Peripubertal blood lead levels and growth among Russian boys

Abstract

BACKGROUND: Childhood blood lead levels (BLL) have been associated with growth impairment. OBJECTIVES: We assessed associations of peripubertal BLL with adolescent growth and near adult height in a longitudinal cohort of Russian boys. METHODS: 481 boys were enrolled at ages 8-9years and followed annually to age 18. At enrollment, BLL was measured, and height, weight, and pubertal staging were obtained annually during 10years of follow-up. Mixed effects models were used to assess the associations of BLL with longitudinal age-adjusted World Health OrganizationZ-scores for height (HT-Z) and body mass index (BMI-Z), and annual height velocity (HV). Interactions between boys' age and BLL on growth outcomes were evaluated. RESULTS: The median (range) BLL was 3.0 (0.5-31.0) mug/dL. At age 18years, 79% of boys had achieved near adult height (HV < 1.0cm/year), and means (SD) for HT-Z and BMI-Z were 0.15 (0.92) and -0.32 (1.24). Over 10years of follow-up, after covariate adjustment, boys with higher ( > /=5mug/dL) BLL compared with lower BLL were shorter (adjusted mean difference in HT-Z=-0.43, 95% CI -0.60, -0.25, p-value < 0.001), translating to a 2.5cm lower height at age 18years. The decrement in height for boys with higher BLL was most pronounced at 12 to 15years of age (interaction p=0.03). Boys with higher BLL were leaner (adjusted mean difference in BMI-Z=-0.22, 95% CI: -0.45, 0.01, p=0.06). CONCLUSIONS: Higher peripubertal BLLs were associated with shorter height through age 18years, suggesting a persistent effect of lead on linear growth.