Department of Research on Smoking and COPD, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, SSA, Mexico City, Mexico.
Rev Invest Clin. 2022 Jan 3;74(1):4-15. doi: 10.24875/RIC.21000159.
A large world population resides at moderate altitude. In the Valley of Mexico (2,240 m above sea level), its inhabitants, breathe approximately 29% more on average and have 10% increased hemoglobin concentrations compared to sea level residents, among other differences. These compensations reduce but not eliminate the impact of altitude hypoxemia. The objective of the manuscript is to review and describe the information available on health and disease at moderate altitudes, mainly with data in Spanish language from Latin-American countries. Young adults in Mexico City have an SaO2 between 92% and 94% versus 97% at sea level, frequently decreasing below 90% during sleep and intense exercise. It is likely that among the population living at this altitude, lung growth, and development during pregnancy and infancy are enhanced, and that after residing for several tens of thousands of years, more important adaptations in oxygen transport and utilization have developed, but we are not certain about it. For patients with respiratory diseases, residing at moderate altitudes implies increased hypoxemia and clinical deterioration, unless supplementary oxygen is prescribed or patients move to sea level. Hyperventilation increases exposure of residents to air pollutants compared to those living in cities with similar concentrations of pollutants, although at sea level. Humans evolved at sea level and lack the best-known adaptations to reside at moderate or high altitudes. Residents of moderate altitudes breathe deeply the city´s air with all its pollutants, and more often require supplementary oxygen.
大量的世界人口居住在中海拔地区。在墨西哥谷（海拔 2240 米），与海平面居民相比，其居民的平均呼吸量增加了 29%，血红蛋白浓度增加了 10%，还有其他差异。这些代偿作用减轻了，但并没有消除高原低氧血症的影响。本文的目的是综述和描述中海拔地区的健康和疾病信息，主要是来自拉丁美洲国家的西班牙语数据。墨西哥城的年轻成年人的 SaO2 在 92%到 94%之间，而在海平面上为 97%，在睡眠和剧烈运动时经常降至 90%以下。在这个海拔高度居住的人群中，肺的生长和发育可能在怀孕期间和婴儿期得到增强，并且在居住了数万年之后，可能已经发展出了更重要的氧气运输和利用适应，但我们并不确定。对于患有呼吸系统疾病的患者来说，居住在中海拔地区意味着会增加低氧血症和临床恶化，除非给予补充氧气或患者搬到海平面地区。与生活在污染物浓度相似的城市的人相比，中海拔地区的居民因过度通气而接触到更多的空气污染物，尽管是在海平面上。人类是在海平面上进化而来的，缺乏适应居住在中海拔或高海拔地区的最佳已知适应性。中海拔地区的居民呼吸着充满所有污染物的城市空气，而且更经常需要补充氧气。
