Should fasting C-peptide levels be used to guide T2DM management?  

For most patients, it is not necessary to measure C-peptide to make treatment decisions. However, it is important to remember that ~5% of adults with new-onset diabetes actually have type 1 diabetes (sometimes called LADA in adults) and not type 2 diabetes. If there are concerns that type 1 diabetes...

I feel that it is imperative to check especially prior to starting a GLP-1.