Secondary hyperparathyroidism and risk factors in patients undergoing peritoneal dialysis in a tertiary hospital

Secondary hyperparathyroidism (SHPT) can lead to significant morbidity, mortality, and additional healthcare resource utilization in chronic kidney disease. Since the introduction of continuous ambulatory peritoneal dialysis (CAPD) policy for end stage renal disease patients in Thailand, no large studies have been conducted to examine parathyroid dysfunction in these patients. The baseline prevalence data are highly required. The present study was conducted to determine the prevalence of SHPT and the risk factors associated with this dysfunction in CAPD patients.

The authors analyzed data of 173 patients who received CAPD at a single center between October 2008 and October 2010. Clinical data and laboratory variables related to parathyroid function were obtained from each patient. Hyperparathyroidism was diagnosed when serum intact parathyroid hormone (iPTH) level was above 300 pg/ml. Variables predicting the development of hyperparathyroidism were calculated by univariate and multivariate logistic regression analysis.

Hyperparathyroidism was identified in 29.48% of the CAPD patients. Significantly lower serum calcium levels (p = 0.037), significantly higher serum phosphate levels (p = 0.016) and significantly greater serum alkaline phosphatase concentrations (p = 0.029) were observed in the patients with hyperparathyroidism. By multiple regression analysis, the duration on CAPD showed a significant positive correlation with iPTH (r = 0.359, p < 0.01) while the total corrected Ca levels had a significant negative correlation with iPTH (r = -0.176, p = 0.023).

There is a high prevalence of hyperparathyroidism in the current Thai CAPD population. Duration on CAPD and hypocalcemia are independent risk factors for the development of hyperparathyroidism.