Sleep duration, obesity and insulin resistance in a multi-ethnic UK population at high risk of diabetes.

AIMS: Investigating the association between sleep duration, obesity, adipokines and insulin resistance (via Leptin:Adiponectin ratio (LAR)), in those at high risk of type 2 diabetes mellitus (T2DM). METHODS: Adults with impaired glucose regulation (IGR) were included. Fasting bloods for inflammatory biomarkers and glycaemic status, 2-h glucose, anthropometrics, objective physical activity, and self-reported sleep were collected. The average number of hours slept in a 24 h period was categorised as ≤5.5, 6-6.5, 7-7.5, 8-8.5, and ≥9 h. Regression models were fitted with sleep (linear and quadratic) and logistic regression used for IGR and adjusted for age, sex, ethnicity, body mass index, waist circumference and objective physical activity. RESULTS: 2848 participants included (593 with inflammatory marker data). Short sleep and long sleep duration were significantly independently associated with higher body mass index (P < 0.001), body weight (P < 0.01), and waist circumference (P < 0.001). 6-7 h of sleep/24 h is associated with the lowest obesity measures. Fasting insulin and LAR were positively associated with sleep duration. Adiponectin levels were negatively associated with sleep duration. CONCLUSIONS: These results support the evidence of an association between short and long sleep duration and indices of obesity. We demonstrate an independent relationship between long sleep duration and insulin resistance.