3 research outputs found
Common variants at 10 genomic loci influence hemoglobin Aâ(C) levels via glycemic and nonglycemic pathways.
Glycated hemoglobin (HbAâ(c)), used to monitor and diagnose diabetes, is influenced by average glycemia over a 2- to 3-month period. Genetic factors affecting expression, turnover, and abnormal glycation of hemoglobin could also be associated with increased levels of HbAâ(c). We aimed to identify such genetic factors and investigate the extent to which they influence diabetes classification based on HbAâ(c) levels
Genome-wide association scan meta-analysis identifies three Loci influencing adiposity and fat distribution.
To identify genetic loci influencing central obesity and fat distribution, we performed a meta-analysis of 16 genome-wide association studies (GWAS, N = 38,580) informative for adult waist circumference (WC) and waist-hip ratio (WHR). We selected 26 SNPs for follow-up, for which the evidence of association with measures of central adiposity (WC and/or WHR) was strong and disproportionate to that for overall adiposity or height. Follow-up studies in a maximum of 70,689 individuals identified two loci strongly associated with measures of central adiposity; these map near TFAP2B (WC, P = 1.9x10(-11)) and MSRA (WC, P = 8.9x10(-9)). A third locus, near LYPLAL1, was associated with WHR in women only (P = 2.6x10(-8)). The variants near TFAP2B appear to influence central adiposity through an effect on overall obesity/fat-mass, whereas LYPLAL1 displays a strong female-only association with fat distribution. By focusing on anthropometric measures of central obesity and fat distribution, we have identified three loci implicated in the regulation of human adiposity
Novel loci for adiponectin levels and their influence on type 2 diabetes and metabolic traits: a multi-ethnic meta-analysis of 45,891 individuals
Circulating levels of adiponectin, a hormone produced predominantly by adipocytes, are highly heritable and are inversely associated with type 2 diabetes mellitus (T2D) and other metabolic traits. We conducted a meta-analysis of genome-wide association studies in 39,883 individuals of European ancestry to identify genes associated with metabolic disease. We identified 8 novel loci associated with adiponectin levels and confirmed 2 previously reported loci (Pâ=â4.5Ă10(-8)-1.2Ă10(-43)). Using a novel method to combine data across ethnicities (Nâ=â4,232 African Americans, Nâ=â1,776 Asians, and Nâ=â29,347 Europeans), we identified two additional novel loci. Expression analyses of 436 human adipocyte samples revealed that mRNA levels of 18 genes at candidate regions were associated with adiponectin concentrations after accounting for multiple testing (p<3Ă10(-4)). We next developed a multi-SNP genotypic risk score to test the association of adiponectin decreasing risk alleles on metabolic traits and diseases using consortia-level meta-analytic data. This risk score was associated with increased risk of T2D (pâ=â4.3Ă10(-3), nâ=â22,044), increased triglycerides (pâ=â2.6Ă10(-14), nâ=â93,440), increased waist-to-hip ratio (pâ=â1.8Ă10(-5), nâ=â77,167), increased glucose two hours post oral glucose tolerance testing (pâ=â4.4Ă10(-3), nâ=â15,234), increased fasting insulin (pâ=â0.015, nâ=â48,238), but with lower in HDL-cholesterol concentrations (pâ=â4.5Ă10(-13), nâ=â96,748) and decreased BMI (pâ=â1.4Ă10(-4), nâ=â121,335). These findings identify novel genetic determinants of adiponectin levels, which, taken together, influence risk of T2D and markers of insulin resistance