Body Mass Index, Smoking Status, and Carotid Intima-Media Thickness in Adults with Cardiometabolic Risk: A Retrospective Analysis of Internal Medicine Records

Background and Objectives: We examined associations of body mass index (BMI) and smoking category with recorded carotid intima-media thickness (IMT) in a predominantly obese clinical cohort. Materials and Methods: This retrospective analysis included 238 internal medicine records from November 2024–December 2025. Linear regression used HC3 confidence intervals. Investigators confirmed MyLab X8 imaging, manual caliper measurement of the distal common carotid far wall, ECG gating, and three measurements per side; original images and reproducibility data were unavailable. Waist and follow-up analyses were exploratory. Results: Obesity was present in 203/234 participants with BMI data; only two had BMI < 25 kg/m2. In the primary model (n = 226), the adjusted IMT difference per 5 kg/m2 BMI was 0.003 mm (95% CI −0.012 to 0.019; p = 0.666); current versus never smoking differed by 0.015 mm (95% CI −0.018 to 0.048; p = 0.380). Each 10 cm greater waist circumference was associated with 0.017 mm greater IMT (95% CI 0.005 to 0.030; p = 0.007; n = 228). BMI and waist were correlated (r = 0.73). Medication adjustment gave similar estimates. Among 179 paired records, mean change was 0.007 mm (95% CI −0.002 to 0.015; p = 0.132). Conclusions: BMI and smoking category were not clearly associated with recorded IMT within this selected cohort. The waist association is hypothesis-generating. Restricted BMI variability, categorical smoking analyses, unavailable original images, and absent reproducibility assessment limit interpretation. These findings do not establish risk-prediction utility, biological progression, or treatment effects.