PMID- 33159695 OWN - NLM STAT- MEDLINE DCOM- 20211220 LR - 20211220 IS - 1472-8206 (Electronic) IS - 0767-3981 (Linking) VI - 35 IP - 4 DP - 2021 Aug TI - Oscillations of C-peptide in the euglycemic clamp and their effect on the pharmacodynamic assessment of insulin preparations. PG - 771-780 LID - 10.1111/fcp.12628 [doi] AB - C-peptide should be continuously suppressed. However, increased postdosing C-peptide is not an uncommon phenomenon in euglycemic clamp studies involving healthy participants. This study aimed to determine the extent to which the postdosing C-peptide increases from the baseline that could affect the accuracy of glucodynamics in euglycemic clamp studies involving healthy subjects. First, 10 healthy males underwent a 10-h euglycemic clamp without exogenous insulin administration to obtain a reference interval (RI) for the ratio of C-peptide after 0 min (CP(t) ) to baseline C-peptide (CP(0) ). Then, the data from a pharmacokinetic and pharmacodynamic study of insulin aspart (IAsp) were analyzed, and 70 eligible clamps were grouped by CP(t) /CP(0) : group A ([CP(t) /CP(0) ](max) ( ) > upper limit of RI), group B (1<[CP(t) /CP(0) ](max)