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Aim: Myo‐inositol supplementation from ~13 weeks' gestation reportedly improves glycaemia regulation in metabolically at‐risk women, with speculation that earlier supplementation might bring further improvement. However, the NiPPeR trial of a myo‐inositol‐containing supplement starting preconception did not lower gestational glycaemia in generally healthy women. We postulated that the earlier timing of supplementation influences the maternal metabolic adaptation for gestational glycaemia regulation. Methods: In total, 585 women were recruited from Singapore, UK and New Zealand for the NiPPeR study. We examined associations of plasma myo‐inositol concentrations at 7 and 28 weeks' gestation with 28 weeks plasma glucose (PG; fasting, and 1 h and 2 h in 75 g oral glucose tolerance test) and insulin indices using linear regression adjusting for covariates. Results: Higher 7‐week myo‐inositol, but not 28‐week myo‐inositol, associated with higher 1 h PG [βadj (95% confidence intervals) 0.05 (0.01, 0.09) loge mmol/L per loge μmol/L, p =.022] and 2 h PG [0.08 (0.03, 0.12), p =.001]; equivalent to 0.39 mmol/L increase in 2 h PG for an average 7‐week myo‐inositol increase of 23.4 μmol/L with myo‐inositol supplementation. Higher 7‐week myo‐inositol associated with a lower 28‐week Stumvoll index (first phase), an approximation of insulin secretion [−0.08 (−0.15, −0.01), p =.020] but not with 28‐week Matsuda insulin sensitivity index. However, the clinical significance of a 7‐week myo‐inositol‐related increase in glycaemia was limited as there was no association with gestational diabetes risk, birthweight and cord C‐peptide levels. In‐silico modelling found higher 28‐week myo‐inositol was associated with lower gestational glycaemia in White, but not Asian, women after controlling for 7‐week myo‐inositol effects. Conclusion: To our knowledge, our study provides the first evidence that increasing first trimester plasma myo‐inositol may slightly exacerbate later pregnancy post‐challenge glycaemia, indicating that the optimal timing for starting prenatal myo‐inositol supplementation needs further investigation. [ABSTRACT FROM AUTHOR]

Mexico harbors great cultural and ethnic diversity, yet fine-scale patterns of human genome-wide variation from this region remain largely uncharacterized. We studied genomic variation within Mexico from over 1000 individuals representing 20 indigenous and 11 mestizo populations. We found striking genetic stratification among indigenous populations within Mexico at varying degrees of geographic isolation. Some groups were as differentiated as Europeans are from East Asians. Pre-Columbian genetic substructure is recapitulated in the indigenous ancestry of admixed mestizo individuals across the country. Furthermore, two independently phenotyped cohorts of Mexicans and Mexican Americans showed a significant association between subcontinental ancestry and lung function. Thus, accounting for fine-scale ancestry patterns is critical for medical and population genetic studies within Mexico, in Mexican-descent populations, and likely in many other populations worldwide.

The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved. One contentious issue is whether the settlement occurred by means of a single migration or multiple streams of migration from Siberia. The pattern of dispersals within the Americas is also poorly understood. To address these questions at a higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. Here we show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call 'First American'. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan speakers on both sides of the Panama isthmus, who have ancestry from both North and South America.

Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs) optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS) data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R² > 0.9 for ancestral components with significant between-subject variance). Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region.

The infant gut microbiome contains a portion of bacteria that originate from the maternal gut. In the infant gut these bacteria encounter a new metabolic environment that differs from the adult gut, consequently requiring adjustments in their activities. We used pilot community RNA sequencing data (metatranscriptomes) from ten mother-infant dyads participating in the NiPPeR Study to characterize bacterial gene expression shifts following mother-to-infant transmission. Maternally-derived bacterial strains exhibited large scale gene expression shifts following the transmission to the infant gut, with 12,564 activated and 14,844 deactivated gene families. The implicated genes were most numerous and the magnitude shifts greatest in Bacteroides spp. This pilot study demonstrates environment-dependent, strain-specific shifts in gut bacteria function and underscores the importance of metatranscriptomic analysis in microbiome studies. [ABSTRACT FROM AUTHOR]

Objectives Gestational diabetes mellitus (GDM) is associated with a higher risk for adverse health outcomes during pregnancy and delivery for both mothers and babies. This study aims to assess the short-term health and economic burden of GDM in China in 2015. Design Using TreeAge Pro, an analytical decision model was built to estimate the incremental costs and quality-of-life loss due to GDM, in comparison with pregnancy without GDM from the 28th gestational week until and including childbirth. The model was populated with probabilities and costs based on current literature, clinical guidelines, price lists and expert interviews. Deterministic and probabilistic sensitivity analyses were performed to test the robustness of the results. Participants Chinese population who gave birth in 2015. Results On average, the cost of a pregnancy with GDM was ¥6677.37 (in 2015 international $1929.87) more (+95%) than a pregnancy without GDM, due to additional expenses during both the pregnancy and delivery: ¥4421.49 for GDM diagnosis and treatment, ¥1340.94 (+26%) for the mother’s complications and ¥914.94 (+52%) for neonatal complications. In China, 16.5 million babies were born in 2015. Given a GDM prevalence of 17.5%, the number of pregnancies affected by GDM was estimated at 2.90 million in 2015. Therefore, the annual societal economic burden of GDM was estimated to be ¥19.36 billion (international $5.59 billion). Sensitivity analyses were used to confirm the robustness of the results. Incremental health losses were estimated to be approximately 260 000 quality-adjusted life years. Conclusion In China, the GDM economic burden is significant, even in the short-term perspective and deserves more attention and awareness. Our findings indicate a clear need to implement GDM prevention and treatment strategies at a national level in order to reduce the economic and health burden at both the population and individual levels. [ABSTRACT FROM AUTHOR]

Background: Gestational Diabetes Mellitus (GDM) is a type of diabetes which occurs during pregnancy. Women with GDM are at greater risk of complications during pregnancy and delivery, while babies born from mothers with GDM are at greater risk of post-natal complications. Using the most updated diagnosis criteria, the GDM prevalence is estimated at 9.3-25.5% worldwide and 9.3-18.9% in China. Our objective was to identify healthcare interventions aimed at GDM prevention and control in China.Methods: A best-evidence synthesis was performed based on a systematic search of literature published between 1997 and October 2015 in PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Wan-fang databases using keywords "Gestational Diabetes Mellitus", "GDM", "Intervention" "Medical Intervention" "Early Medical Intervention", "Dietary Intervention", "Exercise Intervention", "Lifestyle Intervention", "Therapy", "Treatment" and "China". Inclusion criteria were studies conducted in China, reporting GDM healthcare interventions, and published in either Chinese or English. Two reviewers independently assessed eligibility and quality of the studies and extracted the data. Treatment efficacy was examined with weighted pooled odds ratio (OR) meta-analyses.Results: The search resulted in 5961 articles (published in 276 different Chinese language journals and 6 English language journals), of which 802 were included in this synthesis. While 39.4% (n = 316) failed to report the GDM diagnostic criteria used, the remaining studies classified GDM with various international (n = 5) or Chinese (n = 7) diagnostic standards. Treatment interventions were categorized into 6 types: dietary (18.6%), exercise (1.6%), medication (20.7%), health education (9.0%), psychological (2.6%) and combination (47.4%). No interventions aimed at GDM prevention were identified. Meta-analyses demonstrated a statistically significant overall benefit of GDM treatment strategies in reducing the odds of maternal and infant adverse outcomes (ORs range 0.20-0.34, 95% CI 0.17-0.49, P < 0.05 for all). Dietary, western medication, and combined interventions were the most effective inteventions.Conclusions: An increasing number of healthcare interventions were found in China aimed at controlling GDM while no interventions were intended for GDM prevention. Well-designed clinical trials are needed to determine the comparative and cost effectiveness of GDM prevention and treatment strategies. [ABSTRACT FROM AUTHOR]