The plasma concentration of the adipocyte-derived peptide adiponectin is decreased in patients with obesity and type 2 diabetes. The adiponectin gene is located on chromosome 3q27, where a diabetes susceptibility locus has been mapped. Adiponectin gene polymorphisms (single nucleotide polymorphisms [SNPs]) have been associated with BMI, insulin sensitivity, and type 2 diabetes in some cross-sectional studies. Our aim was to assess the contribution of these SNPs in the development of features of the insulin resistance syndrome in a 3-year prospective study in ϳ4,500 French Caucasian subjects from the Epidemiologic Data on the Insulin Resistance Syndrome (DESIR) cohort. For subjects who were normoglycemic at baseline, the 3-year risk of becoming hyperglycemic (diabetes or impaired fasting glucose) was affected by two SNPs: G-11391A and T45G. T he role of the newly described adipocyte-derived peptide adiponectin is still poorly understood. Nevertheless, its plasma concentration is decreased in patients with obesity, type 2 diabetes, or coronary artery disease (1,2). The treatment of diabetic animals with adiponectin has been shown (3,4) to improve insulin sensitivity. The adiponectin gene consists of three exons and two introns located on chromosome 3q27, where a diabetes susceptibility locus has been mapped (5,6). Single nucleotide polymorphisms (SNPs) of the adiponectin gene have been associated with BMI, insulin sensitivity, and type 2 diabetes in some cross-sectional studies (7-9), but these associations have not been seen in all studies (10,11). The aim of our study was to assess the effects of these polymorphisms on the 3-year evolution of features of the insulin resistance syndrome in a large Caucasian population of men and women, aged 30 -64 years, known as the Epidemiologic Data on the Insulin Resistance Syndrome (DESIR) cohort. The influence of baseline plasma adiponectin levels on the 3-year risk of developing hyperglycemia (impaired fasting glycemia or type 2 diabetes) was also estimated. RESEARCH DESIGN AND METHODSThe study population consisted of men and women, aged 30 -64 years, who participated in DESIR, a 9-year follow-up study that aims to clarify the Additional information for this article can be found in two online appendixes at http://diabetes.diabetesjournals.org. DESIR, Epidemiologic Data on the Insulin Resistance Syndrome; IFG, impaired fasting glucose; SNP, single nucleotide polymorphism; WHR, waistto-hip ratio.

SummaryBackgroundRestless legs syndrome is a prevalent chronic neurological disorder with potentially severe mental and physical health consequences. Clearer understanding of the underlying pathophysiology is needed to improve treatment options. We did a meta-analysis of genome-wide association studies (GWASs) to identify potential molecular targets.MethodsIn the discovery stage, we combined three GWAS datasets (EU-RLS GENE, INTERVAL, and 23andMe) with diagnosis data collected from 2003 to 2017, in face-to-face interviews or via questionnaires, and involving 15 126 cases and 95 725 controls of European ancestry. We identified common variants by fixed-effect inverse-variance meta-analysis. Significant genome-wide signals (p≤5 × 10−8) were tested for replication in an independent GWAS of 30 770 cases and 286 913 controls, followed by a joint analysis of the discovery and replication stages. We did gene annotation, pathway, and gene-set-enrichment analyses and studied the genetic correlations between restless legs syndrome and traits of interest.FindingsWe identified and replicated 13 new risk loci for restless legs syndrome and confirmed the previously identified six risk loci. MEIS1 was confirmed as the strongest genetic risk factor for restless legs syndrome (odds ratio 1·92, 95% CI 1·85–1·99). Gene prioritisation, enrichment, and genetic correlation analyses showed that identified pathways were related to neurodevelopment and highlighted genes linked to axon guidance (associated with SEMA6D), synapse formation (NTNG1), and neuronal specification (HOXB cluster family and MYT1).InterpretationIdentification of new candidate genes and associated pathways will inform future functional research. Advances in understanding of the molecular mechanisms that underlie restless legs syndrome could lead to new treatment options. We focused on common variants; thus, additional studies are needed to dissect the roles of rare and structural variations.FundingDeutsche Forschungsgemeinschaft, Helmholtz Zentrum München–Deutsches Forschungszentrum für Gesundheit und Umwelt, National Research Institutions, NHS Blood and Transplant, National Institute for Health Research, British Heart Foundation, European Commission, European Research Council, National Institutes of Health, National Institute of Neurological Disorders and Stroke, NIH Research Cambridge Biomedical Research Centre, and UK Medical Research Council.