ABSTRACT
Objective To explore the effect of high altitude exposure and short-term acclimation on the platelet-associated parameters by studying the changes of platelet-associated parameters in healthy young man.Methods Four hundred and sixtytwo young men were recruited from Chengdu (the elevation of 500m) during Jun.2012 to Aug.2013 according to the inclusion and exclusion criteria,of which 193 had been living in Chengdu (plain group),and 269 flew from Chengdu to Lhasa (3700m) in 2 hours,and then 147 of them were exposed in the high altitude for 1 day (acute high altitude exposure group),and another 122 for 7 days (short-term acclimation group).The demographic data were collected and the blood routine and platelet-associated parameters were measured of all the participants,and then the information collected were compared between the 3 groups.Results Compared to the plain group,the platelet count (PLT),platelet distribution width (PDW) and plateletcrit (PCT) reduced and the mean platelet volume (MPV) increased significantly (P＜0.05) in the acute high altitude exposure group;while all the indexes in short-term acclimation group returned to approach the levels in the plain group,but statistical differences still existed in PLT,PDW and PCT (P＜0.05).The platelet activating factor (PAF) and epinephrine (Epi) decreased markedly in acute high altitude exposure group than in plain group (P＜0.05);while in short-term acclimation group,the PAF returned to approach the level in plain group,and the Epi was further down (P＜0.05).In addition,no marked difference of 5-HT level was observed in the 3 groups (P＞0.05).Pearson correlation analysis indicated that high altitude-induced reduction of oxygen saturation (SpO2) was positively related to the changes of PLT.Conclusions Acute high altitude exposure may reduce PLT,PDW and PCT levels,but elevate MPV and enhance the platelet activity.The reduction of SpO2 might be associated with the changes of PLT,PDW and PCT.Platelet-associated parameters may be recovered to normal with a compensatory effect after short-term acclimation.