Bone turnover in hyperthyroidism before and after thyrostatic management

Hyperthyroidism is associated with enhanced osteoblastic and osteoclastic a ctivity, and patients frequently have low bone mineral density and high bon e turnover. The aim of this study was to examine the bone formation and res orption markers trend in 12 female patients, before and after normalization of thyroid activity. The following measurements were made at baseline and 1 and 6 months after hormone normalization induced by methimazole treatment : total alkaline phosphatase (ALP), bone alkaline phosphatase (BALP), colla gen type C-terminal propeptide (PICP), osteocalcin (BGP), telopeptide (ICTP ), urinary-hydroxyproline/urinary creatinine (uOHP/uCreat), urinary calcium /urinary creatinine (uCa/uCreat) and deoxypyridinoline crosslinks (D-Pyr). Compared with controls, all of these parameters were significantly increase d (ALP p=0.014; BALP p=0.0001; PICP p=0.013; BGP p=0.009; ICTP p=0.0001; uO HP/uCreat p=0.002; uCa/uCreat p=0.044; crosslinks p=0.0001). After treatmen t the values of ALP, BALP and PICP in hyperthyroid patients showed an initi al slight increase and then a significant downwards trend (ALP p=0.008, BAP p=0.001, PICP p=0.026). furthermore, resorption markers showed a significa nt decrease (uOHP/uCreat p<0.005 and D-Pyr p<0.008). As regards lumbar BMD patients, measurements were significantly reduced in comparison with the co ntrol group (p=0.005). Six months after serum thyroid hormones level normal ization, we observed a significant increase (p=0.014 vs baseline). Both neo formation and resorption markers are useful to assess pathological bone tur nover and bone involvement in hyperthyroidism. They could also be employed to monitor the effect of antithyroid treatment on bone and to indicate if b one antiresorption therapy should be considered. (C) 2000, Editrice Kurtis.