BETA-HEXOSAMINIDASE ISOENZYME-A AND ISOENZYME-B IN MIDDLE-AGED AND ELDERLY SUBJECTS - DETERMINANTS OF PLASMA-LEVELS AND RELATION TO VASCULAR-DISEASE

Plasma/serum beta-hexosaminidase (Hex) activity is known to be increas ed in chronic alcoholism, liver disorders, pregnancy and diabetes mell itus. Hex activity also shows an association with risk factors for vas cular disease and heredity for arteriosclerosis. There are several iso enzymes of Hex. Using an enzyme immunoassay for Hex isoenzymes (Hex A and Hex B we studied possible determinants of Hex isoenzymes and their relation to vascular disease in randomly invited (n = 244) 35-95-year -old men and women. In both sexes there were significant age-related i ncreases in Hex activities and men exhibited higher activity of both i soenzymes. Both Hex isoenzymes correlated with age. systolic blood pre ssure, serum triglycerides and liver enzymes, whereas Hex A was distin guished from Hex B by its stronger correlation with blood glucose. In multiple linear regression analysis Hex A was explained to 20.7% by bl ood glucose, age, serum aspartate aminotransferase and glutamyl transp eptidase. Hex B was explained to 14% by age, serum glutamyl transpepti dase and serum triglycerides. There was no significant increase in Hex isoenzymes in subjects with hypertension. diabetes mellitus or myocar dial disease, nor did current smokers exhibit any increase of these en zymes compared to non-smokers. The main conclusion is that liver Funct ion, as reflected by the level of liver enzymes and glucose metabolism , is the major determinant for Hex isoenzymes in plasma.