Association between acute mountain sickness (AMS) and age: a meta-analysis

Abstract

BackgroundAcute mountain sickness (AMS) is a potentially lethal condition caused by acute hypoxia after ascending to altitudes higher than 2500 m in a short time. The main symptom of AMS is headache. Numerous risk factors of AMS have been examined, including gender, obesity, ascent rate, age and individual susceptibility. In previous studies, age was considered a predisposing factor for AMS. However, different opinions have been raised in recent years. To clarify the association between AMS and age, we conducted this meta-analysis.MethodsWe obtained observational studies that explored risk factors for AMS by searching PubMed, Embase, China National Knowledge Internet (CNKI), the Wanfang database and CQVIP for articles published before March 2017. The studies included were required to provide the mean age and its standard deviation for subjects with and without AMS, the maximum altitude attained and the mode of ascent. The Lake Louse Score (LLS) or the Chinese AMS score (CAS) was used to judge the severity of AMS symptoms and incidence. Studies were pooled for the analysis by using a random effects model in RevMan 5.0. Meta-regression and subgroup analyses were conducted to identify sources of heterogeneity using Stata 14.2 and RevMan 5.0.ResultsIn total, 17 studies were included, and the overall number of subjects with and without AMS was 1810 and 3014, respectively. The age ranged from 10 to 76 years. Analysis of the 17 included studies showed that age was not associated with AMS (mean difference (MD) = 0.10; 95% CI: -0.38-0.58; P = 0.69).ConclusionThis meta-analysis suggests that there is no association between age and the risk of AMS. Race, age, and ascent mode are common sources of heterogeneity, which may provide an analytical orientation for future heterogeneity analyses.

Physiological Responses in Humans Acutely Exposed to High Altitude (3480 m): Minute Ventilation and Oxygenation Are Predictive for the Development of Acute Mountain Sickness

“…It is worth mentioning that in this and the present study “sleeping difficulties” was included for AMS diagnosis, which is no longer considered in the updated LLS (Roach et al, 2018). In addition, in the present study, neither age nor sex was associated with the AMS incidence, also being in accordance with other studies (Horiuchi et al, 2018; Wu et al, 2018). New and noteworthy is the finding that not only a pronounced desaturation but also a low ventilatory response during the first hours at high altitude represents an independent predictor of the subsequent development of AMS (Table 3).…”

Physiological Responses in Humans Acutely Exposed to High Altitude (3480 m): Minute Ventilation and Oxygenation Are Predictive for the Development of Acute Mountain Sickness

“…It is worth mentioning that in this and the present study “sleeping difficulties” was included for AMS diagnosis, which is no longer considered in the updated LLS (Roach et al, 2018). In addition, in the present study, neither age nor sex was associated with the AMS incidence, also being in accordance with other studies (Horiuchi et al, 2018; Wu et al, 2018). New and noteworthy is the finding that not only a pronounced desaturation but also a low ventilatory response during the first hours at high altitude represents an independent predictor of the subsequent development of AMS (Table 3).…”

Does age have an impact on acute mountain sickness? A systematic review

“…However, substantial heterogeneity across the included reports was reported. 40 Similarly, the findings from the current systematic review were in line with the results from Wu et al, but our review added further information on the specific effect of old age on the extent of AMS. In fact, the same authors suggested the need of further research in order to focus on the relationship between AMS and age groups (such as children and elderly).…”

Risk and protective factors for acute mountain sickness: a meta-analysis

“…The results of Wu et al [25] coincide with our results in the LLS group, as no statistically significant results were obtained in relation to age. However, the HS group analysis is contradictory to the results of these studies, indicating the great variability of results related to this variable that could be due to the heterogeneity of the included studies.…”

Physiological Responses in Humans Acutely Exposed to High Altitude (3480 m): Minute Ventilation and Oxygenation Are Predictive for the Development of Acute Mountain Sickness

“…It is worth mentioning that in this and the present study “sleeping difficulties” was included for AMS diagnosis, which is no longer considered in the updated LLS (Roach et al, 2018). In addition, in the present study, neither age nor sex was associated with the AMS incidence, also being in accordance with other studies (Horiuchi et al, 2018; Wu et al, 2018). New and noteworthy is the finding that not only a pronounced desaturation but also a low ventilatory response during the first hours at high altitude represents an independent predictor of the subsequent development of AMS (Table 3).…”

Does age have an impact on acute mountain sickness? A systematic review

“…However, substantial heterogeneity across the included reports was reported. 40 Similarly, the findings from the current systematic review were in line with the results from Wu et al, but our review added further information on the specific effect of old age on the extent of AMS. In fact, the same authors suggested the need of further research in order to focus on the relationship between AMS and age groups (such as children and elderly).…”

Risk and protective factors for acute mountain sickness: a meta-analysis

“…The results of Wu et al [25] coincide with our results in the LLS group, as no statistically significant results were obtained in relation to age. However, the HS group analysis is contradictory to the results of these studies, indicating the great variability of results related to this variable that could be due to the heterogeneity of the included studies.…”

Physiological Responses in Humans Acutely Exposed to High Altitude (3480 m): Minute Ventilation and Oxygenation Are Predictive for the Development of Acute Mountain Sickness

“…It is worth mentioning that in this and the present study “sleeping difficulties” was included for AMS diagnosis, which is no longer considered in the updated LLS (Roach et al, 2018). In addition, in the present study, neither age nor sex was associated with the AMS incidence, also being in accordance with other studies (Horiuchi et al, 2018; Wu et al, 2018). New and noteworthy is the finding that not only a pronounced desaturation but also a low ventilatory response during the first hours at high altitude represents an independent predictor of the subsequent development of AMS (Table 3).…”

Does age have an impact on acute mountain sickness? A systematic review

“…However, substantial heterogeneity across the included reports was reported. 40 Similarly, the findings from the current systematic review were in line with the results from Wu et al, but our review added further information on the specific effect of old age on the extent of AMS. In fact, the same authors suggested the need of further research in order to focus on the relationship between AMS and age groups (such as children and elderly).…”

Risk and protective factors for acute mountain sickness: a meta-analysis

“…The results of Wu et al [25] coincide with our results in the LLS group, as no statistically significant results were obtained in relation to age. However, the HS group analysis is contradictory to the results of these studies, indicating the great variability of results related to this variable that could be due to the heterogeneity of the included studies.…”