Prevalence of CKD-MBD in pre-dialysis patients using biochemical markers in Enugu, South-East Nigeria

Background: As kidney function declines, there is a progressive deterioration in mineral homeostasis with disruption of normal serum and tissue concentration of phosphorus and calcium, and changes in circulating levels of hormones-parathyroid hormone (PTH), calcitriol (1,25(OH)² D), and Fibroblast growth factor-23 (FGF-23).
Objective: This study was aimed at determining the prevalence of markers of CKD-MBD in pre-dialysis patients.
Methods: We evaluated consecutively 168 subjects made up of 85 CKD patients and 83 healthy controls, who were attending the renal clinics and medical outpatient of University of Nigeria Teaching Hospital, Enugu. GFR was estimated and serum calcium, phosphorus, alkaline phosphatase, PTH, and 25(OH) D levels assayed.
Results: The prevalence of various mineral bone disease abnormalities were 70% hyper-phosphatemia, 85% hyper-parathyroidism, and 100% low levels of 25 (OH) D among the patients. Estimated GFR correlated negatively with both serum phosphorus, and PTH. Age of the patients ranged from18-76 years with a male to female ratio of 1.7:1. Chronic Glomerulonephritis (CGN), hypertension and diabetes mellitus caused CKD in 75% of the patients. There was no significant decrease in serum calcium levels of patients compared to controls. The patients did not have pathologically raised alkaline phosphatase, although their mean level was significantly higher than that of the control group.
Conclusion: Low 25 (OH) D levels (insufficiency/deficiency), hyperparathyroidism, and hyper-phosphatemia were the obvious markers of CKD-MBD in our pre-dialysis patients. These should be evaluated at presentation in these patients.