Influence of the body weight on the onset and progression of puberty in boys

Background: Unlike in girls, the data on the relationship between pubertal development and body weight in boys are controversial. Methods: We measured the height, body weight, body mass index (BMI), pubic hair stages, testicular volume, penis length and circumference of 4030 boys, aged between 7 and 19 years. According to their body weight, the investigated children and adolescents were divided in four groups at each age: underweight boys (BMI < 12th percentile), boys with normal weight (12th-84.99th percentile), overweight boys (85th-94.99th percentile) and boys with obesity (BMI >= 95th percentile), and their data were compared. Results: The onset of puberty occurred when the boys' weight gained 40.33 +/- 9.03 kg (median 39.00) and BMI was 18.62 +/- 3.12 kg/m(2) (median 17.80), whereas the late stage was reached at weight of 62.44 +/- 10.39 kg (median 61.00) and BMI 21.47 +/- 2.84 kg/m(2) (median 21.20). Earlier maturing boys were heavier than their coevals, whereas underweight boys developed puberty later. Conclusions: The onset and progression of puberty in boys are in a significant positive relationship with weight and BMI. Moreover, in the overweight boys pubertal development begins and comes to the late stage earlier in comparison with normal weight children, whereas in those who are underweight a delay at every stage of the development is observed.