Clinical Utility of Serum C-peptide Concentration for Hospitalized Patients with Hyperglycemia.

Abstract

Background: Serum C-peptide concentration is often utilized for diagnostic, prognostic, or therapeutic assessment in diabetes mellitus. However, there is limited clinical data regarding diagnostic and predictive value of C-peptide measured during hospitalizations for hyperglycemia.

Materials & methods: Adults admitted to Mayo Clinic inpatient facilities due to an acute hyperglycemic emergency between January 2017 and November 2022 were included in our study. Predictive capacity of C-peptide for discontinuation of therapeutic insulin was examined in the entire cohort and the subgroup of non-autoimmune non-pancreatitis diabetes (NANP-DM).

Results: We included 187 patients (63 women) in our study. During hospitalization, patients with type 1 diabetes antibodies displayed diminished serum C-peptide concentration (p=0.014), correlating inversely with subsequent HbA1c% [r= (-0.22), p=0.005]. Initial C-peptide concentrations did not differ between patients requiring insulin therapy during follow-up and those who did not (p=0.16). C-peptide concentrations showed limited predictive capacity for achieving glycemic control. Subgroup analyses in NANP-DM exhibited similar limited capacity for anticipating therapeutic insulin needs and achieving glycemic controls.

Discussion: C-peptide concentration did not exhibit a robust predictive capability for future need of insulin therapy and achieving glycemic control, limiting its utility in clinical practice within inpatient settings.