Sleep duration and incidence of type 2 diabetes: the Multiethnic Cohort

Objectives: As an emerging risk factor for the rising incidence of type 2 diabetes, we examined sleep duration in relation to type 2 diabetes and several biomarkers.& para;& para;Design: Prospective cohort recruited 1993-1996.& para;& para;Setting: The Multiethnic Cohort in Hawaii and California.& para;& para;Participants: A cohort of 151,691 White, African American, Japanese American, Native Hawaiian, and Latinoparticipants: 9695 cohort members had biomarker measurements.& para;& para;Measurements: Sleep duration was self-reported at cohort entry. Diabetes status was obtained from 3 questionnaires and confirmed by 3 administrative data sources. Biomarkers were measured by standard assays 9.6 +/- 2.1 years after cohort entry. We estimated diabetes risk as a lime-varying outcome using Cox regression adjusted for body mass index assessed at 3 time points and other !mown confounders and computed adjusted means of biomarkers by sleep hours.& para;& para;Results: During 7.9 +/- 3.5 years of follow-up, 8487 new diabetes cases were diagnosed. Long sleep duration (>= 9 hours), as compared with 7-8 hours, was significantly associated with higher incidence (hazard ratio, 1.12; 95% confidence interval 1.04-1.21), but the 4% elevated incidence for short sleep duration (<= 6 hours) did not reach significance (95% confidence interval 0.99-1.09). After stratification, the associations appeared stronger in Japanese American than other ethnic groups and in participants without comorbidity. Hours of sleep were positively associated with C-reactive protein and triglycerides and inversely related to high-density lipoprotein cholesterol and adiponectin but not with leptin levels and homeostatic model assessment of insulin resistance.& para;& para;Conclusion: In this multiethnic population, the 12% higher diabetes risk for long sleep hours may be mediated through inflammation, a poor lipid profile, and lower adiponectin levels. (C) 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.