Exposure to lead is associated with decreased femur and spine bone mineral density (BMD) and increased risk for fracture in premenopausal women, according to study results published in Bone.
Lead accumulates at high concentrations in bones after exposure, interfering with bone metabolism and potentially contributing to an increased risk for osteoporosis. Researchers aimed to evaluate the association between lead exposure, BMD, and fracture risk score (FRAX) in adult patients from the National Health and Nutrition Examination Survey (NHANES).
Data were obtained from 1859 individuals from the 2013 to 2014 national survey. Lead exposure was estimated using blood and urine lead levels and BMD was measured using dual-energy x-ray absorptiometry over the femur and spine. Fracture risk was estimated using FRAX scores, which were based on risk factors including age, weight, height, previous history of fracture, and other medical history.
In nonmenopausal women, a 1-unit increase in natural log-transformed blood lead levels was associated with a 0.061 g/cm2 (P =.001) decrease in total femur BMD and a 0.054 g/cm2 (P =.013) decrease in total spine BMD. A 1-unit increase in natural log-transformed urine lead levels was associated with a 0.046 g/cm2 (P =.02) decrease in total femur BMD. There was no association between blood or urine lead levels and BMD in men or menopausal women.
In patients with no history of previous fracture, blood and urine lead levels were positively correlated with increased FRAX scores for hip fracture and major osteoporotic fracture. In patients with a history of fracture, higher blood and urine lead levels were associated with increased 10-year hip fracture risk score.
The researchers noted that the cross-sectional design of the study limits the conclusions that can be made regarding causation between the observed associations.
“[W]e found that lead exposure was associated with decreased BMD values of the femur and spine in premenopausal women,” the researchers concluded. “If the association between lead exposure and BMD is causal, lifetime exposure to lead still threatens human health, and continued efforts to reduce lead exposures are needed.”
Wang WJ, Wu CC, Jung WT, Lin CY. The associations among lead exposure, bone mineral density, and FRAX score: NHANES, 2013 to 2014. Bone. 2019;128:115045.