High altitude hypoxia and Aging

Aging is a life process in which the adaptability of the organism's own functions to the environment and the body's resistance gradually decline. There are two types of human aging: physiological aging and pathological aging.

Physiological aging refers to the natural physiological degeneration process that occurs over time, that is, the changes in the body’s physique. This is a universal law that will apply to all living organisms.Pathological aging refers to changes in the body due to physiological changes. Suffering from certain diseases or changes in old age caused by various external factors (including various diseases) accelerates the aging process. With the continuous progress of science, people's knowledge of aging has continued to advance. There are many theories dealing with the mechanism of aging, including immunology, endocrinology, brain damage, genetics, trace elements, aging, and so on.

High altitude hypoxia is also closely related to aging. According to the statistics of the fourth census of Tibet, the average life expectancy of residents on the Tibetan plateau is 58.37 years, about 10 years less than people living in plain areas.This number decreases with the increase in altitude. The average life expectancy will decrease by 0.2 years when the altitude increases by 100 meters. Through observing the endocrine function, immune function, memory, and skin aging of the plateau people, someone has found that the plateau people have premature aging that is about 5–10 years earlier than people living in plain areas.

At altitudes above 3000m, the decrease in atmospheric pressure and partial pressure of oxygen reduces the amount of oxygen that the body takes in from the outside, which leads to hypoxia of body tissues. Cerebral hypoxia increases anaerobic metabolism and weakens brain cell function and metabolism. Therefore, even healthy elderly people at high altitude have obvious memory loss, and neurological symptoms such as slow response are also more prominent.

The changes in the body caused by hypoxia manifest in many ways, mainly irritability and injury changes. Chronic hypoxia at high altitude can make the body produce more erythropoietin, which promotes the bone marrow to produce more red blood cells to carry more oxygen. This is the body's compensatory function, but at the same time, it also leads to increased blood viscosity, increased blood flow resistance, slow blood flow and microcirculation disturbances, which will affect the blood tissue perfusion and oxygen supply, resulting in mild hypoxic injury of cells. Easily affected are the heart, brain, lung, kidney, and other important organs. The accumultation of these mild hypoxia damages causes different degrees of damage to these organs, accelerates the aging process, and weakens the body's resistance and tolerance to hypoxia. Therefore, hypertension, arteriosclerosis, heart disease, heart rhythm disorders, and cerebrovascular diseases and other diseases increase with the increase of people's age at high altitude.This is the reason why such diseases have increased significantly among the elderly. The aging of the elderly at high altitude is mainly pathological. However, physiological aging and pathological aging often exist at the same time. They are difficult to be strictly distinguished and affect each other.

Studies have shown that the activity of superoxide dismutase (SOD) in residents living in high altitude hypoxic environments for a long time is significantly reduced, while lipid peroxide is increased, indicating that the ability of high altitude residents to clean up superoxide anion free radicals is reduced. Free radicals have obvious toxic effects on the human body. This manifestation of unbalanced free radical metabolism is also one of the important mechanisms leading to aging.

In addition to hypoxia, the aging of plateau people is also affected by other factors, such as individual differences, strong ultraviolet radiation, long sunshine hours, cold weather, and local environmental nutrient deficiencies. All of these have adverse effects on the human body. In short, the aging of people at high altitude is a complex physiological and pathological process that is a synthesis of many factors.

High altitude hypoxia damages the human body, leading to premature aging, which directly affects the health and longevity of the elderly at high altitude. Therefore, it is particularly important to safeguard the health of the elderly in plateau areas. It is necessary to strengthen physical exercises from the pre-aged period to improve the body's tolerance to hypoxia, enhance resistance to the environment, prevent and reduce the occurrence of pain, and delay the process of premature aging.