A new significant and independent risk factor for falls in elderly men and women: a low creatinine clearance of less than 65 ml/min

Objectives: Because impaired renal function is detrimental for the conversion of calcidiol to calcitriol (D-hormone) and since D-hormone analogues have been shown to decrease the risk of falls, we investigated whether creatinine clearance (CrCl) is associated with the number of fallers and falls in elderly men and women. Methods: Within a randomized controlled study, we observed for 36 weeks 186 placebo-treated community-dwelling elderly men and women over 70, in an attempt to determine the influence of baseline CrCl on calcitropic hormone serum levels, as well as the influence of baseline CrCl on the number of fallers and falls over time. With the help of questionnaires, we regularly assessed fall incidence and frequency. The risk of falls and the risk of becoming a faller were assessed in multivariate-controlled logistic regression models according to a cutoff value of the CrCl set at 65 ml/min. Results: At baseline, serum levels of 1.25(OH)₂D₃ and iPTH were, in multivariate-controlled analyses, significantly associated with CrCl (p<0.0001, p=0.001, respectively), whereas serum levels of 25(OH)D₃ were not associated with CrCl. Below a CrCl of 65 ml/min, 1.25(OH)₂D₃ serum levels steadily declined. We therefore chose a CrCl of 65 ml/min as cutoff for further analyses. During the 36 weeks of observation, elderly people with a CrCl of <65 ml/min had, in multivariate controlled analyses, compared with elderly with a CrCl of ≥65 ml/min, a significantly higher incidence of number of fallers (25/70 vs 21/116; OR=4.01; 95% CI, 1.48–10.98; p=0.006), and a significantly higher incidence of falls (28/70 vs 23/116; OR=3.68; 95% CI, 1.38–9.82; p=0.009). Conclusions: For the first time we showed that in a community-dwelling population of elderly men and women, a CrCl of less than 65 ml/min is a significant and independent risk factor for fallers and falls.