C-peptide as a risk factor of coronary artery disease in the general population

Abstract

Objective: To analyse the association between serum C-peptide and coronary artery disease in the general population.

Methods: Follow-up study of 6630 adults from the general population. They were stratified into group 1 (no insulin resistance: C-peptide < third tercile and glycaemia < 100 mg/dL), group 2 (initial insulin resistance: C-peptide ⩾ third tercile and glycaemia < 100 mg/dL) and group 3 (advanced insulin resistance: glycaemia ⩾ 100 mg/dL).

Results: After 3.5 years of follow-up, group 2 had a higher incidence of myocardial infarction (relative risk (RR) = 4.2, 95% confidence interval (CI) = 1.7-10.6) and coronary artery disease (RR = 3.5, 95% CI = 1.9-6.6) than group 1. Group 3 also had increased incidences of both diseases. In multivariable analysis of the entire population, groups 2 and 3 showed significant risks of myocardial infarction and coronary artery disease (RR > 3 and RR > 2, respectively). However, when people with diabetes were excluded, the increased risks were corroborated only in group 2 for myocardial infarction (RR = 2.8, 95% CI = 1.1-6.9; p = 0.025) and coronary artery disease (RR = 2.4, 95% CI = 1.3-4.6; p = 0.007).

Conclusion: Elevated C-peptide is associated with the incidence of myocardial infarction and coronary artery disease in the general population. It can be an earlier predictor of coronary events than impaired fasting glucose.

Keywords: C-peptide; coronary artery disease; insulin resistance; risk factor.