I’ve heard so much about obesity causing insulin resistance, but how would I know if I were significantly resistant? I’m an obese type 1 diabetic (139 kg [306 pounds]) with an undetectable C-Peptide level. I am slowly losing weight and exercising daily. I use quite a bit more insulin (72 units/day) than most thin folks, but less than some others. I understand that the amount of insulin one needs is very individual, but is there a number of units per kilogram of body weight that would suggest a problem in an adult? The prospect of “Double Diabetes” is not appealing. Am I automatically resistant due to my weight or is it possible to be obese and yet have a fairly normal response to insulin? There is no history of type 2 in my family.

With the higher prevalence of type 2 diabetes in our society, many people who have type 1 diabetes may also have the double disadvantage of being markedly insulin resistant. Insulin doses of more than 100 units per day are considered to be higher. Just based on obesity and the presence of type 1 diabetes, you are also insulin resistant. I think your attitude of working on your health over time is good. Keep it up over time and facilitate a healthy weight loss and not an overnight loss of weight that is prone to rebound and additional medical concerns. You might ask why people with type 1 diabetes are insulin resistant. It relates to the idea that the higher insulin levels associated with insulin therapy cause a down-regulation in the insulin receptors. This has been documented in patients who have type 1 diabetes, who are thin, that have received testing with insulin clamp studies.

JTL