In diabetes mellitus the primary aim is to maintain carbohydrate metabolic balance at values close to normal to prevent complications. Glycated hemoglobin is a very important parameter in evaluating diabetic patients, its value can be decisive regarding the therapy. The aim is to follow the metabolic balance in type 1 and 2 diabetic patients, categorized in sub-groups depending on the type of the disease, age, gender and environment. Patients presenting impaired carbohydrate metabolic balance are especially type 1 diabetic teenagers and type 2 diabetic patients from rural areas, especially those with obesity.