I. What is osteoporosis?
It is a disorder of systemic bone metabolism that is characterized by damage to the microstructure of bone tissue, a constant decrease in bone mineral composition and bone matrix in equal proportions, thinning of bone mass, a decrease in the number of bone trabeculae, an increase in bone fragility and an increased risk of fracture. In medicine, osteoporosis was first proposed in 1885, but it was not until the International Symposium on Osteoporosis held in Denmark in 1990 that osteoporosis was given a clear definition and recognized worldwide: primary osteoporosis is a systemic bone disease characterized by a decrease in bone mass and degeneration of bone microstructure, resulting in increased bone fragility and susceptibility to fracture.
The main manifestations are: reduction in bone mass, osteocalcinolysis, compression fracture of the spine, resulting in the appearance of “turtle back”, and some age-related diseases such as dyspnea, osteophytes, hypertension, dementia and diabetes; degeneration of bone microstructure, decrease in bone strength and increase in brittleness, making it difficult to carry the original load.
Second, the harm of osteoporosis
Osteoporosis leads to uneven stress on the bones, or bone fragility, the body produces a reparative response and the formation of bone spurs, the result of this abnormal distribution of bone components, can also cause intervertebral disc protrusion, osteoporosis is often a fracture, osteonecrosis, fracture does not heal the intrinsic cause, rheumatoid and rheumatoid arthritis the greatest harm lies in the subchondral bone tissue cellular changes and loss of function, and the cause and immune cells The cause is closely related to the influx of immune cells from the bone marrow into the joints.
Osteoporosis can have consequences such as bone pain, hunchback, short stature, fractures and even disability. Common osteoporotic fractures include hip fractures and spinal fractures, and they often lead to secondary complications. On the eve of World Osteoporosis Day on October 20, Zhu Hanmin, director of the Osteoporosis Society of Shanghai Medical Association and professor of East China Hospital, raised this warning: osteoporosis can deform vertebral bones and cause gastrointestinal diseases due to abdominal pressure; osteoporosis can also make the spinal bones fragile, bedridden and cause lung infections.
Three, osteoporosis classification
Osteoporosis (sometimes referred to as osteopenia) can be divided into the following categories.
(1) primary osteoporosis: such as senile osteoporosis, postmenopausal osteoporosis, etc.
(2) Secondary osteoporosis: such as hyperthyroidism osteoporosis, diabetic osteoporosis, etc.
(3) Idiopathic osteoporosis of unknown cause: such as hereditary osteoporosis, etc.
According to the scope of the occurrence of osteoporosis can be further divided into the following two categories.
(1) Systemic osteoporosis: such as senile osteoporosis, hyperthyroidism osteoporosis, etc.
(2) limited osteoporosis: such as rheumatoid arthritis osteoporosis, local osteoporosis caused by the fixation of limb plaster, etc.
IV. Etiology of osteoporosis
The factors that cause bone loss in middle-aged and elderly people are very complex, and recent studies have concluded that they are closely related to the following factors.
(1) The reduction of sex hormone secretion in middle and old people is one of the important causes of osteoporosis. It is a recognized fact that estrogen level decreases after menopause, resulting in increased bone resorption.
(2) With age, the secretion of calcium-regulating hormones is dysregulated, resulting in disorders of bone metabolism.
(3) The elderly have a lack of protein, calcium, phosphorus, vitamins and trace elements due to the loss of teeth and lower digestive function, poor bone nano, and less intake of goodness.
(4) With the growth of age, outdoor exercise is also an important reason why the elderly are prone to osteoporosis.
(5) Recent studies in molecular biology have shown that osteoporosis is closely related to vitamin D receptor (VDR) gene variants.
Five, the symptoms of osteoporosis
(1) Pain. The most common symptom of primary osteoporosis is low back pain, which accounts for 70%-80% of the patients with pain. The pain spreads along the spine to both sides, decreases when lying on the back or sitting, increases when posterior extension or prolonged standing or sitting, is light during the day, increases at night and when waking up in the morning, and increases when bending, muscle movement, coughing and bowel movement.
Bone pain generally occurs when 12% or more of bone mass is lost. In elderly osteoporosis, the vertebral trabeculae atrophy and decrease in number, the vertebral body compresses and deforms, the spine flexes forward, and the lumbar rash muscle doubles its contraction in order to correct the forward flexion of the spine, resulting in muscle fatigue and even spasm, producing pain. A recent compression fracture of the thoracolumbar spine can also produce acute pain, with strong pressure pain and percussion pain in the spinal spinous process at the corresponding site, which can generally be gradually reduced after 2-3 weeks, and some patients can present with chronic low back pain. If the corresponding spinal nerve is compressed, radiating pain in the extremities, sensory-motor disorders in both lower extremities, intercostal neuralgia, retrosternal pain similar to angina pectoris, or epigastric pain similar to acute abdomen may occur. If compression of the spinal cord, cauda equina also affects the bladder and rectal function.
(2) Shortening of body length and hunchback. Mostly appear after the pain. The front part of the vertebrae of the spine is almost mostly composed of cancellous bones, and this part is the pillar of the body with a large weight, especially the 11th and 12th thoracic vertebrae and the 3rd lumbar vertebrae, which have a greater load and are easily compressed and deformed, causing the spine to tilt forward and the back curve to increase, resulting in hunchback, and as we grow older, osteoporosis increases and the curvature of the hunchback increases, resulting in significant knee contracture. Each person has 24 vertebrae, the height of each vertebra is about 2cm in normal people, when the elderly osteoporosis vertebral compression, each vertebrae shortened by about 2mm, the average length of the body shortened by 3-6cm.
(3) Fracture. This is the most common and serious complication of degenerative osteoporosis.
(4) Decreased respiratory function. Compression fractures of thoracic and lumbar vertebrae, backward curvature of the spine and thoracic deformity can significantly reduce lung capacity and maximum air exchange, and patients can often experience chest tightness, shortness of breath and dyspnea.
VI. Diagnostic tests for osteoporosis
The diagnosis of osteoporosis needs to rely on a comprehensive analysis of clinical manifestations, bone mass measurement, X-ray film and bone conversion biochemistry indexes.
1.Biochemical examination: The determination of blood and urine minerals and certain biochemical indicators can help determine the state of bone metabolism and the speed of bone renewal rate, which is important for the differential diagnosis of osteoporosis.
(1) Bone formation index.
(2) Bone resorption indicators: urinary hydroxyproline. Urinary hydroxylysine glycoside. Plasma antitartaric acid hydrochloride phosphatase. Urinary collagen pyridine cross-linking (PYr) or type I collagen cross-linking N-terminal peptide (NTX).
(3) Blood and urine bone mineral composition tests: serum total calcium. Serum inorganic phosphorus. Serum magnesium. Urinary calcium, phosphorus, magnesium determination.
2.X-ray examination:, X-ray is still a more popular method to check osteoporosis.
3, bone mineral density measurement.
(1) single photon absorptiometry (SPA).
(2) Dual-energy X-ray absorptiometry (DEXA).
(3)Quantitative CT (QCT).
(4) Ultrasound (USA).
VII. Prevention and treatment of osteoporosis.
The focus of prevention and treatment is to prevent the occurrence of fractures , the bone reserves in young and strong years are more, and in the center of old age even if part of it is lost, the remaining bone is still sufficient to maintain the needs of bone metabolism, in order to prevent osteoporosis or slow down its development, in young and strong years that is to pay attention to exercise and nutrition, and in old age more emphasis should be placed on calcium and sex hormone supplementation.
Postmenopausal women need about 1000-1500mg of calcium daily, much higher than the daily intake, high calcium diet can inhibit age-related osteoporosis, and can reduce the incidence of fractures, calcium absorption requires vitamin D, for those who do not receive enough sunlight, it is appropriate to take vitamin D 600-800 international units daily. The human body’s need for vitamin D increases with age, and its toxic dose varies from person to person; if larger doses are needed, they must be administered under the supervision of a physician.
Although estrogen cannot directly increase bone mass, it can reduce bone resorption, lower serum calcium and phosphorus levels, and reduce urinary calcium and urinary hydroxyproline excretion; estrogen can also increase parathyroid hormone levels and promote intestinal calcium absorption; the dosage of estrogen should be appropriate; the daily dosage of ethylene estradiol is 0.5 to 1 mg per month for 25 days, with 5 days of discontinuation. days. The effect of estrogen application is closely related to the time of administration, and should be used during the perimenopausal period, and should be used with caution in elderly people with arteriosclerosis. Attention should also be paid to not causing liver damage during the use of estrogen. Endometrial proliferation and functional bleeding should be taken into account in the application of estrogen, which may also induce breast cancer, endometrial cancer or cervical cancer. Particular emphasis is placed on baseline control examinations prior to drug administration.
Currently calcium and vitamin D supplementation and change of poor lifestyle habits are considered as the basic treatment for osteoporosis, and medications such as third/ fourth generation bisphosphonates, such as alendronate and zoledronic acid.
Sodium fluoride can stimulate osteoblasts; promote new bone formation and increase the width of bone trabeculae, but the newly formed bone-like mineralization is poor. Sodium fluoride can also cause secondary hyperparathyroidism, which increases bone resorption, so calcium and vitamin D must be given at the same time.
Calcitonin can be used both for the prevention and treatment of osteoporosis. Its main effect is to inhibit osteoclast activity and reduce the number of osteoclasts. Another mechanism is the action on the renal tubules, which facilitates intestinal calcium intake. Calcitonin also has a very useful effect of central analgesia, which is particularly suitable for the perioperative treatment of tumor bone metastases or osteoporotic fractures.
Other applications include parathyroid hormone 1-34 fragments, but they are extremely expensive and not yet available in China. In addition, adequate calcium, protein and vitamin C supplementation and reasonable and appropriate exercise are needed.