Abstract #1407512: Correlation of Severity of Diabetic Retinopathy with Subclinical Hypothyroidism and its Influence on Systolic and Diastolic Function of the Heart

Abstract

This study is aimed to explore the correlation of severity of Diabetic Retinopathy with Subclinical hypothyroidism and its influence on the systolic and diastolic function of the heart. It’s a case control study of 150 patients of type 2 diabetes mellitus [T2DM] with diabetic retinopathy. Serum thyroid profile (free triiodothyronine [FT3], free thyroxine [FT4] and thyroid-stimulating hormone [TSH]) was done and patients were divided into two groups – cases and controls. Cases included patients of diabetic retinopathy [DR] with subclinical hypothyroidism [SCH] and controls included patients of diabetic retinopathy with euthyroidism (ETH). Effect of severity of diabetic retinopathy and thyroid status on diastolic and systolic function of the heart was assessed by 2D-ECHO and tissue doppler imaging [TDI] and compared among the two groups. Men (N 80) had higher prevalence of DR as compared to women (N 70). The prevalence of SCH in DR patients in our study was 26% (N 39) Severe non-proliferative DR [NPDR] was more prevalent in SCH group as compared to ETH group (N 111) (43.60% vs 42.04%). Increased TSH values were linked to the severity of DR more in females of SCH group as compared to males (p<0.0001). Tissue Doppler echocardiography (TDE) revealed decreased mitral annular E velocity in septal localization in the SCH group compared to euthyroid controls (p<0.0001). Based on S/D ratio, the number of patients with grade 2 (38.46% vs 35.90%) and grade 3 left ventricular diastolic dysfunction [LVDD] (28.21% vs 21.79%) were more in SCH group as compared to the ETH group. This indicates that severity of LVDD is seen more in SCH group as compared to the ETH group. Longer duration of diabetes was associated with increased risk of LVDD (p<0.0001). The mean FBS, PPBS and HbA1C were significantly higher in patients who had LVDD indicating that uncontrolled T2DM is associated with increased risk of LVDD (p<0.0001). There was significant difference between A-velocity (p=0.02), E' septal velocity (p<0.0001), E/E' ratio (p<0.0001), Isovolumic relaxation time [IVRT] (p=0.01), deceleration time [DT] (p<0.0001) and left atrial volume index [LAVI] (p<0.0001) between patients with LVDD and without LVDD. Mean ejection fraction [EF] was lower in the patients with LVDD as compared to the absent group (p<0.001). As the severity of DR increased, the severity of LVDD also increased. Mean values of EF decreased as the severity of DR increased indicating that the association between left ventricular dysfunction and diabetic retinopathy. The mean EF of grade 1 (44.54 ± 1.33 vs 50.3 ± 6.62) and grade 2 LVDD patients (42.07 ± 1.33 vs 48.89 ± 6.2) in SCH group was low as compared to ETH group (p<0.0001). SCH was associated with longer duration of diabetes, increasing age and severity of diabetic retinopathy. The prevalence of LVDD and systolic dysfunction was more in patients of SCH as compared to ETH group.