Analysis of myocardial work in different obesity phenotypes and its association with epicardial adipose tissue

Objective To evaluate subclinical cardiac dysfunction across distinct obesity phenotypes using myocardial work (MW) indices, and to investigate the moderating role of epicardial adipose tissue (EAT) on MW impairment. Methods One hundred ninety-two participants were categorized by BMI and metabolic status into four groups: metabolically healthy normal weight (MHNW), metabolically healthy obesity (MHO), metabolically unhealthy normal weight (MUNW), and metabolically unhealthy obesity (MUO). MW indices were measured using speckle-tracking echocardiography. EAT volume was quantified from ECG-gated CT scans. Associations were analyzed using ANCOVA and regression models. Results Despite no significant differences in left ventricular ejection fraction (LVEF) among the groups, MUNW and MUO individuals exhibited significantly impaired MW, characterized by lower global work index (GWI), global constructive work (GCW), and global work efficiency (GWE), alongside higher global waste work (GWW), compared with MHNW controls. MHO patients showed significantly better MW profiles than MUNW and MUO groups. EAT volume was increased in all obesity phenotype groups. Although no direct association was found between EAT volume and MW indices, EAT volume significantly moderated the relationship between Metabolically Unhealthy (MUH) and both GWE and GWW. Conclusions MW detects subclinical dysfunction earlier than LVEF across obesity phenotypes, with impairment progressively worsening from MHO to MUNW to MUO. In metabolically unhealthy individuals with increased EAT volume, more pronounced reductions in GWE and elevations in GWW were observed. Trial Rrgistration This study has been registered in the Chinese Clinical Trial Registry under the registration number ChiCTR2500100754 (registration date: April 15, 2025).