Metabolic syndrome and myocardium steatosis in subclinical type 2 diabetes mellitus: a 1H-magnetic resonance spectroscopy study

Abstract

Background: Metabolic syndrome (MetS) is a cluster of metabolic abnormalities that collectively cause an increased risk of type 2 diabetes mellitus (T2DM) and nonatherosclerotic cardiovascular disease. This study aimed to evaluate the role of myocardial steatosis in T2DM patients with or without MetS, as well as the relationship between subclinical left ventricular (LV) myocardial dysfunction and myocardial steatosis.

Methods and materials: We recruited 53 T2DM patients and 20 healthy controls underwent cardiac magnetic resonance examination. All T2DM patients were subdivide into two group: MetS group and non-MetS. LV deformation, perfusion parameters and myocardial triglyceride (TG) content were measured and compared among these three groups. Pearson's and Spearman analysis were performed to investigate the correlation between LV cardiac parameters and myocardial steatosis. The receiver operating characteristic curve (ROC) was performed to illustrate the relationship between myocardial steatosis and LV subclinical myocardial dysfunction.

Results: An increase in myocardial TG content was found in the MetS group compared with that in the other groups (MetS vs. non-MetS: 1.54 ± 0.63% vs. 1.16 ± 0.45%; MetS vs. normal: 1.54 ± 0.63% vs. 0.61 ± 0.22%; all p < 0.001). Furthermore, reduced LV deformation [reduced longitudinal and radial peak strain (PS); all p < 0.017] and microvascular dysfunction [increased time to maximum signal intensity (TTM) and reduced Upslope; all p < 0.017)] was found in the MetS group. Myocardial TG content was positively associated with MetS (r = 0.314, p < 0.001), and it was independently associated with TTM (β = 0.441, p < 0.001) and LV longitudinal PS (β = 0.323, p = 0.021). ROC analysis exhibited that myocardial TG content might predict the risk of decreased LV longitudinal myocardial deformation (AUC = 0.74) and perfusion function (AUC = 0.71).

Conclusion: Myocardial TG content increased in T2DM patients with concurrent MetS. Myocardial steatosis was positively associated with decreased myocardial deformation and perfusion dysfunction, which may be an indicator for predicting diabetic cardiomyopathy.

Keywords: 1H-magnetic resonance spectroscopy; Metabolic syndrome; Myocardial steatosis; Subclinical myocardial dysfunction.

Fig. 1

Measurement of myocardial triglyceride content by 1H-MRS. Left 4-chamber and 2-chamber cardiac image. The signal voxel was positioned at the interventricular septum in meddle slice. Myocardial triglyceride content was calculated as a percentage related to water and expressed

Fig. 2

Differences in myocardial triglyceride content (a), LV longitudinal PS (b), LV radial PS (c), upslope (d) and TTM (e) among patients in T2DM with MetS, T2DM without MetS, and normal subjects. *p < 0.017

Fig. 3

Relationship between myocardial triglyceride content and LV longitudinal PS, TTM and upslope

Fig. 4

Receiver operating characteristic curve (ROC) analysis to predict the relationship between the myocardial triglyceride content and TTM (a), LV longitudinal PS (b)