Please excuse my lack of knowledge: I am over 50 years old and new to insulin and was told by my endo to use insulin, does it make me type 1 or type 2? I am on 3 units of Lantus and 2-3 units of Novolog as needed to cover the blood sugar rise after meals. I asked if my pancreas were making insulin. The doctor wanted to subject me to the 75g OGTT. It sounds irresponsible because 75g of glucose would probably send my blood sugar to 300. Could a fasting C peptide test indicate if my body is still producing insulin?