0994 Sleep Regularity and Risk of Incident Hypertension in the UK Biobank

Abstract Introduction Irregular sleep schedules are common and have been linked to increased cardiovascular disease (CVD) risk. Hypertension affects nearly a third of adults and is the leading modifiable cause of CVD, but prior evidence for associations between irregular sleep and high blood pressure is mixed. Methods We prospectively studied 55,572 UK Biobank participants with 5 or more days of valid accelerometry data and no history of hypertension or anti-hypertensive medication use (60% women, mean age 61 years). We estimated sleep regularity with the intra-individual standard deviation (SD) of sleep duration (sleep duration SD) and the sleep regularity index (SRI). Time-to-event Cox proportional hazards models estimated adjusted hazard ratios (HR) for incident hypertension—defined as the first occurrence of an ICD-10 I10 diagnosis in linked health records— by levels of sleep regularity. We evaluated effect modification by demographic and other sleep characteristics and interaction with genetic susceptibility for hypertension. Results There were 5,746 incident cases of hypertension over a median of 7.9 years of follow-up. After accounting for demographic, socioeconomic, and lifestyle factors, those with increased sleep duration irregularity (>90 minutes sleep duration SD) had an 18% higher risk of incident hypertension compared to those with sleep duration SD ≤30 minutes (HR [95% confidence interval (CI)]: 1.18 [1.06, 1.31]). Similarly, those with the most irregular day-to-day sleep/wake patterns (the lowest quintile of SRI) had a 40% higher risk for hypertension than those in the highest SRI quintile (95% CI: 1.29, 1.52). These patterns were consistent when sleep duration SD and SRI were treated as continuous variables. We did not observe any (clinically) meaningful effect modification, although joint analysis highlighted that those with the most irregular day-to-day sleep/wake patterns and the highest genetic risk for hypertension had the greatest risk of developing hypertension, compared to those without both adverse factors, consistent with additive effects (HR [95% CI]: 1.91 [1.71, 2.12]). Conclusion These results suggest that maintaining consistent sleep schedules from day to day is associated with lower risk of developing hypertension, regardless of genetic susceptibility for hypertension, further supporting a role for sleep and rhythm regularity in cardiovascular health. Support (if any) R01HL15539