Is It Time to Replace BMI?
Is It Time to Replace BMI?
Facts and Fallacies of obesity & Body Composition in Heart Failure
Published : JACC: Heart Failure – June 2025
By: Dr. Melana Yuzefpolskaya, Dr. Paolo C. Colombo
7 Key Facts Everyone Should Know:
1. Heart failure with preserved ejection fraction (HFpEF) is now more common than HFrEF — and obesity plays a bigger role in HFpEF.
2. Though obesity is a known risk factor for heart disease, studies have shown that overweight heart failure patients sometimes have better outcomes — a puzzling pattern called the “obesity paradox.”
3. This paradox may be due to the limitations of BMI, which doesn’t distinguish between fat vs muscle or show where fat is stored.
4. Fat Distribution and Risk
• Visceral fat (around organs) is more harmful than subcutaneous fat due to proinflammatory effects.
• Metrics like waist circumference, waist-to-hip ratio, and waist-to-height ratio better reflect risk.
• UK NICE recommends waist-to-height ratio over BMI.
• Imaging (CT, MRI) offers precise fat distribution data but lacks standardized cutoffs.
5. Sarcopenia in HF
• Present in ~20% of HF patients; strong predictor of mortality.
• Defined by:
1. Low muscle strength (e.g., grip strength)
2. Low muscle quantity/quality
3. Poor physical performance
• Preferred assessment: DEXA scan (with validated sex-specific cutoffs).
• Other tools: BIA, CT, MRI.
6. A major meta-analysis of over 36,000 HF patients found:
• Low muscle mass = higher mortality
• High subcutaneous fat = potentially protective
• Visceral fat = worse outcomes
7. New weight-loss drugs (like semaglutide and tirzepatide) are effective but can also lead to loss of muscle mass — up to 25% of the total weight lost — which may be harmful in older or frail patients with HF.
Takeaway: BMI is an outdated tool for assessing health risk in heart failure. A deeper look at muscle mass, fat distribution, and functional strength gives a much clearer picture of patient risk — and should guide future care.
