Metabolically Abnormal Obesity and Carotid Plaque Vulnerability: A Vessel Wall MRI Study Linking Obesity Phenotypes...

Carotid plaque vulnerability, driven by metabolic dysfunction and obesity, is a critical determinant of ischemic stroke risk. However, the heterogeneity of obesity phenotypes-defined by metabolic health-remains underexplored in cardiovascular risk stratification. Therefore, this study employs high-resolution magnetic resonance vessel wall imaging to assess differences in high-risk carotid plaque features among obesity subtypes stratified by metabolic dysfunction and body mass index.

This multicenter, cross-sectional study of 1037 Chinese adults with symptomatic carotid atherosclerosis utilized magnetic resonance vessel wall imaging to assess differences in high-risk carotid plaque features-intraplaque hemorrhage (IPH), lipid-rich necrotic core, and fibrous cap rupture-across 4 obesity phenotype subgroups: metabolically healthy normal weight (MHNW), metabolically abnormal normal weight, metabolically healthy obese (MHO), and metabolically abnormal obese (MAO).

Of 1037 eligible patients, the proportion of patients in MHNW, metabolically abnormal normal weight, MHO, and MAO groups was 51.6% (n=535), 6.9% (n=72), 16.7% (n=173), and 24.8% (n=257), respectively. Both prevalences of high-risk carotid plaque (22.5% versus 16.6% in MHNW; P=0.002) and IPH (17.1% versus 10.1% in MHNW; P<0.001) in the MAO group were higher than those in the MHNW and MHO groups (all P<0.05). The MHO group exhibited plaque stability similar to MHNW, whereas metabolically abnormal normal weight had greater maximum wall thickness (P=0.004) than MHO and higher IPH prevalence than MHNW (P=0.054). Several carotid plaque morphological variables significantly differed among the 4 groups (all P<0.05). In further adjusted logistic regression models, MAO was independently associated with IPH (P=0.015), alongside male sex, advanced age, and antihypertensive agent use.

This study redefines the role of obesity in atherosclerosis by prioritizing metabolic health over body mass index, demonstrating that MAO is independently associated with IPH and exhibits elevated high-risk carotid plaque/IPH prevalence versus MHNW/MHO. The robustness of IPH as a metabolic instability indicator warrants particular attention.

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02017756.