirling flow in draft tube is one of the main reasons of vibration in hydraulic turbine. It directly affects the steady operation of hydraulic turbine unit. The pressure fluctuation in draft tube of a large Francis turbine can't be obtained accurately by similarity law from model test, and prototype test is difficult to carry out and costs too much. Therefore, it is necessary to predict pressure fluctuation in draft tube numerically and provide scientific reference for mitigating and suppressing pressure fluctuation. This paper describes a numerical study of unsteady flow in the draft tube of a large Francis turbine in a Hydropower Station of China by using the Reynolds averaged Navier-Stokes (RANS) approach with a Reynolds stress transport model (RSM), validating the numerical results against experimental data. The numerical results successfully represent the vortex rope. The pressure fluctuation patterns in different parts of the draft tube including the cone, elbow and diffuser are analyzed. The pressure fluctuation in the cone and elbow is relative steady, and it has an obvious dominant frequency which is approximately 0.28 and 0.3 times of the runner rotational frequency. These results show very good agreement with experiments. The largest pressure amplitude appears in the draft tube cone downstream side and the draft elbow inside. The pressure fluctuation in the diffuser is stochastic, and the amplitude is small. Additionally, the pressure distributions on the horizontal computational section of the draft tube are analyzed