AUTHOR=Chen Jiming , Wang Xing , Dong Bin , Liu Chen , Zhao Jingjing , Dong Yugang , Liang Weihao , Huang Huiling 

TITLE=Cardiac function and exercise capacity in patients with metabolic syndrome: A cross-sectional study

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2022.974802

DOI=10.3389/fcvm.2022.974802

ISSN=2297-055X

ABSTRACT=<sec><title>Background</title><p>Metabolic syndrome is a pre-diabetes condition that is associated with increased cardiovascular morbidity and mortality. We aimed to explore how exercise capacity, cardiac structure, and function were affected in patients with metabolic syndrome.</p></sec><sec><title>Methods</title><p>Outpatients with echocardiography and exercise stress test combined with impedance cardiography (ETT + ICGG) results available from Nov 2018 to Oct 2020 were retrospectively enrolled. Echocardiographic, ETT + ICG profiles, and exercise performance were compared between patients with metabolic syndrome and the ones without. Sensitivity analyses were performed excluding patients without established coronary heart disease and further 1:1 paired for age and gender, respectively. Multiple linear regression was used to find out related predictors for maximal metabolic equivalents (METs).</p></sec><sec><title>Results</title><p>Three hundred and twenty-third patients were included, among whom 97 were diagnosed as metabolic syndrome. Compared to patients without metabolic syndrome, echocardiography showed that patients with metabolic syndrome had a significantly lower E/A ratio (<italic>p</italic> &lt; 0.001). Besides, they have larger left atrium, larger right ventricle, and thicker interventricular septum (all <italic>p</italic> &lt; 0.001), but similar left ventricular ejection fraction (<italic>P</italic> = 0.443). ICG showed that patients with metabolic syndrome had significantly higher stroke volume at rest and maximum (<italic>p</italic> &lt; 0.001), higher left cardiac work index at rest and maximum (<italic>p</italic> = 0.005), higher systemic vascular resistance (SVR) at rest (<italic>p</italic> &lt; 0.001), but similar SVI (<italic>p</italic> = 0.888). During exercise, patients with metabolic syndrome had lower maximal METs (<italic>p</italic> &lt; 0.001), and a higher proportion suffering from ST-segment depression during exercise (<italic>p</italic> = 0.009). Sensitivity analyses yielded similar results. As for the linear regression model, 6 independent variables (systolic blood pressure, BMI, E/A ratio, the height of O wave, the peak value of LCWi, and the baseline of SVR) had statistically significant effects on the maximal METs tested in exercise (<italic>R</italic> = 0.525, <italic>R</italic><sup>2</sup> = 0.246, <italic>P</italic> &lt; 0.001).</p></sec><sec><title>Conclusion</title><p>Patients with metabolic syndrome had significant structural alteration, apparent overburden of left ventricular work index, pre-and afterload, which may be the main cause of impaired exercise tolerance.</p></sec>