An association between Type 2 diabetes and alpha-antitrypsin deficiency

Alpha(1)-Antitrypsin (AAT) is a serine protease inhibitor which recently has been shown to prevent Type 1 diabetes development, to prolong islet allograft survival and to inhibit pancreatic B-cell apoptosis in vivo. It has also been reported that Type 1 diabetic patients have significantly lower plasma concentrations of AAT, suggesting the potential role of AAT in the pathogenesis of Type 1 diabetes. We have investigated whether plasma AAT levels are altered in Type 2 diabetes.

The study included patients with Type 2 diabetes (n = 163) and non-diabetic control subjects matched for age, sex and smoking habits (n = 158) derived from the population-based Malmö Diet and Cancer study. Plasma samples were analysed for AAT concentration and phenotype and serum glucose, insulin, C-reactive protein and lipid levels were measured. Glycated haemoglobin was also measured.

In the diabetic group, the women had higher mean plasma AAT levels than men (P < 0.05). The mean plasma AAT levels did not differ between diabetic and control subjects. However, the number of individuals with low AAT levels (< 1.0 mg/ml) was 50% higher in the diabetic group (P < 0.05) and the frequency of AAT deficiency genotypes was 50% higher (NS) in diabetic compared with control subjects. In the group of diabetic patients with AAT < 1 mg/ml, AAT directly correlated with systolic blood pressure (P = 0.048) and inversely correlated with waist-hip ratio (P = 0.031).

Our results provide evidence that deficiency of AAT may be associated with an increased risk of developing Type 2 diabetes.