The critical study showing advantages of intensive insulin therapy in comparison with the classic method was Diabetes Control and Complications Trial. Conclusion of that study was unequivocal: hyperglycemia has a significant influence on the development of the chronic diabetes complications. THE AIM of this study was to estimate the influence of the conventional insulin therapy in the past and its duration on the development of complications in patients suffering from type 1 diabetes for more than 5 years.
Material and methods: 185 patients aged 16.7 years (+/-3.4) with diabetes onset in the age 8.4 years (+/-3.8) participated in this study. There were 84 girls and 101 boys. More of them were treated by classic insulin therapy at the beginning of disease (n=148). 37 persons had intensive insulin therapy all the time.
Results: The presence of at least one complication was found in 49 persons (26.5%), two complications - in 14 patients (7.57%) and three complications in 4 patients (2.16%). The conventional therapy duration was twice longer in patients with retinopathy. The significant influence of the age, the age of diabetes onset and duration was found in those patients. Comparing the groups of patients treated conventionally less than 3.5 years and more than 3.5 years it was found that patients in the first group were older, fell ill later and they had longer diabetes duration than patients in the second group. The risk of retinopathy increases from 4.2% to 8.9% in patients treated conventionally more than 3.5 years. The risk of diabetic cataract is 5 times higher in that group.
Conclusions: Chronic complications of diabetes occur in 26.5 % patients with a diabetes duration of at least 5 years. CIT is the risk factor of the eye complications in diabetes, particularly when applied longer than 3.5 years. The prolongation of CIT over 3.5 years increases the risk of retinopathy twice and the risk of cataract 5 times in patients with type 1 diabetes. So the early intensification of insulin therapy reduces the risk of the retinopathy and cataract development in later course of the disease.