A study on WHO Frax score to predict fracture risk in predialysis patients of chronic kidney disease

Abstract

Background: Disturbances in mineral and bone metabolism are prevalent in chronic kidney disease (CKD) and are an important cause of morbidity and decreased quality of life. These disturbances include renal osteodystrophy and CKD-Mineral and Bone Disorder (CKD-MBD). The Frax tool developed by WHO is an attempt to better estimate the fracture risk. It calculates a 10 year probability of osteoporotic fractures of spine, forearm, hip or shoulder based on clinical risk factors with or without BMD measurements.Methods: It is a Cross sectional observational study which was done from 01 November 2013 to 31 March 2015. The study group included 60 cases of pre dialysis Chronic Kidney Disease attending OPD, Emergency or admitted in medicine wards of Dr. RML Hospital, New Delhi. Bone mineral density measured by dual-energy X-ray absorptiometry and all patients were classified according to World Health Organization criteria. DEXA SCAN (manufacturer-Hologic INC.) was done of the lumbar spine, radius bone and neck of the femur. Frax score was calculated as per WHO guidelines.Results: On using the Indian Frax calculator the average 10 year probability for major osteoporotic fractures in stage 4 (9.47±2.62%) was found to be significantly higher (p<0.0001) than that in stage 3 (1.92±0.8%).Similarly, the average 10 year probability for hip fracture in stage 4 (4.61±1.45%) was also found to be significantly higher (p< 0.0001) than that in the stage 3 (0.75±0.49%).Conclusions: The study confirmed the high incidence of low BMD in patients of CKD. The 10 year fracture risk in these patients as predicted by Frax score was significantly higher in CKD patients irrespective of whether the Chinese or the Indian calculator was used.