Journal Article

A Randomly-Controlled Study on the Cardiac Function at the Early Stage of Return to the Plains after Short-Term Exposure to High Altitude

Yan, Ziqiang, Qi, Yushu, Zhou, Qiquan, Luo, Yongjun, Yang, Shengyue, Shi, Zifu, Fan, Yong

2012

Overview

High altitude acclimatization and adaptation mechanisms have been well clarified, however, high altitude de-adaptation mechanism remains unclear. In this study, we conducted a controlled study on cardiac functions in 96 healthy young male who rapidly entered the high altitude (3700 m) and returned to the plains (1500 m) after 50 days. Ninety eight healthy male who remained at low altitude were recruited as control group. The mean pulmonary arterial pressure (mPAP), left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), cardiac function index (Tei index) were tested. Levels of serum creatine kinase isoform MB (CK-MB), lactate dehydrogenase isoenzyme-1 (LDH-1), endothelin-1 (ET-1), nitrogen oxide (NO), serum hypoxia-inducible factor-1α (HIF-1α), 8-iso-prostaglandin F(2α) (8-iso PGF(2α)), superoxide dismutase (SOD) and malonaldehyde (MDA) were measured at an altitude of 3700 m and 1500 m respectively. The results showed that after short-term exposure to high altitude mPAP and Tei index increased significantly, while LVEF and LVFS decreased significantly. These changes were positively correlated with altitude. On the 15(th) day after the subjects returned to low altitude, mPAP, LVEF and LVFS levels returned to the same level as those of the control subjects, but the Tei index in the returned subjects was still significantly higher than that in the control subjects (P<0.01). We also found that changes in Tei index was positively correlated with mPAP, ET-1, HIF-1α and 8-iso PGF(2α) levels, and negatively correlated with the level of NO, LVEF, LVFS, CK-MB and LDH-1. These findings suggest that cardiac function de-adapts when returning to the plains after short-term exposure to high altitude and the function recovery takes a relatively long time.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Acclimatization / Acclimatization - physiology / Accuracy / Adaptation / Adolescent / Adult / Altitude / Altitude acclimatization / Biology / Blood pressure / Blood Pressure - physiology / Cardiology / Chinese medicine / Correlation / Creatine / Creatine kinase / Creatine Kinase - blood / Cytokines - blood / Diastole - physiology / Dinoprost - analogs & derivatives / Dinoprost - blood / Disease / Education / Endothelin / Endothelin 1 / Environmental Exposure / Enzymes / Exposure / Free radicals / Free Radicals - blood / Geography / Heart / Heart diseases / Heart Function Tests / High altitude / High-altitude environments / Hospitals / Humans / Hypertension / Hypoxia / Hypoxia-Inducible Factor 1, alpha Subunit - blood / Hypoxia-inducible factors / Indexing / L-Lactate dehydrogenase / Laboratories / Lactate dehydrogenase / Lactate dehydrogenase isoenzymes / Lactic acid / Lipid peroxidation / Low altitude / Male / Malondialdehyde / Malondialdehyde - metabolism / Medicine / Metabolism / Military medicine / Myocardium - enzymology / Nitrogen oxides / Oxidative stress / Photochemicals / Pulmonary arteries / Pulmonary Artery - physiology / Short term / Superoxide dismutase / Superoxides / Systole - physiology / Time Factors / Traditional Chinese medicine / Veins & arteries / Ventricle / Young Adult