Serum pseudocholinesterase and ceruloplasmin in various types of hyperlipoproteinemia.

Starting from previous observations emphasizing an increased pseudocholinesterase (PCE) activity in obese and hyperlipemic subjects, the behaviour of this enzyme and of ceruloplasmin was studied in connection with changes of serum lipids and lipoproteins in various types of hyperlipoproteinemia. When compared to values detected in 67 middle-aged normal weight normolipemic subjects, PCE activity was found to be significantly greater (smaller than 0.001) in the 49 overweight subjects without obvious hyperlipemia but presenting a moderate increase of the prebeta electrophoretic fraction. PCE activity was much higher in lean or overweight subjects with endogenous hypertriglyceridemia (68 patients with type IV and 86 patients with mixed hyperlipemia). The slight increase of mean values of PCE activity in the 53 subjects with type II-a was due mainly to overweight subjects, while this enzyme's activity was not significantly changed in lean subjects with pure hypercholesterolemia. PCE activity was positively correlated with serum triglyceride (r equals 0.540; p smaller than 0.001) and the prebeta electrophoretic fraction (r equals 610; p smaller than 0.001). The correlation with beta-lipoproteins was not significant. Ceruloplasmin levels were not significantly changed. It is suggested that elevation of PCE activity could be connected to mechanisms leading to an increased secretion rate of lipoproteins.