Person:

Rich-Edwards, Janet

Purpose

Previous studies suggest that hair products containing endocrine disrupting chemicals could alter puberty. We evaluated the association between childhood hair product use and age at menarche in a racially diverse study population.

Methods

We recruited 300 African-American, African-Caribbean, Hispanic, and white women from the New York City metropolitan area who were between 18–77 years of age. Data were collected retrospectively on hair oil, lotion, leave-in conditioner, perm, and other types of hair products used before age 13. Recalled age at menarche ranged from 8 to 19 years. We used multivariable binomial regression to evaluate the association between hair product use and age at menarche (<12 vs. ≥12), adjusting for potential confounders.

Results

African-Americans were more likely to use hair products and reached menarche earlier than other racial/ethnic groups. Women reporting childhood hair oil use had a risk ratio of 1.4 (95% confidence interval [CI]: 1.1–1.9) for earlier menarche, adjusting for race/ethnicity and year of birth. Hair perm users had an increased risk for earlier menarche (adjusted risk ratio = 1.4, 95% CI: 1.1–1.8). Other types of hair products assessed in this study were not associated with earlier menarche.

Conclusions

Childhood hair oil and perm use were associated with earlier menarche. If replicated, these results suggest that hair product use may be important to measure in evaluating earlier age at menarche.

Purpose

We sought to evaluate the association between childhood socioeconomic status (SES) at two time points and age at menarche in a multiracial sample of U.S. girls.

Methods

Our study population consisted of a cohort of female participants enrolled at birth at the New York site of the Collaborative Perinatal Project, who were born during the period 1959–1963 (n = 262). SES at birth, at age 7, and change between birth and age 7 were measured prospectively through an index score of family income, paternal occupation, and education. Data on age at menarche were collected retrospectively through adult self-report. We used multivariable linear regression to examine the association between SES and age at menarche after adjusting for childhood body mass index (BMI) and other covariates associated with age at menarche.

Results

After adjustment, SES at age 7 was positively associated with age at menarche (beta: 0.015, 95% confidence interval [CI]: 0.003–0.024 per unit of SES index). Change in SES was significantly associated with age at menarche; a 20-unit decrease in SES was associated with a 4-month decrease in age at menarche.

Conclusions

Our results suggest that lower SES at 7 years and reductions in SES in early childhood are both associated with an earlier age at menarche.