# Relationship Between Body Composition With Carotid Intima Media Thickness in Young Adults: Tehran Lipid and Glucose Study

## TL;DR

Higher muscle mass in young adults is linked to thicker carotid arteries, suggesting early vascular changes rather than protection, even after adjusting for body fat and other risks.

## Contribution

This study reveals a novel association between higher skeletal muscle mass and increased carotid intima-media thickness in young adults, independent of adiposity and other cardiovascular risk factors.

## Key findings

- Higher skeletal muscle mass index (SMMI) and skeletal muscle mass (SMM) were associated with increased carotid intima-media thickness (cIMT) in both men and women.
- The association between muscle mass and cIMT remained significant even after adjusting for cardiovascular risk factors, indicating a persistent linear relationship.
- Higher muscle mass in young adults may signal early vascular changes rather than protection, especially when paired with higher adiposity.

## Abstract

Body composition, particularly the interplay between skeletal muscle mass and adiposity, has gained attention for its potential impact on cardiovascular health. This study aimed to examine the relationship between body composition and carotid artery intima‐media thickness (cIMT) as an indicator of early atherosclerosis.

This cross‐sectional study was conducted in the Tehran Lipid and Glucose Study (TLGS) cohort, focusing on young adults. Anthropometric measurements, laboratory tests and cIMT assessments were performed. Body composition was assessed using bioelectrical impedance analysis (BIA). The association between skeletal muscle mass index (SMMI) and skeletal muscle mass (SMM) with cIMT was analysed using linear and logistic regression models, adjusted for relevant covariates.

A total of 795 participants (361 women, 434 men) were included in the study. Higher SMMI and SMM quartiles were associated with increased cIMT and a higher risk of high cIMT (above the 75th percentile). For instance, in the age‐adjusted model, the highest quartile (Q4) of SMMI was associated with high cIMT with an OR of 1.80 (95% CI, 1.02–3.20) in men and an OR of 2.17 (95% CI, 1.14–4.13) in women. While these associations were significant after adjustment for age, further adjustment for cardiovascular risk factors attenuated some associations, particularly for SMMI quartiles. However, SMMI and SMM as continuous variables remained positively and significantly associated with cIMT in both sexes (e.g., for fully‐adjusted continuous SMMI: β = 0.010 in men, β = 0.013 in women), indicating a persistent linear relationship independent of major confounders.

In young adults, higher skeletal muscle mass was independently associated with greater cIMT, suggesting it may signal early vascular changes rather than protection, especially when coinciding with higher adiposity. This underscores the need to assess overall body composition and for future longitudinal studies to determine causality.

Our study of 795 young adults found that higher skeletal muscle mass was linked to thicker carotid arteries (increased cIMT), even after considering body fat and other risks. The takeaway: in early adulthood, higher muscle mass—often paired with higher body fat—may signal early vascular changes rather than protection. Cardiovascular health strategies should target optimal overall body composition, not just increasing muscle.