Implications of +647 A/C MT1A polymorphism in type 2 diabetes

Objectives. Metallothioneins (MT) are zinc-binding proteins which, by means of their antioxidant properties, might prevent the development of diabetic cardiovascular complications. A recent investigation shows that A/C +647 MT1A polymorphism affects the intracellular zinc ion release (iZnR) from MT and is associated with longevity. The aim of the present study is to assess the role of + 647 A/C MT1A polymorphism with the susceptibility to type 2 diabetes (DM2). Materials and methods. The case-control association study included 242 old healthy controls and 235 diabetic patients with a diagnosis of CVD (age > 60 yrs). Results. C allele was more prevalent in patients than in controls (OR = 1.54; p = 0.002). C+ carriers showed higher blood glucose levels and glycosylated hemoglobin. A modulation of MT levels and iZnR were observed in relation to +647A/C MT1A polymorphism. Conclusions. An association between +647 A/C MT1A polymorphism and DM2 was found. Moreover, C+ carriers presented a worse glycemic control and an altered zinc homeostasis, suggesting a possible role of MT in the progression of DM2.