RELATION OF RACE, AGE, AND SEX-HORMONE DIFFERENCES TO SERUM LEPTIN CONCENTRATIONS IN CHILDREN AND ADOLESCENTS

We explored the effects of race, age, and sex hormones on the serum le ptin concentrations in 203 white and 88 black children and adolescents cages 9.3-20.5 years). A significant sex by race interaction on serum leptin levels (p = 0.0301) was observed with lower serum leptin conce ntrations, adjusted for subscapular thickness and age, in black boys t han in white boys. Girls had serum leptin levels that were on average 2.15 times those of boys (p < 0.0001). There was an age by sex interac tion (p < 0.0001) with serum leptin concentrations decreasing in boys but not in girls with age. A strongly inverse relationship of serum te stosterone levels with serum leptin levels in boys (p = 0.0067) appear ed to explain this effect of age. In conclusion, the serum leptin conc entration is slightly lower in black boys. A higher testosterone level in boys appears to account for an age-related decline in serum leptin in boys and the overall lower levels in boys than in girls.