The purpose of this study is to evaluate the development and progression of chronic complications (retinopathy, neuropathy, diabetic chronic renal disease, cardiovascular events) in patients with type 1 diabetes treated from the onset of the disease with recommended method of intensive insulin therapy. All patients attended a five-day structured training program during first hospitalization and re-education once year during the observation. After five years of observation and next - once a year chronic complications are assessed. The investigators would like to evaluate also the relationship of the management of the disease, knowledge about the treatment and diabetes, insulin resistance and inflammatory markers with development and progression of chronic complications.

Inclusion Criteria:

• Newly diagnosed type 1 diabetes mellitus with features of complete insulin deficiency (serum C-peptide level <0.05 ng/ml, acetonuria, blood gases disturbances such as: pH <7.30, BE< -6 mmol/l, HCO3 <18 mmol/l)
• Age < 35 years old
• Educational course in intensive insulin therapy started at the onset of the disease after treatment of ketoacidosis
• Written consent

Exclusion Criteria:

• Uncertain type of diabetes mellitus
• Kidney failure (serum creatinine level > 1.1 mg/dl)
• Liver dysfunction (AspAt > 31 U/l, AlAt > 34 U/l)
• Acute inflammatory process
• Other concomitant diseases (i.e. neoplasm)

100 Caucasian patients with newly diagnosed type 1 diabetes admitted to the Department of Internal Medicine and Diabetology, Poznan University of Medical Sciences in years 1994-1999, treated from the onset of the disease with intensive insulintherapy.