Influence of combined C-peptide and insulin administration on renal function and metabolic control in diabetes type 1.

This is the authors' abstract. We don't add key points for this paper.

The possible influence of C-peptide on renal function and metabolic control in patients with type 1 diabetes was examined in a double blind, randomized study. Nine patients received insulin and equimolar amounts of biosynthetic human C-peptide for 1 month (group 1), and nine were given insulin only (group 2). C-Peptide levels in plasma ranged from 0.3-2.6 nmol/L in group 1 during the study, whereas group 2 had undetectable levels. The urinary excretion of albumin in group 1 was 21 +/- 6 micrograms/min before the study and decreased by 40% and 55% after 2 and 4 weeks, respectively (P < 0.05). No change was seen in group 2. The glomerular filtration rate fell by 6% after 2 and 4 weeks (P < 0.05) in group 1, whereas no change was observed in group 2. Fluorescein leakage across the blood-retinal barrier decreased by 30% in group 1 (P < 0.05) and was unaltered in group 2. Hemoglobin-A1c and fructosamine values decreased by 9-16% in group 1 (P < 0.05), but not in group 2. The findings suggest that administration of C-peptide plus insulin, compared to insulin alone, to type 1 diabetic patients may reduce glomerular permeability and improve metabolic control.