Weight reduction and aortic stiffness in obese children and adolescents: a 1-year follow-up study.

Little is known about the effect of weight reduction on aortic stiffness and especially so in the young. The present study investigates whether weight reduction influences aortic stiffness in obese children and adolescents. Carotid-femoral pulse wave velocity (cfPWV) and augmentation index at heart rate 75 (AIx@HR75) were measured in 72 obese patients aged 10-18 years at baseline and after 1-year of lifestyle intervention (follow-up). We found that although the degree of obesity decreased (Δbody mass index z-score: -0.24±0.45, P<0.0001), cfPWV was higher at follow-up (ΔcfPWV: 0.27±0.47 m s(-1), P<0.0001), which was explained by the increase in age (β=0.12 ms(-1)  per year, 95% confidence interval (CI) 0.07-0.17, P<0.0001) and partly by changes in mean arterial pressure and heart rate. Changes in cfPWV were not related to changes in obesity measures. No significant change was found in AIx@HR75 (ΔAIx@HR75: 2.10±9.73%, P=0.072), but changes in AIx@HR75 were related to changes in abdominal fat (Δwaist/height ratio: β=50.3, 95% CI 6.7-94.0, P=0.02) and changes in total body fat percent by dual energy X-ray absorptiometry scan (Δtotal body fat (%): β=0.7, 95% CI 0.1-1.3, P=0.02) when adjusted for gender and relevant baseline confounders. In conclusion, no clear effect of weight reduction was found on aortic stiffness, although changes in AIx@HR75 were associated with changes in both abdominal fat and total body fat percent. The higher cfPWV at follow-up was related to the older age.