Migraine associated with altitude: results from a population‐based study in Nepal

Abstract

Background and purposeA 1988 pilot study in Peru suggested an association between migraine and chronic exposure to high altitude. This study provides epidemiological evidence corroborating this.MethodsIn a cross‐sectional nationwide population‐based study, a representative sample of Nepali‐speaking adults were recruited through stratified multistage cluster sampling. They were visited at home by trained interviewers using a culturally adapted questionnaire. The altitude of dwelling of each participant was recorded.ResultsOf 2100 participants, over half [1100 (52.4%)] were resident above 1000 m and almost one quarter [470 (22.4%)] at ≥2000 m. Age‐ and gender‐standardized migraine prevalence increased from 27.9% to 45.5% with altitude between 0 and 2499 m and thereafter decreased to 37.9% at ≥2500 m. The likelihood of having migraine was greater (odds ratio, 1.5–2.2; P ≤ 0.007) at all higher altitudes compared with <500 m. In addition, all symptom indices increased with altitude across the range <500 m to 2000–2499 m, i.e. median attack frequency from 1.3 to 3.0 days/month (P < 0.001), median duration from 9 to 24 h (P < 0.001) and pain intensity [the proportion reporting ‘bad pain’ (highest intensity)] from 35.5% to 56.9% (P = 0.011). Each of these showed a downward trend above 2500 m.ConclusionsDwelling at high altitudes increases not only migraine prevalence but also the severity of its symptoms.

Primary headache disorders among the adult population of Mongolia: prevalences and associations from a population-based survey

“…There were no differences between low and intermediate altitudes, while above 2000 m there was a trend towards less prevalent migraine. In Nepal, an LTB-supported study (using the same methodology) found a very strong relationship between migraine prevalence (and indices of severity) and altitude up to 2000 m [30, 35], which is not reflected here. Explanation comes to mind: we only had approximations of altitude of each household, and the spread was rather narrow – certainly not as wide as in Nepal [35].…”

Health-care utilization for headache disorders in Nepal: a population-based door-to-door survey

“…A point worthy of emphasis here is that these indices of symptom severity are, clearly, key indicators of need for headache services. We have previously shown that all symptom indices increase with altitude of dwelling across the range < 500 m to 2499 m [36], and this was reflected here in the greater use of medication by high-altitude dwellers. Clearly, this relative excess of need among high-altitude dwellers presents a major challenge to equitable provision of headache services in Nepal.…”

Global, regional, and national burden of migraine and tension-type headache, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

“…This intervention would require greater knowledge of the modifiable factors that drive headache: several have been suggested with varying degrees of scientific support, such as obesity, smoking, indoor and outdoor air pollution, level of physical activity, altitude, blood pressure, and level of stress. 29 , 30 , 31 , 32 Of these factors, altitude and stress are not included as risks in GBD. For the other postulated risks, the evidence for an effect on headaches is, in our opinion, insufficient.…”