[Effect of calcitriol on secondary hyperparathyroidism]

To investigate the calcium-phosphate metabolic condition in maintenance hemodialysis patients with chronic kidney disease (CKD), and to observe the effect of large dose calcitriol on secondary hyperparathyroidism (SHPT).

We tested and compared the serum levels of calcium, phosphate, intact parathyroid hormone (iPTH), and alkaline phosphatase (AKP) in hemodialysis patients at different hemodialysis time (Group A with hemodialysis period ≤3 years and Group B with hemodialysis period >3 years). We also detected those indexes before and after treating SHPT with large dose calcitriol. Twenty SHPT patients were divided into Group I (enlargement of parathyroid gland or nodule detected by color Doppler ultrasound) and Group II (normal parathyroid gland detected by color Doppler ultrasound).

In the maintenance hemodialysis patients, the serum phosphate was (2.11±0.38) mmol/L and iPTH was (581.11±487.75) pg/mL. The serum level of iPTH in Group B was higher than that in Group A [(828.13±690.39) pg/mL vs (477.94±324.73) pg/mL, P<0.001]. In Group I, the serum level of iPTH [before vs after: (2471.7±898.3) pg/mL vs (2510.4±825.7) pg/mL] and AKP [before vs after: (524.2±18.8)U/L vs (511.3±19.3)U/L] did not change after the treatment of large dose calcitriol (P>0.05). In Group II, the serum level of iPTH [before vs after: (1358.5±302.8) pg/mL vs (369.3±43.4) pg/mL, P<0.001] and AKP [before vs after: (565.9±23.9)U/L vs (234.8±21.1)U/L, P<0.001] decreased significantly after the treatment of large dose calcitriol.

Patients with longer time of hemodialysis have a higher level of iPTH. Large dose calcitriol can improve the clinical syndrome of SHPT, and decrease the level of iPTH and AKP in SHPT patients with normal parathyroid gland.