Leptin serum concentrations predict the responsiveness of obese children and adolescents to weight excess reduction program

BACKGROUND: A role for leptin to predict weight gain is still controversial. OBJECTIVE AND DESIGN: To determine the relationship between baseline serum leptin values and responsiveness to an educational-based weight excess reduction program (WERP), 418 (241 males and 185 females) obese subjects, aged 9 -15 y, were recruited. WERP required 2 y of follow-up. Body mass index (BMI) was evaluated at baseline and at each semester of follow-up. The obese subjects were subdivided into responsives and non-responsives, according to reduction or not of their BMI Z-scores during the WERP. Leptin concentrations were assayed at baseline and were included together with other independent variables in statistical multiple regression analysis. RESULTS: At a preliminary multiple regression analysis, a significant positive correlation between leptin values and BMI Z-score reduction at the second, third and fourth semester of follow-up was registered. To determine the odds ratio of the subjects who were responsive or non-responsive at the various semesters of WERP follow-up, a stepwise logistic regression was used incorporating the same predictors, with the serum leptin values subdivided into quintiles and responsiveness and non-responsiveness as a binary outcome variable. The model offered a satisfying goodness of fit as shown by the sensitivity and specificity. The odds ratio of being responsive were significantly increased by greater quintiles of leptin serum concentrations. Furthermore, such odds ratios were much higher in pubertal than in prepubertal subjects. CONCLUSIONS: These findings support a significant role for serum leptin concentration in predicting BMI changes as a response to an educational excess weight reduction program.