Intact Parathyroid Hormone (iPTH) Assay: An Early Approach for Bone Health Assessment in Chronic Renal Failure

Background: Chronic kidney disease (CKD) is a global public health burden with significantly increasing mortality. Chronic kidney disease leads to various complications, including anemia, cardiovascular complications, salt and water retention, metabolic acidosis, electrolyte disorders, and chronic kidney disease-mineral and bone disorder (CKD-MBD), amongst which CKD-MBD is a particularly important complication that develops early.

Materials and methods: In the present study, various biochemical analytes were assessed for their significance in monitoring the CKD-MBD in different stages of CKD. Only biochemistry markers were assessed in the present study, as X-rays and other radiological markers give positive results in the very late stages of CKD.

Results: The level of intact parathyroid hormone (iPTH) was raised or highly normal from the very early stages of chronic renal failure (CRF), and the differences in progressive stages were highly significant p<0.05. The correlation of iPTH with different biochemistry test parameters of CRF, such as creatinine, estimated glomerular filtration rate (eGFR), vitamin D, calcium, and inorganic phosphate, was also checked to determine its efficacy in the detection of CKD-MBD and, consequently, in preventing the complication of CKD. Parathyroid hormone (PTH) showed a significant positive correlation with creatinine in Stages 4 and 5 (p<0.05 in both stages). It was also observed that with the increase in the PTH level, there was a decrease in the estimated glomerular filtration rate in both Stage 4 and 5 patients.

Conclusion: The level of iPTH was significantly increased from Stage 2 onwards; hence, it can be used as a diagnostic marker of CKD-MBD from the initial stages. Subsequent to diagnosis, the progression of CKD-MBD can be prevented by choosing the appropriate intervention from the wide array of treatment options available.