Stroke at Moderate and High Altitude

Syed, Maryam Jamil; Khatri, Ismail A.; Alamgir, Wasim; Wasay, Mohammad

doi:10.1089/ham.2021.0043

Cited by 7 publications

(7 citation statements)

References 25 publications

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“…This is because people like to drink alcohol and eat high-fat foods, such as beef, mutton and animal offal, to keep warm to resist the cold climate and low-calorie, hypoxic environment. [42][43][44] Studies have found that smoking cessation can reduce stroke incidence and improve stroke prognosis and recurrence. A 2018 foreign study showed that quitting smoking within 6 months of a stroke or transient ischaemic attack significantly reduced the incidence of recurrent stroke, myocardial infarction or death within 4.8 years.…”

Section: Discussionmentioning

confidence: 99%

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Prevalence of stroke and associated risk factors: a population-based cross-sectional study from the Qinghai-Tibet Plateau of China

et al. 2022

BMJ Open

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Background and objectivesThe epidemiology of stroke at high altitudes has not been extensively studied, especially at heights of 4000 m and above. Thus, stroke prevention and treatment at high altitudes are challenging. We conducted a cross-sectional study to estimate the prevalence of stroke, the detection rate of individuals at high risk of stroke and the risk factors for stroke in the Qinghai-Tibet Plateau in China, a high altitude plateau that inhabits approximately 15 million people.DesignA population-based cross-sectional study in the Qinghai-Tibet Plateau.SettingData were collected from participants through face-to-face screening using a primary screening table. The table relied on the China National Stroke Screening and Prevention Project.ParticipantsA total of 10 700 residents aged ≥40 years and living on the Qinghai-Tibet Plateau for more than 6 months participated from January 2019 to December 2021.Main outcome measuresThe primary screening table included basic demographic information, medical history information, personal lifestyle habits and physical examination information.ResultsA total of 10 056 people were included in the analysis. The prevalence of stroke was 2.3% (95% CI 2.0% to 2.6%), and the detection rate of individuals at high risk of stroke was 26.2% (95% CI 25.3% to 27.0%). The prevalence of stroke and the detection rate of individuals at high risk of stroke increased with altitude (p<0.01), and the prevalence of stroke at high altitudes was almost 2.2 times that at mid-altitudes (p<0.01). After full adjustments, age, residence, hypertension, family history of stroke and smoking were significantly associated with stroke (p<0.05).ConclusionsThe prevalence of stroke, the related risk factors and the detection rate of high-risk individuals were clarified. The prevalence rates of hypertension, overweight or obesity and diabetes in the Qinghai-Tibet Plateau were all higher than the Chinese average. Higher-altitude exposure may be an independent risk factor for stroke.

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Section: Discussionmentioning

confidence: 99%

“…High-altitude residents are prone to hypertension, overweight or obesity and dyslipidaemia. This is because people like to drink alcohol and eat high-fat foods, such as beef, mutton and animal offal, to keep warm to resist the cold climate and low-calorie, hypoxic environment 42–44…”

Section: Discussionmentioning

confidence: 99%

Prevalence of stroke and associated risk factors: a population-based cross-sectional study from the Qinghai-Tibet Plateau of China

et al. 2022

BMJ Open

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“…(3) long-term stays (>60 days) above 2,500 m, to exclude highaltitude natives/residents and prolonged job-related sojourns (e.g., working in a hut or for the military); (4) intermittent bouts of hypoxic exposure; (5) studies including subjects exclusively in a sitting position during hypoxic exposure, to exclude venous stasis ("travel thrombosis") as a potential confounder; (6) patients with preexisting diseases possibly interfering with hemostasis; (7) studies on HAPE and high-altitude cerebral edema (HACE) patients [although studies with a clearly defined asymptomatic population (control group) were included for further analysis]; and 8) any form of medical treatment interfering with hemostasis.…”

Section: Inclusion and Exclusion Criteriamentioning

confidence: 99%

“…These "coagulopathies" at high altitude mostly present as venous thrombosis or/and venous thromboembolism (VTE; deep venous thrombosis, pulmonary thromboembolism, mesenteric vein thrombosis, and cerebral venous sinus thrombosis [CVST]) (3)(4)(5). Cases of coronary stent thrombosis have even been reported, and cerebrovascular stroke occurring at high altitude was discussed in association with increased thrombogenicity (6). In the literature, a multitude of articles point to high altitude itself as an independent factor for adverse changes in the hemostatic system (7).…”

Section: Introductionmentioning

confidence: 99%

The Influence of Environmental Hypoxia on Hemostasis—A Systematic Review

Treml

Wallner

Blank

et al. 2022

Front. Cardiovasc. Med.

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Humans have been ascending to high altitudes for centuries, with a growing number of professional- and leisure-related sojourns occurring in this millennium. A multitude of scientific reports on hemostatic disorders at high altitude suggest that hypoxia is an independent risk factor. However, no systematic analysis of the influence of environmental hypoxia on coagulation, fibrinolysis and platelet function has been performed. To fill this gap, we performed a systematic literature review, including only the data of healthy persons obtained during altitude exposure (<60 days). The results were stratified by the degree of hypoxia and sub-categorized into active and passive ascents and sojourns. Twenty-one studies including 501 participants were included in the final analysis. Since only one study provided relevant data, no conclusions regarding moderate altitudes (1,500–2,500 m) could be drawn. At high altitude (2,500–5,400 m), only small pathophysiological changes were seen, with a possible impact of increasing exercise loads. Elevated thrombin generation seems to be balanced by decreased platelet activation. Viscoelastic methods do not support increased thrombogenicity, with fibrinolysis being unaffected by high altitude. At extreme altitude (5,400–8,850 m), the limited data showed activation of coagulation in parallel with stimulation of fibrinolysis. Furthermore, multiple confounding variables at altitude, like training status, exercise load, fluid status and mental stress, prevent definitive conclusions being drawn on the impact of hypoxia on hemostasis. Thus, we cannot support the hypothesis that hypoxia triggers hypercoagulability and increases the risk of thromboembolic disorders, at least in healthy sojourners.

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“…Among different types of cerebrovascular disorders, cerebral infarction accounts for 48.4%, cerebral haemorrhage for 37.2%, subarachnoid haemorrhage for 9.8% and cerebral embolism for 4.6%. It has been observed that individuals residing in high-altitude areas have a higher prevalence of various cerebrovascular disorders, with ischaemic cerebrovascular diseases being the most common 3…”

Section: Introductionmentioning

confidence: 99%

Prevalence and risk factors of stroke in high-altitude areas: a systematic review and meta-analysis

Zheng,

Luo,

et al. 2023

BMJ Open

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ObjectiveThe primary objective of this study is to investigate the prevalence and risk factors of stroke in high-altitude areas through a comprehensive systematic review and meta-analysis.DesignThis study adopts a systematic review and meta-analysis design.Data sourcesA thorough search was conducted on databases including PubMed, Web of Science, Embase, Cochrane Library, MEDLINE and SCOPUS, covering the period up to June 2023.Eligibility criteriaStudies reporting the prevalence of stroke in high-altitude areas and exploring related risk factors were included, regardless of whether they involved clinical samples or the general population. Studies with incomplete, outdated or duplicate data were excluded.Data extraction and synthesisWe performed eligibility screening, data extraction and quality evaluation of the retrieved articles. Meta-analysis was employed to estimate the prevalence and risk factors of stroke in high-altitude areas. The Newcastle-Ottawa Scale was used to assess the risk of bias.ResultsA total of 17 studies encompassing 8 566 042 participants from four continents were included, with altitudes ranging from 1500 m to nearly 5000 m. The pooled prevalence of stroke in high-altitude areas was found to be 0.5% (95% CI 0.3%–7%). Notably, the prevalence was higher in clinical samples (1.2%; 0.4%–2.5%) compared with the general population (0.3%; 95% CI 0.1%–0.6%). When considering geographic regions, the aggregated data indicated that stroke prevalence in the Eurasia plate was 0.3% (0.2%–0.4%), while in the American region, it was 0.8% (0.4%–1.3%). Age (OR, 14.891), gender (OR, 1.289), hypertension (OR, 3.158) and obesity (OR, 1.502) were identified as significant risk factors for stroke in high-altitude areas.ConclusionsThe findings of this study provide insights into the pooled prevalence of stroke in high-altitude areas, highlighting variations based on geographic regions and sampling type. Moreover, age, gender, hypertension and obesity were found to be associated with the occurrence of stroke.PROSPERO registration numberCRD42022381541.

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Stroke at Moderate and High Altitude

Cited by 7 publications

References 25 publications

Prevalence of stroke and associated risk factors: a population-based cross-sectional study from the Qinghai-Tibet Plateau of China

Prevalence of stroke and associated risk factors: a population-based cross-sectional study from the Qinghai-Tibet Plateau of China

The Influence of Environmental Hypoxia on Hemostasis—A Systematic Review

Prevalence and risk factors of stroke in high-altitude areas: a systematic review and meta-analysis

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