A study in the April 15 issue of the Journal of Clinical Sleep Medicine suggests that obstructive sleep apnea severity is higher in African-American men than Caucasian men in certain age ranges, even after controlling for body mass index (BMI). There was no difference in AHI between African-American and white women. The authors suggested that potential mechanisms include anatomic differences that affect upper airway mechanics and collapsibility, as well as differences in the neurochemical control of breathing.