Association of obstructive sleep apnea with exercise capacity, and mortality in a population-based study – results of SHIP-TREND

Study Objectives Sleep and physical fitness are interrelated, with cardiovascular risk factors potentially influencing this relationship. Sleep disturbances and reduced exercise capacity are linked to higher mortality. This study examined associations between sleep characteristics, cardiopulmonary exercise testing (CPET) measures, and all-cause mortality and assessed whether reduced exercise capacity mediates the link between impaired sleep and mortality. Methods We analyzed 1001 participants from the population-based SHIP-TREND cohort (2008–2012) who underwent single-night polysomnography and symptom-limited CPET. Associations between sleep and CPET measures, as well as mortality, were assessed using multivariable linear and Cox regression models. Results Participants were aged 54 (44; 63) years; 47.1% were women. The apnea-hypopnea index (AHI) was 4.9 (1.4; 13.7) events·h −1 , higher in men (7.9 [2.6; 18.8]) than in women (2.6 [0.7; 9.2]; p<0.001). Peak oxygen uptake (VO 2peak ) was lower in women (22 [18; 25] ml·min −1 ·kg −1 ) than in men (27 [22; 32]; p<0.001). Higher AHI and oxygen desaturation index were inversely associated with VO 2peak . Over a median 10.3-year follow-up, 73 deaths occurred. AHI was significantly associated with all-cause mortality across models (HR 1.31–1.72). Mediation analysis demonstrated a significant direct effect, whereas the indirect effect via VO 2 peak was not statistically significant. Conclusions In the SHIP-TREND-0 cohort, elevated AHI is associated with reduced VO 2peak and increased all-cause mortality. Mediation analysis suggested a possible, but not statistically significant, contribution of impaired cardiopulmonary fitness to the relationship between sleep apnea and mortality, highlighting a potential role of fitness that warrants further investigation.