Jessie P. Bakker, Jia Weng, Rui Wang, Susan Redline, Naresh M. Punjabi, Sanjay R. Patel

No data exist as to the role of ethnicity in the associations between obstructive sleep apnea (OSA), sleep duration, and metabolic dysfunction. To examine links between OSA, objectively-measured habitual sleep duration, and fasting glucose in United States ethnic groups. The Multi-Ethnic Study of Atherosclerosis is a multi-site community-based study which conducted polysomnography and wrist-actigraphy. In 2,151 subjects (1,839 in fully-adjusted models), the apnea-hypopnea index was used to classify OSA as none (0-4.9 /hour), mild (5-14.9 /hour), or moderate-to-severe (≥15 /hour). Actigraphic sleep duration was classified as short (≤5 hours/night), intermediate (>5, <8 hours/night), or long (≥8 hours/night). Subjects were classified as having normal fasting glucose (<100mg/dL and no hypoglycemic medication use) or abnormal fasting glucose (≥100mg/dL and/or hypoglycemic medication use). Measurements & Main Results: The sample was 45.8% male, age 68.5±9.2 (mean±SD) years, and 27.3% African-American, 37.2% Caucasian, 11.8% Chinese, 23.8% Hispanic. The prevalence of abnormal fasting glucose was 40.2%. Relative to non-apneics, moderate-to-severe OSA was significantly associated with abnormal fasting glucose in African-Americans (odds ratio [OR] 2.14, 95% CI 1.12 - 4.08) and Caucasians (OR 2.85, 95% CI 1.20-6.75), but not among Chinese or Hispanic subjects, after adjusting for site, age, gender, waist circumference, and sleep duration (p=0.06 for ethnicity-by-OSA severity interaction). In contrast, sleep duration was not significantly associated with abnormal fasting glucose after considering the influence of OSA. This large multi-ethnic study confirmed previous reports of an independent association between OSA and metabolic dysfunction, and suggested that this association may vary by ethnicity.