Improvement of early vascular changes and cardiovascular risk factors in obese children after a six-month exercise program.

OBJECTIVES

The present study aimed to assess the effect of a 6-month exercise program in obese children on flow-mediated vasodilation (FMD) carotid intima-media thickness (IMT) and cardiovascular risk factors (RF).

BACKGROUND

Childhood obesity contributes to adult obesity and subsequent cardiovascular disease. Physical inactivity is a major RF for obesity, endothelial dysfunction, and elevated carotid IMT, culminating in early atherosclerotic disease.

METHODS

Sixty-seven obese subjects (age 14.7 +/- 2.2 years) were randomly assigned to 6 months' exercise or non-exercise protocol. We examined the influence of exercises (1 h, 3 times/week) on FMD, IMT, and cardiovascular risk profile.

RESULTS

Compared with lean control subjects, obese children demonstrated at baseline significantly impaired FMD (4.09 +/- 1.76% vs. 10.65 +/- 1.95%, p < 0.001), increased IMT (0.48 +/- 0.08 mm vs. 0.37 +/- 0.05 mm, p < 0.001), and a number of obesity-related cardiovascular RF. Significant improvements were observed in the exercise group for IMT (0.44 +/- 0.08 mm, p = 0.012, -6.3%) and FMD (7.71 +/- 2.53%, p < 0.001, +127%). This improvement correlated with reduced RF, such as body mass index standard deviation scores, body fat mass, waist/hip ratio, ambulatory systolic blood pressure, fasting insulin, triglycerides, low-density lipoprotein/high-density lipoprotein ratio, and low-degree inflammation (C-reactive protein, fibrinogen).

CONCLUSIONS

The present study documented increased IMT, impaired endothelial function, and various elevated cardiovascular RF in young obese subjects. Regular exercise over 6 months restores endothelial function and improves carotid IMT associated with an improved cardiovascular risk profile in obese children.