Association between obesity and acute high-altitude disease / 中国组织工程研究

ABSTRACT

BACKGROUND: The occurrence and severity of acute high-altitude disease(AHAD) are determined by the speed entering the highland, the altitude of highland and seasons. The association between obesity and AHAD has not been fully investigated.OBJECTIVE: To investigate the association between obesity and acute high-altitude in people exposed rapidly to the highland.DESIGN: Comparative observation.SETTING: Department of Cardiology, General Hospital of Chinese PLA and Department of Cardiology, Tibetan General Hospital of Chinese PLA.PARTICIPANTS: The experiment was conducted at the Department of Cardiology, General Hospital of Tibetan Military Area Command of Chinese PLA in August 2006. Totally 82 Henan subjects aged 28-45 years were selected from the male workers constructing the Qinghai-Tibet Railway and their managers with acute high-altitude exposure. They had never been to the highland before, and all agreed to the detection.METHODS: ①Every subject completed the AHAD self-report questionnaire at sea level and 12 hours and 24 hours after ascending high-altitude. The items in the questionnaire included symptoms of headache, gastrointestinal symptoms,fatigue or weakness, dizziness, and insomnia. Each symptom was graded from 0-3 with 0 as no symptoms, 1 as mild symptoms, 2 as moderate symptoms, and 3 as severe symptoms and a total score of 15. A score of 4 or more could by identified as AHAD. ②The height and body mass were measured to calculate the body mass (BMI). Those with BMI≥28 kg/m2 served as the obesity group [n =39, mean age (35±8) years], and those with BMI of 18.5-23.9 kg/m2 as the normal body mass group [n =43, mean age (35±8) years]. ③Arterial blood was taken to evaluate arterial oxygen saturation (SO2), arterial oxygen pressure (PaO2) and arterial carbon dioxide pressure (PaCO2) at baseline and 24 hours after ascending high-altitude. ④The measurement data was compared by t test.MAIN OUTCOME MEASURES: BMI, vital capacity of lungs, SO2, PaO2 and PaCO2 levels of obese and normal people.RESULTS: Totally 39 obese people and 43 normal people were involved in the result analysis. ①AHAD score No symptom was reported at sea level in all participants (scored 0), but the AHAD scores in the obesity group were significantly higher than those in normal group 12-hour and 24-hour after ascending high-altitude. ②Blood gas analysis:At sea level, there were no statistical differences in the levels of SO2, PaO2, and PaCO2 between two groups (P ＞ 0.05).But 24 hours after ascending high-altitude, SO2 and PaO2 of the obesity group were much lower than in the normal group (P＜ 0.01), and PaCO2 was significantly higher than in the normal group (P＜ 0.01).CONCLUSION: Obese men are more vulnerable to high-altitude hypoxia than people with normal body mass. Obesity is an important risk factor for the development of acute high-altitude disease.