Evaluation of bone mineralization metabolism in children under renal replacement therapy

Bone disease is common in patients with end-stage renal disease and renal failure. In this study, we planned to show the relationship between the factors affecting bone mineral metabolism, medical treatments and biochemical markers used in renal transplantation, hemodialysis (HD) and peritoneal dialysis (PD) treatment. In our study, patients who were diagnosed as chronic renal failure between 1998 and 2018 in the Pediatric Nephrology Outpatient Clinic of Uludağ University Faculty of Medicine, Department of Pediatric Health and Diseases were included in the study and received renal transplantation, HD and PD. The causes of renal insufficiency, age at diagnosis, age at onset of treatment, sexes, drugs taken for treatment of bone mineral disorder, blood pressure values and percentiles, glucocorticoid use, presence of acidosis were recorded. Serum urea, creatinine, blood urea nitrogen (BUN), hemoglobin, hematocrit, calcium (Ca), phosphorus (P), albumin, cholesterol, triglyceride, alkaline phosphotase (ALP), parathormone (PTH) and vitamin D levels were recorded. We found that the acidosis rate decreased at 12 th month in the patients included in the study. There was a statistically significant decrease in hypertension between 0th and 12th months in renal transplant patients. Hemoglobin values were significantly lower in hemodialysis patients at 12th month compared to renal transplant patients. In our study, urea, creatinine and BUN were found to be significantly lower in the renal transplant group than in the HD and PD group at 12th month. Negative correlation of serum urea, BUN, creatinine levels with Ca and vitamin D was found statistically in renal transplant patients. A positive correlation was found between urea, BUN, creatinine and P and PTH. In our study, positive correlation was found between serum albumin, Ca and vitamin D and negative correlation between P and PTH in renal transplant patients. In PD patients, we found a positive correlation between serum albumin and Ca and a negative correlation between P. In our study, we found a negative correlation between Ca and ALP and PTH and a positive correlation with vitamin D in renal transplant patients. We found a positive correlation between P and PTH in PD patients. We found a significant decrease in P value in renal transplantation, HD and PD patients in the evaluation of 0th and 12th months. PTH levels were significantly lower in renal transplant patients compared to PD group at 12th month, whereas PTH levels were significantly lower in 3 groups when compared to 0th and 12th months. On average, we found PTH levels to be lower in patients receiving calcium-containing phosphate binders and calcitriol as a combined therapy, but we also found on average higher serum Ca and lower P values. In conclusion, we have shown correlations between other parameters of PTH, P, Ca and ALP, which are markers of chronic renal disease mineral bone disease and we think that all these parameters should be evaluated together and treatment should be considered as a whole for good bone health and growth. Key Words: Chronic kidney disease in children, bone mineral disease, PTH, calcium, renal osteodystrophy.