Echocardiographic Evaluation of Diastolic Dysfunction in Asymptomatic Type 2 Diabetes Mellitus Patients

INTRODUCTION:As per the latest edition of International Diabetes Federation(IDF) Diabetes Atlas, diabetes mellitus currently affects approximately 371 million people worldwide, and majority (90%-95%) have type 2 diabetes mellitus, which is considered a metabolic cum vascular disease. The morbidity and mortality due to type 2 DM is due to its micro and macrovascular complications which affect nearly every organ system in the body -particularly heart. There is a marked increase in incidence of congestive heart failure, coronary artery disease in diabetic patients. The relative risk of developing heart failure is 3.8 in diabetic men and 5.5 in diabetic women, when compared with non-diabetic individuals. Despite similar left ventricular systolic dysfunction, patients with diabetes have more pronounced heart failure symptoms, use more diuretics, and have an adverse prognosis compared with those without diabetes; one putative explanation for these discrepancies is diastolic dysfunction of the left ventricle in diabetes mellitus. Left ventricular diastolic dysfunction thus represent the first stage of diabetic cardiomyopathy preceding changes in systolic function. The diastolic abnormalities are present in diabetic patients without overt diabetic complications of cardiovascular system, reinforcing the importance of early examination of ventricular function in individuals with diabetes mellitus. MATERIALS AND METHODS: This was a cross sectional study, conducted over a period of one year from August 2012 to August 2013. 50 patients with type 2 DM who had no symptoms of cardiovascular disease with normal BP and normal ECG were enrolled. Informed consent was obtained from the patients and they underwent a thorough physical examination, supported by laboratory investigations. A Doppler 2D echo was done in each patient and a calculation of LV ejection fraction, LA dimension, E velocity, A velocity and E/A ratio were done. E/A ratio of < 1with increased LA size and normal ejection fraction of > 60% was used as echo diagnostic criteria for LV diastolic dysfunction. RESULTS: Our study consisted of 50 patients with type 2 DM, 30(60%) were females and 20(40%) males. Majority of patients were in the age group of 40 -70 years. Diastolic dysfunction was present in 24(48%) patients out of whom 8 were males and 16 females. The maximum number of patients with LV diastolic dysfunction was in age group 50 -59 years. There was a linear increase in prevalence of diastolic dysfunction with increasing age, increased duration of diabetes mellitus and increasing HbA1c levels. There was also significant correlation between LV diastolic dysfunction (LVDD) and microangiopathy. Out of 13 patients who had diabetic retinopathy, 8 patients had LVDD and out of 11 patients with microalbuminuria, 9 patients had LVDD.CONCLUSION: LV diastolic dysfunction is an early manifestation of diabetic cardiomyopathy. Its prevalence correlates with duration of diabetes, HbA1c values and presence of microangiopathy. LVDD contributes significantly to morbidity of congestive heart failure in diabetic patients. Echocardiography is a very useful noninvasive tool in detecting LVDD in asymptomatic type 2 DM patients.