Background: Recent post hoc analysis proved the efficacy and tolerability of risedronate in osteoporotic patients with renal impairment, but the combination of active vitamin D in chronic kidney disease (CKD) patients taking glucocorticoids remains unknown.
Methods: We conducted a prospective study enrolling 114 CKD patients (creatinine clearance > or =30 ml/min/1.73 m(2)) receiving glucocorticoid therapy for > or =6 months. Eighty-eight subjects who had received active vitamin D (aVD) were randomly assigned to either a group treated with aVD only (group A), or to a group also receiving risedronate 2.5 mg/day (group B). The remaining patients (group C) received risedronate only.
Results: After 1 year 100 subjects were analysed. Risedronate was effective on the lumbar spine, but not on the femoral neck. The lumbar bone mineral density (BMD) significantly increased by 2.8 and 2.5% in groups B and C, respectively, but decreased by 1.0% in group A. Serum N-terminal telopeptides of type I collagen (S-NTX) and bone alkaline phosphatase (ALP) fell significantly in groups B and C at 3 and 6 months, respectively, while in group A S-NTX remained unchanged and bone ALP significantly increased. There was no significant difference between groups B and C regarding BMD and bone markers. The reduction rate of S-NTX (bone ALP) at 6 months predicted the increase in lumbar BMD at 1 year with a sensitivity of 73% (34%) and a specificity of 46.2% (100%).
Conclusions: Risedronate is effective in increasing BMD with or without aVD in CKD patients receiving long-term glucocorticoid therapy. Bone markers are of some use in predicting the response to anti-resorptive therapy.