Does Residual C-Peptide Production Prevent Complications? If so, how can we replace C-Peptides?

http://www.voanews.com/english/Scien…6-19-voa27.cfm
Study Findings Give Renewed Hope to People with Juvenile DiabetesBy Rosanne Skirble

Does Residual C-Peptide prevent complications? I know pork insulin in the beginning had C-Peptides in it and that C-Peptides are now removed, via the manufacturing process, from human insulin. If C-Peptides were not removed from the insulin would this mean less complications? Can C-Peptides be replaced through injection, either added to the insulin again or separately? Would injected C-Peptide have a protective effect? Or would C-Peptide have to be produced by the human body to have the protective effect? If anybody has any info., please respond.