Anxiety and Autonomic Dysfunction in Asthma Patients

This analytical cross-sectional study investigated the complex relationship between anxiety severity, autonomic nervous system (ANS) status, heart rate variability (HRV), and clinical control in patients with bronchial asthma. The study enrolled 60 asthmatic patients aged 35-65 years (30 men and 30 women) undergoing inpatient treatment at the Allergology Center in Dnipro, Ukraine, during 2024-2025. Participants were symmetrically allocated into four age- and sex-matched factorial cells (15 patients each) based on their asthma control status (controlled versus uncontrolled) and the presence or absence of clinically significant anxiety assessed via the Hospital Anxiety and Depression Scale (HADS). Pulmonary function was evaluated by spirometry (Spirolab III®, MIR) to determine forced expiratory volume in 1 second (FEV1). Autonomic status was quantified using 5-minute electrocardiographic recordings captured with a Polar H10 chest sensor and processed via Kubios HRV Scientific software to extract key time-domain (MHR, SDNN, RMSSD) and frequency-domain (LF, HF, LF norm, HF norm, LF/HF ratio) parameters. Factorial analysis using a rank-based Aligned Rank Transformation (ART) ANOVA revealed strong, independent main effects of asthma control on pulmonary function and major spectral HRV measures, alongside a profound independent main effect of anxiety on total heart rate variability indexed by SDNN (F=80.20, p<0.001). Patients with comorbid anxiety demonstrated a significant shift toward sym­pathetic dominance driven primarily by the severe suppression of parasympathetic activity. In patients with controlled asthma and anxiety, the LF/HF ratio reached a peak of 1.96 (1.39-2.55), while RMSSD and SDNN decreased to 10.60 (8.10-13.20) ms and 23.50 (17.90-29.30) ms, respectively. Conversely, uncontrolled asthma in the absence of anxiety was characterized by a distinct hyper-vagal state, exhibiting the highest RMSSD value of 45.60 (34.80-56.90) ms and the lowest LF/HF ratio of 0.64 (0.49-0.79). Crucially, significant interaction effects were detected for RMSSD and LF norm, whereas the interaction for HF norm was not statistically significant, indicating that the association of anxiety with these outcomes was not uniform across asthma-control strata. Secondary analyses revealed a strong inverse correlation between anxiety severity and total HRV (Spearman's ρ= -0.882 for the entire cohort) and a powerful synergistic relationship between psychological distress and autonomic imbalance regarding overall asthma controllability (multiple correlation coefficient =0.914). In conclusion, clinically significant anxiety in bronchial asthma induces a profound autonomic dysregulation that disrupts the predictable physiological links between the lungs and the cardiorespiratory axis, leading to a consistent decline in clinical asthma control. Short-term HRV assessment using validated wearable sensors represents a practical, non-invasive digital tool for routine clinical settings, and systematic psychological screening should be integrated into comprehensive asthma management strategies to optimize therapeutic outcomes.