[Extreme long duration of type 1 diabetes mellitus].

Mortality in type 1 diabetes, although showing a declining trend, is significantly higher than standard mortality. The case study focuses on a woman who lived for 91 years; she was insulin-dependent for 86 years and has been treated by a single physician - the author - for over 55 years. She was diagnosed with diabetes in 1932 at the age of five. Her diabetes was first treated with rapid-acting insulin three times daily, then from 1940 with rapid-acting and protamine zinc insulin once daily, while later on pork, then human crystalline zinc insulin was used, followed by a mixture of rapid-acting and NPH insulin for the last 16 years. The reason behind the above treatment regimen was that the patient obsessively insisted on a once daily insulin dose and the duration was shown to be 24 hours for each insulin. The continuous overdose of a single insulin for decades has resulted in hypoglycemic episodes almost daily, with consequent high fluctuations in blood glucose levels. She performed urine glucose tests using a polarimeter from the mid-1930s to the sixties, then used test strips until the early eighties, and later switched to blood glucose self-testing. Her HbA levels have been around 7% (53 mmol/mol) for the last 25 years. She did not develop retinopathy or nephropathy, only severe neuropathy caused complaints during the last years of her life. In addition, her vision continued to deteriorate due to age-related dry macular degeneration. She is a Joslin 75-year medalist. For the last two months of her life, she gave permission for degludec + glulisine insulin intensive treatment. Her death was caused by myocardial infarction. Although minimizing blood glucose fluctuations and sustaining good metabolic control significantly improve the life expectancy of people with diabetes, in our case neither has existed for well over half a century. Therefore, no explanation was found for the extremely long duration of diabetes and longevity. Orv Hetil. 2020; 161(5): 193-197.