Serum enzymes in diabetes mellitus.

Serum enzymes that show changed activities in diabetes mellitus can be divided into four groups: Group I includes some lysosomal enzymes-f.3-glucuronidase N-acetyl-fl-glucosaminidase, acid phosphatase, and amylase-that show increased activity correlated with blood sugar concentration. Because lysosomal enzymes as well as liver amylase show latency and may be “activated” by several agents, their increased activity in the serum of diabetics might be a manifestation of an activation occurring in tissues. Group II includes alkaline phosphatase and trehalase, which are increased but not correlated with blood sugar concentration. Their enhanced activity may reflect tissue metabolic disorders. Group Ill includes enzymes that increase in the postketotic period almost regularly-phosphohexose isomerase -or in only the most severe cases-aminotransferases and several dehydrogenases-because of tissue damage caused by metabolic and circulatory alterations. Cholinesterase, on the other hand, is decreased. Group IV includes any of the above-mentioned enzymes, and still others, that may be more active in diabetics with complications such as hepatIc and renal involvement and obesity.