Pubertal correlates in black and white girls

Objectives Since pubertal maturation is an important covariate in studies that evaluate physical and social changes that occur during the teen years, we examined pubertal parameters in a group of US girls. Study design Black and White girls recruited at age 9 were followed annually for 10 years. Preece-Baines model 1 was used to estimate tempo and growth parameters. The temporal trend between age of menarche and onset of puberty was calculated. Results The study included 615 (77.2% prepubertal) white and 541 (49.4% prepubertal) black participants. Mean onset of puberty was 10.2 and 9.6 years in white and black girls, respectively, menarche was 12.6 and 12.0, achievement of Tanner growth stage 5 was 14.3 and 13.6, and achievement of adult height was 17.1 and 16.5 years. The Pearson's correlation coefficient between menarche and onset of puberty was .37. Conclusions Menarche is often used as a marker for onset of puberty and for timing of puberty. Data gathered over the past 20 years suggest only moderate correlation between menarche and onset of puberty (.37-.38), which has decreased significantly during the last 50 years. This suggests the existence of both similar and unique factors that impact the age at onset of puberty and age at menarche.