Genome-wide association study investigating short and long sleep duration: a cross-population meta-analysis

Sleep duration has been linked to a wide range of negative health outcomes and to reduced life expectancy. We conducted genome-wide association studies of short (≤5 hours) and long (≥10 hours) sleep duration in adults of European, African, East Asian, and admixed-American ancestry from UK Biobank and the Million Veteran Program. In a cross-population meta-analysis we identified 84 independent loci for short sleep and 1 for long sleep. We estimated SNP-based heritability for both sleep traits in each ancestry based on population derived linkage disequilibrium (LD) scores using cov-LDSC. We identified positive genetic correlation between short and long sleep traits (r g = 0.16±0.04; P=0.0002), as well as similar patterns of genetic correlation with other psychiatric and cardiometabolic phenotypes. Mendelian randomisation revealed a directional causal relationship between short sleep and depression, and a bidirectional causal relationship between long sleep and depression.