Pubertal pathways and the relationship to anthropometric changes in childhood: The Fels longitudinal study.

OBJECTIVE To examine the relationship of the initial manifestation of pubertal development in children to anthropometric measurements recorded during the early childhood and adolescence. METHODS The Fels Longitudinal study is an observational study of growth and development of healthy white children. A total of 109 boys and 75 girls with serial self-assessments of Tanner stages of genital/breast and pubic hair developments provided data for a longitudinal analysis with a linear mixed model. RESULTS About 11.0% of boys and 22.7% of girls witnessed the appearance of pubic hair (adrenarche) prior to the onset of genital/breast growth (gonadarche/thelarche) and about 13.7% of boys and 22.7% of girls experienced the onset of gonadarche/thelarche prior to adrenarche. The remaining 75.3% of boys and 54.7% of girls were concordant for adrenarche and gonadarche/thelarche. During the first two years of life, boys and girls with earlier gonadarche and thelarche than adrenarche were found to have more rapid weight gain than those with earlier adrenarche than gonadarche/thelarche. During early childhood from age 2 - 7 years, those girls with early thelarche had higher body mass index (BMI) and waist circumference to height ratio (waist/height) than those with early adrenarche. In children of ages 8 - 20, girls with early gonadarche had higher BMI z-scores than those with early adrenarche. CONCLUSION Girls with early thelarche and later adrenarche, have more rapid mean weight gain during the first two years of life, higher BMI and waist/height during early childhood, and higher BMI z-scores during adolescence. Boys with early gonadarche and later adrenarche experienced more rapid weight gain during the first two years of life than boys with early adrenarche and later gonadarche. In other words, girls with early thelarche are more likely to be triggered by early accumulation of fat mass than those with early adrenarche.