Abstract
STUDY OBJECTIVES: The aim of the current study was to evaluate the association between obstructive sleep apnea (OSA) and exercise capacity in middle-aged women. METHODS: Consecutive middle-aged female subjects without cardiovascular disease, aged 45 to 65 years, from two gynecological clinics underwent detailed clinical evaluation, portable sleep study, and treadmill exercise test. RESULTS: We studied 232 women (age: 55.6 ± 5.2 years; body mass index [BMI]: 28.0 ± 4.8 kg/m(2)). OSA (apnea-hypopnea index ≥ 5 events/h) was diagnosed in 90 (39%) and obesity (BMI > 30 kg/m(2)) in 76 (33%) women, respectively. Participants with OSA were older, had a higher BMI, and an increased frequency of arterial hypertension compared to women without OSA. Multiple logistic regression models were used to evaluate the association between OSA and exercise capacity, controlling for traditional risk factors including BMI, age, hypertension, diabetes, and sedentary lifestyle. In multivariate analysis, the presence of obesity without OSA was associated with low exercise capacity (odds ratio [OR] 2.88, 95% confidence interval [CI] 1.02-8.11, P = .045), whereas the presence of OSA without obesity was not (OR 1.07, 95% CI 0.31-3.69, P = .912). However, the coexistence of obesity and OSA increased markedly the odds of reduction in exercise capacity (OR 9.40, CI 3.79-23.3, P < .001). CONCLUSIONS: Obesity and OSA are common conditions in middle-aged women and may interact to reduce exercise capacity. These results highlight the importance of obesity control programs among women, as well as the diagnosis of comorbid OSA in older women.