SEVERE obesity was associated with increased risks of acute respiratory failure and mechanical ventilation among patients hospitalised with heart failure with preserved ejection fraction (HFpEF), challenging the concept of a uniformly protective obesity paradox across chronic kidney disease stages.
The findings, drawn from more than 1.18 million hospitalisations, highlighted the respiratory vulnerability associated with Class III obesity in patients with coexisting cardiovascular and kidney disease.
Researchers conducted a retrospective cohort study using data from the National Inpatient Sample between 2016 and 2020.
The analysis included 1,182,104 hospitalisations involving adults with HFpEF, stratified according to body mass index (BMI) category and chronic kidney disease (CKD) stage.
To reduce potential confounding, hospitalisations involving underweight BMI, malnutrition, cachexia, end-stage renal disease or dialysis, metastatic malignancy, active chemotherapy, advanced liver disease, and amyloidosis were excluded.
The primary outcomes were acute respiratory failure and endotracheal intubation or mechanical ventilation.
Researchers performed multivariable logistic regression within individual CKD stages, using hospitalisations without a coded BMI of at least 25 kg/m² as the reference group.
Class III obesity, defined as BMI ≥40 kg/m², was the only obesity category consistently associated with both primary respiratory outcomes across the evaluated CKD stages.
Increased odds of acute respiratory failure were observed from CKD Stage 1 through Stage 4, with reported adjusted odds ratios ranging from 1.549 (95% CI: 1.173–2.047) to 1.500 (95% CI: 1.440–1.562).
Increased odds of endotracheal intubation or mechanical ventilation emerged at CKD Stage 2 and persisted through Stage 4.
However, the associations did not demonstrate a clear stepwise increase with advancing CKD stage.
These findings suggested that severe obesity was associated with respiratory vulnerability across multiple stages of kidney dysfunction in hospitalised patients with HFpEF.
Among hospitalisations involving CKD Stage 4, Class III obesity was additionally associated with vasopressor use, acute kidney injury, and in-hospital mortality.
The findings challenged the notion that obesity consistently confers a protective effect in patients with HFpEF, particularly when respiratory outcomes are considered.
However, the retrospective analysis could not establish causality, and the researchers characterised the findings as hypothesis-generating.
Overall, the study highlighted the potential importance of severe obesity when assessing respiratory risk in hospitalised patients with HFpEF and coexisting CKD.
Further investigation using clinical data is needed to confirm these associations and clarify their implications for patient management.
Reference
Sattarzadeh A et al. Severe obesity, chronic kidney disease, and respiratory complications in hospitalized patients with HFpEF: A nationwide analysis. Am J Heart Plus. 2026
Adobestock/ Studio Romantic
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