The influence of real-time blood glucose levels on left ventricular myocardial strain and strain rate in pediatric patients with type 1 diabetes mellitus - a speckle tracking echocardiography study

BACKGROUND Echocardiographic myocardial performance parameters such as strain and strain rate are increasingly used to assess systolic and diastolic function in patients with diabetes mellitus and several other clinical and scientific scenarios. While long-term metabolic marks such as HbA1C are inherently assessed in diabetic patients, the actual blood glucose level at the very moment of the echocardiographic study has not yet been taken into account for the assessment of cardiac mechanics. The aim of this study was to investigate the influence of real-time blood glucose levels on left ventricular (LV) myocardial strain and strain rate in pediatric patients with type 1 diabetes mellitus (T1DM). METHODS We performed speckle tracking echocardiography on 39 normotensive pediatric patients with uncomplicated type 1 diabetes mellitus (mean age 11.5 ± 3.5 years, 40 % female) and 44 sex- and age-matched healthy controls (mean age 11.4 ± 2.9 years, 45 % female). T1DM patients were sub-categorized according to their blood sugar levels (with a cutoff of 150 mg/dL) at the moment of the echocardiographic exam. Investigators were blinded to the participants' study group status. RESULTS Interestingly, diabetic patients with higher blood sugar levels demonstrated significantly increased LV circumferential strain (p = 0.003) and strain rate (p = 0.005) as well as global longitudinal strain rate (p = 0.002) in comparison to T1DM patients with lower blood sugar levels or healthy controls. CONCLUSIONS For the investigation of myocardial performance with sensitive methods such as speckle tracking echocardiography in diabetic study populations real-time blood sugar levels should be taken into account. Further studies are needed to verify these findings in large-scale patient cohorts and serial intra-individual measurements in different metabolic states.