Increasing rates of obese and overweight children in the United States may be contributing to a later onset of puberty in boys, say researchers at the U-M Health System.
In a new study published in the February issue of the Archives of Pediatrics and Adolescent Medicine, researchers show that a higher body mass index (BMI) during early and mid-childhood for boys is associated with later onset of puberty. This is one of the first longitudinal studies in the United States to examine the association between weight status and timing of puberty in boys.
“We found that increased body fatness is associated with a later onset of puberty in boys, the opposite of what we have seen in girls, as heavier girls tend to develop earlier, rather than later. Our study shows that the relationship between body fat and timing of puberty is not the same in boys as it is in girls,” says pediatric endocrinologist Dr. Joyce Lee, the study’s lead author.
With childhood obesity rates more than doubling in the United States during the past two decades, it has become increasingly important to better understand the ways in which excess body fat can impact children’s growth and development, she adds.
“Although there have been a number of longitudinal studies looking at the link between body fat and puberty in girls, few studies have been performed in boys. The results of our study suggest that excess weight may lead to a later onset of puberty in boys. Our findings have important implications for understanding sex differences in physiological mechanisms of puberty,” says Lee, assistant professor in the Department of Pediatrics and Communicable Diseases.
To study the association between weight and the onset of puberty, Lee and her colleagues looked at 401 boys from diverse socioeconomic backgrounds in 10 regions of the United States using data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development.
The study examined children’s BMI trajectories, which is the way children’s body fatness changes over the course of childhood. Children were divided into low, intermediate and high BMI trajectories. Children in the low group were on the thinner side throughout childhood, while children in the high group were on the heavier side.
Additional U-M co-authors are Niko Kaciroti and Dr. Julie Lumeng.
