RACIAL-DIFFERENCES IN SLEEP-DISORDERED BREATHING IN AFRICAN-AMERICANSAND CAUCASIAN

In this case-control family study of sleep-disordered breathing (SDB), we describe the distributions of SDB and SDB risk factors in African- Americans and Caucasians. A total of 225 African-Americans and 622 Cau casians, ages 2 to 86 yr, recruited as members of families with an ind ividual with known sleep apnea (85 index families) or as members of ne ighborhood control families (63 families) were studied with an overnig ht home sleep-study, questionnaires, and physical measurements. A subs ampre underwent cephalometry. Outcome measures were the respiratory di sturbance index (RDI) and a binary variable indicating the presence of increased apneic activity (IAA). In both races, a strong relationship was demonstrated between the (log transformed) RDI and age and age(2) . African-Americans with SDB were younger than Caucasians with SDB (37 .2 +/- 19.5 versus 45.6 +/- 18.7 yr, p < 0.01). In subjects less than or equal to 25 yr, RDI level and IAA prevalence were higher in African -Americans (odds ratio, adjusted for obesity, sex, proband sampling, a nd familial clustering, 1.88, 1.03 to 3.52, 95% CI). In this age group , racial differences also were observed in the relationship between RD I and age (p < 0.001 for the RDI-age interaction). This suggests that young African-Americans may be at increased risk for sleep apnea.