Puberty-associated differences in total cholesterol and triglyceride levels according to sex in French children aged 10-13 years

PURPOSE: To assess the relationships between lipid levels and sexual maturi ty, independently of age-related differences, and to investigate possible d ifferences related to sexual maturity across the percentiles of the lipid d istributions. METHODS: Fasting serum total cholesterol and triglyceride concentrations we re measured in 6577 boys and 6605 girls, aged from 10 to 13 years, with dif ferent Tanner stages. The total cholesterol and triglyceride mean and perce ntile levels were estimated according to age ansi Tanner stage by ordinary least squares and percentile regression models, separately in both sexes. RESULTS: In boys and girls, total cholesterol levels were significantly ass ociated with pubertal stage after controlling for age. At age 12, the estim ated mean levels in boys varied from 4.82 mmol/L for Tanner 1 to 4.41 for T anner 5. The corresponding values were 5.05 and 4.62 mmol/L in girls, for w hom the association with maturity was stronger in the upper than in the low er percentiles (p < 0.0001); between the extreme Tanner stages, the 95th pe rcentiles of coral cholesterol differed by 0.80 mmol/L, in comparison to 0. 19 mmol/L fur the 5th percentiles. Therefore, 1.8% of girls and 0.7% of buy s were classified differently whether Tanner stage was used or not to asses s hypercholesterolemia (concentrations in the upper 5% of the distributions ). Triglycerides were positively related to sexual maturity independently o f age, but the discrepancies between classifications were lower; 1.1% in gi rls and 0.4% in boys. CONCLUSIONS: Our findings emphasize the importance of sexual maturity, even fur a given age, for interpreting lipid levels in children. Ann Epidemiol 2000;10:316-323. (C) 2000 Elsevier Science Inc. All rights reserved.