Osteoporosis itself has no specific symptoms; its main consequence is the increased risk of bone fractures. Osteoporotic fractures are those that occur in situations where healthy people would not normally break a bone; they are therefore regarded as fragility fractures. Typical fragility fractures occur in the vertebral column, rib, hip and wrist.
[edit] Fractures
The symptoms of a vertebral collapse ("compression fracture") are sudden back pain, often with radiculopathic pain (shooting pain due to nerve compression) and rarely with spinal cord compression or cauda equina syndrome. Multiple vertebral fractures lead to a stooped posture, loss of height, and chronic pain with resultant reduction in mobility.[4]
Fractures of the long bones acutely impair mobility and may require surgery. Hip fracture, in particular, usually requires prompt surgery, as there are serious risks associated with a hip fracture, such as deep vein thrombosis and a pulmonary embolism, and increased mortality.
[edit] Falls risk
The increased risk of falling associated with aging leads to fractures of the wrist, spine and hip. The risk of falling, in turn, is increased by impaired eyesight due to any cause (e.g. glaucoma, macular degeneration), balance disorder, movement disorders (e.g. Parkinson's disease), dementia, and sarcopenia (age-related loss of skeletal muscle). Collapse (transient loss of postural tone with or without loss of consciousness) leads to a significant risk of falls; causes of syncope are manifold but may include cardiac arrhythmias (irregular heart beat), vasovagal syncope, orthostatic hypotension (abnormal drop in blood pressure on standing up) and seizures. Removal of obstacles and loose carpets in the living environment may substantially reduce falls. Those with previous falls, as well as those with a gait or balance disorder, are most at risk.[5]
9/06/2009
Pathogenesis
The underlying mechanism in all cases of osteoporosis is an imbalance between bone resorption and bone formation. In normal bone, there is constant matrix remodeling of bone; up to 10% of all bone mass may be undergoing remodeling at any point in time. The process takes place in bone multicellular units (BMUs) as first described by Frost in 1963.[2] Bone is resorbed by osteoclast cells (which derive from the bone marrow), after which new bone is deposited by osteoblast cells. [3]
The three main mechanisms by which osteoporosis develops are an inadequate peak bone mass (the skeleton develops insufficient mass and strength during growth), excessive bone resorption and inadequate formation of new bone during remodeling. An interplay of these three mechanisms underlies the development of fragile bone tissue.[3] Hormonal factors strongly determine the rate of bone resorption; lack of estrogen (e.g. as a result of menopause) increases bone resorption as well as decreasing the deposition of new bone that normally takes place in weight-bearing bones. The amount of estrogen needed to suppress this process is lower than that normally needed to stimulate the uterus and breast gland. The α-form of the estrogen receptor appears to be the most important in regulating bone turnover.[3] In addition to estrogen, calcium metabolism plays a significant role in bone turnover, and deficiency of calcium and vitamin D leads to impaired bone deposition; in addition, the parathyroid glands react to low calcium levels by secreting parathyroid hormone (parathormone, PTH), which increases bone resorption to ensure sufficient calcium in the blood. The role of calcitonin, a hormone generated by the thyroid that increases bone deposition, is less clear and probably not as significant as that of PTH.[3]
Osteoblasts, several displaying a prominent Golgi apparatus, actively synthesizing osteoid containing two osteocytes.
The activation of osteoclasts is regulated by various molecular signals, of which RANKL (receptor activator for nuclear factor κB ligand) is one of best studied. This molecule is produced by osteoblasts and other cells (e.g. lymphocytes), and stimulates RANK (receptor activator of nuclear factor κB). Osteoprotegerin (OPG) binds RANKL before it has an opportunity to bind to RANK, and hence suppresses its ability to increase bone resorption. RANKL, RANK and OPG are closely related to tumor necrosis factor and its receptors. The role of the wnt signalling pathway is recognized but less well understood. Local production of eicosanoids and interleukins is thought to participate in the regulation of bone turnover, and excess or reduced production of these mediators may underlie the development of osteoporosis.[3]
Trabecular bone is the sponge-like bone in the ends of long bones and vertebrae. Cortical bone is the hard outer shell of bones and the middle of long bones. Because osteoblasts and osteoclasts inhabit the surface of bones, trabecular bone is more active, more subject to bone turnover, to remodeling. Not only is bone density decreased, but the microarchitecture of bone is disrupted. The weaker spicules of trabecular bone break ("microcracks"), and are replaced by weaker bone. Common osteoporotic fracture sites, the wrist, the hip and the spine, have a relatively high trabecular bone to cortical bone ratio. These areas rely on trabecular bone for strength, and therefore the intense remodeling causes these areas to degenerate most when the remodeling is imbalanced.
The three main mechanisms by which osteoporosis develops are an inadequate peak bone mass (the skeleton develops insufficient mass and strength during growth), excessive bone resorption and inadequate formation of new bone during remodeling. An interplay of these three mechanisms underlies the development of fragile bone tissue.[3] Hormonal factors strongly determine the rate of bone resorption; lack of estrogen (e.g. as a result of menopause) increases bone resorption as well as decreasing the deposition of new bone that normally takes place in weight-bearing bones. The amount of estrogen needed to suppress this process is lower than that normally needed to stimulate the uterus and breast gland. The α-form of the estrogen receptor appears to be the most important in regulating bone turnover.[3] In addition to estrogen, calcium metabolism plays a significant role in bone turnover, and deficiency of calcium and vitamin D leads to impaired bone deposition; in addition, the parathyroid glands react to low calcium levels by secreting parathyroid hormone (parathormone, PTH), which increases bone resorption to ensure sufficient calcium in the blood. The role of calcitonin, a hormone generated by the thyroid that increases bone deposition, is less clear and probably not as significant as that of PTH.[3]
Osteoblasts, several displaying a prominent Golgi apparatus, actively synthesizing osteoid containing two osteocytes.
The activation of osteoclasts is regulated by various molecular signals, of which RANKL (receptor activator for nuclear factor κB ligand) is one of best studied. This molecule is produced by osteoblasts and other cells (e.g. lymphocytes), and stimulates RANK (receptor activator of nuclear factor κB). Osteoprotegerin (OPG) binds RANKL before it has an opportunity to bind to RANK, and hence suppresses its ability to increase bone resorption. RANKL, RANK and OPG are closely related to tumor necrosis factor and its receptors. The role of the wnt signalling pathway is recognized but less well understood. Local production of eicosanoids and interleukins is thought to participate in the regulation of bone turnover, and excess or reduced production of these mediators may underlie the development of osteoporosis.[3]
Trabecular bone is the sponge-like bone in the ends of long bones and vertebrae. Cortical bone is the hard outer shell of bones and the middle of long bones. Because osteoblasts and osteoclasts inhabit the surface of bones, trabecular bone is more active, more subject to bone turnover, to remodeling. Not only is bone density decreased, but the microarchitecture of bone is disrupted. The weaker spicules of trabecular bone break ("microcracks"), and are replaced by weaker bone. Common osteoporotic fracture sites, the wrist, the hip and the spine, have a relatively high trabecular bone to cortical bone ratio. These areas rely on trabecular bone for strength, and therefore the intense remodeling causes these areas to degenerate most when the remodeling is imbalanced.
Osteoporosis
Osteoporosis is a disease of bone that leads to an increased risk of fracture. In osteoporosis the bone mineral density (BMD) is reduced, bone microarchitecture is disrupted, and the amount and variety of non-collagenous proteins in bone is altered. Osteoporosis is defined by the World Health Organization (WHO) in women as a bone mineral density 2.5 standard deviations below peak bone mass (20-year-old healthy female average) as measured by DXA; the term "established osteoporosis" includes the presence of a fragility fracture.[1] Osteoporosis is most common in women after menopause, when it is called postmenopausal osteoporosis, but may also develop in men, and may occur in anyone in the presence of particular hormonal disorders and other chronic diseases or as a result of medications, specifically glucocorticoids, when the disease is called steroid- or glucocorticoid-induced osteoporosis (SIOP or GIOP). Given its influence is the risk of fragility fracture, osteoporosis may significantly affect life expectancy and quality of life.
Osteoporosis can be prevented with lifestyle changes and sometimes medication; in people with osteoporosis, treatment may involve both. Lifestyle change includes preventing falls and exercise; medication includes calcium, vitamin D, bisphosphonates and several others. Fall-prevention advice includes exercise to tone deambulatory muscles, proprioception-improvement exercises; equilibrium therapies may be included. Exercise with its anabolic effect, may at the same time stop or reverse osteoporosis.
From Wikipedia, the free encyclopedia
Osteoporosis can be prevented with lifestyle changes and sometimes medication; in people with osteoporosis, treatment may involve both. Lifestyle change includes preventing falls and exercise; medication includes calcium, vitamin D, bisphosphonates and several others. Fall-prevention advice includes exercise to tone deambulatory muscles, proprioception-improvement exercises; equilibrium therapies may be included. Exercise with its anabolic effect, may at the same time stop or reverse osteoporosis.
From Wikipedia, the free encyclopedia
9/03/2009
Osteoporosis: a Silent Killer of Bones
Osteoporosis is a bone disease. It is virtually a disease on account of which the bones generally become fragile and weak. Osteoporosis if not taken proper care of lead may to the breakage of the bones thus leading to a fracture. Osteoporosis generally is found to be very much typical in certain parts of the body, say for instance in the hips, wrists, spinal cord and also in the vertebras. Osteoporosis is like a silent killer which attacks an individual without prior symptoms.
Simply a sneezing, a tight hug, stepping, bending down to get something can cause Osteoporosis. Osteoporosis is also known by another name called "porous bone." There are certain factors which are associated with Osteoporosis. These factors are termed as "Risk Factors." Some of the factors are as mentioned below:
• Gender: Sex plays a major concern in the occurrence of Osteoporosis. Females have a more probability of being attacked with Osteoporosis than the male generation. Sometimes Osteoporosis is also related with menopause. Osteoporosis is estimated to have been attacking the women folk as and when they reach the stage of menopause. Thus when a woman reaches the age of around 45 years and when she is attacked with menopause that is when she experiences the stoppage of menstruation, the velocity of Osteoporosis is found to be more.
• Age: Age is yet another risk factor of Osteoporosis. The more a person advances in age, the more is the risk of being attacked with Osteoporosis. It is generally during the old age that the bones become very much weak and fragile and thus they are prone to get attacked with Osteoporosis.
• Body dimensions: Women with thin and lean body physique have more the chance of being attacked with Osteoporosis.
• Ethnicity: Ethnicity plays a major role in respect of Osteoporosis. Here we can state that Asian as well as the Caucasian women folk has a high risk of Osteoporosis then when compared to American, African and Latin women.
• Hereditary: Family history is also adversely related with Osteoporosis. Present generation whose fore-fathers suffered from Osteoporosis, has more risk of Osteoporosis.
Besides these, anorexia, certain medications, smoking of cigarette, excessive drinking of alcohol and also maintenance of a low lifetime diet with less amount of vitamin D and calcium also causes Osteoporosis.
As it is always said that prevention is better then cure, thus Osteoporosis can also be prevented by undertaking certain precautions in the early stage of one's development. As the demand of calcium is found to be very high in the growing stage of one's development, thus a good amount of calcium products should be undertaken from the early developmental stages. Inadequacy of calcium in one's body has a greater prospect to be affected by Osteoporosis. So it is always advisable to undertake certain calcium products in one's diet like yogurt, milk, cheese, ice cream, green and leafy vegetables, like broccoli, spinach etc, fish like salmon and sardines, dry fruits like almonds, juices and squash etc. Thus according to the different stages of one's development right from the stage of infancy to old age, the intake of calcium should be adjusted accordingly in order to prevent Osteoporosis.
Simply a sneezing, a tight hug, stepping, bending down to get something can cause Osteoporosis. Osteoporosis is also known by another name called "porous bone." There are certain factors which are associated with Osteoporosis. These factors are termed as "Risk Factors." Some of the factors are as mentioned below:
• Gender: Sex plays a major concern in the occurrence of Osteoporosis. Females have a more probability of being attacked with Osteoporosis than the male generation. Sometimes Osteoporosis is also related with menopause. Osteoporosis is estimated to have been attacking the women folk as and when they reach the stage of menopause. Thus when a woman reaches the age of around 45 years and when she is attacked with menopause that is when she experiences the stoppage of menstruation, the velocity of Osteoporosis is found to be more.
• Age: Age is yet another risk factor of Osteoporosis. The more a person advances in age, the more is the risk of being attacked with Osteoporosis. It is generally during the old age that the bones become very much weak and fragile and thus they are prone to get attacked with Osteoporosis.
• Body dimensions: Women with thin and lean body physique have more the chance of being attacked with Osteoporosis.
• Ethnicity: Ethnicity plays a major role in respect of Osteoporosis. Here we can state that Asian as well as the Caucasian women folk has a high risk of Osteoporosis then when compared to American, African and Latin women.
• Hereditary: Family history is also adversely related with Osteoporosis. Present generation whose fore-fathers suffered from Osteoporosis, has more risk of Osteoporosis.
Besides these, anorexia, certain medications, smoking of cigarette, excessive drinking of alcohol and also maintenance of a low lifetime diet with less amount of vitamin D and calcium also causes Osteoporosis.
As it is always said that prevention is better then cure, thus Osteoporosis can also be prevented by undertaking certain precautions in the early stage of one's development. As the demand of calcium is found to be very high in the growing stage of one's development, thus a good amount of calcium products should be undertaken from the early developmental stages. Inadequacy of calcium in one's body has a greater prospect to be affected by Osteoporosis. So it is always advisable to undertake certain calcium products in one's diet like yogurt, milk, cheese, ice cream, green and leafy vegetables, like broccoli, spinach etc, fish like salmon and sardines, dry fruits like almonds, juices and squash etc. Thus according to the different stages of one's development right from the stage of infancy to old age, the intake of calcium should be adjusted accordingly in order to prevent Osteoporosis.
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