•Acute infection, malignant disease, renal (abnormal creatinine), hepatic (more than two-fold increased transaminases), pulmonary, neurological (epilepsy) or major psychiatric diseases, manifested atherosclerosis
•Fasting plasma glucose > 5.6 mmol/l
•Known alcohol or drug abuse
•HIV-antibody positive
•Subjects likely to fail to comply with the study protocol
•Smoking (>1 cigarette/month)
•Subjects who do not give informed consent