Items in AFP with MESH term: Bone Density
ABSTRACT: Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. The thyroid-stimulating hormone value is typically measured in a third-generation assay capable of detecting approximately 0.01 microU per mL (0.01 mU per L). Subclinical hyperthyroidism may be a distinct clinical entity, related only in part to Graves' disease or multinodular goiter. Persons with subclinical hyperthyroidism usually do not present with the specific signs or symptoms associated with overt hyperthyroidism. A detailed clinical history should be obtained, a physical examination performed and thyroid function tests conducted as part of an assessment of patients for subclinical hyperthyroidism and to evaluate the possible deleterious effects of excess thyroid hormone on end organs (e.g., heart, bone). A reasonable treatment option for many patients is a therapeutic trial of low-dose antithyroid agents for approximately six to 12 months in an effort to induce a remission. Further research regarding the etiology, natural history, pathophysiology, and treatment of subclinical hyperthyroidism is warranted.
ABSTRACT: Dieting behaviors and nutrition can have an enormous impact on the gynecologic health of adolescents. Teenaged patients with anorexia nervosa can have hypothalamic suppression and amenorrhea. In addition, these adolescents are at high risk of osteoporosis and fractures. Unfortunately, data suggest that estrogen replacement, even in combination with nutritional supplementation, does not appear to correct the loss of bone density in these patients. Approximately one half of adolescents with bulimia nervosa also have hypothalamic dysfunction and oligomenorrhea or irregular menses. Generally, these abnormalities do not impact bone density and can be regulated with interval dosing of progesterone or regular use of oral contraceptives. In contrast, the obese adolescent with menstrual irregularity frequently has anovulation and hyperandrogenism, commonly referred to as polycystic ovary syndrome. Insulin resistance is thought to play a role in the pathophysiology of this condition. While current management usually involves oral contraceptives, future treatment may include insulin-lowering medications, such as metformin, to improve symptoms. Because all of these patients are potentially sexually active, discussion about contraception is important.
ABSTRACT: Osteoporosis affects nearly 28 million elderly Americans. Its major clinical manifestation is fragility fractures of the spine, hip, and distal radius. Low bone mass is the most important risk factor for a fragility fracture. In 1994, the World Health Organization defined osteoporosis on the basis of a bone mineral density that is 2.5 standard deviations below that in peak young normal persons. Three common imaging modalities used to assess bone strength are dual-energy x-ray absorptiometry, quantitative computed tomography, and calcaneal ultrasonography. The first two modalities measure bone mineral density in both the lumbar spine and peripheral sites. It is thought that calcaneal ultrasonography measures bone architecture and density. Unlike the other studies, ultrasonography currently cannot be used for monitoring skeletal changes over time or evaluating response to therapy.
ABSTRACT: Osteoporosis is characterized by low bone mineral density and a deterioration in the microarchitecture of bone that increases its susceptibility to fracture. The World Health Organization defines osteoporosis as a bone mineral density that is 2.5 standard deviations or more below the reference mean for healthy, young white women. The prevalence of osteoporosis in black women is one half that in white and Hispanic women. In white women 50 years and older, the risk of osteoporotic fracture is nearly 40 percent over their remaining lifetime. Of the drugs that have been approved for the prevention or treatment of osteoporosis, the bisphosphonates (risedronate and alendronate) are most effective in reducing the risk of vertebral and nonvertebral fractures. Risedronate has been shown to reduce fracture risk within one year in postmenopausal women with osteoporosis and in patients with glucocorticoid-induced osteoporosis. Hormone therapy reduces fracture risk, but the benefits may not outweigh the reported risks. Teriparatide, a recombinant human parathyroid hormone, reduces the risk of new fractures and is indicated for use in patients with severe osteoporosis. Raloxifene has been shown to lower the incidence of vertebral fractures in women with osteoporosis. Salmon calcitonin is reserved for use in patients who cannot tolerate bisphosphonates or hormone therapy.
Prevention of Osteoporosis and Fractures - Article
ABSTRACT: Osteoporosis and low bone density are associated with a risk of fracture as a result of even minimally traumatic events. The estimated lifetime risk of osteoporotic fracture is as high as 50 percent, especially in white and Asian women. The use of caffeine, tobacco and steroids is associated with a decrease in bone density. Cognitive impairment, vision problems and postural instability increase the risk of falling and sustaining a fracture. Medications such as long-acting sedative hypnotics, anticonvulsants and tricyclic antidepressants also increase this risk. Combinations of clinical and radiographic findings can predict fracture risk more effectively than bone densitometry, but often only after the first fracture has occurred. The addition of dietary calcium and/or vitamin D is clearly both cost-effective and significant in reducing the likelihood of fractures. Bisphosphonates reduce fracture risk but at a cost that may be prohibitive for some patients. Estrogen and estrogen-receptor modulators have not been well studied in randomized trials evaluating the reduction of fractures, but they are known to increase bone density. Pharmacologic therapy and the reduction of sensory and environmental hazards can prevent osteoporotic fractures in some patients.
ABSTRACT: Osteoporosis afflicts 75 million persons in the United States, Europe and Japan and results in more than 1.3 million fractures annually in the United States. Because osteoporosis is usually asymptomatic until a fracture occurs, family physicians must identify the appropriate timing and methods for screening those at risk. Prevention is the most important step, and women of all ages should be encouraged to take 1,000 to 1,500 mg of supplemental calcium daily, participate in regular weight-bearing exercise, avoid medications known to compromise bone density, institute hormone replacement therapy at menopause unless contraindicated and avoid tobacco and excessive alcohol intake. All postmenopausal women who present with fractures as well as younger women who have risk factors should be evaluated for the disease. Physicians should recommend bone mineral density testing to younger women at risk and postmenopausal women younger than 65 years who have risk factors for osteoporosis other than being postmenopausal. Bone mineral density testing should be recommended to all women 65 years and older regardless of additional risk factors. Bone mineral density screening should be used as an adjunct to clinical judgment only if the results would influence the choice of therapy or convince the patient to take appropriate preventive measures.
ABSTRACT: Osteoporosis affects more than 28 million Americans. With the advent of accessible and affordable diagnostic studies, awareness and recognition of this disease by patients and clinicians are growing. Osteoporotic fractures of the spine and hip are costly and associated with significant morbidity and mortality. Over the past decade, a surge of new antiosteoporotic drugs have been labeled or are awaiting labeling by the U.S. Food and Drug Administration. One class of agents used to treat osteoporosis is the bisphosphonates, which inhibit bone resorption, cause an increase in bone mineral density and reduce the risk of future fractures caused by aging, estrogen deficiency and corticosteroid use. Overall, bisphosphonates have been shown to have a strong safety and tolerability profile.
Fracture Prevention in Postmenopausal Women - Clinical Evidence Handbook
NIH Releases Statement on Osteoporosis Prevention, Diagnosis, and Therapy - Practice Guidelines
Screening for Osteoporosis in Postmenopausal Women - Putting Prevention into Practice