Long term vascular changes in type 1 diabetes
Clinical aspects and biological markers -
30 years follow-up of the Oslo Study
The Oslo Study was planned by Professor Kristian F. Hanssen and Knut Dahl-Jørgensen forty years ago. In 1980-81 fortyfive type 1 diabetes patients aged 18-42 years with diabetes duration 13 years, were block-randomized to either insulin pump treatment (CSII), multiple injections or standard treatment with two daily mixed insulin injections for four years. This was the first study in the world to compare these three regimens and to explore if intensive insulin treatment was superior to standard treatment. Insulin pumps were superior with near normal blood glucose values and less hypoglycemia compared to multiple injections with pens, and both better then two daily insulin regimens. After 4 years the randomization all patients offered intensified treatment, because early retinopathy, nephropathy and neuropathy were retarded by intensified treatment regimens. Later the DCCT study confirmed these findings. The Oslo Study patients were followed prospectively for 30 years. After 18 years an unexpected high frequency and degree of atherosclerosis in the coronary arteries of the heart was detected by intravascular ultrasound in patients without symptoms of cardiovascular disease. The degree of atherosclerosis correlated with cholesterol and also long term blood glucose control, underlining the importance of optimal blood glucose control in preventing cardiovascular death. Kari Anne Sveen performed the 30 years follow-up and worked to unravel the biochemical mechanism for why high blood sugar is so harmful to blood vessels and nerves, and studied how the changes in the proteins due to high blood glucose, measuring Advanced Glycation Endproducts (AGEs), is linked to late complications. She is now continuing using the Oslo Study materials for more in depth studies on progression of atherosclerosis and its prognostic factors as AGEs and circulating autoantibodies against modified lipids and epigenetic factors influencing the development and progression of late diabetes complications.
The study is still active in 2021.