We studied six healthy male subjects to determine whether a four-hour infusion of synthetic human C-peptide sufficient to achieve mean (±SD) peripheral plasma concentrations of 1.3 ± 0.7 pmol/mL affected plasma glucose, serum insulin, or plasma glucagon. Subjects were studied in a fasting state and following an oral glucose load during four-hour 0.9% NaCl (control) and C-peptide (mean dose: 70 nmol) infusions. No differences were observed between saline and C-peptide infusions for mean values of fasting plasma glucose (94 ± 6 v 87 ± 5 mg/dL), serum insulin (3 ± 1 v 2 ± 1 μU/mL), or plasma glucagon (124 ± 65 v 112 ± 70 pg/dL). Following oral glucose ingestion no differences were detected between saline and C-peptide infusions for mean peak values of plasma glucose (168 ± 18 v 168 ± 31) and serum insulin (59 ± 6 v 57 ± 21) or mean nadir values of plasma glucagon (80 ± 73 v 75 ± 70). There was a slight delay in the insulin rise following oral glucose on the C-peptide infusion day, but differences between mean values for individual sampling times were not statistically significantly different.
Bibliographical noteFunding Information:
From the Department of Medicine, Division of Endocrinology and Metabolism and the General Clinical Research Center, University of Minnesota, Minneapolis. Supported by the General Clinical Research Center Branch of the Division of Research Resources, NIH (RR 400). The Eli Lilly Company (Indianapolis, Indiana), and The American Diabetes Association, Minnesota Afiliate. Dr Hoogwerf is the recipient of a Special Emphasis Research Career Award (IKOI AG00151) in Diabetes and Aging from The National Institute on Aging. Address reprint requests to Dr Byron J. Hoogwerf. Department of Endocrinology. Cleveland Clinic Foundation, Cleveland, OH 44106. o 1986 by Grune & Stratton, Inc. 0026-0495/86/3502-0006$03.00/0