Aims To examine the effect of Type 2 diabetes mellitus (DM) on enzymes of importance for oxygen-dependent killing of microorganisms by leucocytes.
Methods Twenty patients with Type 2 DM and 20 nondiabetic controls provided blood samples for analysis.
Results The superoxide dismutase (SOD) activity was lower by 41% in polymorphonuclear leucocytes (PMNL) from patients with Type 2 DM than in controls (3.42 ± 0.32 U/mg of protein vs. 5.79 ± 0.71 U/mg of protein, P < 0.005). Glutathione peroxidase (GSHPx) and glutathione reductase (GR) activities of Type 2 DM patients were 73.04% and 81.12% of control values (0.84 ± 0.07 nkat/mg of protein vs. 1.15 ± 0.10 nkat/mg of protein, P < 0.023, and 2.02 ± 0.12 nkat/mg of protein vs. 2.49 ± 0.16 nkat/mg of protein, P < 0.023, respectively). The catalase activity showed no significant difference. A significant increase (141.37% of control) in the concentration of thiobarbituric acid reactive products was observed (9.91 ± 0.78 μmol/l vs. 7.01 ± 0.47 μmol/l, P < 0.003). A positive correlation between thiobarbituric acid reactive products and glucose, glycated haemoglobin and fructosamine in the serum of diabetic patients was observed.
Conclusion These findings may explain some of the mechanisms underlying the increased susceptibility to certain infection in patients with Type 2 DM.
Diabet. Med. 16, 74–78 (1999)