Many T1 diabetics have been found to have insulin resistance (IR). IR is a T2 characteristic, and seems out of place with a T1. These individuals are usually given Metformin to help reduce the IR. A T1 with IR and taking a T2 drug is called a "double diabetic". I was diagnosed with IR in 1998 and took T2 drugs (Avandia and Metformin) for 13 years. The Metformin was the best for me. I had gained weight in the 1990's and Metformin caused me to lose that weight, and reduce my IR. The insulin dosages were also reduced. I have known for many years that the more insulin I use, the more weight I gain. I stopped using Metformin about a year ago, and my weight is very stable. My weight is supposed to be in the 170-200 range, and my current weight is 179.
Just one extra note. A double diabetic does not have T2. It is not possible for a T1 to become a T2. My pancreas stopped producing insulin when I was 6, so I was T1 then and always will be. A T2 still produces insulin at the time of diagnosis.