Abstract 2540: Weight Loss Reverses Aortic Distensibility Changes In Subjects With Severe Uncomplicated Obesity. A One year Follow Up Study.
Objective: Obesity has been linked to reduced aortic elastic function but studies of central aortic distensibility (AD) in obesity are limited. Our hypothesis was that AD changes in severe obesity are at least partially reversible over one year following weight loss.
Method: Fifty subjects (37 uncomplicated obese BMI 38.4±7.2, 13 normal weight BMI 21.9±1.8), all with no identifiable cardiac risk factors, underwent MR imaging of the aorta. AD was assessed at three levels; the ascending (Ao) and proximal descending aorta (PDA) at the level of the pulmonary artery and the abdominal aorta (AA). Fourteen obese subjects underwent repeat aortic imaging after a one year period of weight loss, averaging 14.6 ± 11.5 % total body weight.
Results: Obesity was associated with a significant decrease in AD at all three levels (Ao 4.3 ± 1.7 vs 5.9 ± 2.0 mm/Hg-1 x 10 -3; p<0.01, PDA 4.11 ± 1.3 vs 6.2 ± 1.3; p<0.001, DDA 5.21 ± 1.7 vs 9.1 ± 2.7; p<0.001). More distal aortic regions were associated with relatively larger reductions in aortic distensibility compared to more proximal regions. After weight loss, there was a significant increase in AD in the abdominal aorta (6.6 ± 2.1 vs 4.7 ± 1.5; p<0.001), while AD improvements in proximal sections did not reach statistical significance (Ao 4.4 ± 2.8 vs 4.2 ± 1.5; p=0.6, PDA 4.8 ± 1.9 vs 4.2 ± 0.9; p=0.2).
Conclusion: Obesity is associated with reduced aortic elastic function, which is most pronounced distally. After one year of weight loss, the AA showed statistically significant improvements in AD. Thus, in uncomplicated obesity, aortic elastic properties are improved after one year of weight loss. Distal aortic elastic function is more sensitive to changes in BMI.