GLUT1 gene polymorphism in non-insulin-dependent diabetes mellitus: genetic susceptibility relationship with cardiovascular risk factors and microangiopathic complications in a Mediterranean population.

OBJECTIVE: It has been suggested that the polymorphic variation of GLUT1 glucose transporter may contribute to genetic susceptibility to type 2 diabetes in some populations. We have evaluated the GLUT1-XbaI polymorphism in an association study of a Caucasian Mediterranean population and its role in the susceptibility to displaying either microangiopathic complications or any of the risk factors associated with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 193 type 2 diabetic patients (104 women and 89 men, 31-82 years of age, diabetes duration 13.2 +/- 6.2 years) and 90 healthy subjects (48 women and 42 men, 20-72 years of age) were recruited for the association study. For the evaluation of nephropathy and retinopathy, type 2 diabetic patients were matched with those not having microangiopathic complications.
RESULTS: Genotypic or allelic frequencies did not differ significantly between controls and type 2 diabetic patients. Regarding the distribution of clinical or metabolic parameters according to GLUT1 genotype, patients with X1X1 genotype tended to have higher diastolic blood pressure levels compared with the remaining genotypes (P = 0.008). There were no differences in genotypic or allelic distribution among patients for either the presence or absence of retinopathy or nephropathy.
CONCLUSIONS: We conclude that GLUT1 loci did not contribute significantly to type 2 diabetes in this cohort and is not a determinant for cardiovascular risk factors or chronic microangiopathic complications associated with type 2 diabetes. The weak association with diastolic hypertension must be confirmed in other populations.