Association between Severity of Diabetic Retinopathy and Cardiac Function in Patients with Type 2 Diabetes

Abstract

Background. The purpose of this research was to assess the relationship between the severity of diabetic retinopathy (DR) and indexes of left ventricle (LV) structure and function in type 2 diabetes mellitus (T2DM). Methods. Retrospective analysis of 790 patients with T2DM and preserved LV ejection fraction. Retinopathy stages were classified as no DR, early nonproliferative DR, moderate to severe nonproliferative DR, or proliferative DR. The electrocardiogram was used to assess myocardial conduction function. Echocardiography was used to evaluate myocardial structure and function. Results. Patients were divided into three groups based on the DR status: no DR group (NDR, $n=475$ ), nonproliferative DR group (NPDR, $n=247$ ), and proliferative DR group (PDR, $n=68$ ). LV interventricular septal thickness (IVST) increased significantly with more severe retinopathy (NDR: $10.00\pm 1.09$ ; NPDR: $10.42\pm 1.21$ ; and PDR: $10.66\pm 1.58$ ; $P$ < 0.001). Multivariate logistic regression analysis showed that the significant correlation of IVST persisted between subjects with no retinopathy and proliferative DR (odds $\text{ratio}=1.35$ , $P=0.026$ ). Indices of myocardial conduction function were assessed by electrocardiogram differences among groups of retinopathy (all $P<0.001$ ). In multiple-adjusted linear regression analyses, the increasing degree of retinopathy was closely correlated with heart rate ( $\beta =1.593$ , $P=0.027$ ), PR interval ( $\beta =4.666$ , $P=0.001$ ), and QTc interval ( $\beta =8.807$ , $P=0.005$ ). Conclusion. The proliferative DR was independently associated with worse cardiac structure and function by echocardiography. Furthermore, the severity of retinopathy significantly correlated with abnormalities of the electrocardiogram in patients with T2DM.