Gender differences in the sleep variables contributing to excessive daytime sleepiness among patients with obstructive sleep apnea.

PURPOSE: Excessive daytime sleepiness (EDS) is a main symptom in patients with obstructive sleep apnea (OSA); however, patients with OSA have significant variability in their reported EDS which cannot be fully explained by the apnea-hypopnea index (AHI). The purpose of this study was to investigate gender differences regarding the sleep test variables contributing to excessive daytime sleepiness.

METHODS

Retrospective study of 578 men and 270 women with suspected OSA who underwent home overnight sleep test. We assessed the correlation between sleep test variables and EDS, using the Epworth Sleepiness Scale (ESS).

RESULTS

Among the group of men, correlation was found between ESS to BMI (r = .107, p = .010), AHI (r = .158, p < .001), number of apneas (r = .129, p = .002), number of hypopneas (r = .115, p = .006), number of blood oxygen desaturations (r = .145, p  < .001), and percent of time the blood oxygen saturation was under 90% (r = .130, p = .002). However, among the group of women, no significant correlation was found between any of the sleep test parameters or BMI to ESS. Among the group of women, a negative correlation was found between age and EDS (r = - .208, p < .001).

CONCLUSION

Men showed correlations between sleep test variables and EDS, while women did not show such correlations. The results suggest that men's sleepiness is more influenced by OSA and sleep variables compared to women. To our knowledge, this is the first study which shows difference between genders in the influence of sleep variables and OSA on EDS.