CLINICAL AND BIOCHEMICAL STUDY OF FIBROBLAST GROWTH FACTOR 23 IN CHRONIC KIDNEY DISEASE

Understanding the contributory role of increased fibroblast growth factor23 (FGF23) and secondary hyperparathyroidism to changes in minerals and bone metabolism among chronic kidney disease (CKD) patients is a challenge. So the present study aimed to evaluate the role of FGF23 in CKD of various grades and potential utility for early diagnosis of disturbed bone and mineral metabolism among such patients. This hospital based-cross sectional study has been conducted on 100 CKD patients of various grades. Colorimetric assays of serum urea, creatinine, phosphorous and calcium, while, ELISA assays of parathormone hormone (PTH) and FGF23, were done to all included patients. The overall results showed frequent abnormally high serum FGF23 among CKD grade 3 and 4 compared to other grades. Also there was significant positive correlation between the serum FGF234 levels and the CKD grade (r=0.21, p = 0.03). Significant positive correlations between serum levels of FGF23 vs. both urea and PTH (r=0.19, p=0.04 and r= 0.31, p=0.002 respectively) with significant negative correlations between serum FGF23 levels vs. both total calcium and eGFR (r=-0.21, p=0.02 and r=- 0.39, p=0.0001 respectively). There were non-significant correlations between serum FGF23 and age, weight, height, BMI and phosphorous (p˃0.05). FGF23 is better negative than positive predictive biomarker for calcium and phosphorous disturbances in CKD patients at cut off point 2.9 and 3.1 pg/ml respectively. In conclusion, FGF23 is an emerging biomarker in CKD and its follow up measurement could be helpful for early diagnosis of CKD-MBD.