Discretionary Screen Time and Progression From Prediabetes to Type 2 Diabetes: Mediating Roles of Sleep and the...

To examine the association of discretionary screen time with the risk of type 2 diabetes among individuals with prediabetes, and to explore the mediating roles of sleep and the triglyceride-glucose (TyG) index.

This prospective cohort study included 41 978 participants with prediabetes from the UK Biobank. Discretionary screen time comprised television viewing and leisure computer use. Sleep was assessed using five dimensions: duration, chronotype, insomnia, snoring and daytime dozing. The TyG index was calculated as an indicator of insulin resistance. Incident type 2 diabetes was confirmed through linked hospital, primary care and death registry records.

Compared with < 2 h/day of discretionary screen time, > 5 h/day was associated with a 26% higher risk of type 2 diabetes (hazard ratio (HR): 1.26, 95% confidence interval (CI): 1.12, 1.40). Restricted cubic spline analyses revealed a non-linear association between discretionary screen time and type 2 diabetes (P _{for nonlinear} = 0.006). Television viewing (HR: 1.35, 95% CI: 1.21, 1.51) and leisure computer use (HR: 1.04, 95% CI: 0.88, 1.23) showed different associations with type 2 diabetes. Exploratory mediation analyses indicated that sleep and the TyG index mediated 30.2% of the association, with 10.7% mediated through sleep and 18.1% through the TyG index.

Higher discretionary screen time was associated with an increased risk of type 2 diabetes among individuals with prediabetes, partly mediated by poor sleep and insulin resistance. Reducing discretionary screen time may be a meaningful preventive strategy against type 2 diabetes, with sleep health as an important mediator.