Influence of haemodialysis on lipase activity.

Our aim was to determine whether the increase in serum pancreatic lipase values, reported in patients with chronic renal failure maintained on haemodialysis, is the result of haemoconcentration by fluid removal during dialysis, or whether it is due to lipase stimulation by endothelial lipoprotein lipase, induced by the heparin used as an anticoagulant. We therefore compared the increases in serum lipase, when heparin was used, with those observed when this was replaced by the antithrombotic agent, defibrotide, which has no effect on lipoprotein lipase. In addition, in order to determine the effects of haemoconcentration, variations in total protein concentration and haematocrit values were determined on the same samples, both before and after dialysis. The results showed a statistically significant post-dialysis increase in lipase only when heparin was used (p < 0.03). There was also a mean percentage post-dialysis increase of 16.2% in total protein (p < 0.0001) and 15.5% in haematocrit (p < 0.0001), due to fluid removal. No significant correlation in percentage increases was found between lipase vs total protein or haematocrit values. These findings suggest that heparin-induced lipoprotein lipase stimulation is the principal cause of the post-dialysis increase in pancreatic lipase, and that fluid removal during dialysis makes only a minor contribution to this increase.