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Renal hyperparathyroidism, a CKD complication, is associated with increased parathyroid hormone levels from calcium, phosphate, and Vitamin D imbalances. It is 12-54% prevalent worldwide and associated with significant mortality and morbidity. This study aimed to determine the local prevalence and the factors associated with it among dialysis patients.
A cross-sectional study was conducted wherein all ESRD patients aged 19-75 years old and on maintenance dialysis >3months were included. The mean intact parathyroid hormone (iPTH), Vitamin D, ionized calcium, phosphorus and alkaline phosphatase were recorded. Correlation of age, gender, pre-dialysis co-morbidities, dialysis vintage and frequency were determined using spearman rank correlation coefficient, chi-square test and regression analysis.
A total of 240 chronic dialysis patients in our unit were identified. Out of the 240 patients, 168 patients were included. There were 147 patients with elevated iPTH, giving an 87.5% prevalence. Age was negatively correlated with iPTH (r=-0.212, p=0.006, 95%CI-0.352,-0.062) and as they age, their iPTH is predicted to decrease by 15.195pg/mL (p=<0.01). Dialysis vintage had positive correlation with iPTH (r=0.369, p=<0.01, 95%CI0.227,0.512) and the longer they were on dialysis, their predicted iPTH will be higher by 93.637pg/mL (p=<0.01). Dialysis frequency was positively correlated with iPTH (r=0.19, p=0.016, 95%CI 0.036,0.344) and the more frequent their sessions were, their predicted iPTH will increase by 353.508 pg/mL (p=<0.012). Three pre-dialysis co-morbidities showed positive correlation with iPTH and their presence can increase the iPTH significantly {hypertensive nephrosclerosis: x2=9.44; p=0.024, diabetic kidney disease: x2=19; p=<0.01, chronic glomerulonephritis: x2=12.680; p=<0.01}.
The 87% prevalence rate supported the high prevalence world-wide. Factors identified were age, presence of pre-dialysis co-morbidities, longer dialysis vintage, and frequent dialysis sessions (3x a week). Shorter dialysis interval stimulates parathyroid gland from increased blood flow triggered during dialysis and altered calcium handling by the kidneys, subsequently leading to hormone secretion.