Serum xylosyltransferase activity in diabetes mellitus patients as a possible marker of reduced proteoglycan biosynthesis

Abstract

Objective: Proteoglycan metabolism is altered in diabetic patients. The xylosyltransferases are the initial and rate-limiting enzymes in the biosynthesis of the glycosaminoglycan chains in proteoglycans. Here, we analyzed whether the changed proteoglycan metabolism leads to altered serum xylosyltransferase levels in diabetics.

Research design and methods: Serum xylosyltransferase activity was determined in 100 diabetic patients and 100 blood donors using a novel HPLC electrospray ionization tandem mass spectrometry assay.

Results: Serum xylosyltransferase activities in male and female diabetic patients were significantly decreased compared to the corresponding normoglycemic controls (male patients, mean value 19.3 mU/l, SD 4.44; male controls, 26.6 mU/l, SD 2.79; female patients, 18.9 mU/l, SD 3.14; female controls, 21.8 mU/l, SD 3.74; p<0.0001). No significant differences were detected between patients with type 1 or type 2 diabetes.

Conclusions: Our data show a decreased xylosyltransferase activity in diabetes mellitus, a disease which is accompanied by an altered proteoglycan biosynthesis.