Background: Recent studies have shown that early onset of puberty may attribute to the increasing prevalence of obesity. The purpose of this study was to analyze the association between precocious puberty and obesity by comparing the body composition of girls with precocious puberty to those of control group.
Methods: A total number of 252 girls aged 7 to 10 years [86 in control group, 75 subjects in early puberty group, and 91 girls in central precocious puberty (CPP) group] were included. Anthropometric measurements including height, weight, body mass index, body fat percent, waist circumference and bone age were measured. Endocrine investigations including estradiol, basal and gonadotropin releasing hormone (GnRH) stimulated peak level of luteinizing hormone (LH) were compared among the CPP group, early puberty and control group using Kruskal Wallis test.
Results: The mean height was highest in CPP (135.6 ± 6.2 cm in CPP, 133.9 ± 7.7 in early puberty, 128.9 ± 5.5 in control). The body weight (P < 0.0001), BMI (P = 0.003), waist circumference (P = 0.0001) and total body fat percent (P = 0.003) were significantly higher in the early puberty group than in CPP group.
Conclusion: The results were consistent with obesity being an important contributing factor in early onset of puberty, especially in girls.

Keywords: Precocious puberty, Obesity, Body mass index, Body composition