Sleep risk factors modify the association between c-reactive protein and type 2 diabetes: A prospective cohort study.

Objective: To investigate the prospective association between serum CRP levels and T2D incidence and explore whether such association was modified by sleep risk factors.

Methods: The study included 366 746 participants without diabetes and exhibited CRP measures at baseline from the UK Biobank. Sleep risk factors included sleep duration, insomnia, snoring, chronotype, and daytime sleepiness. Cox proportional hazards model was used to estimate the hazard ratio (HR), and 95 % confidence interval (CI) of T2D associated with CRP levels. Interactions between CRP and sleep risk factors were also tested.

Results: During a median follow-up of 10.4 years, 14 200 T2D cases were identified. The HRs (95 % CIs) of T2D were 1.31 (1.21-1.43), 1.62 (1.50-1.75), 1.98 (1.83-2.13), and 2.38 (2.21-2.57), respectively, in higher quintile groups of CRP levels compared with the lowest group (p-value for trend <0.001). There were interactions of CRP levels with self-reported sleep duration, snoring, and daytime sleepiness (p-value for interaction = 0.002, 0.0002, and 0.0001). The associated risks between T2D and the elevation in CRP were more evident among participants with high-risk sleep factors.

Conclusions: Our study indicates that the elevation in serum CRP levels is associated with a higher T2D incidence; and such relation is modified by sleep risk factors including sleep duration, snoring, and daytime sleepiness.