Baroreflex sensitivity following acute upper-body exercise in the cold among stable coronary artery disease patients

• Published in: Frontiers in physiology 2023-10, Vol.14, p.1184378-1184378
• Main Authors: Pikkarainen, Kalle, Valtonen, Rasmus I. P., Hintsala, Heidi E., Kiviniemi, Antti, Crandall, Craig G., Perkiömäki, Juha, Hautala, Arto J., Tulppo, Mikko P., Jaakkola, Jouni J. K., Ikäheimo, Tiina M.
• Format: Article
• Language: English
• Subjects: autonomic nervous system; baroreflex; blood pressure variability; cold; exercise; Physiology; upper-body exercise
• ISSN: 1664-042X; 1664-042X
• DOI: 10.3389/fphys.2023.1184378

Background: A cold environment and exercise separately affect the autonomic nervous system (ANS), baroreflex sensitivity (BRS), and blood pressure variability (BPV) but their combined effects on post-exercise recovery are not known. Our cross-over trial examined these responses following upper-body static and dynamic exercise performed in a cold and neutral environment in patients with coronary artery disease (CAD). Methods: 20 patients with stable coronary artery disease performed both graded static (10%–30% of maximal voluntary contraction) and dynamic (light, moderate and high perceived intensity) upper-body exercise at −15°C and +22°C for 30 min. Electrocardiogram and continuous blood pressure were measured to compute post-exercise (10 and 30 min after exercise) spectral powers of heart rate (HR), blood pressure variability and BRS at low (0.04–0.15 Hz) and high (0.15–0.4 Hz) frequencies. Results: Static upper-body exercise performed in a cold environment increased post-exercise high frequency (HF) spectral power of heart rate (HF RR) ( p < 0.001) and reduced heart rate ( p = 0.001) and low-to-high frequency (LF/HF) ratio ( p = 0.006) more than in a neutral environment. In addition, post-exercise mean BRS ( p = 0.015) and high frequency BRS ( p = 0.041) increased more following static exercise in the cold than in a neutral environment. Dynamic upper-body exercise performed in a cold environment reduced post-exercise HF BRS ( p = 0.019) and systolic blood pressure ( p = 0.003). Conclusion: Static upper-body exercise in the cold increased post-exercise BRS and overall vagal activity but without reduced systolic blood pressure. Dynamic upper-body exercise in the cold reduced post-exercise vagal BRS but did not affect the other parameters. The influence of cold exposure on post-exercise autonomic and cardiovascular responses following static upper-body exercise require further studies. This information helps understanding why persons with cardiovascular diseases are vulnerable to low environmental temperature. ClinicalTrials.gov: NCT02855905 (04/08/2016).