Sociodemographic contributors to hypoxia and hypercapnia-induced dyspnea

Dyspnea is the subjective sensation of breathing discomfort. This symptom is commonly experienced in hospitalized patients, including those receiving mechanical ventilation. In severe cases, dyspnea has been linked to increased mortality in patients with chronic lung disease as well as poorer clinical outcomes in ICU patients. This outcome may be driven by dyspnea-induced anxiety caused, in part, by a higher work of breathing and carbon dioxide-induced air-hunger. While prior work has provided a detailed understanding of the neurophysiological mechanisms underlying dyspnea, we know little about the drivers of individual variation in how this symptom manifests. Sociodemographic factors may play a role in the psychological mechanisms underlying the sensation of dyspnea, similar to previously reported links between demographic factors and the experience of subjective pain. Therefore, this study aimed to investigate if sociodemographic factors contributed to self-reported dyspnea severity under controlled conditions of modified arterial oxygen and carbon dioxide partial pressures. We hypothesized that higher levels of stress related to medical access (including financial concerns) would lead to either blunting or exacerbation of dyspnea severity. To test this hypothesis, we recruited healthy men and women between the ages of 18 and 49. Participants completed a questionnaire examining sources of financial, social, and medical stress. They then completed a dyspnea simulation experiment in which they reported dyspnea severity while breathing controlled oxygen and carbon dioxide tensions to target 6 combinations of end-tidal PCO2 (45 or 55 mmHg) and inspired oxygen tensions (150, 80, or 68 mmHg). Preliminary data suggests that individuals who have higher difficulty accessing healthcare are more likely to report higher dyspnea severity, particularly under less challenging treatment trials such as room air (p<0.001, R=0.57) and 45 mmHg end-tidal PCO2 (p=0.001, R=0.82). This suggests that anxiety related to accessing medical care may impact subjective sensations of key symptoms linked to disease outcomes. The experiment and compensation was funded by the Dean's Collaborative Seed Grant from the UC Riverside School of Medicine. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.