Early signs of cardiovascular impairment in young smokers detected by Post-occlusive Reactive Hyperemia

Introduction: Smoking is currently recognised as a major risk factor for many disease and we believe that its deleterious effects impact our body physiology earlier than later. The present study explores the potential capacity of the post-occlusive reactive hyperemia (PORH) manouver as an early detector of cardiovascular impairment by comparing cardiocirculatory adaptive responses to PORH in young healthy smokers and non-smokers. Methods Twenty-seven healthy adults (15 women, 12 men, mean age of 23.7 ± 4.4 years old) were recruited, including 13 smokers and 14 non-smokers matched for sex, body mass index, and height. Smokers reported regular tobacco consumption for at least one year. Baseline haemodynamic parameters, including systolic and diastolic blood pressures (approximately 121/74 mmHg in the total population), ankle–brachial index (~1.1), and resting pulse rate (70.1 ± 9.1 min - ¹), were within normal ranges and comparable between groups. The PORH protocol comprised baseline, occlusion, and recovery phases. Occlusion was obtained with a pressure cuff (200 mmHg for two minutes) in the arm (brachial artery). Peripheral perfusion was continuously recorded by Laser Doppler flowmetry (LDF) at the index fingertips and by Polarized Spectroscopy (Tissue Viability Imager - TiVi) on the dorsal hand skin. Primary outcomes were the perfusion drop in the occlusion period and time to peak perfusion and full recovery following cuff release. Discussion Perfusion fell to near-zero levels during occlusion in all participants, with similar profiles across groups. However, during early recovery, smokers exhibited a significantly longer time to peak perfusion than non-smokers (p < 0.01, LDF). TiVi data supported these findings by revealing slower and more heterogeneous red blood cell accumulation in smokers, particularly during late recovery, when non-smokers achieved higher perfusion values more rapidly (p < 0.05, TiVi). Conclusion These results show that even light “healthy” young smokers present measurable differences in their cardiovascular adaptive responses to the acute changes evoked by reactive hyperemia (PORH), affecting both the sympathetic withdraw response (early recovery) and the endothelial response (late recovery). The PORH manoeuvre also emerges as a sensitive, non-invasive method with the potential to detect early changes in cardiovascular homeostasis that should be further explored. This abstract was presented at the American Physiology Summit 2026 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.