Independent Predictors of Circulating Trimethylamine N-oxide (TMAO) and Resistin Levels in Subjects with Obesity: Associations with Carotid Intima-Media Thickness and Metabolic Parameters

Background: obesity is a major contributor to cardiometabolic risks, including subclinical atherosclerosis and insulin resistance. This study investigates the roles of Trimethylamine N-oxide (TMAO) and resistin as obesity predictors, examining their associations with carotid intima-media thickness (CIMT) and metabolic parameters; Methods: sixty adults (18–71 years), spanning normal weight to obesity, were assessed for body mass index (BMI), waist-to-hip ratio (WHR), and waist circumference (WC). Body composition was measured using the TANITA BC-418 device, while subclinical atherosclerosis was evaluated via CIMT with the Aixplorer MACH 30 ultrasound system. Blood samples were analyzed for TMAO, resistin, and metabolic biomarkers; Results: TMAO, resistin, CIMT, fat mass, glucose, HbA1c, and lipid profiles significantly increased across BMI categories (p<0.001). TMAO correlated strongly with CIMT (r=0.674, p<0.001), indicating its role in subclinical atherosclerosis. Logistic regression identified TMAO (threshold 380; AUC=0.880, accuracy=91.7%) as a predictor of cardiometabolic risk. Resistin was associated with CIMT, WHR, and total cholesterol, inversely linked to LDL cholesterol (p=0.003). Less active participants exhibited higher TMAO (p=0.001) and resistin (p=0.02). Family histories of obesity and diabetes correlated with elevated TMAO, while resistin linked to shorter sleep duration and diabetes history, highlighting their importance in obesity-related cardiometabolic risks; Conclusions: TMAO is closely associated with abdominal fat, insulin resistance, and subclinical atherosclerosis, while resistin relates to lipid profiles and aging. Together, they provide a nuanced predictive model for obesity-related cardiometabolic risks, reinforcing their value in risk stratification and targeted management.