Pre-Clinical Diastolic Dysfunction in Diabetes Mellitus

Background: Studies have reported a high prevalence of pre-clinical diastolic dysfunction among patients with DM. Diabetic patients are often complicated by subsequent development of heart failure, maybe primary or secondary to hypertension / CAD. Abnormalities of both systolic and diastolic performance in diabetic subjects have been demonstrated in various human studies. However, diastolic dysfunction precedes systolic dysfunction. Studies in the West have demonstrated a direct correlation between duration of diabetes and diastolic dysfunction. Hence we attempted to identify the correlation between duration of diabetes mellitus and subsequent LV diastolic dysfunction (E/e' ratio) by conventional and tissue doppler imaging in our local population. Methods: We retrospectively identified all diabetic patients with a Doppler mitral valve imaging (both transmitral and tissue doppler) assessment of diastolic dysfunction at Sri Ramachandra Medical College, Chennai from January -May 2015. Overall, 112 diabetic patients were identified and subjected to a tissue Doppler echocardiographic assessment of diastolic dysfunction after obtaining informed consent. Diastolic dysfunction was defined as Ratio of a passive transmitral left ventricular (LV) inflow velocity to tissue Doppler imaging velocity of the medial mitral annulus during passive filling (E/e') ratio >15. Patients with coronary disease, hypertension, high body mass index, heart failure, mitral valve or aortic valve regurgitation or stenosis were excluded. Results: Of the 112 patients identified, no patient withdrew his/her consent. 69 male patients and 43 female patients were identified with a mean age of 55 years. Of these 51 patients had an average duration of diabetes for more than 4 years.42 (38.4%) patients among this group had diastolic dysfunction (i.e.) E/e' ratio of > 15. Patients with diabetes of less than 4 years' duration had either normal or intermediate level of diastolic dysfunction. Using Chi-square test, we determined that there is a significant association between duration of diabetes and development of diastolic dysfunction (E/e') (x2 = 107.974, Df = 4, 0.000<0.05 significant) in the patients with diabetes for more than 4 years. Conclusion: Our current study demonstrates that pre-clinical diastolic dysfunction is high in DM patients and there is a direct correlation between duration of DM and diastolic dysfunction. Significant diastolic dysfunction occurs 4 years after the onset of DM independent of coronary disease or hypertension. Such patients must be advised regarding strict glycaemic control and followed up for development of frank diastolic dysfunction.