Urinary c‐peptide creatinine ratio (UCPCR) as a predictor of coronary artery disease in type 1 diabetes mellitus

BACKGROUND: Elevated C‐peptide has been suggested as a risk factor for coronary artery disease (CAD). Elevated urinary C‐peptide to creatinine ratio (UCPCR) as an alternative measurement is shown to be related to insulin secretion dysfunction; however, data regarding UCPCR predictive value for CAD in diabetes mellitus (DM) are scarce. Therefore, we aimed to assess the UCPCR association with CAD in type 1 DM (T1DM) patients. METHODS: 279 patients previously diagnosed with T1DM included and categorized into two groups of CAD (n = 84) and without‐CAD (n = 195). Furthermore, each group was divided into obese (body mass index (BMI) ≥ 30) and non‐obese (BMI < 30) groups. Four models utilizing the binary logistic regression were designed to evaluate the role of UCPCR in CAD adjusted for well‐known risk factors and mediators. RESULTS: Median level of UCPCR was higher in CAD group compared to non‐CAD group (0.07 vs. 0.04, respectively). Also, the well‐acknowledged risk factors including being active smoker, hypertension, duration of diabetes, and body mass index (BMI) as well as higher levels of haemoglobin A1C (HbA1C), total cholesterol (TC), low‐density lipoprotein (LDL) and estimated glomeruli filtration rate (e‐GFR) had more significant pervasiveness in CAD patients. Based on multiple adjustments by logistic regression, UCPCR was a strong risk factor of CAD among T1DM patients independent of hypertension, demographic variables (gender, age, smoking, alcohol consumption), diabetes‐related factors (diabetes duration, FBS, HbA1C), lipid profile (TC, LDL, HDL, TG) and renal‐related indicators (creatinine, e‐GFR, albuminuria, uric acid) in both patients with BMI≥30 and BMI < 30. CONCLUSION: UCPCR is associated with clinical CAD, independent of CAD classic risk factors, glycaemic control, insulin resistance and BMI in type 1 DM patients.