Cardiac Function is Preserved in Adolescents With Well-Controlled Type 1 Diabetes and a Normal Physical Fitness: A Cross-Sectional Study

Abstract

Background Cardiovascular diseases and exercise intolerance elevate mortality in type 1 diabetes mellitus (T1DM). Left ventricular systolic and diastolic function are already affected in T1DM adolescents displaying poor glycaemic control (A1c>7.5%) and exercise intolerance. We investigated to what extent left ventricular function is affected by disease severity/duration and whether this is related to exercise capacity. Methods Transthoracic echocardiography was performed in 19 T1DM adolescents (14.8±1.9 years, A1c 7.4±0.9%) and 19 controls (14.4±1.3 years, A1c 5.3±0.2%) matched for age and Tanner stage. Diastolic and systolic (ejection fraction (EF)) function were assessed. Cardiopulmonary exercise testing was used to evaluate exercise capacity (V̇ O2peak). Results V̇ O2peak and left ventricular systolic and diastolic function were similar in both groups. Within T1DM, EF was negatively associated with disease duration (r=-0.79 corrected for age, BMI-SDS, glucose variability and V̇ O2peak, p=0.011). Regression analyses revealed that 37.6% of the variance in EF could be attributed to disease duration. Conclusion Although left ventricular systolic and diastolic function are preserved in T1DM with adequate exercise capacity, disease duration negatively affects EF. The detrimental effects of T1DM seem to be driven by disease duration, rather than by disease severity, at least during adolescence. Young T1DM patients might therefore benefit from cardiovascular evaluation, in order to detect cardiovascular abnormalities early in the disease course and therefore improve cardiovascular health on the long term.