C-Peptide Replacement Therapy and Sensory Nerve Function in Type 1 Diabetic Neuropathy.
EKBERG, KARIN PHD 1; BRISMAR, TOM MD, PHD 2; JOHANSSON, BO-LENNART MD, PHD 1; LINDSTROM, PER MD, PHD 3; JUNTTI-BERGGREN, LISA MD, PHD 1; NORRBY, ANDERS MD 4; BERNE, CHRISTIAN MD, PHD 5; ARNQVIST, HANS J. MD, PHD 6; BOLINDER, JAN MD, PHD 7; WAHREN, JOHN MD, PHD 1
[Article]
Diabetes Care.
30(1):71-76, January 2007.
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OBJECTIVE: C-peptide replacement in animals results in amelioration of diabetes-induced functional and structural abnormalities in peripheral nerves. The present study was undertaken to examine whether C-peptide administration to patients with type 1 diabetes and peripheral neuropathy improves sensory nerve function.
RESEARCH DESIGN AND METHODS: This was an exploratory, double-blinded, randomized, and placebo-controlled study with three study groups that was carried out at five centers in Sweden. C-peptide was given as a replacement dose (1.5 mg/day, divided into four subcutaneous doses) or a dose three times higher (4.5 mg/day) during 6 months. Neurological examination and neurophysiological measurements were performed before and after 6 months of treatment with C-peptide or placebo.
RESULTS: The age of the 139 patients who completed the protocol was 44.2 /- 0.6 (mean /- SE) years and their duration of diabetes was 30.6 /- 0.8 years. Clinical neurological impairment (NIA) (score >7 points) of the lower extremities was present in 86% of the patients at baseline. Sensory nerve conduction velocity (SCV) was 2.6 /- 0.08 SD below body height-corrected normal values at baseline and improved similarly within the two C-peptide groups (P < 0.007). The number of patients responding with a SCV peak potential improvement >1.0 m/s was greater in C-peptide-treated patients than in those receiving placebo (P < 0.03). In the least severely affected patients (SCV < 2.5 SD below normal at baseline, n = 70) SCV improved by 1.0 m/s (P < 0.014 vs. placebo). NIA score and vibration perception both improved within the C-peptide-treated groups (P < 0.011 and P < 0.002). A1C levels (7.6 /- 0.1% at baseline) decreased slightly but similarly in C-peptide-and placebo-treated patients during the study.
CONCLUSIONS: C-peptide treatment for 6 months improves sensory nerve function in early-stage type 1 diabetic neuropathy.
(C) 2007 by the American Diabetes Association, Inc.
