Genetic Susceptibility to Type 2 Diabetes, Television Viewing, and Atherosclerotic Cardiovascular Disease Risk

BACKGROUND: Type 2 diabetes (T2D) is a major risk factor for atherosclerotic cardiovascular disease (ASCVD). This study examined the interplay between watching television and T2D genetic risk for risk of ASCVD. METHODS: We included 346 916 White British individuals from UK Biobank. A weighted polygenic risk score for T2D was calculated on the basis of 138 genetic variants associated with T2D. Time spent watching television was self-reported and categorized into 2 groups: ≤1 h/d and ≥2 h/d. Over a median 13.8-year follow-up, 21 265 incident ASCVD events were identi-fied. Models using Cox regression with age as the underlying time scale adjusted for potential confounders (demographic, anthropometric, lifestyle factors, and medication use) were fit. RESULTS: Compared with watching television for ≤1 h/d, watching ≥2 h/d was associated with 12% (95% CI, 1.07–1.16) higher hazards of ASCVD, independently of T2D genetic risk. Joint analyses (with low T2D genetic risk and ≤1 h/d of television viewing as reference) indicated that medium and high T2D genetic risk was not associated with higher hazards of ASCVD as long as television viewing was ≤1 h/d. The P values for multiplicative and additive interactions between T2D genetic risk and television viewing were 0.050 and 0.038, respectively. The 10-year absolute risk of ASCVD was lower for high T2D genetic risk combined with ≤1 h/d of television viewing (2.13%) than for low T2D genetic risk combined with ≥2 h/d of television viewing (2.46%). CONCLUSIONS: Future clinical trials of lifestyle-modification interventions targeting specific types of screen-based sedentary activities could be implemented to individuals at high genetic risk of T2D for primary prevention of ASCVD.