Hello MMPP,
I'm a volunteer and not a medical professional, nor a medical researcher. Our main focus is on Type 1 diabetes which is an autoimmune disease. Many of us here are long time diabetics or caregivers for a diabetic family member.
In my general readings, I hadn't come across any info on free radicals & diabetes until I began to study up to attempt to answer your question.
Here is a website I found when searching on the phrase "diabetes free radicals" These article from reputable sources mentions Type 1 but not Type 2. THey seem quite technical.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3075947&dopt=Citation
http://www.findarticles.com/p/articles/mi_m0922/is_8_52/ai_106395066
and
http://www.karlloren.com/data/p14.htm
If you're interested in Type 2, its precursors and treatments, visit this site from the American Diabetes Association, which has a greater focus on Type 2.
http://www.diabetes.org/home.jsp
Sorry I couldn't answer your questions directly, but I hope this information is helpful.
thank you so much. i'm working on a dissertation paper and i hope it helps.