All patients with diabetes above age 18 are eligible for this study, irrespective of type, duration of diabetes or treatment. Diabetes will be defined according to the current diagnosis criteria suggested by the American Diabetes Association (fasting plasma glucose ≥ 7mmol/L, occasional plasma glucose ≥11.1mmol/L (plus typical symptoms), a 2hour plasma glucose of ≥11.1mmol/L after a 75g oral glucose tolerance test, or a HbA1c ≥ 6.5%), but patients under treatment with ≥2 oral hypoglycemic agents (OHA) and/or insulin in the absence of proof of a diagnosis by fasting, random plasma glucose or oral glucose tolerance test will also be included. The type of diabetes will be diagnosed clinically in most cases. In equivocal cases classification will be based on previously reported criteria with the assistance of laboratory test results.