Effect of bisphosphonates on renal function in patients with osteoporosis

Abstract

The aim of this study was to analyze renal function and its long-term evolution in patients treated with bisphosphonates (BP) for osteoporosis. MethodsOne hundred patients (89F/11M) (mean age of 70±9 years) treated with BP for osteoporosis during at least 1 year were consecutively included. Renal function (evaluated by serum creatinine and Cockroft-Gault for estimation of creatinine clearance [CrCl] before and after treatment), and clinical data (presence of hypertension, diabetes and anti-inflammatory treatment) were recorded in all patients. Renal insufficiency was considered as CrCl<60ml/min and impaired renal function as a decrease of≥25% CrCl during treatment. ResultsThe mean treatment time with BP was 49±31 months. Thirty-nine percent of patients had CrCl<60 before starting BP and only three patients had creatinine≥1.4mg/dl. Patients with CrCl<60 were older (78±7 vs. 66±7, P<0.001) than patients with CrCl>60. In the whole group, there were no significant changes in renal function during BP treatment (baseline creatinine 0.91±0.2 vs. 0.89±0.3 post-treatment; CrCl baseline 66±20 vs. 66±23 post-treatment, P=ns). However, 10% of patients had renal function impairment independently of the type of BP treatment and comorbidities. Age was correlated with serum creatinine values (r=0.27, P=0.007) and the changes of creatinine (r=0.26, P=0.009) and CrCl values (r=–0.25, P=0.012). A CrCl<45ml/min was an independent predictor of renal function impairment. ConclusionsNearly 40% of patients treated for osteoporosis have renal insufficiency, a finding related to age. Although a significant decrease in CrCl was not observed in relation to BP treatment, 10% of patients showed impairment in renal function, suggesting the need to control CrCl in these patients.