Preclinical Alterations in Myocardial Microstructure in People with Metabolic Syndrome

Abstract

Objective: Metabolic syndrome (MetS) can lead to myocardial fibrosis, diastolic dysfunction, and eventual heart failure. This study evaluated alterations in myocardial microstructure in people with MetS by using a novel algorithm to characterize ultrasonic signal intensity variation.

Methods: Among 254 participants without existing cardiovascular disease (mean age 42 ± 11 years, 75% women), there were 162 with MetS, 47 with obesity without MetS, and 45 nonobese controls. Standard echocardiography was performed, and a novel validated computational algorithm was used to investigate myocardial microstructure based on sonographic signal intensity and distribution. The signal intensity coefficient (SIC [left ventricular microstructure]) was examined.

Results: The SIC was significantly higher in people with MetS compared with people with (P < 0.001) and without obesity (P = 0.04), even after adjustment for age, sex, body mass index, hypertension, diabetes mellitus, and the ratio of triglyceride (TG) to high-density lipoprotein (HDL) cholesterol (P < 0.05 for all). Clinical correlates of SIC included TG concentrations (r = 0.21, P = 0.0007) and the TG/HDL ratio (r = 0.2, P = 0.001).

Conclusions: This study's findings suggest that preclinical MetS and dyslipidemia in particular are associated with altered myocardial signal intensity variation. Future studies are needed to determine whether the SIC may help detect subclinical diseases in people with metabolic disease, with the ultimate goal of targeting preventive efforts.

Figure 1

Measures of myocardial backscatter in individuals with MetS, obesity without MetS, and non-obese controls. Panel A displays the signal intensity coefficient, and panel B the myocardial structure index. Error bars represent standard errors.

Figure 2

Correlation between myocardial microstructure (SIC) and triglyceride concentrations. Given skewed distributions, both SIC and triglyceride concentrations are log-transformed.

Figure 3

The SIC is higher among individuals with abnormal triglyceride-to-HDL cholesterol ratios greater than 3.