Status of Serum Calcium, Phosphate and Intact Parathyroid Hormone in Predialysis Chronic Kidney Disease Patients of Stage-3 to Stage-5 Compared To KDOQI Guideline.

The chronic kidney disease (CKD) is associated with a variety of bone disorders and disorders of calcium and phosphorus metabolism. Bone disease associated with chronic kidney disease having higher rate of CKD progression and increased risk of death. To see the status of serum calcium, phosphate and intact parathyroid hormone in pre-dialysis CKD (stage- 3 to 5) patients. This was a across sectional study done in outpatient department of Nephrology of National Institute of Kidney Diseases and Urology, Dhaka, between 1st June 2012 to 31st May 2013. The patients of CKD stage 3, 4 and 5 yet not on dialysis attending out patients department of Nephrology, NIKDU by using MDRD-4 equation according to K/DOQI guidelines and reviewing previous medical records and investigation reports were enrolled in this study. There after serum calcium (corrected for serum albumin), phosphate and iPTH levels were measured and compared with the recommended target ranges in K/DOQI guideline. The number of patients with serum levels according to K/DOQI guidelines for different stages CKD(3,4,5) were as follows: serum calcium: 56.6, 58.5 and 76.7; serum phosphate: 55.2, 58.5 and 56.7; iPTH 37.9, 12.2 and 36.7 and Ca x P product 100.0, 97.6 and 86.7, respectively. The percentages of patients (who received drug) with serum calcium levels within according to K/DOQI guidelines for stages 3, 4 and 5 were as follows: serum calcium: 63.2%, 64.7% and 83.3%; respectively, serum phosphate: 63.2%, 61.8% and 66.7%; respectively, iPTH 42.1%, 14.7% and 4.7% and Ca x P product 100.0%, 100.0% and 87.5%, respectively. On the other hand patients who didn't receive drug the percentages of patients with serum calcium levels according to K/DOQI guidelines for CKD stages 3, 4 and 5 were as follows: serum calcium: 50.0%, 28.6% and 50.0%; respectively, serum phosphate: 40.0%, 42.9% and 16.7%; respectively, iPTH 30.0%, 14.7% and 16.7% and Ca x P product 100.0%, 85.7% and 83.3%, respectively. The patients achieving the four recommendations of K/DOQI guidelines was 4(13.8%) in stage-3, 3(7.3%) in stage-4 and 5(16.7%) in stage-5. More than half of the pre-dialysis patients of CKD were within target range of serum calcium and phosphate recommended in K/DOQI guideline and this proportion was more in those who were taking both phosphate binder and Vit-D. Ca x P was within target range in almost all patients so it may not be an important parameter for therapeutic decision making. However majority of the patients were out of target range of iPTH even though having normal serum calcium and phosphate level. So emphasis should be given in monitoring of iPTH level in early stages of CKD.