Beyond Lean Mass: Body Roundness Index (BRI) Is Independently Associated with Cardiometabolic Health and Physical Performance in Tactical Personnel

Authors

Dongju Lee, Texas A&M University - College StationFollow
Michael J. Conner, Bond University - Gold CoastFollow
Steve E. Martin, Texas A&M University - College StationFollow
Drew E. Gonzalez, Sam Houston State University - HuntsvilleFollow

Abstract

Abdominal obesity and low muscle mass increase cardiometabolic disease (CMD) risk. Firefighters and law enforcement officers may have high lean body mass (LBM), but occupational stressors raise their risk of abdominal obesity and CMD. Body roundness index (BRI) measures abdominal fat, but it's unclear whether high LBM can counteract the metabolic damage caused by abdominal adiposity in these personnel. PURPOSE: To evaluate (1) the associations of BRI and LBM with cardiometabolic and physical outcomes and (2) LBM's moderating effect (BRI × LBM interaction) on how abdominal obesity relates to health risks. METHODS: A cross-sectional study involving 158 first responders analyzed LBM via dual-energy X-ray absorptiometry (DXA) and calculated BRI based on height and waist circumference. The outcomes were classified into cardiometabolic markers (such as SBP, MAP, blood glucose, blood lipids, and CRP), aerobic capacity (including treadmill TTE, treadmill TTE normalized to LBM, and VO₂max), and muscular performance (push-ups and handgrip strength). A 3-step hierarchical linear regression was used: Step 1 adjusted for potential confounders (i.e., age, sex, and occupation); Step 2 evaluated the independent effects of BRI and LBM, while Step 3 examined their interaction. RESULTS: Model 2 (adding DXA variables) improved the explanation of variance for all 11 variables (p<0.05). BRI emerged as the dominant independent predictor of cardiometabolic risk factors: SBP (β=0.27), MAP (β=0.21), BG (β=0.29), HDL (β=-0.26), TG/HDL (β=0.20), and CRP (β=0.39) (all p<0.05). BRI was also a key inhibitory factor (p<0.001) for TTE (β=-0.40) and VO₂max (β=-0.40). For TTE-LBM, Model 2 explained an additional 59% of the variance (ΔR²=0.590, p<0.001), with BRI remaining a negative predictor (β=-0.28, p<0.001), indicating impaired muscular efficiency. BRI was also a strong negative predictor of push-ups (β=-0.38) and handgrip strength (β=-0.28) (all p<0.001). Except for HDL (p=0.034), no BRI × LBM interaction effects were observed across the other ten variables. CONCLUSIONS: High LBM does not counteract the negative effects of abdominal obesity on most cardiometabolic and performance outcomes, except HDL. BRI, regardless of LBM, is a key factor for increased risk and reduced capacity, impairing fitness, CPET, and strength. Thus, optimizing health and readiness should address abdominal obesity (via BRI) alongside traditional methods.

Recommended Citation

Lee, Dongju; Conner, Michael J.; Martin, Steve E.; and Gonzalez, Drew E. (2026) "Beyond Lean Mass: Body Roundness Index (BRI) Is Independently Associated with Cardiometabolic Health and Physical Performance in Tactical Personnel," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 18, Article 162.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss18/162