Association of sleep duration and incidence of diabetes modified by tea consumption: a report from the Shanghai men's health study.

•The Shanghai Men's Health Study, a large population-based cohort study, was used to assess association between sleep duration and risk of type 2 diabetes incidence.•The study found a J-shaped association between sleep duration and diabetes risk (i.e., higher risk of diabetes was associated with longer sleep duration).•This association was also observed among people who already had factors linked to poor quality of sleep, such as smoking, drinking, obesity, hypertension, and comorbidity. Tea drinking could modify this association.•The results suggest that targeting these higher-risk individuals for more rigorous diabetes screening and prevention could provide public health benefits.