Repeated remote ischaemic preconditioning can prevent acute mountain sickness after rapid ascent to a high altitude

Zhen Wang; Bo Lv; Lin Zhang; Ran Gao; Wenbo Zhao; Lin Wang; Zhaojun Min; Zhen Mi; Yang Song; Jing Zhang; Yabin Yu; Xunming Ji; Junjie Li; Liyong Wu

doi:10.1080/17461391.2021.1927197

Repeated remote ischaemic preconditioning can prevent acute mountain sickness after rapid ascent to a high altitude

Eur J Sport Sci. 2022 Aug;22(8):1304-1314. doi: 10.1080/17461391.2021.1927197. Epub 2021 May 23.

Authors

Zhen Wang¹, Bo Lv^{2

3}, Lin Zhang⁴, Ran Gao¹, Wenbo Zhao¹, Lin Wang¹, Zhaojun Min⁵, Zhen Mi⁵, Yang Song¹, Jing Zhang¹, Yabin Yu⁶, Xunming Ji^{7

8}, Junjie Li¹, Liyong Wu¹

Affiliations

¹ Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, People's Republic of China.
² Department of Neurology, PKUCare Zibo Hospital, Zibo, People's Republic of China.
³ Department of Neurology, People's Hospital of Yuncheng County, Heze, People's Republic of China.
⁴ Department of Emergency, People's Hospital of Rizhao, Rizhao, People's Republic of China.
⁵ Department of Geriatric Medicine, People's Hospital of Lhasa, Lhasa, People's Republic of China.
⁶ Capital Institute of Pediatrics, Beijing, People's Republic of China.
⁷ Cerebrovascular Diseases Research Institute, Xuanwu Hospital, Capital Medical University, Beijing, People's Republic of China.
⁸ Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, People's Republic of China.

PMID: 33977839
DOI: 10.1080/17461391.2021.1927197

Abstract

Background: This study assessed the effectiveness of 4 different repeated remote ischaemic preconditioning (RIPC) protocols varying in duration and frequency for preventing acute mountain sickness (AMS) after rapid ascent to high altitude.

Methods: In a randomized but not blinded design, participants were assigned to receive either of the four RIPC treatments at low altitude (Group A, once daily for 1 week; Group B, twice daily for 1 week; Group C, once daily for 4 weeks; and Group D, twice daily for 4 weeks) or control (no specific sham treatment). Participants were then flown to a high altitude (3650 m). The primary outcome was the incidence and severity of AMS evaluated by the Lake Louise score (LLS) after arrival; vital signs were collected simultaneously.

Results: A total of 250 participants (50 per group; mean age 38.56 ± 0.76 years) were included. The overall AMS incidence was 26.4%. A total of 20 AMS cases (40%) occurred in the control group, 15 cases (30%) both in the RIPC A and RIPC B groups (RR 1.3; 95%CI 0.8-2.3; χ² = 1.099; p = 0.29), and 8 cases (16%) both in the RIPC C and D groups (RR 2.5; 95%CI 1.2 - 5.2; χ² = 7.143, p < 0.01), with significantly lower LLSs in the RIPC C and D groups (F = 6.51, p < 0.001). The scores of gastrointestinal symptoms (F = 7.42, p < 0.001) and dizziness (F = 9.82, p < 0.001) but not headache (F = 0.60, p > 0.05) were lower in the RIPC groups compared to control. The blood oxygen saturation level (SpO₂) decreased less in the RIPC B, C and D groups compared to control after arrival at a high altitude (F = 11.42, p < 0.001). The number of RIPC treatments received was moderately correlated with SpO₂ (R = 0.38, p < 0.001), and SpO₂ was moderately inversely correlated with the LLS (R = -0.48, p < 0.001).

Conclusion: This study demonstrated that a four-week RIPC intervention but not a one-week regimen reduced AMS incidence and severity; however, a placebo effect might have contributed to these results.

Keywords: Lake Louise score; Remote ischaemic preconditioning; acute mountain sickness; high altitude.

Publication types

Randomized Controlled Trial

MeSH terms

Acute Disease
Adult
Altitude
Altitude Sickness* / epidemiology
Altitude Sickness* / prevention & control
Humans
Ischemic Preconditioning*
Oximetry