ObjectiveObstructive Sleep Apnea (OSA) is linked to classical symptoms of snoring and excessive sleepiness. However, many women with OSA may present with a diverse profile. The influence of age on the clinical differences between genders is unclear. This survey aimed to compare the clinical and polysomnographic findings of OSA between adult males and females, but considering different age groups. MethodsThis cross-sectional study comprised a sample of 472 consecutive adult patients with OSA who underwent full-night polysomnography. Data from the medical and polysomnographic records was obtained, as well as the score on Portuguese validated version of the Epwoth Sleepiness Scale (ESS). Comparisons of main clinical aspects of OSA between genders were stratified according to three groups: young (< 30 years old), middle-aged (30 - 50 y.o.), and older patients (> 50 y.o.). ResultsMen comprised the majority of the sample (male/female ratio of 1.6). Apnea-Hypopnea Index (AHI) was higher in men than women (median [interquartile range]: 29.7 [18.1-47.8] vs. 21.9 [11.5-36.1]; p < 0.0001), and body mass index alike (mean ± standard deviation: 29.0±4.9 vs. 27.6±5.2; p = 0.004). Snoring was more common in male than in female patients (92% vs. 84.7%; p = 0.015). In the subset of subjects younger than 30 years-old the differences between genders were prominent (male/female; AHI: 19.6 [13.1-28.1] vs. 11.8 [7.7-18.8], p = 0.012; sno ring: 89.7% vs. 55.2%, p = 0.007), accompanied by a trend to lower score in ESS in male patients (7.1 ± 4.3 vs. 9.2 ± 4.3; p = 0.066). DiscussionResults suggest that a classical clinical picture of snoring and severe daytime sleepiness is lacking in a considerable proportion of OSA sufferers, particularly young women, who tend to be sleepier than male patients. The awareness of OSA in young women should be based more in mild excessive daily sleepiness than in other typical OSA symptoms.