The study aims to evaluate IFG, IGT or unknown type 2 diabetes mellitus in new classes at high risk to develop alterations of glucose metabolism and definition of new pathogenic mechanisms of insulin resistance and atherosclerosis.

The following classes of subjects at high risk will be considered:First degree relatives of patients with type 2 diabetes mellitus, patients with cardiovascular disease and stroke, patients with heart valve disease. age will be > 30 years, both gender.

The primary outcome of the study is evaluation of glucose tolerance, insulin sensitivity and insulin secretion before and 2 hours post-glucose load Secondary outcomes are evaluation of endothelial function, of natriuretic peptides and free fatty acids, and inflammation before and 2 hours post-glucose load. New candidate genes will be also evaluated.

Inclusion Criteria:

• Fasting glucose levels <126 mg/dl
• Age >30 years
• Both male and female

Exclusion Criteria:

• Type 1 diabetes
• Known type 2 diabetes mellitus
• Pregnancy
• Impaired kidney and liver function
• Previous history of malignancies