Nonspecific hyperamylasemia and hyperlipasemia in diabetic ketoacidosis: incidence and correlation with biochemical abnormalities.

OBJECTIVES: Amylase and lipase estimations are the standard tests to diagnose acute pancreatitis (AP). Elevation of amylase and lipase < or = 3 times normal may be nonspecific, but elevation of either one > 3 times normal is reported to be diagnostic of AP. The aim of this study was to evaluate the incidence and magnitude of nonspecific elevations of amylase and lipase in diabetic ketoacidosis (DKA) and to correlate their elevation with known metabolic derangements of DKA.

METHODS: A total of 150 consecutive episodes of DKA in 135 patients were evaluated for serum amylase, lipase, and biochemical markers of DKA on admission and 24 h later. Patients were divided according to the following: 1) Clearly nonspecific amylase elevation (CNSA): Amylase elevation < 3 times normal plus normal or < 3 times lipase; 2) Clearly nonspecific lipase elevation (CNSL): Lipase elevation < 3 times normal plus normal or < 3 times amylase; and 3) Probably nonspecific amylase or lipase elevation (PNSA or PNSL): > 3 times elevation of amylase or lipase or both with normal abdominal CT.

RESULTS: Elevated amylase and lipase levels ranged from 111 to 1257 IU/L (normal 30-110 IU/L) and 25-529 IU/dl (normal < 24 IU/dl) (CT-proven AP = 16, excluded). Nonspecific amylase elevation (CNSA + PNSA) = 25 (16.6%) cases, CNSA in 10 (6.6% of all DKA or 27% of amylase elevations), and PNSA in 15 (10% of all DKA or 41% of amylase elevations). Nonspecific lipase elevation (CNSL + PNSL) = 36 (24%), CNSL in 23 (15.3% of all DKA or 47% of all lipase elevations), and PNSL in 13 (8.7% of all DKA or 26.5% of all lipase elevations). Multiple regression analyses showed significant correlation of pH and serum osmolality with amylase elevation. Lipase elevation showed positive correlation with serum osmolality alone.

CONCLUSIONS: In DKA nonspecific elevations of amylase and lipase occur in 16-25% of cases. Amylase elevation is correlated with pH and serum osmolality, but lipase elevation is correlated with serum osmolality alone. Diagnosis of AP based soley on elevated amylase or lipase, even > 3 times normal, is not justifiable.