Serum enzymes of lysosomal origin as indicators of the metabolic control in diabetes: comparison with glycated hemoglobin and albumin.

Several lysosomal enzymes (beta-N-D-acetylglucosaminidase, beta-D-glucuronidase, alpha-D-galactosidase, beta-D-galactosidase, alpha-L-fucosidase, alpha-D-glucosidase, alpha-D-mannosidase, beta-D-glucosidase), glycated albumin and glycated hemoglobin (HbA1c) were determined in the serum of 81 insulin-dependent diabetics with different degrees of metabolic control (optimal, 21 patients; good, 39 patients; poor, 21 patients) and without signs of complications, and in 42 control subjects. All parameters examined increased in serum in inverse proportion to the degree of metabolic control. A highly significant correlation (p less than 0.01) was found between lysosomal enzymes and both glycated albumin and HbA1c. All parameters correlated with hyperglycemia, glycated albumin having the highest r-value (0.586) and lysosomal enzymes the lowest one. Unlike glycated albumin and HbA1c, serum levels of lysosomal enzymes in patients with optimal metabolic control were undistinguishable or even lower than those of controls. A 2-month longitudinal monitoring of a patient who was hospitalized in conditions of poor metabolic control and adequately treated, proved that lysosomal enzymes diminished in serum parallel to glycated albumin and HbA1c in relation to improvement of the metabolic situation. The conclusion is drawn that serum lysosomal enzymes are good indicators of the metabolic control of diabetic patients probably reflecting the overall metabolic state connected with insulin action rather than hyperglycemia.