LAUSR

BACKGROUND Heart failure (HF) is a leading cause of morbidity and mortality and while linked to sleep apnea, it is unclear which physiological stressors most strongly associate with incident disease. Here we tested whether Sleep Apnea-Specific Hypoxic Burden (SASHB) predicts incident HF in two independent cohort studies. METHODS The samples were derived from two cohort studies: The Sleep Heart Health Study (SHHS), which included 4881 middle-aged and older adults (54.4% women), age: 63.6±11.1 years; and the Outcomes of Sleep Disorders in Older Men (MrOS), which included 2653 men, age 76.2±5.4 years. We computed SASHB as the sleep apnea-specific area under the desaturation curve from pre-event baseline. We used Cox models for incident heart Failure (HF) to estimate the adjusted hazard ratios for natural log-transformed SASHB and apnea-hypopnea index (AHI) adjusting for multiple confounders. RESULTS The SASHB predicted incident HF in men in both cohorts while AHI did not. Men in SHHS and MrOS had adjusted hazard ratios (per 1SD increase in SASHB) of 1.18 (95% CI: 1.02-1.37) and 1.22 (95% CI: 1.02-1.45), respectively. Associations with SASHB were observed in men with both low and high AHI levels. Associations were not significant in women. CONCLUSIONS In men, the hypoxic burden of sleep apnea was associated with incident HF after accounting for demographic factors, smoking, and co-morbidities. The findings suggest that quantification of an easily measured index of sleep apnea related hypoxias may be useful for identifying individuals at risk for heart disease while also suggesting targets for intervention.