Study objectives: To evaluate sex differences in predictors of obstructive sleep apnea (OSA) as per outcomes from home sleep apnea testing. Design: This was a retrospective analysis of a large repository of anonymous test results and pretest risk factors for OSA. Setting and patients: A total of 272,705 patients were referred for home sleep apnea testing from a variety of clinical practices for suspected sleep disordered breathing across North America from 2009 to 2013. Interventions: Not applicable. Measurements and results: Predictors of OSA (apnea hypopnea index (4%)>= 5) were evaluated by multiple logistic regression; sex differences were evaluated by interaction effects. Middle age was the single most robust predictor of OSA for both sexes and was particularly foretelling for females (P<0.001) even after controlling for measures of adiposity and medical conditions. Females over the age of 45 years were much more likely to have OSA compared to their younger counterparts (78.7% vs 42.5%, respectively; odds ratio: 5.0) versus males (88.1% vs 68.8%, respectively; odds ratio: 3.4). Snoring, although more frequently reported by males, was similarly predictive of OSA for both sexes. Witnessed apneas and measures of adiposity were better predictors of OSA for males than females. Insomnia, depression, and use of sleep medication, although more commonly reported in females, did not predict OSA. Hypertension, although equally reported by both sexes, performed better as a predictor in females (P<0.001), even after controlling for age, measures of adiposity, and other medical conditions. Diabetes, heart disease, stroke, and sleepiness did not contribute unique variance in OSA in adjusted models. Conclusion: This study found that males and females report different symptoms upon clinical evaluation for suspected sleep apnea, with some of the "classic" OSA features to be more common in and robustly predictive for males. The finding that advancing age uniquely and robustly predicted OSA in females reinforces our understanding that age-related changes in sex hormones play a role in the development and/or manifestation of sleep disordered breathing. Need exists for sex-specific prediction models and quantification of menopausal status in OSA screening tools.
