Influence of copper-zinc sulfide ores elements on bone tissue remodeling and regulative factors

Aim. Characterize the intensity of bone remodeling, balance of hormones and local cytokines regulating bone remodeling and bone metabolism, at chronic intake of copper-zinc sulfide ores elements.

Methods. A total of 101 miner, producing copper-zinc sulfide ore by underground mining, and 30 employees of ground services of OAO «Uchaly Mining and Processing Plant», were examined. Experimental studies were performed on 60 white adult male rats, distributed to control and experimental groups. The experimental animals of the study group got copper-zinc sulfide ore powder in a 2% starch solution daily for 3 months as a suspension at the dose of 60 mg per 100 g of body weight. The serum levels of testosterone, parathyroid hormone, total thyroxine and triiodothyronine, cortisol, 25-hydroxyvitamin D, soluble Receptor activator of nuclear factor kappa-B ligand, osteoprotegerin, sclerostin and C-terminal telopeptide of collagen type I, as well as bone alkaline phosphatase activity were determined.

Results. Miners who were diagnosed with decreased bone density had increased level of C-terminal telopeptide of collagen type I, with bone alkaline phosphatase activity similar to the control group. In miners with physiological level of bone density, there was no statistically significant decrease in blood testosterone level, in the groups with low and very low bone mineral density there was a statistically significant decrease in testosterone level and increased level of parathyroid hormone. Experimental animals exposed to sulfide ore had serum levels of testosterone, 25-hydroxyvitamin D, thyroxine and triiodothyronine decreased, and increased level of parathyroid hormone and cortisol. Together with that, blood concentration of sclerostin was increased, level of osteoprotegerin - decreased, and soluble Receptor activator of nuclear factor kappa-B ligand was not changed.

Conclusion. Long-term intake of copper-zinc sulfide ore leads to an imbalance of bone remodeling with a predominance of resorption. It is associated with the reduction of testosterone, calcidiol and thyroid hormones levels providing anabolic and anti-catabolic effect on bone metabolism, and overproduction of parathyroid hormone and cortisol, stimulating osteolysis. Receptor activator of nuclear factor kappa-B ligand / osteoprotegerin ratio and sclerostin level increases.