Comparison of Two Biphasic Insulin Regimens

Inclusion Criteria: * regular attendees of Outpatient Clinic of the Diabetes Centre of the 1st Department of Internal Medicine of University Hospital in Thessaloniki Greece * The patients were on Premixed Human Insulin 30/70 twice daily with or without metformin * baseline HbA1c\<7% Exclusion Criteria: * the presence of type 1 Diabetes Mellitus * stage 4 Chronic Kidney Disease * use of antidiabetic medications other than insulin and metformin * major cardiovascular event during the last six months * acute illness and hospitalization during the last two weeks * pregnancy * absence of good metabolic control assessed with self-monitoring of blood glucose during the week before entering the study (\>20% of the measurements \<80mg/dl or \>130mg/dl) * inability of the patients to understand the study procedures and sign the consent form