Bone Metabolism and Turnover Rates in Diabetic Kidney Disease- A Cross-Sectional Observational Study

Abstract

BACKGROUNDWith the increasing trend in the diabetic population and the diabetic nephropathy, it is necessary for us to look into the bone metabolism in the diabetics with CKD. This study aims to describe the bone metabolism and the bone turnover rates in diabetic kidney disease and to see if there is a difference between diabetic and non-diabetic CKD in the bone turnover rates. MATERIALS AND METHODSWe did a cross-sectional observational study between January and June 2016 at the Govt. Kilpauk Medical College with 90 CKD patients. Of them 44 were diabetics with a mean age of 56.18 +/-8.88 and 46 were non-diabetics with a mean age of 52.19 +/-14.55. Patients were analysed for various biochemical parameters. The data were analysed using SPSS (Statistical Package for Social Sciences) ver 16.01. RESULTS82% of our diabetic CKD patients have diabetic retinopathy. Diabetic retinopathy is not associated with abnormalities in bone turnover (odds ratio= 1). For the diabetic CKD (n= 44), the prevalence of hypoparathyroidism is 4.5%, hyperparathyroidism is 59%, hyperparathyroidism more than twice the upper limit of normal is 36.36%, hypocalcaemia is 15.9%, hypercalcaemia is 4.5%, hypophosphataemia is 20.45% and vitamin D deficiency is 95.45%. The most common bone turnover abnormality observed in diabetics in our study is the mixed turnover state (30%) followed by osteomalacia (21%), whereas in non-diabetics, high turnover state (26%) is the most common abnormality, but there is no statistically significant difference between the two (p= 0.81). Low turnover state in diabetics and non-diabetics in our study are 7% and 9% respectively. CONCLUSIONThus, we conclude that a mixed bone turnover state followed by osteomalacia is commoner in diabetic CKD than other patterns. Diabetic retinopathy is not predictive of the bone turnover state. Diabetic and non-diabetic CKD need not be considered as separate entities as far as bone metabolism is considered.