Pancreatic enzymes in patients with end-stage renal disease maintained on hemodialysis

We determined serum levels of total amylase, amylase isoenzymes, and lipase in a group of 34 asymptomatic patients with end-stage renal disease (ESRD) before and after hemodialysis. In addition, one ESRD patient was studied during an episode of acute pancreatitis. We also determined amylase activity in the saliva. The results were compared with those obtained in a group of 19 normal individuals. Predialysis serum total amylase activity in the 34 asymptomatic ESRD patients was significantly greater than that found in the control group, and remained unchanged after hemodialysis. Serum lipase activity in the 34 asymptomatic ESRD patients was significantly increased before hemodialysis, and rose further after hemodialysis. The observed rise in serum lipase activity correlated with the cumulative dose of heparin given during dialysis. None of the 34 asymptomatic ESRD patients showed a discernible P3 isoamylase band, despite elevation of serum total amylase level. In contrast, the patient with acute pancreatitis exhibited a marked rise in serum P3 isoamylase (14-17%), along with a marked and transient rise in serum total amylase and lipase above their elevated baseline values. Interestingly, the amylase content of saliva in the ESRD patients was significantly lower than that found in the control group. In conclusion, ESRD patients exhibit a marked elevation of serum amylase and lipase levels in the absence of clinical pancreatitis. The observed hyperamylasemia is not associated with increased P3 isoamylase level unless pancreatitis is present. Furthermore, serum lipase rises with hemodialysis, presumably because of the lipolytic effect of heparin used during this procedure. Accordingly, serum sample for lipase determination should be obtained before dialysis.