Obesity in adolescents is associated with insulin resistance, which increases the risk for type 2 diabetes. Consequently, health care professionals are confronted to the challenge of properly treating this condition. The objective of the present study was to examine the impact of a 16-week lifestyle modification program on insulin resistance in obese adolescents.
Twenty-nine obese adolescents (16 boys and 13 girls) from 11 to 16 years of age (14.0 ± 1.6 years) were selected to participate in the study. Each subject was followed by a multidisciplinary team and trained three sessions per week for 16 weeks. The exercise program focused on endurance type activities and all training sessions were supervised and performed in groups. Physical and metabolic variables were measured at baseline and at the end of the intervention. We have used the homeostasis model (HOMA-IR) assessment formula to estimate insulin resistance.
At baseline, adolescents who were more insulin resistant were characterized by a more disturbed fasting plasma lipoprotein-lipid profile compared to adolescents who were less insulin resistant (p<0.02). The highest improvement in cardiometabolic risk factors after the lifestyle modification program were observed among adolescents characterized by the highest intervention-induced changes in insulin resistance (p<0.004). Finally, intervention induced-changes in insulin resistance were significantly correlated with changes in waist circumference (p<0.04). No significant correlation was found between changes in body mass index and changes in insulin resistance after the lifestyle intervention.
These results suggest that reducing waist circumference can have a positive impact on insulin resistance in obese adolescents. Such observations would reinforce the importance of including waist circumference as part of routine pediatric care screening.