Abstract 037: The Association of Early Menarche and Changes in LDL-C During Adolescence for African-American and White Girls
Introduction: LDL cholesterol transiently decreases during puberty, and then increases again in late adolescence. However, the association of earlier pubertal development and LDL-C changes among adolescents is not well established, especially among African-American girls.
Objective: To examine race-specific associations of early menarche and change in LDL-C during adolescence.
Methods: The National Growth and Health Study (NGHS) was a 10-year prospective study of 2,379 girls, aged 9-10 at baseline, from four areas of the United States. Girls with missing age at menarche (n=22) or clinic (n=1) information were excluded from analyses. We used mixed effects regression models to test the association of early menarche, defined as less than median age at menarche for race in NHANES III (<12.1 for African-American, and <12.6 years for white girls) and serial measures of LDL-C, adjusted for age, study center, parental education, and percent body fat at each visit. Time was defined as follow-up year 1 (mean age 10) through year 10 (mean age 19), and included as a quadratic term in all models.
Results: The analytic sample included 2,356 girls (1,200 African-American; 1,156 white). Early (vs. later) menarche (-1.90 mg/dl, p=0.05) and African American race (-1.72 mg/dl, p =0.08) were associated with lower average LDL-C over the 10-year time period. LDL-C increased less during late adolescence in African-American than in white girls (β race*time2 = -0.11 mg/dl; p-interaction=0.01), and further, the relationship of menarche to the shape of the LDL-C curve differed by race, as indicated by different quadratic time terms (race*menarche*time2; p-interaction=0.02).
Conclusion: LDL-C was lower among girls with early vs. later menarche during adolescence. By late adolescence, white girls with early menarche tended to experience faster gains in LDL-C compared with later maturing white girls. Additional research is needed to determine if this pattern continues into adulthood.
- © 2013 by American Heart Association, Inc.