THE OCCURRENCE OF SLEEP-DISORDERED BREATHING AMONG MIDDLE-AGED ADULTS

Background. Limited data have suggested that sleep-disordered breathin g, a condition of repeated episodes of apnea and hypopnea during sleep , is prevalent among adults. Data from the Wisconsin Sleep Cohort Stud y, a longitudinal study of the natural history of cardiopulmonary diso rders of sleep, were used to estimate the prevalence of undiagnosed sl eep-disordered breathing among adults and address its importance to th e public health. Methods. A random sample of 602 employed men and wome n 30 to 60 years old were studied by overnight polysomnography to dete rmine the frequency of episodes of apnea and hypopnea per hour of slee p (the apnea-hypopnea score). We measured the age- and sex-specific pr evalence of sleep-disordered breathing in this group using three cutof f points for the apnea-hypopnea score (greater-than-or-equal-to 5, gre ater-than-or-equal-to 10, and greater-than-or-equal-to 15); we used lo gistic regression to investigate risk factors. Results. The estimated prevalence of sleep-disordered breathing, defined as an apnea-hypopnea score of 5 or higher, was 9 percent for women and 24 percent for men We estimated that 2 percent of women and 4 percent of men in the middl e-aged work force meet the minimal diagnostic criteria for the sleep a pnea syndrome (an apnea-hypopnea score of 5 or higher and daytime hype rsomnolence). Male sex and obesity were strongly associated with the p resence of sleep-disordered breathing. Habitual snorers, both men and women, tended to have a higher prevalence of apnea-hypopnea scores of 15 or higher. Conclusions. The prevalence of undiagnosed sleep-disorde red breathing is high among men and is much higher than previously sus pected among women. Undiagnosed sleep-disordered breathing is associat ed with daytime hypersomnolence.