Department of Pediatrics
Medical Subject Headings
Child; Cohort Studies; Dose-Response Relationship, Drug; *Environmental Exposure; Environmental Pollutants; Humans; Insulin-Like Growth Factor I; Lead; Linear Models; Luminescence; Luminescent Measurements; Male; Russia; Spectrophotometry, Atomic
BACKGROUND: Childhood lead exposure has been associated with growth delay. However, the association between blood lead levels (BLLs) and insulin-like growth factor 1 (IGF-1) has not been characterized in a large cohort with low-level lead exposure.
METHODS: We recruited 394 boys 8-9 years of age from an industrial Russian town in 2003-2005 and followed them annually thereafter. We used linear regression models to estimate the association of baseline BLLs with serum IGF-1 concentration at two follow-up visits (ages 10-11 and 12-13 years), adjusting for demographic and socioeconomic covariates.
RESULTS: At study entry, median BLL was 3 mug/dL (range, < 0.5-31 mug/dL), most boys (86%) were prepubertal, and mean +/- SD height and BMI z-scores were 0.14 +/- 1.0 and -0.2 +/- 1.3, respectively. After adjustment for covariates, the mean follow-up IGF-1 concentration was 29.2 ng/mL lower (95% CI: -43.8, -14.5) for boys with high versus low BLL (>/= 5 mug/dL or < 5 mug/dL); this difference persisted after further adjustment for pubertal status. The association of BLL with IGF-1 was stronger for mid-pubertal than prepubertal boys (p = 0.04). Relative to boys with BLLs < 2 mug/dL, adjusted mean IGF-1 concentrations decreased by 12.8 ng/mL (95% CI: -29.9, 4.4) for boys with BLLs of 3-4 mug/dL; 34.5 ng/mL (95% CI: -53.1, -16.0) for BLLs 5-9 mug/dL; and 60.4 ng/mL (95% CI: -90.9, -29.9) for BLLs >/= 10 mug/dL.
CONCLUSIONS: In peripubertal boys with low-level lead exposure, higher BLLs were associated with lower serum IGF-1. Inhibition of the hypothalamic-pituitary-growth axis may be one possible pathway by which lead exposure leads to growth delay.
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Citation: Environ Health Perspect. 2013 Jul;121(7):854-8. doi: 10.1289/ehp.1206105. Link to article on publisher's site
Fleisch, Abby F.; Burns, Jane S.; Williams, Paige L.; Lee, Mary M.; Sergeyev, Oleg; Korrick, Susan; and Hauser, Russ, "Blood lead levels and serum insulin-like growth factor 1 concentrations in peripubertal boys" (2013). Lee Lab Publications. 56.