Occupational cadmium exposure and calcium excretion, bone density and osteoporosis in men.

Abstract

BACKGROUND: Exposure to cadmium has been associated with osteoporosis and fracture risk in women and in elderly, but studies in middle-aged men are lacking. METHODS: In 83 male (ex-)workers [mean age 45 y (range: 24-64)] of a radiator factory using cadmium-containing solder, we investigated the association between urinary cadmium excretion (as an index of lifetime body-burden), bone mineral density (BMD) in distal forearm, hip and lumbar spine (by dual-energy photon absorptiometry) and urinary calcium excretion. RESULTS: Geometric mean urinary cadmium concentration was 1.02 microg/g creatinine (5(th)-95(th) percentile: 0.17-5.51). BMD was negatively correlated with urinary exposure to cadmium: the partial correlation coefficients (r) adjusted for age, body-mass index and current smoking were -0.30 (p = 0.008) for BMD in the forearm, -0.27 (p = 0.017) in the hip and -0.17 (p = 0.15) in the spine. Urinary calcium correlated positively (r = 0.23; p = 0.044) with the urinary cadmium excretion. Adjusted for the same covariates, the risk of osteoporosis (defined as a T-score below -2.5 in at least one measured bone site) increased dose-dependently. Compared with the lowest tertile of urinary cadmium, the risks were 4.8 and 9.9-fold higher in the middle and highest tertile, respectively. Only four (5%) men had evidence of renal tubular dysfunction (ss2-microglobuline >300 microg/g creatinine). CONCLUSIONS: Even in the absence of renal tubular dysfunction, occupational exposure to cadmium is associated in men with lower BMD, a higher risk of having osteoporosis and higher urinary calcium excretion, suggesting a direct osteotoxic effect of cadmium. (c) 2010 American Society for Bone and Mineral Research.