Endocrine Abstracts

Introduction: Heart failure (HF) morbidity and mortality are increasing at an alarming rate in people with type 2 diabetes (T2D). Myocardial dysfunction may develop without ischemic heart disease (IHD), hypertension, or valvular pathologies, and which is defined as diabetic cardiomyopathy (DCM). Although the pathophysiology of DCM is unclear, DCM is initially characterised by myocardial fibrosis, dysfunctional remodelling, and associated diastolic dysfunction, later by systolic dysfunction, and eventually by clinical HF. Retinal quantitative traits have been seen associated with cardiovascular complications in T2D. Previous studies have shown that the presence of narrowing retinal arterioles and decreased fractal dimension – a novel biomarker of microvascular density- have been associated with IHD and HF, independent of well-known cardiovascular (CV) risk factors. A novel paradigm of DCM focuses on pro inflammatory signalling originating from the myocardial microvasculature. Nevertheless, phenotyping the cardiac microvasculature in this population is not feasible in clinical settings. In comparison, the retinal microvasculature can be completely noninvasively and reproducibly evaluated. Currently, there is a paucity about the current evidence about retinal traits and DCM. This scoping review aims to map existing literature and provide a summary of retinal parameters and DCM in people with T2D. This includes risk factors, interventions and identification of research gaps in the literature.

Methods: Electronic databases (MEDLINE, EMBASE, and, Web of Science) were systematically and independently searched following the Joanna Briggs Institute (JBI) guidelines until February 2023. Two independent researchers assessed the literature and conducted the review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines for Scoping Reviews (PRISMA-ScR).

Results: Of the 1072 articles screened, 15 articles met inclusion criteria. The majority were cross-sectional and prospective studies concentrated in North America and Europe. In people with T2D, the presence of moderate and severe retinopathy was associated with heart failure and subclinical left ventricular myocardial dysfunction. Moreover, low retinal vascular fractal dimension was associated with congestive heart failure.

Conclusion: There has been much optimism that quantitative retinal traits may associate with diabetic cardiomyopathy beyond conventional CV risk factors. However, evidence is scarce in people with T2D compared to population-based studies. Clearly, further studies are necessary to understand the potential phenotypes including echocardiographic findings and underlying mechanisms for DCM in people with T2D.