Elevation of serum alkaline phosphatase activity and related enzymes in diabetes mellitus.

Of 101 consecutive hospitalised diabetic patients, 29 had elevated serum enzyme activities attributable to recognized clinical entities; 17% of the remainder had raised alkaline phosphatase (AP) activity, 15% had raised aspartate aminotransferase (GOT) activity, and 12% raised lactate dehydrogenase (LDH) activity in serum. Ketoacidosis and death within 3 months were commoner among patients with elevated serum enzyme activities than among those with normal enzymes. Study of 200 consecutive new untreated diabetics when first seen at an out-patient clinic revealed 15 with clinically explainable abnormal serum enzyme activities. Of the remainder, 11% had raised AP activity, 12% raised GOT activity, and 21% raised LDH activity in serum; these patients tended to have higher blood sugar concentrations than the subjects with normal serum enzymes. These abnormalities seem to be an intrinsic feature of diabetes mellitus which do not relate to duration, complications, or treatment of the disease. They do not seem to be directly related to hepatic involvement.