Hyperphosphatemia is frequently seen in patients with end-stage renal disease (ESRD). Hyperphosphatemia usually results in a high calcium-phosphorus product (CPP) which may subsequently lead to artery and become a risk factor of cardiovascular complications. Alendronate, due to its effect of inhibiting osteoclasts, is approved for treatment of osteoporosis. Previous reports found the use of bisphosphonates could suppress arterial calcification in hemodialysis dialysis patients. The aim of this study is to evaluate the safety and efficacy of alendronate to suppress coronary artery and aortic calcifications, as well as to improve bone density in chronic peritoneal dialysis (PD) patients.

This study will include ESRD patients who had received maintenance PD for more than 3 months, have high CPP level (≧55), and have chest X-ray proven aortic calcification or coronary artery calcification. All participants are randomly allocated to either group 1 or group 2. Group 1 patients receive alendronate 70 mg once weekly in the first 16 weeks, while group 2 patients receive the same dose of drug every week in the second 16 weeks. The extent of coronary artery and aortic calcification is evaluated by using multi-detector spiral computed tomography, whereas bone mineral density is measured by dual-energy X-ray absorptiometry. Both examinations are performed at week 0, 16 and 32 for each participant. Laboratory studies and possible adverse reactions were regularly monitored.

We expect that alendronate can alleviate the progression of arterial calcification or even improve it. Bone density may also be improved after treatment. Besides, we wish to find the independent factor(s) influencing the efficacy of alendronate. These results may help clinical physicians for early intervention and prevention of cardiovascular complications in ESRD patients.