GENDER DIFFERENCES IN SLEEP-DISORDERED BREATHING IN A COMMUNITY-BASEDSAMPLE

Gender differences in the relative frequency of sleep-disordered breat hing (SDB) have been observed in surveys of patient groups referred fo r clinical evaluation compared with population surveys. In this study, we assessed the associations of gender, SDB, and symptoms of SDB in 3 89 participants (16 to 84 yr of age) in an ongoing genetic-epidemiolog ic study of sleep apnea. Subjects included index probands with laborat ory-confirmed obstructive sleep apnea syndrome (laboratory sample, n = 36) and their family members and neighbors (the community sample). SD B was assessed with overnight in-home monitoring of airflow, oximetry, heart rate, and chest wall impedance, and symptoms were assessed with standardized questionnaires. In the entire sample, SDB, defined as a respiratory disturbance index [RDI] greater than or equal to 15, was m ore prevalent among males (38%) than among females (15%) (p < 0.05). M ales predominated by a ratio of 8:1 in the laboratory sample (31 males , five females). In contrast, the proportion of males to females with SDB was only 2:1 in the community sample, in which an RDI greater than or equal to 15 was observed among 26% of males and 13% of females. In the laboratory sample, females tended to be younger and were signific antly heavier than males. However, in the community sample, females wi th SDB were older than male apneic subjects (63.4 +/- 13.9 versus 47.2 +/- 15.6 years, mean +/- SD; p < 0.01), and included a majority of po stmenopausal women (75%). No differences in body mass index were noted between males and females with SDB recruited from the community. Comp ared with males, females consistently underreported symptoms of snorin g, snorting, gasping, and apnea. After adjusting for RDI, women were 2 to 3 times less likely than males to report these symptoms. We conclu de that SDB is common in older females, and occurs frequently in the a bsence of morbid obesity. SDB may be recognized less frequently clinic ally in females, in part because of underreporting of symptoms of dist urbed breathing during sleep.