Endocrine Abstracts

The objective of this study was to determine the correlation between serum zinc level and neutrophil respiratory burst in patients with type 2 diabetes mellitus. 40 type 2 diabetic patients (20 with foot ulcers) and 20 healthy controls were recruited. The local ethical committee approved the study, and written, informed consent was obtained from every participant before enrolment in the study. 20 millilitres of heparinized venous blood were taken from each individual in the fasting state. Neutrophils were isolated and purified by gradient concentration centrifugation. Neutrophil respiratory burst was measured in the baseline and stimulated states by a semi-quantitative nitroblue tetrazolium (NBT) reduction test. Neutrophils were separately stimulated with phorbol-12,13-myristate acetate (PMA) and N-formyl-methionine-leucine-phenylalanine (FMLP). Serum zinc was measured by atomic absorption spectrophotometry. In patients with foot ulcers, we found a significant negative correlation between serum zinc and neutrophil NBT index in the resting state (Pearson's R = minus 0.604; P = 0.029). In the same group, there was a significant positive correlation between serum zinc and neutrophil NBT index, when stimulated by both PMA (Pearson's R = 0.698; P = 0.008) and FMLP (Pearson's R = 0.759; P = 0.003). These findings were not duplicated in either patients with uncomplicated diabetes or healthy controls. We conclude that in type 2 diabetes complicated by foot ulceration, a negative correlation exists between serum zinc level and neutrophil respiratory burst in the resting state, and a positive correlation in the stimulated state. These findings may be explained by neutrophil hyperfunction in the resting state and respiratory burst dysfunction in the stimulated state in diabetic patients.