Changes in body mass index, leptin and adiponectin in Japanese children during a three-year follow-up period: a population-based cohort study

OBJECTIVE: The study examined changes in and relationship between body mass index (BMI), leptin and adiponectin levels over a 3-year period in a pediatric population-based cohort. STUDY DESIGN: A 3-year prospective cohort study of 268 boys and 251 girls aged 9–10 in Ina, Saitama, Japan. RESULTS: Median body mass index (BMI) significantly increased from baseline (age 9–10) to follow up (age 12–13) in boys from 17.1 to 18.3 kg/m(2 )(P < 0.001) and in girls from 16.5 to 18.5 kg/m(2 )(P < 0.001), respectively. Adiponectin values significantly decreased from baseline to follow up in boys (13.5 to 8.9 μg/ml, respectively) (P < 0.001) and in girls (12.4 to 9.5 μg/ml, respectively) (P < 0.001). Leptin values at follow up significantly decreased from baseline in boys (4.9 to 2.3 ng/dl, respectively) (P < 0.001) and also in girls (5.3 to 5.1 ng/dl, respectively) (P = 0.049). A relatively strong correlation was seen in BMI (Spearman's correlation coefficient, r = 0.864, P < 0.001 in boys; r = 0.873, P < 0.001 in girls), adiponectin (r = 0.705, P < 0.001 in boys; r = 0.695, P < 0.001 in girls), and leptin (r = 0.449, P < 0.001 in boys; r = 0.610, P < 0.001 in girls) before and after the three-year period. The ratio of follow up to baseline BMI was negatively correlated with that for adiponectin (r = -0.224, P < 0.001 in boys; r = -0.165, P = 0.001 in girls) and positively correlated with that for leptin (r = 0.518, P < 0.001 in boys; r = 0.609, P < 0.001 in girls). CONCLUSION: This study demonstrated that baseline adiponectin, leptin and BMI values measured at ages 9–10 correlated with those measured three years later. However, adiponectin values decreased and leptin values increased in those subjects whose BMI increased during over this period.