Biochemical and clinical effects of continuous positive airway pressure combined with sildenafil on inflammatory and hemodynamic profiles in obese asthma patients with pulmonary arterial hypertension

Background: Obesity-associated asthma complicated by pulmonary arterial hypertension (PAH) involves multifactorial biochemical dysregulation, including endothelial dysfunction, oxidative stress, and chronic inflammation. This study aimed to evaluate the combined biochemical and clinical effects of continuous positive airway pressure (CPAP) and sildenafil on pulmonary function, inflammatory biomarkers, and hemodynamic parameters in obese asthma patients with PAH. Methods: A total of 134 patients (BMI >30 kg/m2, FEV1 < 70% pred, PASP > 30 mmHg) were enrolled and divided into a treatment group (n = 63, CPAP + sildenafil) and a control group (n = 71, sildenafil alone). Pulmonary and hemodynamic indices (PaÜ2, FiÜ2, PASP, OI, and PaO2/FiO2), lung function parameters (FEV1 , PEF), and asthma control test (ACT) scores were assessed at baseline and follow-up (6 and 12 months). Serum interleukin-6 (IL-6), tumor necrosis factor-a (TNF-<span style="color: rgb(32, 33, 34); font-family: sans-serif; font-size: 16px; background-color: rgb(248, 249, 250);">α</span>), and fractional exhaled nitric oxide (FeNO) were quantified to evaluate biochemical inflammation. Correlation analysis was performed between biomarker changes and ACT improvements. Results: The CPAP + sildenafil group showed significantly higher post-treatment PaÜ2 levels, lower PASP and FiÜ2 values, improved OI, and greater increases in PaO2/FiO2 and FEV1 percentages compared with the control group (P < 0.001). Biochemical assays revealed substantial reductions in serum IL-6 and TNF-<span style="color: rgb(32, 33, 34); font-family: sans-serif; font-size: 16px; background-color: rgb(248, 249, 250);">α</span> levels, as well as FeNO concentrations, in the combination group. Post-treatment changes in IL-6 (r= 0.68, P < 0.0001), TNF-<span style="color: rgb(32, 33, 34); font-family: sans-serif; font-size: 16px; background-color: rgb(248, 249, 250);">α</span> (r= 0.59, P < 0.0001), and FeNO (r= 0.72, P < 0.0001) were strongly correlated with improved ACT scores, suggesting a close biochemical-clinical relationship between airway inflammation and therapeutic response. Conclusions: CPAP combined with sildenafil exerts dual biochemical and clinical benefits in obese asthma patients with PAH by enhancing oxygenation, lowering pulmonary artery pressure, and suppressing inflammatory cytokine activity. The observed reductions in IL-6, TNF-<span style="color: rgb(32, 33, 34); font-family: sans-serif; font-size: 16px; background-color: rgb(248, 249, 250);">α</span>, and FeNO highlight the biochemical basis of treatment efficacy and the potential of these markers as laboratory indicators for monitoring therapeutic outcomes.