Obesity May Mask Heart Failure by Lowering NT-proBNP Levels: Study
Portugal: Researchers have found in a new study that obesity may mask heart failure by lowering NT-proBNP levels. Obesity was associated with reduced N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations despite a higher burden of heart failure symptoms and structural cardiac abnormalities. The findings indicate that standard fixed NT-proBNP cut-offs may not reliably exclude heart failure in individuals with obesity.
The study, published in the European Journal of Heart Failure, was conducted by Cristina Gavina and colleagues as part of the PORTHOS population-based investigation in Portugal. NT-proBNP is a widely used biomarker in heart failure evaluation, helping clinicians rule in or rule out the condition. However, its interpretation has largely relied on uniform threshold values that may not account for differences in body composition.
In the large population-based analysis of adults aged 50 years and older, researchers evaluated the relationship between different measures of adiposity—body mass index (BMI), waist circumference, and waist-to-height ratio—and circulating NT-proBNP levels. Out of 2,498 participants, obesity prevalence varied widely depending on the metric used, ranging from about one-quarter of participants by BMI criteria to more than 70% when assessed using the waist-to-height ratio.
The study led to the following findings:
- A consistent inverse relationship was observed between body fat and NT-proBNP levels.
- Higher BMI was associated with progressively lower NT-proBNP concentrations.
- NT-proBNP levels decreased by approximately 50 pg/mL for every 5 kg/m² increase in BMI.
- Increasing adiposity may reduce or dilute natriuretic peptide levels, potentially masking underlying cardiac disease.
- Individuals with obesity and NT-proBNP levels below 125 pg/mL still showed a higher burden of heart failure.
- Compared with lean individuals with higher NT-proBNP levels, these patients had nearly twice the odds of heart failure symptoms.
- They also had more than three times the likelihood of structural abnormalities on echocardiography.
- These findings were observed despite obese participants being younger on average and having much lower median NT-proBNP levels.
These findings suggest that fixed NT-proBNP cut-offs may underestimate heart failure in individuals with obesity, potentially delaying diagnosis. With rising global obesity rates, this limitation is likely to become increasingly important, especially for heart failure with preserved ejection fraction, which is more prevalent in this group.
The authors noted that although the inverse relationship between adiposity and NT-proBNP is biologically plausible and aligns with previous studies, the findings should be interpreted with caution. The analysis was based on a single national cohort without external validation, and the number of obese participants with low NT-proBNP levels was limited. The lack of long-term follow-up also restricts the assessment of clinical outcomes.
Overall, the study indicates that NT-proBNP interpretation should consider body size and adiposity. In patients with obesity and elevated cardiovascular risk, a “normal” NT-proBNP level may not reliably exclude heart failure, underscoring the need for more individualized diagnostic approaches.
Reference:
Gavina, C., Ferreira, J. P., Mendes, L. L., Bernardo, F., Gonçalves, S., Pimenta, J., Franco, F., Diaz, S., Savarese, G., & Baptista, R. Anthropometric adiposity measures and natriuretic peptides in heart failure screening: Population-based evidence from the PORTHOS study. European Journal of Heart Failure. https://doi.org/10.1093/ejhf/xuag154
Next Story