Early age at menarche and allostatic load: data from the Third National Health and Nutrition Examination Survey.

PURPOSE: To examine whether there is an association between early age at menarche and allostatic load-a measure of cumulative biologic risk-using data from the Third National Health and Nutrition Examination Survey (NHANES III).
METHODS: A total of 2470 (weighted N=25,544,838) women aged between 17 and 30 years with interview and examination data who did not report oral contraceptive use before menarche and were not missing data on the exposure or outcome were included. Early menarche was defined as menarche at age 10 or younger. The allostatic load score was the sum of the number of 11 components for which an individual had a value within the high-risk range.
RESULTS: The prevalence of early menarche was 7%. Although the overall allostatic load scores were low when compared with older adults, the mean allostatic load score was higher among those with menarche at ages 10 or younger compared with those with later ages at menarche (1.99 vs. 1.33). After adjusting for age, race/ethnicity, level of education, household poverty income ratio, smoking, and depression history, women with high allostatic load scores had more than 2 times the odds as those with low scores of experiencing menarche at age 10 or earlier (OR=2.18; 95% CI, 1.29-3.68).
CONCLUSIONS: This study is the first to report and examine the relationship between age at menarche and allostatic load. Future studies involving prospective measurement of allostatic load biomarkers may prove essential for disentangling the association between allostatic load and early age at menarche.