Changes of bone and mineral metabolism in patients with hyperthyroidism before and after treatment

Objective: To investigate the changes of bone and mineral metabolism in patients with hyperthyroidism before and after treatment.

Methods: Enzyme linked immunosorbent assay was used to measure bone-specific alkaline phosphatase (BAP) and deoxypyridinoline (DPD); radioimmunoassay to to measure serum calcitonin (CT), parathyroid hormone (PTH-M), bone GLA protein (BGP) and other markers related to bone metabolism; dual energy X-ray absorptiometry to measure bone mineral density (BMD) of spine(L2-4) and femur(Neck, Troch, Ward's) in 45 patients with hyperthyroidism before and after treatment and 58 healthy volunteers.

Results: The urinary DPD level was elevated by 527% in patients with hyperthyroidism before treatment. Compared to controls the serum ALP, BAP, BGP elevated by 62%, 146%, 87% (P < 0.001), BMD decreased to various extent, and women L2-4, Ward's were marked (P < 0.05). The results after treatment and before treatment showed that urinary DPD decreased by 79%; serum ALP, BAP, BGP decreased by 19.5%, 24.7%, 27.5% respectively (P < 0.001, 0.05, 0.05, > 0.05). All sites BMD increased, and women Troch sites were marked (P < 0.05). The correlation analysis showed that the urinary DPD was positively correlated with serum BGP(r = 0.349 P < 0.05). FT4 was positively correlated with BAP, ALP and DPD respectively) (r = 0.353, P < 0.05, r = 0.294 P = 0.05, r = 0.426 P < 0.01).

Conclusions: Hyperthyroidism bone disease is caused by excessive serum thyroid hormone that speeds up bone turnover and marked bone absorption compared to bone formation.