Background: Apnea, depression, and metabolic abnormalities are independent predictors of excessive daytime sleepiness (EDS) in patients with sleep apnea. Exercise is beneficial for apnea, depression, and metabolic abnormalities; however, its association with EDS is not known.
Study objectives: To evaluate the contribution of lack of regular exercise, depression, and apnea severity on daytime sleepiness in patients with sleep apnea.
Participants and design: One thousand one hundred six consecutive patients (741 men and 365 women) referred to the sleep disorders clinic for symptoms consistent with sleep apnea. Daytime sleepiness was assessed with the Epworth Sleepiness Scale and activity was evaluated with a quantifiable Physical Activity Questionnaire.
Results: Compared with women, men had a higher apnea hypopnea index (AHI) (40.4 +/- 1.2 vs 31.0 +/- 1.8), lower body mass index (BMI) (35.3 +/- 0.3 kg/m2 vs 39.6 +/- 0.5 kg/m2), and higher rate of regular exercise (39.1% vs 28.8%) ( p < 0.05). Linear regression analysis of the total sample after adjusting for age, BMI, sex, central nervous system medication, and diabetes showed that logAHI, depression, and lack of regular exercise were significant predictors of sleepiness. Predictors of mild or moderate sleepiness for both sexes were depression and logAHI, whereas predictors of severe sleepiness for men were lack of regular exercise, depression, and minimum SaO2 and, for women, logAHI.
Conclusions: In obese apneic patients, lack of regular exercise (only in men), depression, and degree of apnea are significant predictors of EDS. This association is modified by sex and degree of sleepiness. Assessment and management of depression and physical exercise should be part of a thorough evaluation of patients with sleep apnea.