Bone density

After midlife, you begin to lose bone tissue. This can result in porous, brittle bones. Exercise actually encourages the body to keep bone tissue dense and strong. 

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Bone ash Bone black Bone cement Bone coal Bone density... 

PTH has a dual effect on bone cells, depending on the temporal mode of administration given intermittently, PTH stimulates osteoblast activity and leads to substantial increases in bone density. In contrast, when given (or secreted) continuously, PTH stimulates osteoclast-mediated bone resorption and suppresses osteoblast activity. Further to its direct effects on bone cells, PTH also enhances renal calcium re-absorption and phosphate clearance, as well as renal synthesis of 1,25-dihydroxy vitamin D. Both PTH and 1,25-dihydroxyvitamin D act synergistically on bone to increase serum calcium levels and are closely involved in the regulation of the calcium/phosphate balance. The anabolic effects of PTH on osteoblasts are probably both direct and indirect via growth factors such as IGF-1 and TGF 3. The multiple signal transduction... 

Osteoporosis is a common condition, in which bone density is decreased as a consequence of an imbalance between bone formation (osteoblast) and bone loss (osteoclast). This leads to fragile bones, which are at an increased risk for fractures. The term porosis means spongy, which describes the large holes seen in these bones. 

A major regulator of bone metabolism and calcium homeostasis, parathyroid hormone (PTH) is stimulated through a decrease in plasma ionised calcium and increases plasma calcium by activating osteoclasts. PTH also increases renal tubular calcium re-absorption as well as intestinal calcium absorption. Synthetic PTH (1-34) has been successfully used for the treatment of osteoporosis, where it leads to substantial increases in bone density and a 60-70% reduction in vertebral fractures. 

Application of vitamin K-antagonistic anticoagulants like warfarin gave no clearcut results concerning bone density or a changed risk for bone fractures. 

Osteoporosis is a loss of bone density occurring when the loss of bone substance exceeds the rate of bone formation. Bones become porous, brittle, and fragile. Compression fractures of the vertebrae are common. This disorder occurs most often in postmenopausal women, but can occur in men as well. 

Taking the contraceptive hormones provides health benefits not related to contraception, such as regulating the menstrual cycle and decreased blood loss, and incidence of iron deficiency anemia, and dysmenorrhea Health benefits related to the inhibition of ovulation include a decrease in ovarian cysts and ectopic pregnancies. hi addition, there is a decrease in fibrocyctic breast disease, acute pelvic inflammatory disease endometrial cancer, ovarian cancer, maintenance of bone density, and symptoms related to endometriosis in women taking contraceptive hormones. Newer combination contraceptives such as norgestimate and ethinyl estradiol... 

Osteopetrosis (marble bone disease), characterized by increased bone density, is due to inability to resorb bone. One form occurs along with renal tubular acidosis and cerebral calcification. It is due to mutations in the gene (located on chromosome 8q22) encoding carbonic anhydrase II (CAII), one of four isozymes of carbonic anhydrase present in human tissues. The reaction catalyzed by carbonic anhydrase is shown below ... 

FELSON D T, ZHANG Y, HANNMAN M T, KIEL D P, WILSON P W, ANDERSON J J (1993) The effect of postmenopausal estrogen therapy on bone density in elderly women. N Engl J Med. 329 1141-6. 

POTTER S M, BAUM J A, TENG H, STILLMAN R J, SHAY N F, ERDMAN J W Jr. (1998) Soy prOteUl aud isoflavones their effects on blood lipids and bone density in postmenopausal women. Am J Clin Nutr. 68 1375S-1379S. 

HSU 0 s, SHEN w w, HSUEH, Y M and YEH s L (2001) Soy isoflavone supplementation in postmenopausal women. Effects on plasma lipids, antioxidant enzye activities and bone density. JReprod Med 46, 221-6. 

The most common adverse effects from inhaled corticosteroids include oropharyngeal candidiasis and hoarse voice. These can be minimized by rinsing the mouth after use and by using a spacer device with metered-dose inhalers. Increased bruising and decreased bone density have also been reported the clinical importance of these effects remains uncertain.1,2,19... 

Patients with IBD, particularly those with CD, are also at risk for bone loss. This may be a function of malabsorption or an effect of repeated courses of corticosteroids. Patients with IBD should receive a baseline bone density measurement prior to receiving corticosteroids. Vitamin D and calcium supplementation should be used in all patients receiving long-term corticosteroids. Oral bisphosphonate therapy may also be considered in patients receiving prolonged courses of corticosteroids or in those with osteopenia or osteoporosis. 

Therapeutic modalities for amenorrhea are targeted at restoring the normal menstrual cycle. The goals of treatment are to preserve bone density, prevent bone loss, and restore ovulation, thus improving fertility as desired. Amenorrhea resulting from conditions contributing to hypoestrogenism also may affect quality of life via the induction of hot flashes (premature ovarian failure), dyspareunia, and in prepubertal females, lack of secondary sexual characteristics and absence of menarche. 

Peripheral bone mineral density measurements cannot be used for diagnosis because they do not correlate with central measurements. However, they are useful in identifying patients who are candidates for central DXA and who are at increased risk of fracture.5 It also may be useful in patients who have had multiple fractures or in low-risk patients. Additionally, peripheral measurement of bone mineral density generally is less expensive than central DXA and is easily accessible. Instruments used for peripheral bone densitometry are portable, which allows bone density to be measured in pharmacies and health-fair screening booths. 

Monitor for beneficial effects on bone density. The AACE recommends a follow-up DXA scan annually for the first 2 years after initiating drug therapy and every other year thereafter. Changes in bone mineral density may fluctuate from year to year. 

In postmenopausal women, recently reported evidence supporting the use of aromatase inhibitors in the adjuvant setting is intriguing and may usurp the role of tamoxifen. Three different approaches to therapy have been undertaken with these new agents (1) direct comparison with tamoxifen for adjuvant hormonal therapy, (2) sequential use after 5 years of adjuvant tamoxifen therapy, and (3) sequential use after 2 to 3 years of adjuvant tamoxifen. Based on results of several studies, it has been concluded that therapy for postmenopausal women with ER-positive breast cancer should include an aromatase inhibitor.27,47 It is still unclear if the aromatase inhibitor should be used instead of tamoxifen or sequentially after receiving tamoxifen for 2 to 5 years.27 Concerns surrounding loss of bone density, changes in blood lipids, and cardiac and vascular disease require further study.27... 

Encourage patients on long-term PN to engage in regular low-intensity exercise. Yearly bone density measurements also should be performed on patients on long-term PN and when metabolic bone disease is suspected. 

Osteoporosis Disease of the bones characterized by a loss of bone density or mass, resulting in brittle, weak bones that are susceptible to fracture (porous bones). 

Reported that only coffee among caffeine sources was the significant predictor of hip fracture, although no association between caffeine intake and forearm fracture found. No association between bone density and caffeine intake, although caffeine was found to have significant negative effect on calcium metabolism. 

Caffeine intake inversely associated with bone density, independent of dietary anthropometric and hormonal factors. 

Lloyd, T., Schaeffer, J., Walker, M., Demers, L., Urinary hormonal concentrations and spinal bone densities of premenopausal vegetarian and nonvegetarian women, American Journal of Clinical Nutrition, 54, 1005, 1991. 

A 60-year-old male develops elevation of blood pressure, hyperglycemia., decreased bone density, and occult blood in his stool. Which of the following agents is associated with these adverse effects ... 

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