Risk stratification using magnetic resonance imaging-derived, personalized z-scores of visceral adipose tissue, subcutaneous adipose tissue, and liver fat in persons with obesity
Jennifer Linge, Per Widholm, Daniel Nilsson, Alexander Kugelberg, Torsten Olbers, Olof Dahlqvist Leinhard
Abstract
BackgroundIndividual patterns of fat accumulation (visceral-, subcutaneous-, and/or liver fat) can determine cardiometabolic risk profile.ObjectiveTo investigate risk stratification using personalized fat z-scores in persons with body mass index (BMI) 30-40 kg/m2 from the UK Biobank imaging study.SettingPopulation-based studyMethodsWhole-body Magnetic resonance (MR) images of 40174 participants from the UK Biobank imaging study were analyzed for visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (aSAT), and liver fat (LF) and used to calculate sex-, and body size invariant fat z-scores (VATz, aSATz, LFz). Associations between z-scores and later incident cardiovascular disease (CVD) and type 2 diabetes (T2D) were investigated using Cox proportional-hazards modelling and Kaplan-Meier curves in participants with BMI 30-40 kg/m2.Results6716 participants had BMI 30-40 kg/m2 and within this group, CVD was positively associated with VATz (crude hazard ratio (cHR) [95% CI]: 1.30 [1.20-1.40], p<0.001), and negatively associated with aSATz and LFz (cHR: 0.91 [0.85-0.99], p=0.028 and 0.88 [0.82-0.95], p=0.002). All z-scores remained significant after adjustment for sex, BMI, and age, but only VATz when also adding previous CVD. T2D were positively associated with VATz and LFz (cHR: 1.53 [1.40-1.67], p<0.001 and 1.35 [1.23-148], p<0.001) and negatively associated with aSATz (cHR: 0.90 [0.81-0.99], p=0.026). All z-scores remained significant after adjustment for sex, BMI, and age.ConclusionsPersonalized MR-derived fat z-scores can identify phenotypes of obesity with specific cardiometabolic risk profiles regardless of BMI. Current guidelines for bariatric surgery based on BMI exclude some of these high-risk patients.