Association of life-course severe sleep apnoea with the risk of all-cause mortality: the offset effect of physical activity

Objectives The detrimental association of mortality with sleep apnoea may increase with apnoea severity. To assess the association between life-course severe sleep apnoea and all-cause mortality and to investigate whether and to what extent the association was compensated by physical activity.Methods The prospective cohort study included 407,128 individuals (mean age 56.26 years) from the UK Biobank. Severe sleep apnoea was defined as hospital admission. Moderate-to-vigorous physical activity (MVPA) was measured from frequency per week and duration per day via self-report. Cox proportional hazards regression models were performed to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).Results A total of 29,004 death (7.1%) events occurred (median of follow-up 12.7 years). The multi-adjusted HRs (95% CIs) of all-cause mortality were 1.57 (1.12-2.21) for early-life severe sleep apnoea, 1.30 (1.16-1.46) for mid-life severe sleep apnoea, and 2.75 (1.31-5.77) for early- to mid-life severe sleep apnoea, respectively. In joint effect analysis, compared to participants with an inactive level of physical activity and mid-life severe sleep apnoea, the HR (95% CI) of all-cause mortality was 0.57 (0.44-0.74) in those with sufficient physical activity and mid-life severe sleep apnoea. For physical activity intensity, a medium proportion of vigorous physical activity (VPA) per week buffered 56% impacts of mid-life severe sleep apnoea on all-cause mortality (HR = 0.44; 95% CI, 0.31-0.64).Conclusions Not only mid-life severe sleep apnoea but also early-life severe sleep apnoea is positively associated with all-cause mortality. MVPA could compensate for the risk of all-cause mortality in relation to mid-life severe sleep apnoea.