The purpose of the study is to determine if the administration of small doses of Acarbose can prevent or delay the appearance of Type 2 Diabetes Mellitus in a population of subjects with prediabetes.

Inclusion Criteria:

• Age > 40 and < 75 years old
• Men and women
• Able to give voluntary informed consent
• Existence of one or more of the following risk factors:
• Body Mass Index (BMI) > 27 mg/Kg2
• One or more family members with diabetes determined by anamnesis.
• Personal antecedents of previous blood glucose anomalies (gestational diabetes reverted after the lactation time, before-during surgical stress, fasting glycaemia > 110 mg/dL (6,1 mM) and < 126 mg/dL (7 mM) registered in the Clinical History during the last 3 years, etc.)
• Previous consumption of drugs with hyperglycaemic capacity for a period of 3 months continuously or more than 6 months discontinuously

Exclusion Criteria:

• Type 2 DM
• Pregnancy during the study
• Nursing women
• Major debilitating (e.g. collagen vascular diseases, failure of major organ, psychosis, severe infections, neutropenia, BMI < 20 mg/Kg2)
• Subjects taking a prohibited drug (see protocol)
• Subjects taking drugs that can impair intestinal motility and/or carbohydrate absorption (i.e. cholestyramine, neomycin)
• Recent cardiovascular events (within last 6 months) such as myocardial infarction, cerebrovascular accident, congestive heart failure
• Serum creatinine > 2 mg/Dl
• Fasting triglycerides > 10 mm/L (> 885 mg/dL)
• AST elevation > 2.5 times above the upper limit of normal
• Subjects with hyper/hypothyroidism non compensated
• Subjects with documented gastrointestinal diseases that are likely to be associated with abnormal intestinal motility or altered absorption of nutrients (e.g. gastroparesia, malabsorption syndrome, chronic diarrhoea states, enteropathies, inflammatory bowel diseases, partial intestinal obstruction, large hernias)
• Subjects with any emotional disorder or substance abuse (e.g. severe depression, alcohol or drug abuse)
• Hypersensitivity to Acarbose