Background and Objective: Chronic kidney disease is associated with an increased risk of fragility fractures. A retrospective study was conducted to compare outcomes after 3 years of alendronate treatment in postmenopausal osteoporotic Japanese women with or without renal dysfunction (RD).
Methods: One hundred and thirty-five postmenopausal osteoporotic Japanese women (mean age at baseline: 68 years) who had been treated with alendronate in our outpatient clinic for more than 3 years were analysed. The lumbar spine bone mineral density (BMD) of patients was measured using dual energy x-ray absorptiometry, and urinary levels of cross-linked N-terminal telopeptides of type I collagen (NTX) and serum levels of alkaline phosphatase (ALP) were monitored during the 3-year treatment period. The incidence of osteoporotic fractures was also assessed.
Results: Twenty-six women had RD with an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2. The urinary NTX and serum ALP levels significantly decreased and the lumbar spine BMD significantly increased, compared with the baseline values, in a manner that was similar among women with or without RD. However, the incidence of non-vertebral fractures, but not that of vertebral fractures, was significantly higher among women with RD than among women without RD.
Conclusions: Alendronate treatment appeared to have a similar effect on surrogate markers in postmenopausal osteoporotic Japanese women with or without RD. However, further studies are needed to confirm that RD may increase the risk of non-vertebral fractures in patients treated with alendronate.