Determinants of Poor Glycemic Control in Type 2 Diabetes Patients With Coronary Artery Disease: A Case‐Control Study

ABSTRACT Background and Aim Poor glycemic control increases the risk of cardiovascular complications in patients with type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD). The current study identified determinants of poor glycemic control in Iranian T2DM patients with CAD. Methods This case–control study included T2DM patients with CAD who were admitted to Golestan Hospital in Ahvaz (Iran) during 2 years. Demographic, clinical, and biochemical data were collected. According to their glycemic control status, patients were divided into two groups: uncontrolled glycemia (Group 1, n = 350; hemoglobin A1c [HbA1c] > 7%) and controlled glycemia (Group 2, n = 350; HbA1c ≤ 7%). Results The study assessed 700 T2DM patients with CAD (458 males and 242 females). Their average age was 60.51 ± 9.76 years. Compared to patients with optimal glycemic control, those with uncontrolled glycemia were younger, had higher rates of dyslipidemia, previous myocardial infarction, smoking, chronic kidney disease, hypertension, peripheral artery disease, diabetes for a longer period, higher body mass index (BMI), lower ventricular ejection fraction, greater levels of total cholesterol, HbA1c, fasting blood glucose, triglycerides, triglyceride‐glucose (TyG) index, and low‐density lipoprotein cholesterol ( p < 0.05). In addition, there were substantial differences in the prevalence of New York Heart Association (NYHA) functional class, angiographic findings (including severe calcification, type B2/C lesions, chronic total occlusion lesions, thrombotic lesions, and ostial lesions), as well as the use of oral glucose‐lowering medications and insulin between the two groups ( p < 0.05). Furthermore, 42.6% of patients exhibited triple vessel disease, and 60% of them had HbA1c level > 7%. Diabetes duration, BMI, and TyG index were significant independent predictors of glycemic control. Conclusion This study revealed that CAD patients with good glycemic control had better clinical and cardiovascular status. HbA1c may serve as a valuable parameter for risk stratification in these patients.