Preclinical Systolic and Diastolic Dysfunctions in Metabolically Healthy and Unhealthy Obese Individuals

Abstract

Background: Despite the substantial overlap of obesity and metabolic disease, there is heterogeneity with respect to cardiovascular risk. We sought to investigate preclinical differences in systolic and diastolic function in obesity, and specifically compare obese individuals with and without metabolic syndrome (MS).

Methods and results: Obese individuals without cardiac disease with (OB/MS+, n=124) and without (OB/MS-, n=37) MS were compared with nonobese controls (n=29). Diastolic function was assessed by transmitral and tissue Doppler. Global longitudinal strain (LS) and time-based dyssynchrony were assessed by speckle tracking. Both OB/MS- and OB/MS+ groups had similar ejection fraction but worse systolic mechanics as assessed by LS and dyssynchrony when compared with nonobese controls. Specifically, OB/MS- had 2.5% lower LS (SE, 0.7%; P=0.001 in multivariable-adjusted analyses) and 10.8 ms greater dyssynchrony (SE, 3.3 ms; P=0.002), and OB/MS+ had 1.0% lower LS (SE, 0.3%; P<0.001) and 7.8 ms greater dyssynchrony (SE, 1.5 ms; P<0.001) when compared with controls. Obesity was associated with impaired diastolic function regardless of MS status, as evidenced by greater left atrial diameter and left ventricular mass although diastolic dysfunction was more pronounced in OB/MS+ than in OB/MS- individuals.

Conclusions: Obesity is associated with subclinical differences in both systolic and diastolic function regardless of the presence or absence of MS although MS seems to be associated with worse diastolic dysfunction. When compared with controls, metabolically healthy obese had lower LS, greater dyssynchrony, and early diastolic dysfunction, supporting the notion that obesity per se may have adverse cardiovascular effects regardless of metabolic disease.

Keywords: cardiovascular diseases; heart diseases; metabolic syndrome X; obesity; risk factors.

Figure 1

Strain measures by study group, including non-obese controls, obese individuals without metabolic syndrome (OB/MS−), and obese individuals with metabolic syndrome (OB/MS+). Panel A shows differences in global longitudinal strain, and panel B shows time-based dyssynchrony. Values represent adjusted means and standard errors, after accounting for age, sex, systolic blood pressure, and the use of anti-hypertensive medications.

Figure 1

Strain measures by study group, including non-obese controls, obese individuals without metabolic syndrome (OB/MS−), and obese individuals with metabolic syndrome (OB/MS+). Panel A shows differences in global longitudinal strain, and panel B shows time-based dyssynchrony. Values represent adjusted means and standard errors, after accounting for age, sex, systolic blood pressure, and the use of anti-hypertensive medications.