Cardiovascular

Beyond Body Mass Index: Body Roundness Index, Inflammation, and Death.

Lin D, Chua S, Lee J • Journal of the American Heart Association • 2026

PubMed 42657751 DOI 10.1161/JAHA.125.048324

TL;DR

BRI provides superior mortality prediction compared with BMI, likely due to its association with visceral adiposity and inflammation, with CRP mediating 23.9% of BRI's effect on all-cause death while no significant mediation was observed with BMI.

Key Findings

Results

BRI showed a significant J-shaped association with death, with increased risks at extremes of the index.

The J-shaped relationship indicates that both very low and very high BRI values were associated with elevated mortality risk.
The association was observed in a cohort of 341,336 adults free of cardiovascular disease at baseline.
Mean follow-up duration was 19.1 years.
The study population was drawn from the Taiwan MJ cohort.

Results

BRI outperformed BMI in discriminating all-cause mortality in multivariable models.

Area under the receiver operating characteristic curve (AUC) for BRI was 70.5% versus 59.3% for BMI for all-cause death.
The difference in AUC represents an approximately 11.2 percentage point improvement in discriminatory ability.
Anthropometric, laboratory, and lifestyle data were incorporated into the multivariable models.
The analysis was conducted across 341,336 adults with a mean follow-up of 19.1 years.

Results

BRI outperformed BMI in discriminating cardiovascular mortality in multivariable models.

AUC for BRI was 75.4% versus 62.7% for BMI for cardiovascular death.
The difference in AUC represents an approximately 12.7 percentage point improvement in discriminatory ability for cardiovascular death.
Both anthropometric indices were compared under the same multivariable modeling framework.

Results

Categorical net reclassification improvement analysis indicated that BRI significantly enhanced risk prediction for both all-cause and cardiovascular death compared with BMI.

Net reclassification improvement (NRI) for all-cause death was 44.5%.
Net reclassification improvement for cardiovascular death was 30.2%.
NRI analysis quantifies how much better BRI correctly reclassifies individuals into higher or lower risk categories relative to BMI.

Results

CRP levels significantly mediated BRI's effect on all-cause and cardiovascular death, whereas no significant mediation was observed for BMI.

CRP mediated 23.9% of BRI's effect on all-cause death.
CRP mediated 13.2% of BRI's effect on cardiovascular death.
No significant CRP-mediated pathway was observed for BMI on either outcome.
Mediation analysis was used to evaluate the role of inflammation in the relationship between anthropometric indices and death.
These findings suggest inflammation is a mechanistic pathway linking BRI, but not BMI, to mortality.

Background

BMI was identified as failing to reflect fat distribution, motivating the comparison with BRI as a surrogate for central obesity.

BMI is widely used to assess obesity but does not capture fat distribution patterns.
BRI has been proposed as a better surrogate for central obesity.
Direct comparisons of the predictive power of BRI versus BMI for mortality had remained limited prior to this study.
The authors linked BRI's superior performance to its association with visceral adiposity and inflammation.

What This Means

This research suggests that a newer body measurement called the Body Roundness Index (BRI) is significantly better than the traditional Body Mass Index (BMI) at predicting who is likely to die from any cause or from heart disease. The study followed over 341,000 adults in Taiwan for an average of about 19 years and found that BRI — which accounts for body shape and fat distribution around the abdomen — was far more accurate than BMI at identifying high-risk individuals, with discrimination scores roughly 11–13 percentage points higher. Additionally, BRI correctly reclassified individuals into more appropriate risk categories far more often than BMI did. A key finding was that inflammation, measured by a blood marker called C-reactive protein (CRP), helped explain part of why higher BRI values are linked to greater death risk. CRP accounted for about 24% of BRI's association with all-cause death and 13% of its association with cardiovascular death, while no such inflammatory pathway was found for BMI. This suggests that BRI captures something biologically meaningful — specifically, the harmful effects of fat stored around the organs (visceral fat), which drives inflammation — that BMI simply misses. This research suggests that health systems and clinicians may benefit from considering BRI alongside or instead of BMI when assessing patients' obesity-related health risks. Because BRI better reflects where fat is stored in the body and links more directly to inflammatory processes, it could help identify people at elevated risk who might appear 'normal' by BMI standards. The findings also point to inflammation as a potential target for reducing obesity-related deaths, though further research would be needed to confirm whether interventions that lower CRP translate into improved outcomes in this context.

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Citation

Lin D, Chua S, Lee J. (2026). Beyond Body Mass Index: Body Roundness Index, Inflammation, and Death.. Journal of the American Heart Association. https://doi.org/10.1161/JAHA.125.048324

Key Findings

What This Means

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