Polymorphonuclear leucocyte respiratory burst activity correlates with serum zinc level in type 2 diabetic patients with foot ulcers.

Patients with diabetes mellitus (DM) are prone to infection, in part due to phagocyte dysfunction and impaired polymorphonuclear (PMN) leucocyte superoxide generation. Another frequently mentioned factor in the pathogenesis of infection in DM patients is altered zinc status. This study aims to evaluate the association between serum zinc level and PMN respiratory burst activity in patients with type 2 DM. Thirty-nine type 2 DM patients (19 with foot ulcers) and 20 healthy controls are studied. Respiratory burst activity is evaluated at baseline and in stimulated states by a nitro blue tetrazolium (NBT) reduction test. Serum zinc level is evaluated by atomic absorption spectrophotometry. Although not statistically significant, PMNs from diabetics with foot ulcers appeared to be slightly hyperactivated at the baseline state. The NBT index was significantly lower in DM patients with foot ulcers after stimulation. Mean serum zinc level was significantly lower in diabetics with foot ulcers compared to those without foot ulcers. A significant negative correlation between serum zinc level and NBT index at baseline was seen in patients with foot ulcers, but this changed to a significant positive correlation after stimulation. These findings may be explained by PMN hyperactivity at baseline and by respiratory burst dysfunction following stimulation in diabetic patients.