title: Correlations between fasting plasma C-peptide, glucagon-stimulated plasma C-peptide, and urinary C-peptide in insulin-treated diabetics.
abstract: This study correlated fasting plasma C-peptide (CP), plasma CP 6 min after stimulation with 1 mg glucagon i.v., and the mean of three 24-h urinary excretions of C-peptide (UCP)/creatinine in 132 insulin-treated diabetics. Patients were divided into three groups: group 1, stimulated CP less than 0.06 nM (n = 51); group 2, stimulated CP 0.06-0.60 nM (n = 48); and group 3, stimulated CP greater than 0.60 nM (n = 33). In all patients fasting CP was closely correlated to stimulated CP (r = .988, P less than .001), whereas the correlations between UCP and both fasting CP (r = .904, P less than .001) and stimulated CP r = .902, P less than .001) were slightly less pronounced. The associations between UCP and both fasting CP (r = .716, P less than .001) and stimulated CP (r = .731, P less than .001) were modest in group 2, and even more so in group 3 (r = .557, P less than .001 and r = .641, P less than .001, respectively). In conclusion, fasting CP is closely correlated to glucagon-stimulated CP in insulin-treated diabetics and can probably be used equally well in the assessment of beta-cell function. The associations between UCP and both fasting and glucagon-stimulated CP are less pronounced, especially in patients with well-preserved beta-cell function.
authors.forename: H J
authors.initials: HJ
authors.lastname: Gjessing
authors.forename: L E
authors.initials: LE
authors.lastname: Matzen
authors.forename: A
authors.initials: A
authors.lastname: Frøland
authors.forename: O K
authors.initials: OK
authors.lastname: Faber
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002096:C-Peptide / Q000097:blood / Q000378:metabolism* / Q000652:urine; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D005215:Fasting; D005260:Female; D005934:Glucagon; D006801:Humans; D007515:Islets of Langerhans / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged
chemical_list: D002096:C-Peptide; D005934:Glucagon