MP379RISK FACTORS OF HIP FRACTURES IN CHRONIC KIDNEY DISEASE PATIENTS

Abstract

Introduction and Aims: In theWesternWorld the general population is getting older. This implies a higher prevalence of osteoporosis as well as a greater incidence of patients with chronic kidney disease. These two conditions increase the risk of bone fractures. Metabolic and hormonal disarrangement in end-stage renal disease (ESRD) negatively affects bone remodeling as it promotes a decrease in Vitamin D availability, hyperphosphatemia, hypocalcemia, high secretion of parathormone and chronic metabolic acidosis. The NHANES III showed that even moderate-to-severe CKD patients may present with a significant increased risk of fracture which is justified by hyperparathyroidism at the early stages of the disease. Methods: In this study, we analyzed the risk factors of hip fractures in a population of pre-dialysis CKD patients. In an observational study, we included 300 patients of our pre-dialysis clinic, followed between 2005 and 2013. We used descriptive statistics, and univariate and multivariate logistic regression in order to identify risk factors of hip fractures and the receiver operating characteristic (ROC) curves were drawn to determine a cut point for the serum levels of 25(OH)2D3 and phosphorus for predicting hip fractures. Results: The mean age of our patients was 69.38 years, the mean eGFR (MDRD) was 20.40 ml/min, 60% (180) were female and 12,6% (38) had hip fractures. In a multivariate logistic regression model adjusted to age, gender, Diabetes Mellitus, Charlson comorbidity index, eGFR, calcium, phosphorus, PTH, 25 OHD, osteocalcin and albumin, we found that 25(OH)2D3 (OR= 0.584, 95% CI, 0.468 to 0.728 p=0.0001), phosphorus (OR= 3.125, 95% CI, 1.333 to 3.262, p=0.009) and eGFR (OR=0.767,95% CI, 0.309 to 0.927 p=0.022) were independent risk factors of hip fractures. ROC curve analysis showed that 25(OH)2D3 (AUC=0.864 , P<0.001) and phosphorus (AUC= 0.762, p= 0.012), are de predictors of hip fractures in patients with chronic kidney disease on pre- dialysis. The mean cut-off value obtained for 25 (OH)2D3 was 17 ng /mL and for phosphorus the mean cut-off value was 4.1 mg/dL. Conclusions: In our study, bone mineral disease and kidney disease are risk factors for hip fractures independent of age, gender and comorbidities.