INCREASED BONE-RESORPTION DURING THE FIRST-YEAR AFTER STROKE

Background and Purpose-Significant bone mineral density (BMD) reductio n occurs in stroke patients on the hemiplegic side compared with the i ntact side, To elucidate the pathogenesis of hip fractures in this pop ulation, we measured serum markers of bone metabolism and BMD in the s troke patients within 1 year (early group) and between 1 and 2 years a fter onset of hemiplegia (long-term group). Methods-Sera were collecte d from 51 patients from the early group and 93 patients from the long- term group. All patients had hemiplegia. Sera were assayed for pyridin oline cross-linked carboxy-terminal telopeptide of type I collagen (IC TP; a bone resorption marker) and bone Gla protein (a bone formation m arker). The z score of BMD was determined in both second metacarpals. Results-Serum ICTP concentrations (ng/mL) were higher in the early gro up (15.4+/-4.1) than in the long-term group (6.7+/-4.4). Bone Gla prot ein was normal or low in both groups. Multiple regression analysis ide ntified Barthel Index, degree of hemiplegia, and illness duration as i ndependent determinants of ICTP in the early group, whereas Barthel In dex, degree of hemiplegia, and serum calcium were determinants of ICTP in the long-term group. There were statistically significant correlat ions between the z score of the hemiplegic side and age, Barthel Index , degree of hemiplegia, illness duration, 25-hydroxyvitamin D (25-OHD) , and ICTP in the early group and between the z score and degree of he miplegia and 25-OHD level in the long-term group. Conclusions-The path ogenesis of reduced BMD differed between the early and long-term strok e groups. These results suggest that in the early group, increased bon e resorption caused by immobilization was responsible for osteopenia o n the hemiplegic side, whereas the degree of hemiplegia and 25-OHD lev el were the determinants of osteopenia in the long-term group.