RÉSUMÉ
BACKGROUND: Ehlers-Danlos syndrome (EDS) may be linked to dysfunction in the autonomic nervous system, affecting collagen production and processing. These collagen abnormalities lead to a condition called dysautonomia. Findings underscore the need for further investigation into autonomic nervous system function in EDS which involves larger studies to strengthen the evidence of non-invasive screening tools like cardiovascular reflex tests. These tests might offer a valuable way to assess an individual's risk for future complications. OBJECTIVE: This study aimed to assess autonomic reactivity in EDS patients using cardiovascular reflex tests. METHODS: This study was conducted at the Department of Physiology, Naraina Medical College and Research Centre, Kanpur (Uttar Pradesh). The cardiovascular reflex test was used to identify 60 individuals, 30 of whom were EDS patients and 30 were healthy controls, with a common age limit of 18-25 years. Cardiovascular reflex tests, such as the delta heart rate, lying-to-standing test (LST), deep breathing test (DBT), and Valsalva maneuver, were performed and recorded for each subject. IBM SPSS Statistics for Windows, Version 21.0 (Released 2012; IBM Corp., Armonk, New York, United States) was used for the compilation and analysis of data. RESULTS: The expiration-to-inspiration (E:I) ratio and delta heart rate of the EDS patients both significantly decreased as compared to the healthy control group (1.10±0.02 versus 1.22±0.77 and 14.03±0.31 versus 15.52±0.32). The Valsalva ratio of the EDS patients decreased (1.28±0.01) as compared to the healthy control group (1.46±0.01), which was statistically significant. The 30:15 ratio in the EDS patients was significantly decreased compared to the healthy control group (1.08±0.01 versus 1.15±0.01). The handgrip test and cold pressor test results were statistically insignificant. CONCLUSION: The study suggests a connection between EDS and autonomic nervous system dysfunction, causing symptoms like tachycardia and hypotension. It recommends exploring non-invasive cardiovascular reflex tests as a tool to identify autonomic dysfunction in EDS patients and predict long-term cardiovascular complications. These tests offer valuable insights into autonomic function.