Environmental cadmium exposure and forearm bone density

Abstract

Environmental exposure to cadmium may give rise to osteomalacia combined with renal dysfunction, so called 'Itai-Itai disease', which was endemic in the heavily polluted area in Japan. The main focus of this study was to investigate whether environmental exposure to cadmium is associated with low bone mass in a population living near a smelter. A total of 790 persons (302 males and 488 females), who were all over 35 years old and resided in areas near a lead, zinc and cadmium smelter and in a control area in southeast China, completed a questionnaire, and bone mineral density was measured by SPA-4 single photon absorptiometry at the radius and ulna. Cadmium content of urine was determined by graphite-furnace atomic absorption spectrophotometry as a measure of dose. The present study shows that forearm bone densities were negatively correlated with urinary cadmium excretion (p < 0.001) and forearm bone density decreased linearly with age (p < 0.001) and urinary cadmium (p < 0.01), suggesting a dose-effect relationship between cadmium dose and bone mineral density. Based on the World Health Organization criteria, (bone mineral density < -2.5 SDs below the normal young adult), the prevalence of osteoporosis in women increased from 34.0% in the control area to 51.9% in the heavily polluted area (p < 0.01) among subjects over 50 years old, and the odds ratio value was 2.09 (95% CI: 1.08-4.03) for the highly polluted area compared with the control area. A striking observation in the study was a marked increase of the prevalence of fracture in the cadmium-polluted area in both sexes. It was concluded that environmental exposure to cadmium is associated with an increased loss of bone mineral density in both gender, leading to osteoporosis and increased risk of fractures, especially in the elderly and in females.

Relationship between environmental exposure to cadmium and bone metabolism in a non-polluted area of Japan

“…We mainly investigated the relationships between cadmium-associated biomarkers and bone metabolic markers, as well as ultrasonic bone evaluation parameters, because previous studies reported that bone absorption was accelerated by cadmium intake. The other parameters will be investigated in a further study [31][32][33][34][35][36][37][38][39][40][41][42]. Correlation between two substances in urine was calculated from the original measured values, adjusted by age and logarithmic transformed creatinine, while correlations between substances in urine and other parameters were calculated from values in urine corrected by urinary creatinine adjusted by age [43].…”

“…Several population-based studies showed an association between osteoporosis and environmental cadmium exposure. Zhu and colleagues [39] investigated a population living in an area near a lead, zinc, and cadmium smelter and a population in a control area in southeast China. Forearm bone mineral densities of the participants were measured by SPA-4 single-photon absorptiometry.…”

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

“…Clinical features associated with osteoporosis include increased morbidity (ie, pain, physical impairment, and decreased quality of life), increased risk of new fractures, and increased mortality. (7) Studies among populations from Belgium, (4,8) Sweden, (9)(10)(11) Japan, (12) and China (13,14) showed associations between osteoporosis and low-level environmental cadmium exposure. The generally accepted interpretation has been that cadmiuminduced renal tubular damage (2) decreases the calcium reabsorption in the nephron, resulting in hypercalciuria (2) and low BMD and hence increased fracture risk, (4,11) particularly in postmenopausal women (4,8) or men in the older age group.…”

Effects of thirty elements on bone metabolism

“…Cadmium can cause renal tubular dysfunction, decrease bone mineral density, and cause hypercalciuria, all factors that can increase risk of fracture, osteomalacia, and osteoporosis [44][45][46][47][48][49]. Although cadmium toxicity affects both genders, elderly females are more susceptible than men, especially after menopauses [50][51][52][53].…”