Background: Acute 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.Methods: We 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.Results: In total

17 studies were included

and the overall number of subjects with and without AMS was 1810 and3014

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）.Conclusions: This 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.