摘要：目的研究急性轻、中度缺氧对人的情绪及焦虑状态的影响。方法利用低压舱模拟300 m(对照)、2800 m、3600 m、4400 m高度缺氧暴露1 h，采用情绪状态问卷（POMS）和状态—焦虑问卷（S-AI），考察了18名健康男性青年受试者的情绪变化。结果随着高度的增加，POMS问卷中紧张—焦虑（T），困惑—迷茫（C）和疲惫—惰性（F）消极情绪状态值及S—AI得分逐渐增加，而其中的积极情绪状态值即有力—好动（V）得分则依此下降(P＜0.05或P＜0.01)，但POMS中愤怒-敌意（A）和抑郁-沮丧（D）的得分并无显著变化(P＞0.05)。2800 m 急性暴露的即刻，紧张-焦虑（T）和S-AI得分显著高于对照水平（P＜0.05），而暴露1 h后又下降至地面水平。结论急性轻、中度缺氧暴露1h在2800 m高度水平即对人的情绪及心境产生负面影响，随着高度的增加上述影响进一步加重。

中图分类号：R852.11文献标识码：A

文章编号：1002-0837(2000)01-0001-05

Effects of Acute Mild and Moderate Hypoxia on Human Mood State

LI Xue-yi，WU Xing-yu，WU Yan-hong，WANG Tao

(Department of Aerospace Medicine DAM,Fourth Military Medical University FMMU,Xi'an 710032)

FU Chuan，SHEN Xiao-feng

(Department of Steward Medicine,China Southwest Airlines,Chengdu 610202)

abstract:Objective To explore the effects of acute mild and moderate hypoxia on human mood state.Method The mood states of 18 healthy male volunteers were evaluated by self-assessment questionnaires,profile of mood state (POMS) and state anxiety inventory (S-AI) after random exposure to simulated altitude of 300 m (control)，2800m,3600 m and 4400 m for 1 h in a hypobaric chamber.Result The data at 300 m level were taken as the baseline control.The negative mood state factor points (tension,fatigue etc.) increased gradually as the altitude level increased while V (vigor-activity) points had a tendency to decrease (P＜0.05 or P＜0.01).No significant difference was found in the points of (D,A) even under exposure to 4400 m(P＞0.05).At the early period of 2800 m exposure the tension points of POMS and S-AI scores were higher than those of control level (P＜0.05) then dropped to baseline level when exposure to this altitude for 1 h.Conclusion Exposure to acute mild hypobaric hypoxia at 2800 m for 1 h has adverse effect on mood state of healthy person and the negative effect was further aggravated with the increment of altitude level.

Key words：hypoxia;emotions;profile of mood state;state anxiety inventory

The rapid advances in powered flight in military and civilian aviation have made it possible to more crews and passengers to ascend rapidly to high altitude than ever;the technologic advance that occurred and continues to occur demands the development of parallel medical system to serve those who fly.It is well known that there are extensive highland regions in our country,and with one sixth of these areas are high above 3000 m.The effects of hypoxia on human cognitive performance must be further assessed because human beings have to work and live in environments with reduced oxygen levels.

Although effects of a rapid ascent to high terrestrial altitude on cognition have been well documented^［4～12］,the generalizations of effects of altitude on mood,behavior and cognitive functions such as memory,attention,thinking and so on are complicated by differences between studies including the specific tasks or dimensions measured in the response to altitude sojourns.Emotion which reflect the shifting of external and internal environment and mood state might be more sensitive to hypoxia than cognitive functions,so investigations designed to measure mood state changes during acute hypoxia are needed.Therefore this study is aimed to describe the effects of hypoxia on mood state by self-assessment questionnaires,profile of mood state (POMS) and state anxiety inventory (S-AI).

Method

SubjectsThe subjects were eighteen healthy young male non-smoking and non-drinking freshmen of the Fourth Military Medical University,aged 16～18 years.All had normal or corrected to normal vision and normal color vision.All were normal residents at altitude below 300 m and none have been to plateau prior to this trial.Participation in the experiments and exposure was voluntary.

Altitude SimulationThe test were carried out in a hypobaric chamber afforded by DAM,FMMU.The subjects were randomly exposed to hypoxia equivalent to altitudes 300 m,2800 m,3600 m and 4400 m,meanwhile they were asked to answer the questionnaires twice in 1 h period at each altitude(5 and 60 min after ascent to altitude respectively).The questionnaires to be finished in this experiment required about 5～7 min to complete.The order of altitude level presentation was randomly chosen by the chamber controller and without knowledge of the subjects and experimenters inside the chamber.The project and experimental protocol were approved by the department of technology and engineering of DAM.The hypobaric chamber ascended to the test altitude at a speed of 15 m/s and maintained for 1 h.After having finished all tests,the hypobaric chamber descended to the ground level (300 m high above sea level in Xi'an) at a speed of 5 m/s.Subjects were told to swallow and do Valsalva maneuver to prevent otitic Barotrauma durig the descent.The chamber was continuously ventilated with fresh air;noise:75 dB(A);relative humidity and temperature were maintained at 25%～43% and 20.4℃～25.1℃ respectively.All subjects wore flight headgear and earplugs inside the chamber to shield off of noise.All tests were performed at 18:30～21:30 to eliminate influence of circadian rhythm.The time between two ascents was longer than 48 h.

ProcedureTo gain familiarity with the facilities,tests and environment,all subjects practiced the questionnaires for 2～3 times prior to the experiment.They were briefly told about the purpose and process of the experiment in order to gain their sincere cooperation.Analysis of variance for repeated measurement was carried out to compare with the baseline data of 300 m to minimize confounding of other factors,i.e.noise,fatigue,learning effects etc.All the test operations were carried out in standard order and with fixed apparatuses by same instructor in order to reduce errors.

QuestionnairesThe POMS is a questionnaire from neurobehavioral core test battery of WHO organized by Mcnair et al^［1,2］.Its Chinese version consists of 65 adjective words with 5-point scale degrees of agreement,resulting in 6 kinds of mood statesT:tension-anxiety;D:depression-dejection;A:anger-hostility;V:vigor-activity;

F:fatigue-inertia;C:confusion-bewilderment.The Chinese version of the state anxiety inventory Questionnaires (S-AI)^［3］ composed by 20 titles with 4-point scale was used for estimation of anxiety of mood state.

Statistical analysesThe analysis of variance (ANOVA) and two-tailed paired T-test were used on the scores of questionnaires to analyze the effects of hypoxia on mood state.All statistical analyses were carried out using Statistical Package for the Social Science(SPSS).Statistical analysis consisted of scores of means and standard deviation（±s）,and auto-control was used to compare differences between control and each altitude group based on the subject's own baseline points.For all analyses probability level of less than 0.05 was accepted as significant.

Result

Changes of POMS after 1 h exposure to different altitud