High altitude medicine & biology最新文献

Background: This study examined the effects of chronic high-altitude hypoxic exposure on attention networks in indigenous primary school students, integrating cardiovascular indices to explore underlying physiological mechanisms.

Methods: Three real-world altitude groups were established: low (2,200 m), mid (3,200 m), and high (4,200 m). Cardiovascular function was assessed via systolic blood pressure, diastolic blood pressure, and heart rate. Attentional performance was evaluated using the Attention Network Test (ANT), which provides measures of alerting, orienting, and executive control efficiency.

Results: Cardiovascular indices followed a nonlinear pattern across altitudes, with systolic blood pressure, diastolic blood pressure, and heart rate being significantly higher at mid-altitude compared to both low and high altitudes. In contrast, attention performance exhibited an opposite trend: alerting and executive control efficiency were relatively reduced at mid-altitude but were comparable between the low- and high-altitude groups. Orienting efficiency did not differ significantly across the three altitude groups.

Conclusions: The findings reveal a dissociation between physiological regulation and cognitive performance under chronic hypoxia. To explain these results, we propose a U-shaped model of cardiovascular adaptation, where mid-altitude represents an incomplete compensatory state, while prolonged exposure at higher altitudes leads to stabilized cardiovascular function and preserved attentional performance. This integrative framework underscores the crucial role of physiological adaptation in shaping cognitive outcomes in high-altitude environments.

Wei, Shuna, Xiaoju Liu. High-altitude environment and chronic obstructive pulmonary disease: epidemiology, pathological mechanisms and clinical management. High Alt Med Biol. 00:00-00, 2026Background:Chronic obstructive pulmonary disease (COPD) is a significant global health concern. Environmental factors such as low oxygen and temperature, along with poor living habits in high-altitude areas, contribute to regional variations in the occurrence and progression of COPD. There is currently a lack of systematic reviews on the relationship between high-altitude environments and COPD, which hinders effective prevention and treatment.

Methods: This narrative review comprehensively sorts out and analyzes the research on COPD in high-altitude areas from three aspects: epidemiological characteristics, pathophysiological mechanisms, and clinical management.

Results: Epidemiologically, COPD mortality increases with altitude; however, prevalence rates remain debated. Pathophysiologically, factors include hypoxia-inducible factor regulation, hemodynamic changes, air pollution particles promoting inflammation and oxidative stress, as well as gene mutations like PPARA and SERPINA1. Clinically managing COPD in high-altitude regions requires individualized approaches that consider environmental conditions.

Conclusion: High-altitude environments exacerbate COPD through hypoxic stress, pollutant exposure, and genetic variations. Future efforts should focus on developing a risk prediction model for COPD that incorporates altitude parameters to enhance targeted prevention and treatment strategies in these areas.

Cameron, Hannah, Marion McDevitt, Bengt Kayser, Craig Kutz, Suvash Dawadi, and Alana Hawley. Risk determinants of acute mountain sickness in trekkers in the Nepali Himalaya: a 36-year follow-up. High Alt Med Biol. 27:17-22, 2026.

Introduction: Non-acclimatized trekkers risk developing acute mountain sickness (AMS) at high altitudes. We surveyed trekkers on the Annapurna Circuit in Nepal (peak 5,416 m) to assess AMS incidence and risk factors. Results were compared to 1986, 1998, and 2010 surveys.

Methods: Paper and electronic surveys were distributed to English-speaking trekkers who stopped at the Manang Aid Post (3,500 m). AMS was assessed with the Lake Louise Score (LLS; cutoffs ≥3 and ≥5) and the Environmental Symptom Questionnaire AMS-C score (cutoff ≥0.7).

Results: One hundred and forty-three surveys were returned. Incidence of AMS was 45%, 29%, and 19% (LLS ≥3, LLS ≥5, and AMS-C). AMS incidence was similar to that in 2010 and lower than in 1986 and 1998. In this study, body mass index (BMI) was a significant risk factor for AMS. Seventy-five percent of trekkers had elementary awareness of AMS, compared to 42% in 2010. Trekkers had slower ascent rates and 49% used prophylactic acetazolamide, compared to 44% (2010), 12% (1998), and 1% (1986).

Conclusions: BMI was a predictor of AMS. Awareness of AMS was greater when compared to past studies; however, AMS rates stayed relatively stable between 2010 and the present. Whether awareness reduces the incidence of other potentially lethal altitude illnesses requires further investigation.

McLaughlin, Kyle, Steve Roy, Marika Falla, Giacomo Strapazzon, Andrew M. Luks, Ken Zafren, Hermann Brugger, Martin Musi, Iztok Tomazin, John Ellerton, Ghan Bahadur Thapa, and Peter Paal. Pharmacological prophylaxis and supplemental oxygen for unacclimatized rescuers at very high altitude: scoping review and 2025 joint recommendations of the International Commission for Mountain Emergency Medicine and the International Society for Mountain Medicine. High Alt Med Biol. 27:60-77, 2026.

Background: Mountain rescuers and pilots rapidly ascending to altitudes above 3,500 m are exposed to the detrimental effects of hypobaric hypoxia, including cognitive and physical impairment, as well as high-altitude illness (HAI). We conducted a scoping review of oxygen supplementation and pharmacologic measures to improve cognitive and physical performance and prevent HAI in unacclimatized rescuers rapidly ascending above 3,500 m during rescue missions.

Methods: Following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, 723 articles were screened, 133 reviewed and a total of 50 articles were included for data extraction, based on the intervention: 6 on oxygen, 29 on acetazolamide (AZ), 17 on dexamethasone (DEX), 3 on nifedipine, and 5 on phosphodiesterase-5 inhibitors.

Discussion: Supplemental oxygen improves physical and cognitive performance at high altitude and is recommended for rapid ascent rescues >30 minutes between 3,500 and 4,000 m, and for rescues of any duration above 4,000 m. If oxygen is administered, pharmacological prophylaxis is not required. If oxygen is unavailable, AZ or DEX can be used for rapid ascent rescues above 3,500 m for longer than 3 hours to reduce the incidence and severity of acute mountain sickness. At altitudes above 5,000 m or for rescues requiring prolonged physical work, the use of both AZ and DEX is recommended.

Conclusions: To enhance the safety and effectiveness of high-altitude rescues, we provide recommendations for the use of supplemental oxygen and pharmacologic prophylaxis to reduce the risk of HAI and improve cognitive and physical performance during rapid ascents to altitudes >3,500 m.

Tu, Ke, Lei Tian, Qi Zhu, Kailian Bai, Lin Li, Mengmei Fu, Mengxia Wang, Lei Zhang, Zhuo Zhan, Haoxi Li, Xiaojun Li, Ruofan Yi, Cheng Jiang, Hua Huang, and Mingming Zhang. Intraoperative opioid-free anesthesia with dexmedetomidine and esketamine versus conventional general anesthesia in laparoscopic cholecystectomy at 3,600 m: a randomized trial on hemodynamic stability and postoperative recovery. High Alt Med Biol. 27:8-16, 2026.

Background: Opioid-free anesthesia (OFA) is gaining attention as an alternative to opioid-based techniques. However, its hemodynamic and clinical characteristics at high altitudes, where hypoxia and resource limitations prevail, remain unclear.

Methods: In this single-blind randomized trial, 48 patients undergoing laparoscopic cholecystectomy at 3,600 m were assigned to either a conventional general anesthesia (CGA) group (sevoflurane, sufentanil, remifentanil) or an OFA group (sevoflurane, dexmedetomidine, esketamine). The primary outcome was intraoperative mean arterial pressure (MAP); secondary outcomes included heart rate (HR), awakening time, sedation level, patient satisfaction, postoperative pain, postoperative nausea and vomiting (PONV), perioperative medication use, and adverse events.

Results: Compared with CGA, the OFA group maintained higher intraoperative MAP, with significant differences after induction (OFA: 87.9 ± 12.3 vs. CGA: 77.2 ± 11.7 mmHg, p < 0.005) and 10 minutes after incision (OFA: 83.5 ± 14.9 vs. CGA: 72.5 ± 9.8 mmHg, p < 0.005). The CGA group exhibited a significant MAP decline at 10 minutes postincision (72.5 ± 9.8 vs. baseline: 83.0 ± 9.1 mmHg, p < 0.001), whereas the OFA group showed a transient MAP increase after intubation (96.1 ± 16.1 vs. baseline: 85.8 ± 7.8 mmHg, p < 0.01). HR trends paralleled MAP changes. Awakening time was significantly longer with OFA (OFA: 20.4 ± 7.5 min vs. CGA: 10.6 ± 8.2 min, p < 0.001), while pain scores at 6 and 12 hours were lower (p < 0.005). Sedation, satisfaction, PONV, and medication use were comparable. No severe adverse events occurred.

Conclusions: At high altitudes, OFA with dexmedetomidine and esketamine exhibited distinct clinical characteristics compared with opioid-based anesthesia, maintaining blood pressure and postoperative analgesia but less effectively blunting intubation-induced pressor responses and prolonging awakening time. These factors should be weighed when selecting anesthesia strategies in resource-limited, high-altitude settings, particularly when managing large numbers of patients.

Vargas, Abel, Veronica Penuelas, Karapet G. Mkrtchyan, Kathy Pham, Shyleen Frost, Esteban A. Moya, James J. Yu, Tatum S. Simonson, and Erica C. Heinrich. Innate immune phenotypes during acute high-altitude exposure. High Alt Med Biol. 27:33-41, 2026.

Introduction: High altitude is a physiologically stressful environment due to limited oxygen availability. Decades of study reveal the complex plasticity in many physiological systems that manifests at high altitude to maintain oxygen delivery. However, there are gaps in our knowledge regarding how high-altitude exposure influences immune function. Since tissue and cellular hypoxia occur during injury and infection, we hypothesized that sustained hypoxemia during high-altitude travel may impact inflammatory and immune phenotypes due to crosstalk between hypoxia and inflammatory response pathways.

Methods: We recruited 17 healthy participants and examined their immune phenotypes at sea level and during 3 days at 3,800 m elevation. Specific attention was paid to neutrophil phenotypes because changes in these cells have not been reported at high altitude.

Results: We found several impacts of high altitude on immune cell populations, including shifts in monocytes from classical to intermediate (p = 0.004 after 1 night at high altitude [HA1], and p < 0.001 after 2 nights at high altitude [HA2]) and nonclassical subsets (p = 0.013 on HA2), and increases in total B cells (p = 0.001 on HA2, p = 0.004 [HA3]). An effect of altitude was found for neutrophil CD15 expression (p < 0.001), with a trend toward increased expression over time at high altitude. Higher Acute Mountain Sickness (AMS) scores on the second day at high altitude were associated with more pronounced shifts to nonclassical monocyte populations (R² = 0.79, p = 0.001). These data indicate that acute high-altitude travel results in a pro-inflammatory immune response, which may contribute to AMS. This response appears to blunt with acclimatization, although elevation in B cells remain by HA3.

Zhang, Xingkai, Liang He, Kai Li, Wen Li, Li Wang, Ling Chen, and Qinghai Shi. Causal relationships between high-altitude adaptation, metabolic traits, and tumors: insights from Mendelian randomization. High Alt Med Biol. 27:23-32, 2026.

Background and objectives: Previous studies suggest that high-altitude adaptation (HAA) and metabolic traits in high-altitude populations correlate with tumor risk, but causal mechanisms remain unclear. This Mendelian randomization (MR) study investigated genetic links between HAA, metabolic traits, and tumor susceptibility while exploring potential mediation effects.

Methods: Genome-wide association studies data for HAA, metabolic traits, and tumors were sourced from public databases. Inverse variance weighting served as the primary analytical method, supplemented by weighted mode, MR-Egger, and weighted median. Sensitivity analyses and two-step MR (TSMR) assessed robustness and mediation pathways.

Results: We identified a potential association between HAA and a decreased risk of pancreatic cancer (odds ratio [OR] = 8.94e-8, p = 0.011) and cervical cancer (OR = 8.04e-6, p = 0.005). In contrast, HAA showed a potential link to an increased risk of esophageal cancer (OR = 3230.25, p = 0.03) and hepatocellular carcinoma (OR = 2080.07, p = 0.015). Several metabolic traits, particularly platelet-related indices, were identified as potentially associated with tumorigenesis. However, although possible mediating pathways were suggested, no metabolic trait demonstrated a statistically significant mediating effect.

Conclusion: These findings highlight HAA's complex role in tumor susceptibility and provide a genetic framework for understanding tumor disparities in high-altitude regions.

Danzeng, Zhuoga, Rui Zhang, Luobu Gesang, Jin Wang, Bai Ci, Zejuan Wang, Zhuoma Ciren, Quzhen Gesang, Yangzong Suona, Xiaona Liu, Quzong Zhaxi, Cuomu Baima, Binyun Liu, Zhuoga Baima, Wei Cong, and Qiangba Dingzeng. Efficacy and safety of extended-release acetazolamide capsules for the prevention of acute mountain sickness: a randomized, double-blind, placebo-controlled phase III trial. High Alt Med Biol. 27:1-7, 2026.

Background: Acute mountain sickness (AMS) frequently affects individuals ascending rapidly to high altitudes. Data on acetazolamide prophylaxis in Asian populations remain limited. To evaluate the efficacy and safety of acetazolamide for the prevention of AMS in the Han Chinese population.

Methods: In this multicenter, randomized, double-blind, placebo-controlled phase III trial, 288 healthy Chinese Han adults traveled from Peking (43.5 m) to Lhasa (3,670 m). Participants received either extended-release acetazolamide (500 mg once daily) or placebo, starting 2 days before ascent and continuing for 4 days postarrival. The primary endpoint was AMS incidence (Lake Louise Score [LLS] ≥3 with headache).

Results: Among 284 completers, AMS incidence was significantly lower with acetazolamide (36.9% vs. 55.9%, p = 0.0013). Moderate/severe AMS (LLS > 5) was also reduced (9.9% vs. 24.5%, p = 0.0012). SpO₂ levels were consistently higher in the treatment group (p < 0.0001). Adverse events, including paresthesia and polyuria, were mild and self-limiting.

Conclusion: Once-daily extended-release acetazolamide (500 mg) effectively prevents AMS and is well-tolerated in healthy Asian individuals. This regimen may enhance adherence and serve as a practical prophylactic option for high-altitude travelers.