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BLOOD LEAD AND SECONDARY SEXUAL CHARACTERISTICS AND MENSES IN U.S. GIRLS
Citation:
Wu, T., P Mendola, AND G. M. Buck. BLOOD LEAD AND SECONDARY SEXUAL CHARACTERISTICS AND MENSES IN U.S. GIRLS. Presented at 35th Annual Meeting of the Society for Epidemiologic Research, Palm Desert, CA, June 19-21, 2002.
Description:
Blood Lead and Secondary Sexual Characteristics and Menses in U.S. Girls. *T. Wu, P. Mendola, and G.M. Buck (SUNY at Buffalo, Buffalo, NY 14214)
Purpose: To investigate the association between blood lead and puberty (presence of public hair, breast development, and menarche). Methods: Using data from the Third National Health and Nutrition Examination Survey, study sample comprised 1,722 girls aged 8-16 years, among whom 1,250 (age 10-16) had information on menses. Tanner stage II or higher was used to define presence of pubic hair and breast development. Blood lead (~m~g/dl) was categorized as low (0-2), moderate (2.1-4.9), or high (?5). Proportion of girls having attained, and mean age at onset of, each puberty measure were estimated at the various lead levels. Logit model was used to adjust for ethnicity, age, family size, residence in metro area, and family income. Results: In the study sample (n=1,722), 54.3%, 35.7%, and 10.0% had low, moderate and high blood lead, respectively. Mean ages (years) at onset of pubic hair, breast development, and menses were 9.9, 9.7, and 12.1 for girls with low; 10.2, 9.8 and 12.7 for girls with moderate; and 10.6, 10.0 and 13.2 for girls with high blood lead levels. Overall, blood lead levels were significantly associated with the puberty measures, but association was stronger among younger girls. Among 8 years old girls, 19.2%, 14.1%, and 8.5% of girls in low, moderate or high blood lead groups had pubic hair compared to 97.0%, 95.7%, and 84.6% for girls aged 12 years of age, respectively. The association of blood lead with each pubertal characteristic remained significant even after multivariate adjustment. Conclusion: Higher blood lead levels were associated with delayed onset of puberty measures, but further invetigation is needed to elucidate the mechanisms underlying this cross-sectional association.
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