Pulmonary Function Abnormalities in Heart Failure Subtypes: Impact of Upper Body Adiposity

Study objective: Heart failure (HF) syndrome is associated with pulmonary system abnormalities that have a direct impact on mortality. Heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) are distinct subtypes of HF with different pathophysiologies, clinical presentations, and treatment approaches. Obesity is highly prevalent in HFpEF and significantly contributes to its development. Importantly, obesity and high abdominal adiposity can have significant effects on pulmonary function. Therefore, HFpEF patients may have more pronounced pulmonary function impairment than HFrEF patients in part due to higher prevalence of upper body adiposity. Hypothesis: We hypothesized that lung volumes would be lower in patients with HFpEF compared to those with HFrEF and CTL. Further, we hypothesized that higher upper body adiposity (measured as trunk fat by dual-energy X-ray absorptiometry) would be associated with lower lung volumes in patients with HFpEF. Methods: HFpEF patients (n=26), HFrEF patients (n=26) and CTL (n=36) performed pulmonary function tests according to ATS/ERS guidelines. Total lung capacity (TLC), residual volume (RV), forced vital capacity (FVC), and forced expiratory volume in one second (FEV 1 ) were measured and absolute and % predicted values are reported. Dual-energy X-ray absorptiometry scans quantified % trunk fat. Absolute lung volumes were compared across groups using ANCOVA with age as a covariate and % predicted lung volumes were compared using one-way ANOVA. Results: HFpEF patients were older than HFrEF patients and CTL (HFpEF: 71±9 vs. HFrEF: 65±9 vs. CTL: 63±11 yrs, both p0.05). HFpEF patients had higher % trunk fat than CTL (p0.05) (HFpEF: 46±11 vs. HFrEF: 42±8 vs. CTL: 38±11%). HFpEF patients had lower FVC (HFpEF: 3.0±0.7 vs. HFrEF: 3.7±1.0 vs. CTL: 3.8±0.8 L), FEV 1 (HFpEF: 2.3±0.5 vs. HFrEF: 2.8±0.8 vs. CTL: 2.9±0.6 L), TLC (HFpEF: 5.5±1.3 vs. HFrEF: 6.3±1.4 vs. CTL: 6.4±1.1 L), and % predicted TLC than CTL (all, p0.05). There was a negative relationship between % trunk fat and TLC for HFpEF patients (r= -0.51, p0.05). Conclusion: These findings demonstrate that patients with HF have smaller lung volumes than CTL. Further, our findings suggest that upper body adiposity may be an important contributing factor to these pulmonary system abnormalities in HFpEF. None. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.