A preliminary report of gender differences in residual sleepiness of CPAP-treated obstructive sleep apnea

Background Males and females present different sleep alterations, so the aim of the study was to investigate gender differences in residual excessive sleepiness (RES) post continuous positive airway pressure (CPAP) treatment in a population with obstructive sleep apnea (OSA). Methods The study was conducted on consecutive subjects with moderate-severe OSA treated by CPAP for one year. Clinical and sleep data were collected from the sample, including RES calculated according to an Epworth sleepiness scale (ESS) threshold score >10 points at yearly follow-up. Of this sample, gender differences were investigated. Results 157 patients (125 males and 32 females) with a mean age of 62,84±11,81 years were included in the study. Overall, females were more obese (p = 0,001) with no differences in OSA severity compared to males.At yearly follow-up, sleepiness was significantly reduced in both sexes but 25 % of males reported RES compared to 13 % of females (p = 0,03). In addition, females were more adherent to CPAP (p = 0,008) than males.However, by observing the residual sleepiness data, it was noticed that sleepy females were more elderly and obese than sleepy males. Females also presented a higher nocturnal time with oxygen saturation <90 % (T90) with more cognitive symptoms. Conversely, sleepy males reported higher number of OSA-related symptoms and more history of comorbidities. Conclusion The report suggests that sleepy males have many symptoms with history of multimorbidity, while sleepy females are elderly, obese and have more cognitive symptoms maybe due to worse hypoxia during sleep. Nonetheless, larger sample studies are needed to confirm our findings.