Discretionary Screen Time and Progression From Prediabetes to Type 2 Diabetes: Mediating Roles of Sleep and the Triglyceride‐Glucose Index

AIMS: 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. MATERIALS AND METHODS: 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. RESULTS: = 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. CONCLUSIONS: 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.