Effects of two-month physical-endurance and diet-restriction programmes on lipid profiles and insulin resistance in obese adolescent boys

Aim. - The aim of this study was to assess the impact of a two-month programme of physical endurance and dietary restriction, alone and combined, on plasma lipids and insulin resistance in obese adolescents. Methods. - A total of 24 obese adolescent boys participated in programmes of either dietary restriction (R), physical endurance at the point of maximum lipid oxidation (LIPOXmax) (E) or diet combined with training (R + E). Anthropometric characteristics, metabolic measures and biochemical analyses were performed in all subjects before and after the interventions. An estimated insulin resistance was calculated using the homoeostasis model assessment (HOMA-IR) index. Results. - At the end of the two-month programmes, adolescents in the R+E group showed greater reductions in body mass index (-3.9 +/- 0.7 kg/m(2)) and waist circumference (-12.3 +/- 4.8 cm) (P < 0.001) than either the R or E group. A significant decrease (P < 0.01) in HOMA-IR index (-2.13 +/- 0.11), plasma triglycerides, LDL and total cholesterol was also seen in the R + E group. Moreover, at the end of the programme, the ratio of HDL cholesterol to triglycerides was significantly increased from baseline in the R + E group (0.93 +/- 0.09 vs. 0.68 +/- 0.11; P < 0.01). Conclusion. - Compared with either moderate physical endurance or dietary restriction, a combination of both resulted in a significant decrease in cardiovascular risk factors and HOMA-IR index in obese adolescent boys. (C) 2008 Elsevier Masson SAS. All rights reserved.