The Relationship between Zinc, Glycemic Control and Microvascular Complications of Diabetes Mellitus

Zinc is the second most abundant trace element in human body. The relationship between zinc and insulin is well known. Zinc is involved in the synthesis, storage and release of insulin and zinc deficiency may be associated with different metabolic disorders such as diabetes mellitus (DM). The aim of this study was to evaluate the serum zinc level and its correlation with glycemic control and microvascular complications in diabetic patients. In this cross-sectional study, 128 cases of type 2 DM, 30-60years of age were randomly selected on the basis of clinical history. Zinc level, HbA1c and urine micro albumin were measured. The Michigan Neuropathy Screening Instrument (MNSI) was used for evaluation of distal neuropathy. The subjects had mean age of 52.2±7.5 years old. Mean duration of DM was 8.3±7.4 years, mean HbA1c was 7.7±1.8% and mean zinc level was 101.5±26.5 μg/dl. There was a significant correlation between zinc and score of neuropathy (P=0.03). A subtle reduction in plasma zinc level was observed among patients with urine microalbumin ≥ 30 mg (96.0±14.9) in comparison to patients with urine microalbumin <30 mg (103.1±29.2) (P=0.09). By multiple regression analysis, after adjustment for age, BMI, sex and duration of diabetes, no significant association was noted between zinc level and HbA1c. It was shown that plasma zinc concentration may have association with complications of type 2 DM such as neuropathy. This correlation was significant even in normal zinc level that should be considered by public health authorities.