Obesity is globally prevalent and highly heritable, but the underlying genetic factors remain largely elusive. To identify genetic loci for obesity-susceptibility, we examined associations between body mass index (BMI) and ~2.8 million SNPs in up to 123,865 individuals, with targeted follow-up of 42 SNPs in up to 125,931 additional individuals. We confirmed 14 known obesity-susceptibility loci and identified 18 new loci associated with BMI (P<5×10−8), one of which includes a copy number variant near GPRC5B. Some loci (MC4R, POMC, SH2B1, BDNF) map near key hypothalamic regulators of energy balance, and one is near GIPR, an incretin receptor. Furthermore, genes in other newly-associated loci may provide novel insights into human body weight regulation.

Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence phenotype. Genome-wide association (GWA) studies have identified >600 variants associated with human traits1, but these typically explain small fractions of phenotypic variation, raising questions about the utility of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait2,3. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P=0.016), and that underlie skeletal growth defects (P<0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants, and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented amongst variants that alter amino acid structure of proteins and expression levels of nearby genes. Our data explain ∼10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to ∼16% of phenotypic variation (∼20% of heritable variation). Although additional approaches are needed to fully dissect the genetic architecture of polygenic human traits, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.

Waist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body-mass-index (up to 77,167 participants), following up 16 loci in an additional 29 studies (up to 113,636 subjects). We identified 13 novel loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1, and CPEB4 (P 1.9 × 10−9 to 1.8 × 10−40), and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex-difference 1.9 × 10−3 to 1.2 × 10−13). These findings provide evidence for multiple loci that modulate body fat distribution, independent of overall adiposity, and reveal powerful gene-by-sex interactions.

To identify previously unknown genetic loci associated with fasting glucose concentrations, we examined the leading association signals in ten genome-wide association scans involving a total of 36,610 individuals of European descent. Variants in the gene encoding melatonin receptor 1B (MTNR1B) were consistently associated with fasting glucose across all ten studies. The strongest signal was observed at rs10830963, where each G allele (frequency 0.30 in HapMap CEU) was associated with an increase of 0.07 (95% CI ¼ 0.06-0.08) mmol/l in fasting glucose levels (P ¼ 3.2 Â 10 À50 ) and reduced beta-cell function as measured by homeostasis model assessment (HOMA-B, P ¼ 1.1 Â 10 À15 ). The same allele was associated with an increased risk of type 2 diabetes (odds ratio ¼ 1.09 (1.05-1.12), per G allele P ¼ 3.3 Â 10 À7 ) in a meta-analysis of 13 case-control studies totaling 18,236 cases and 64,453 controls. Our analyses also confirm previous associations of fasting glucose with variants at the G6PC2 (rs560887, P ¼ 1.1 Â 10 À57 ) and GCK (rs4607517, P ¼ 1.0 Â 10 À25 ) loci.Blood and plasma fasting glucose levels are tightly regulated within a narrow physiologic range by a feedback mechanism that targets a particular fasting glucose set point for each individual 1,2 . Disruption of normal glucose homeostasis and substantial elevations of fasting glucose are hallmarks of type 2 diabetes (T2D) and typically result from sustained reduction in pancreatic beta-cell function and insulin secretion.However, even within healthy, nondiabetic populations there is substantial variation in fasting glucose levels. Approximately one-third of this variation is genetic 3 , but little of this heritability has been explained. There is growing evidence to suggest that common variants contributing to variation in fasting glucose are largely distinct from those associated with major disruptions of beta-cell function that predispose to T2D. Common sequence variants in the GCK (glucokinase) promoter 4-6 , and around genes encoding the islet-specific glucose-6-phosphatase (G6PC2) 5,6 and the glucokinase regulatory protein (GCKR) 7-9 , have each been associated with individual variation in fasting glucose levels, but have, at best, weak effects on T2D

Context: Vitamin D deficiency is common among older people and can cause mineralization defects, bone loss, and muscle weakness.Objective: The aim of this study was to investigate the association of serum 25-hydroxyvitamin D (25-OHD) concentration with current physical performance and its decline over 3 yr among elderly. Design:The study consisted of a cross-sectional and longitudinal design (3-yr follow-up) within the Longitudinal Aging Study Amsterdam.Setting: An age-and sex-stratified random sample of the Dutch older population was used.Other Participants: Subjects included 1234 men and women (aged 65 yr and older) for cross-sectional analysis and 979 (79%) persons for longitudinal analysis.Main Outcome Measure(s): Physical performance (sum score of the walking test, chair stands, and tandem stand) and decline in physical performance were measured.Results: Serum 25-OHD was associated with physical performance after adjustment for age, gender, chronic diseases, degree of urbanization, body mass index, and alcohol consumption. Compared with individuals with serum 25-OHD levels above 30 ng/ml, physical performance was poorer in participants with serum 25-OHD less than 10 ng/ml [regression coefficient (B) ϭ Ϫ1.69; 95% confidence interval (CI) ϭ Ϫ2.28; Ϫ1.10], and with serum 25-OHD of 10 -20 ng/ml (B ϭ Ϫ0.46; 95% CI ϭ Ϫ0.90; Ϫ0.03). After adjustment for confounding variables, participants with 25-OHD less than 10 ng/ml and 25-OHD between 10 and 20 ng/ml had significantly higher odds ratios (OR) for 3-yr decline in physical performance (OR ϭ 2.21; 95% CI ϭ 1.00 -4.87; and OR ϭ 2.01; 95% CI ϭ 1.06 -3.81), compared with participants with 25-OHD of at least 30 ng/ml. The results were consistent for each individual performance test.Conclusions: Serum 25-OHD concentrations below 20 ng/ml are associated with poorer physical performance and a greater decline in physical performance in older men and women. Because almost 50% of the population had serum 25-OHD below 20 ng/ml, public health strategies should be aimed at this group. V ITAMIN D DEFICIENCY is common in the older population (1-3) and can result in secondary hyperparathyroidism, bone loss, and fractures (4 -7). Osteomalacia, caused by severe vitamin D deficiency, is characterized by mineralization defects, bone and muscle pain, and weakness of the proximal muscles (8, 9). Older people are especially at risk of developing vitamin D deficiency due to low exposure to sunshine (10), decreased capacity of the older skin to synthesize vitamin D (11), and low dietary vitamin D intake (9).Although the role of vitamin D in maintaining skeletal health is well known, knowledge about its role in relation to physical performance is still limited, and it is unknown whether vitamin D status can predict decline in physical performance. It was demonstrated in a randomized double-blind clinical trial that supplementation with vitamin D and calcium can prevent hip fractures and other nonvertebral fractures in nursing home residents (12). The effect of vitamin D supplementation on f...