Objectives Retinol-binding protein 4 (RBP4) is an adipokine associated with insulin resistance (IR) and obesity-related metabolic disorders. We compared RBP4 levels between coronary artery disease (CAD) patients and controls to evaluate its association with cardiovascular risk factors.
Methods Sixty patients with coronary angiography-confirmed CAD (including 30 patients with CAD and hyperinsulinemia (CAD/HIns group)) and 29 healthy subjects were enrolled. Serum RBP4, insulin resistance indexes and cardiovascular risk factors were assessed in these subjects.
Results Serum RBP4 levels in the CAD/HIns group were higher than in the CAD and control groups (P < 0.01). RBP4 level were significantly associated with cardiovascular risk factors, such as body mass index (BMI), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), uric acid (UA), high sensitivity C reactive protein (hsCRP) and adiponectin (APN) (P < 0.01). Two-hour postprandial insulin (2hPIns), homeostatic model assessment of insulin resistance (HOMA-IR) and APN were independent factors associated with RBP4 (r = 0.224, r = 0.456, r = 0.294, P < 0.01).
Conclusions The present study shows that RBP4 is associated with cardiovascular risk factors related to insulin resistance and CAD. Circulating RBP4 could be a marker of metabolic complications and atherosclerosis and could be used to assess CAD.