Spectrum of mineral bone disorder in patients with CKD stage 3-5 from eastern India

Abstract

Introduction:
 Chronic kidney disease mineral bone disorder (CKD-MBD) is a major determinant of CKD associated morbidity and morbidity. We sought to find the spectrum of CKD-MBD in Eastern India.
 Methodology:
 This cross-sectional study was conducted at the Department of Nephrology Institute of Postgraduate Medical Sciences and Research Seth Sukhlal Karnani Memorial hospital Kolkata India from June 2013 and July 2014. The patients with newly diagnosed stage 3-5 CKD were evaluated for bone mineral abnormalities. Patients already on some form of phosphate binders or vitamin D analogs were excluded.
 Results:
 Total of 242 patients was included. Male to female ratio was 2.1:1. 52.1% had Diabetic nephropathy. Mean eGFR was 26.51±12.33 ml/min/1.73m2. 36.8% had CKD stage 3, 46.7% CKD stage 4 and 16.5 % had CKD stage 5. 56% had hyperphosphatemia (Phosphate>4.0mg/dl). 30% had hypocalcaemia (corrected calcium <8.5mg/dl). 53.4% had Vit D deficiency (25-OH Vit D < 20ng/ml) and 64.9% had hyperparathyroidism (iPTH>65pg/ml). There was a significant negative correlation of eGFR with Phosphate, iPTH and ALP. The distribution of phosphate, ALP and iPTH across CKD stage 3-5 was significantly different; p-<0.001. 21.3% of patients with iPTH more than twice the upper limit of normal had normal ALP. There was no significant difference in serum calcium and 25-OH Vit D levels across CKD stage 3-5.
 Conclusions:
 CKD-MBD has a high prevalence. Secondary hyperparathyroidism is the most common type of CKD-MBD. 25-OH Vit D and serum calcium are determined predominantly by diet and exposure to sunlight. ALP can’t serve as a surrogate marker for iPTH.