Hypercalcemia Causes More Severe Acute Pancreatitis: An International Multicenter Cohort Study.

: Hypercalcemia is a rare etiology of acute pancreatitis; only a few cases have been reported in the literature, and the severity of hypercalcemia-induced AP is unknown. We aimed to assess the occurrence and severity of hypercalcemia-induced AP and compare it with the clinical characteristics of AP caused by other etiological factors. : We collected data from patients from the Hungarian Acute Pancreatitis Registry who had AP, a serum calcium level above 2.6 mmol/L, and no other AP etiology. AP patients with etiologies other than hypercalcemia served as control. : A total of 1.20% of our AP patients (16/1328) had a clear hypercalcemic etiology, 5.05% (67/1328) had a mixed etiology, and 1245 patients were in the control group. Severe AP, organ failure, and renal failure were significantly more common in patients with hypercalcemia-induced AP than in the control or the mixed etiology groups. Heart failure was significantly more frequent in the clear hypercalcemia-induced group than in patients with normal serum calcium AP. Respiratory failure was significantly more common in the clear hypercalcemia-induced AP group than in the mixed etiology-induced group. There was no significant difference in other analyzed parameters. The outcome of AP was not associated with the severity of hypercalcemia within the hypercalcemic group. : Compared with AP of different etiologies, hypercalcemia-induced AP is more likely to develop into severe AP and organ failure (heart and kidneys).