Cardiovascular mortality in obstructive sleep apnea in the elderly: role of long-term continuous positive airway pressure treatment: a prospective observational study

Abstract

Rationale: Obstructive sleep apnea (OSA) is a risk factor for cardiovascular death in middle-aged subjects, but it is not known whether it is also a risk factor in the elderly.

Objectives: To investigate whether OSA is a risk factor for cardiovascular death and to assess whether continuous positive airway pressure (CPAP) treatment is associated with a change in risk in the elderly.

Methods: Prospective, observational study of a consecutive cohort of elderly patients (≥65 yr) studied for suspicion of OSA between 1998 and 2007. Patients with an apnea-hypopnea index (AHI) less than 15 were the control group. OSA was defined as mild to moderate (AHI, 15-29) or severe (AHI, ≥30). Patients with OSA were classified as CPAP-treated (adherence ≥ 4 h/d) or untreated (adherence < 4 h/d or not prescribed). Participants were monitored until December 2009. The end point was cardiovascular death. A multivariate Cox survival analysis was used to determine the independent impact of OSA and CPAP treatment on cardiovascular mortality.

Measurements and main results: A total of 939 elderly were studied (median follow-up, 69 mo). Compared with the control group, the fully adjusted hazard ratios for cardiovascular mortality were 2.25 (confidence interval [CI], 1.41 to 3.61) for the untreated severe OSA group, 0.93 (CI, 0.46 to 1.89) for the CPAP-treated group, and 1.38 (CI, 0.73 to 2.64) for the untreated mild to moderate OSA group.

Conclusions: Severe OSA not treated with CPAP is associated with cardiovascular death in the elderly, and adequate CPAP treatment may reduce this risk.