Obesity is recognized as an independent risk factor for the development of heart failure (HF). Still, in established HF, mild-to-moderate obesity is associated with substantially improved survival compared to normal weight, a phenomenon known as the “obesity-survival paradox.”1,2 Measuring cardiovascular (CV) risk in obesity and HF with reduced ejection fraction (HFrEF) outcomes historically have applied body mass index (BMI) to measure adiposity. However, experts noted that BMI failed to account for location/amount of body fat or the weight of the skeleton, etc.; newer, more accurate adiposity indices may be needed.
The Butt et al (2023) study, “Anthropometric measures and adverse outcomes in heart failure with reduced ejection fraction: revisiting the obesity paradox,” sought to compare newer anthropometric measurements versus BMI in patients with HFrEF enrolled in the PARADIGM-HF.3 The primary outcome was HF hospitalization or CV death. The study also assessed whether these newer indices would reinforce the obesity-survival paradox. Correlation between anthropometric indices and outcomes was adjusted as needed for other prognostic variables, including natriuretic peptides.
Anthropometric indices used in the study included: BMI; body roundness index (BRI); body surface area (BSA); body shape index (BSI); hip circumference (HC); relative fat-mass index (RFM); waist circumference (WC); waist-hip ratio (WHR); waist-to-height ratio (WHtR); weight–adjusted-waist index (WWI).
Newer Anthropometric Indices Showed Prognostic Value
Study results confirmed the obesity-survival paradox in a lower mortality risk in patients with BMI ≥25 kg/m2 (compared to normal weight); however, when adjusted for other prognostic variables, the paradox disappeared. In fact, the obesity-survival paradox also occurred in the waist-to-height ratio (WHtR; as representative of indices not incorporating weight); yet, when results were adjusted for other variables, the paradox vanished (adjusted hazard ratio [aHR] for all-cause mortality: 1.10 [95% confidence interval {CI}, 0.87–1.39]).
In the association of greater adiposity with a higher risk of HF hospitalization or CV death, both BMI and WHtR showed greater risk. This risk was more evident with WHtR than with BMI, persisting even after adjustment for prognostic variables (aHR for HF hospitalization for WHtR: 1.39 [95% CI, 1.06–1.81]).
Anthropometric Indices Did Not Generate the Obesity-Survival Paradox
The study determined that newer anthropometric indices did not support the O-S paradox in patients with HFrEF. However, alternative measurement indices not incorporating weight revealed a robust association between greater adiposity and higher HF hospitalization risk. It may be time to consider using newer anthropometric measurements than BMI to calculate CV risks.
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Author: Saskia van Tetering
References:
- Butt JH et al. Anthropometric measures and adverse outcomes in heart failure with reduced ejection fraction: revisiting the obesity paradox. Eur Heart J. 2023;00:1-20. doi:10.1093/eurheartj/ehad083.
- Horwich TB et al. Obesity and the Obesity Paradox in Heart Failure. Progress in Cardiovasc Dis. 2018;61(2):151-156. doi:10.1016/j.pcad.2018.05.005.
- McMurray JVJ et al. Antiotensive-Neprilsyin Inhibition versus Enalapril in Heart Failure (PARADIGM-HF). N Eng J Med. 2014;371:993-1004. doi:10.1056/NEJMoa1409077.