(1) Reduce the body water content of the elderly over 60 years old, which is 5 1.5% (60% normal) for males and 42%-45.5% (50% normal) for females. Therefore, the elderly should pay attention to dehydration when using antipyretics.
(2) Fat increase With the increase of age, metabolism gradually slows down and calorie consumption gradually decreases, so calorie intake is often higher than consumption, and the remaining calories are converted into fat and stored, which gradually increases the proportion of adipose tissue and makes the body gradually obese. The fat content of human body is inversely proportional to the water content, and the fat content is parallel to the total cholesterol content in blood, so the blood lipid increases with age.
(3) The number of cells is reduced, and the organs and weight are reduced. The decrease of cells is gradually aggravated with the increase of age. The number of tissue cells in this 75-year-old man has decreased by about 30%. Due to cell atrophy, death and water loss, the weight of various organs and bodies of the elderly is reduced, especially muscles, gonads, spleen and kidneys. The most obvious cell atrophy is muscle, muscle elasticity is reduced, strength is weakened, and fatigue is easy. Tendons and ligaments in the elderly are atrophied and stiff, which leads to slow movement and slow response.
(4) organ function decline. Mainly manifested in the reduction of the reserve capacity, adaptability and resistance of various organs.
2. Aging metabolism (three metabolic imbalances)
In metabolism, young people are characterized by progress, assimilation and synthesis, while old people are characterized by retrogression, alienation and decomposition, which usually begin before the symptoms of aging appear.
(1) Changes in glucose metabolism, the function of glucose metabolism in the elderly is decreased, and they are prone to diabetes. Studies have proved that abnormal glucose metabolism accounts for 16% over 50 years old and 25% over 70 years old.
(2) Changes of lipid metabolism With the aging of random bodies, lipid peroxides formed by unsaturated fatty acids are easy to accumulate, and the latter are easy to produce free radicals. Serum lipoprotein is also the source of free radicals. With the increase of age, blood lipids increase obviously, and it is easy to suffer from hyperlipidemia, atherosclerosis, hypertension and cerebral hemorrhage.
(3) Changes in protein metabolism The aging of protein metabolism is an important material basis for the decline of human physiological function. With the decrease of serum albumin content and the increase of total globulin, protein molecules can form large inactive molecules with age and accumulate in cells, resulting in the decline of cell vitality and function. Protein's metabolic decomposition is greater than synthesis in the elderly, and its digestion and absorption function is decreased. With the increase of age, the quantity and quality of various protein have a downward trend. When protein is mildly deficient, there will be symptoms such as fatigue, weight loss and decreased resistance. Severe deficiency can lead to malnutrition, edema, hypoproteinemia and decreased liver and kidney function. The long-term excessive high-protein diet of the elderly will aggravate the burden of organs such as liver and kidney whose functions have declined. With the increase of age, translation errors are prone to occur in the process of protein synthesis, leading to cell senescence and death.
(4) Changes in inorganic metabolism The permeability of cell membrane and ion exchange ability of the elderly are low. The most obvious abnormal inorganic metabolism is osteoarthropathy, especially osteoporosis.
3. Changes in adaptability The adaptability of the elderly to changes in the internal and external environment declines, and they are prone to palpitation and shortness of breath during physical activities, and the recovery time after activities is prolonged. The adaptability to cold and heat is weakened, and it is easy to get heatstroke in summer and catch a cold in winter. Some young people can easily cope with physical and mental work, and the elderly are often unable to afford it. Due to the decline of posture adaptability, the blood pressure of the elderly fluctuates greatly and their metabolic ability is low, such as oral or intravenous glucose load or intravenous calcium load. Hyperglycemia or hypercalcemia lasts for a long time, indicating that the internal environment stability of the elderly is lower than that of the young.