Osteoporosis is a degenerative change in human bone tissue with age, where bone mass (bone mineral and bone matrix) is continuously lost in proportion to age, but at a slow rate, and is a physiological change, a physiological degenerative process that occurs and is experienced by every older person. Osteoporosis is a systemic disease of bone metabolism characterized by a decrease in bone strength and an increased risk of fracture. Bone strength mainly reflects the integrity of bone density and bone mass. It is a common and prevalent disease in middle-aged and elderly people. There are usually no specific clinical manifestations until fractures occur. The disease is more common in women than men, and is commonly seen in postmenopausal women and the elderly. With the increase of the elderly population in China, the incidence of osteoporosis is on the rise, and it is a health problem of concern in China and worldwide. The specific cause of osteoporosis has not been fully clarified, but it is generally believed to be related to the following factors: 1. Endocrine factors Female patients suffer from osteoporosis due to estrogen deficiency, while men suffer from decreased testosterone levels due to hypogonadism. Osteoporosis is particularly common in postmenopausal women, and premature ovarian failure causes osteoporosis to appear earlier, suggesting that a decrease in estrogen is an important factor in the occurrence of osteoporosis. There is a sudden and significant acceleration of bone loss within 5 years after menopause, with annual bone loss of 2% to 5% being common. About 20% to 30% of early menopausal women have bone loss >3%/year, known as rapid bone loss, while 70% to 80% of women have bone loss <3%/year, known as normal bone loss. Lean women are more prone to osteoporosis and fractures than fat women, as a result of the conversion of androgens to estrogens in the latter's adipose tissue. Compared to normal women of similar age, no significant differences in blood estrogen levels were seen in patients with osteoporosis, suggesting that decreased estrogen is not the only factor causing osteoporosis. In general, the presence of physiological decompensation of renal function in the elderly is manifested by reduced production of 1,25-(OH2)D3 and lower blood calcium, which in turn stimulates the secretion of parathyroid hormone, so most scholars report that blood parathyroid hormone concentrations often increase with age, with increases of up to 30% or more. Studies of parathyroid function in postmenopausal women with osteoporosis have shown hypo-, normal-, and hyper-function. It is generally believed that osteoporosis in the elderly is associated with hyperparathyroidism. Some studies have shown lower calcitonin levels in women than in men in all age groups, and lower calcitonin levels in women in the menopausal group than in menopausal women, so it is thought that lower calcitonin levels may be one of the reasons for women's susceptibility to osteoporosis. The increased value of blood calcitonin in women after intravenous calcium drip was significantly lower than that in men, and both the basal and increased values of blood calcitonin were negatively correlated with age. The Department of Endocrinology at Peking Union Medical College Hospital reported that no significant difference in calcitonin reserve function was seen in premenopausal and postmenopausal healthy volunteers who underwent intravenous calcitonin excitation tests. In contrast, calcitonin reserve function was reduced in both patients with reduced bone mass and osteoporosis, with the latter being more pronounced, suggesting that reduced calcitonin reserve function may be involved in the development of osteoporosis. Blood calcitonin levels in postmenopausal women with osteoporosis have mostly been reported to be reduced, but normal and mildly elevated levels have also been reported. Osteoblast function, 1-alpha-hydroxylase activity of the kidney, which is impaired with aging, and the associated decrease in 1,25-(OH2)D3 concentration, are also involved in the formation of osteoporosis. Other endocrine disorders, such as Cushing syndrome (Cushing syndrome), produce excessive endogenous corticosteroids or chronic thyrotoxicosis, leading to increased bone resorption or excretion, which are all related to the formation of osteoporosis. 2, genetic factors Osteoporosis is common in whites, especially in northern Europeans, followed by Asians, while blacks are rare. Bone density is an important indicator for the diagnosis of osteoporosis, and the value of bone density is mainly determined by genetic factors, followed by the influence of environmental factors. The difference in BMD between young twins has been reported to be four times greater than the difference between monozygotic twins; while in adults the difference in BMD between twins is 19 times greater than that between monozygotic twins. In 1994, Morrison et al. reported that the vitamin D receptor genotype predicted differences in BMD, accounting for 75% of the overall genetic effect, and that BMD was about 15% higher in bb genotypes than in BB genotypes after adjustment for various environmental factors; in terms of vertebral fracture incidence, bb The incidence of vertebral fractures was about 10 years later in bb genotypes than in BB genotypes, and the incidence of hip fractures was only 1/4 of that of BB genotypes in bb genotypes. The preliminary results of this study show that there are significant differences among races and countries, and the final results need to be further investigated. Other studies such as the relationship between collagen and estrogen receptor genes and osteoporosis have also been reported, but no definite conclusion has been reached yet. 3, nutritional factors It has been found that calcium intake in adolescence is directly related to the peak bone mass in adulthood. Calcium deficiency leads to increased PTH secretion and bone resorption, and people with low calcium diet are prone to osteoporosis. Vitamin D deficiency leads to impaired mineralization of the bone matrix and can lead to osteochondrosis. Long-term protein deficiency causes insufficient synthesis of bone mechanism protein, resulting in backward new bone production, and if there is also calcium deficiency, osteoporosis will appear faster. Vitamin C is indispensable in the synthesis of bone matrix hydroxyproline, which can maintain the normal growth of bone matrix and maintain bone cells to produce sufficient amount of alkaline phosphatase, such as lack of vitamin C can reduce the synthesis of bone matrix. 4, waste factors Muscles produce mechanical force on bone tissue, muscles developed strong bones, then high bone density value. Due to the reduced activity of the elderly, muscle strength is weakened, mechanical stimulation is less, bone volume is reduced, while the weakened muscle strength and coordination disorders make the elderly more prone to falls, accompanied by a reduction in bone volume is prone to fractures. When the elderly are bedridden for a long time after a stroke or other disease, they lose bone mass due to disuse factors and are prone to osteoporosis. 5. Drugs and diseases Anticonvulsants, such as phenytoin sodium, phenobarbital, and carbamazepine, cause treatment-related vitamin D deficiency, as well as impaired intestinal calcium absorption and secondary hyperparathyroidism. Excessive use of acid preparations, including aluminum preparations, can inhibit phosphate absorption and lead to the breakdown of bone minerals. Glucocorticoids directly inhibit bone formation, decrease intestinal absorption of calcium, increase renal excretion of calcium, secondary parathyroid dysfunction, and production of sex hormones. Long-term use of heparin is associated with osteoporosis, and the exact mechanism is not known. Chemotherapeutic agents, such as cyclosporine A, have been shown to increase bone renewal in rodents. Cytokines produced by tumor cells in tumors, especially multiple myeloma, activate osteoclasts, as well as leukemia and lymphoma in children or adolescents, in which osteoporosis is often limited. Gastrointestinal disorders such as inflammatory bowel disease lead to malabsorption and eating disorders. Anorexia nervosa leads to rapid weight loss as well as malnutrition and is associated with absence of menstruation. Dysgerminogenic anemia, resulting from excessive bone marrow hyperplasia and thinning of the trabecular junction, and secondary hypogonadism in such patients. 6, other factors Alcohol abuse has a direct toxic effect on bone. Smoking increases the liver's metabolism of estrogen and its direct effect on bone, in addition to causing weight loss and early menopause. Long-term high-intensity exercise can lead to idiopathic osteoporosis.