Blood lead level association with lower body weight in NHANES 1999-2006

Background: Lead exposure is associated with low birth-weight. The objective of this study is to determine whether lead exposure is associated with lower body weight in children, adolescents and adults. Methods: We analyzed data from NHANES 1999-2006 for participants aged >= 3 using multiple logistic and multivariate linear regression. Using age- and sex-standardized BMI Z-scores, overweight and obese children (ages 3-19) were classified by BMI >= 85th and >= 95th percentiles, respectively. The adult population (age >= 20) was classified as overweight and obese with BMI measures of 25-29.9 and >= 30, respectively. Blood lead level (BLL) was categorized by weighted quartiles. Results: Multivariate linear regressions revealed a lower BMI Z-score in children and adolescents when the highest lead quartile was compared to the lowest lead quartile (beta (SE) = -033 (0.07), p < 0.001), and a decreased BMI in adults (beta (SE) = -2.58 (025), p < 0.001). Multiple logistic analyses in children and adolescents found a negative association between BLL and the percentage of obese and overweight with BLL in the highest quartile compared to the lowest quartile (OR = 0.42, 95% CI: 030-0.59; and OR = 0.67, 95% CI: 052-0.88, respectively). Adults in the highest lead quartile were less likely to be obese (OR = 0.42,95% CI: 035-0.50) compared to those in the lowest lead quartile. Further analyses with blood lead as restricted cubic splines, confirmed the dose-relationship between blood lead and body weight outcomes. Conclusions: BLLs are associated with lower body mass index and obesity in children, adolescents and adults. Published by Elsevier Inc.