Negative association between Low-dose blood lead levels and bone mineral density in U.S. children: a cross-sectional study from NHANES 2005–2010

Background Relationship between lead exposure and children's bone health remains controversial. The aim of this study was to investigate the relationship between blood lead levels (BLL) and femur bone mineral density (BMD). All data came from the National Health and Nutrition Examination Survey (NHANES) database, 2005–2010. Methods A total of 3331 subjects aged 8–18 years were enrolled in this study. Multivariate linear regression models were used to explore the relationship between BLL and femur BMD. And further stratified analyses by gender and ethnicity. Additionally smooth curve fitting was used to explore the saturation threshold effect between the two. Result There was a significant negative correlation between BLL and BMD in different parts of the femur in children. For every 1ug/dl increase in BLL, total femur BMD, femoral neck BMD, femoral trochanter BMD, and femoral intertrochanteric BMD decreased by 0.008 g/cm2, 0.007 g/cm2, 0.007 g/cm2, and 0.008 g/cm2, and the saturation threshold for BLL were 1.73ug/dl; 1.61ug/dl, 1.80 ug/dl, and 1.66ug/dl. Conclusion This study shows that low-dose blood lead levels, even those within the reference range, can have a significant negative impact on children's bone health.