Insulin resistance linked to subtle myocardial dysfunction in normotensive Turner syndrome young patients without structural heart diseases

Background Turner syndrome (TS) patients have increased cardiovascular risk. This cardiovascular risk is famously attributed to structural abnormalities of the left side of the heart such as aortic stenosis and aortic coarctation. However, due to insulin resistance and subsequent pathogenic mechanisms, normotensive TS patients without structural abnormalities may develop varying degrees of myocardial dysfunction. The aim of this research was to examine the role of speckle tracking echocardiography in early detection of Turner cardiomyopathy and to correlate this myocardial dysfunction with measures of insulin resistance. Methods This cross-sectional case control study included 30 children with TS and 30 age-matched healthy controls. TS patients were excluded if: hypertensive, with major structural abnormalities of the heart or other systemic diseases that may affect myocardial function. Conventional speckle tracking echocardiography and glucose-insulin ratio were performed for all study subjects. Results Routine echocardiographic parameters of left ventricular systolic function were similar in cases and controls while global longitudinal and circumferential strain (GLS and GCS) were lower in patients with TS than controls: (-13.2±1.1 vs. -18.3±2.4, p-value<0.000) and (-11.3±1.1 vs. -16.3±2.1, p-value<0.000), respectively. Fasting glucose:insulin ratio (FGIR) proved to be the best predictor of myocardial dysfunction in TS patients by multivariate analysis. Conclusions This study points towards the potential role of two-dimensional (2D) speckle tracking echocardiography in early detection of subtle systolic myocardial dysfunction in TS patients. It also points towards the implication of insulin resistance in precipitation of the observed dysfunction in TS patients.