Impact of obstructive sleep apnea on abdominal aortic diameters

Although obesity has been reported to be a potential risk factor for abdominal aortic dilatation, the impact of obstructive sleep apnea (OSA) on the abdominal aortic diameter remains unknown. We retrospectively reviewed 427 patients aged >45 years who underwent polysomnography and abdominal computed tomography from November 2008 to February 2012. Aortic diameters were measured at 3 locations: upper, infrarenal, and lower abdominal aorta. OSA was defined as non-OSA (apnea-hypopnea index [AHI] <10, n = 58), mild to moderate (AHI 10 to 30, n = 167), and severe (AHI ≥30, n = 202). Adjusted diameter was not significantly different among OSA severity categories at the upper (21.0, 21.3, and 21.4 mm, respectively) and infrarenal aorta (19.5, 20.2, and 19.9 mm, respectively) but was significantly different at the lower abdominal aorta (17.3, 18.2, and 18.2 mm, respectively, p = 0.006) with larger diameters in patients with OSA. Multivariate linear regression analyses revealed that risk profiles for aortic dilatation varied according to the location and gender and that OSA (AHI ≥10) was an independent risk factor for infrarenal and lower abdominal aortic dilatation only in men (β = 0.10 and 0.18, p = 0.049 and 0.001, respectively). In conclusion, OSA may enhance dilatation of the distal abdominal aorta in men.