Prevalence of asymptomatic silent myocardial ischemia among type 2 diabetes mellitus patients in Bangalore - A hospital-based cross-sectional study

Background: Earlier diagnosis of asymptomatic coronary artery disease (CAD) in diabetics may prevent catastrophic cardiac events and hence warrants the need for detection of silent myocardial ischemia (SMI). Therefore, the study aimed to assess the role of treadmill test (TMT) in patients who were asymptomatic, to detect and estimate the occurrence of SMI (positive exercise TMT), and to find the association between presence of SMI and duration of diabetes mellitus (DM). Methodology: A cross-sectional study was undertaken among 162 DM cases (type 2) with a mean age of 55.32 ± 11.89 years, who had undergone a TMT without any CAD evidence clinically. All the subjects had normal 12 lead electrocardiography and underwent TMT. Results: Among 162 subjects, TMT was positive in 63 (38.9%) study subjects. TMT positivity for inducible ischemia in type 2 DM patients was associated with increasing age, higher body mass index (BMI), smoking, higher HbA1C, albuminuria, retinopathy, and atherosclerotic cardiovascular disease (ASCVD) risk score. Smoking, diabetic retinopathy, and urine albumin were associated with TMT significantly (P value < 0.005). A significant linear increasing trend in proportion of TMT positive over HbA1c was observed. Mean height of TMT-positive subjects (159.2 ± 7.47 cm) was more than TMT-negative subjects (P < 0.005). The mean BMI (29.69 ± 3.58 kg/m2) and triglycerides (173.87 ± 112.7 mg/dl) of TMT-positive subjects were more than TMT-negative subjects (P < 0.005). Conclusion: CAD prevalence is greater in asymptomatic cases of type 2 DM in this geographic region. A significant linear increasing trend was observed in TMT positive over HbA1c. Hence, TMT can be incorporated in routine screening for SMI in patients suffering from diabetes.