Relationship between Bone Turnover and Bone Density at the Proximal Femur in Stroke Patients

Abstract

To investigate the relationship between the rate of bone turnover and bone loss at the proximal femur in stroke patients. This study was performed between January 1, 2005 and August 31, 2006 at the Stroke Rehabilitation Unit, Istanbul Physical Medicine and Rehabilitation Training Hospital, Istanbul, Turkey. One hundred six patients who had a stroke for the first time were included in the study. The control group consisted of 33 age- and gender-matched healthy subjects. Bone mineral density (BMD) was measured at the proximal hip region by dual energy X-ray absorptiometry (DXA). Serum osteocalcin (OC) and C telopeptide of type 1 collagen (CTX) levels were measured. Barthel Index (BI) was used for the evaluation of daily activities. Ambulation status of the patients was recorded. Mean age was 65.1 +/- 9.8 years in the patient group and 51% were male. Mean disease duration was 16.9 +/- 9.1 months. Mean BI score was 60.5 +/- 25.8 on admission. Femoral neck BMD values were 0.873 +/- 0.95 g/cm(2) and 0.816 +/- 0.180 g/cm(2) for control subjects and hemiplegic sides of the patient group, respectively. Femur total BMD values were 0.948 +/- 0.119 g/cm(2) and 0.872 +/- 0.187 g/cm(2) for control group and hemiplegic sides of the patients, respectively. Femoral neck and femur total BMD values in the hemiplegic side were lower than those of controls' (P < .05). There was no statistically significant difference between the proximal femur BMD values of the intact and hemiplegic sides. Negative correlation was found between the proximal femur BMD values of both the intact and hemiplegic sides, and serum OC and CTX levels. Bone resorption rate was higher among the patients with stroke; however, bone formation rate was normal in this group. Serum CTX levels showed correlation with ambulation status. Femoral neck BMD values on the intact side were lower in the patient group with disease duration of more than 1 year compared to those with shorter disease duration. As a result of this study bone turnover was inversely correlated with bone density at the hip of both hemiplegic and intact sides in stroke patients. Evaluation of bone turnover might be helpful to predict bone loss and to find out the stroke patients with bone loss who can not be decided to begin antiresorptive treatment with bone density measurement.