Relevance of bone mineral density, bone quality and falls in reduction of vertebral and non-vertebral fractures

All epidemiological studies conclude that without prompt, concerted and well-designed prevention programs, the increasing cost related to osteoporotic fractures will become an unbearable burden for the community within the next fifteen years. However, the most effective way of setting up such preventive strategies is not yet unequivocally defined. Low bone mass and microarchitectural damage of bone tissue may account for a large part of the epidemiology of vertebral fractures. Extraskeletal determinants, including low muscle strength, poor balance and gait, all resulting in an increased propensity to fall, also play a major role in the occurrence of hip fracture. Depending on the localization of the fractures, the relative importance of skeletal and extraskeletal risk factors can significantly differ. For prevention of vertebral fractures, drugs affecting bone mass and skeletal architecture may provide a substantial benefit while hip fracture prevention will be more successfully targeted by multi-faceted strategies concentrating not only on the skeletal dimension of the fracture but also aiming, either pharmacologically or through multi-intervention programs, at a reduction in the incidence and in the consequences of falls in the elderly.     

The prevention and treatment of osteoporosis: a review

Osteoporosis is a disorder characterized by reduced bone strength, diminished bone density, and altered macrogeometry and microscopic architecture. Adult bone mass is the integral measurement of the bone mass level achieved at the peak minus the rate and duration of subsequent bone loss. There is clearly a genetic predisposition to attained peak bone mass, which occurs by a person's mid-20s. Bone loss with age and menopause are universal, but rates vary among individuals. Both peak bone mass and subsequent bone loss can be modified by environmental factors, such as nutrition, physical activity, and concomitant diseases and medications. Osteoporosis prevention requires adequate calcium and vitamin D intake, regular physical activity, and avoiding smoking and excessive alcohol ingestion. Risk of fracture determines whether medication is also warranted. A previous vertebral or hip fracture is the most important predictor of fracture risk. Bone density is the best predictor of fracture risk for those without prior adult fractures. Age, weight, certain medications, and family history also help establish a person's risk for osteoporotic fractures. All women should have a bone density test by the age of 65 or younger (at the time of menopause) if risk factors are present. Guidelines for men are currently in development. Medications include both antiresorptive and anabolic types. Antiresorptive medications--estrogens, selective estrogen receptor modulators (raloxifene), bisphosphonates (alendronate, risedronate, and ibandronate) and calcitonins--work by reducing rates of bone remodeling. Teriparatide (parathyroid hormone) is the only anabolic agent currently approved for osteoporosis in the United States. It stimulates new bone formation, repairing architectural defects and improving bone density. All persons who have had osteoporotic vertebral or hip fractures and those with a bone mineral density diagnostic of osteoporosis should receive treatment. In those with a bone mineral density above the osteoporosis range, treatment may be indicated depending on the number and severity of other risk factors.     

Management of osteoporosis

Osteoporosis or osteopenia occurs in about 44 million Americans, resulting in 1.5 million fragility fractures per year. The consequences of these fractures include pain, disability, depression, loss of independence, and increased mortality. The burden to the healthcare system, in terms of cost and resources, is tremendous, with an estimated direct annual USA healthcare expenditure of about $17 billion. With longer life expectancy and the aging of the baby-boomer generation, the number of men and women with osteoporosis or low bone density is expected to rise to over 61 million by 2020. Osteoporosis is a silent disease that causes no symptoms until a fracture occurs. Any fragility fracture greatly increases the risk of future fractures. Most patients with osteoporosis are not being diagnosed or treated. Even those with previous fractures, who are at extremely high risk of future fractures, are often not being treated. It is preferable to diagnose osteoporosis by bone density testing of high risk individuals before the first fracture occurs. If osteoporosis or low bone density is identified, evaluation for contributing factors should be considered. Patients on long-term glucocorticoid therapy are at especially high risk for developing osteoporosis, and may sustain fractures at a lower bone density than those not taking glucocorticoids. All patients should be counseled on the importance of regular weight-bearing exercise and adequate daily intake of calcium and vitamin D. Exposure to medications that cause drowsiness or hypotension should be minimized. Non-pharmacologic therapy to reduce the non-skeletal risk factors for fracture should be considered. These include fall prevention through balance training and muscle strengthening, removal of fall hazards at home, and wearing hip protectors if the risk of falling remains high. Pharmacologic therapy can stabilize or increase bone density in most patients, and reduce fracture risk by about 50%. By selecting high risk patients for bone density testing it is possible to diagnose this disease before the first fracture occurs, and initiate appropriate treatment to reduce the risk of future fractures.     

Risk factors and prevention of osteoporosis-related fractures

In order to effectively prevent osteoporosis-related fractures, one must aim to prevent both osteoporosis, as well as the events and circumstances that may lead to injury, ultimately resulting in fracture. Among all the osteoporotic fractures that can occur, hip fractures are associated with a severe decrease in quality of life and high mortality, which reaches 51% at one year post-fracture in nonagenarians. Prevention of osteoporosis should ideally begin in childhood, aiming to achieve high peak bone mass accompanied by an inherently healthy lifestyle throughout life, in order to minimize bone loss during middle and third age, and in parallel to avoid or diminish other fracture risk factors. There are numerous fracture risk factors, including age, gender, race, lifestyle and concomitant medical conditions, which either cannot or can be modified, to a greater or lesser degree. Falls consist a previously underestimated risk factor, responsible for a large percentage of fractures. International and national strategies aimed at public awareness, early identification of those at increased risk for fracture and preventive or therapeutic intervention may succeed in subduing the currently increasing prevalence of osteoporotic fractures.     

Treatment of Osteoporosis and Prevention of New Fractures: Role of Intravenously Administered Bisphosphonates

ObjectiveTo evaluate the usefulness of intravenously administered bisphosphonates for improving absorption, tolerability, adherence, and outcomes in the treatment and prevention of osteoporosis.MethodsData published from 1996 to 2009 relevant to the treatment of osteoporosis, with emphasis on bisphosphonates, fracture risk, adherence to therapy, frequency of dosing, intravenous treatment, tolerability, cost-effectiveness, and quality of life, were reviewed.ResultsAlthough bisphosphonates are currently the standard of care for treatment of postmenopausal osteoporosis and osteoporosis in men, oral formulations are associated with poor absorption and potential irritation of the upper gastrointestinal tract. These issues necessitate complicated and restrictive dosing regimens, which in turn lead to poor compliance and persistence. Intravenous formulations such as 3 mg of ibandronate given quarterly and 5 mg of zoledronic acid administered once yearly avoid problems relating to absorption and tolerability by bypassing the gastrointestinal tract. Intravenously administered ibandronate is presumed (by virtue of similar or superior improvements in bone mineral density) to have antifracture efficacy similar to that of orally administered ibandronate given daily, which has been shown to produce significant reductions in vertebral fractures during a 3-year period in comparison with placebo. Zoledronic acid, 5 mg once yearly, has been shown to produce a significant reduction in the risk of morphometric vertebral fractures, clinical vertebral fractures, hip fractures, and nonvertebral fractures versus placebo during a 3-year interval in patients with postmenopausal osteoporosis and also to yield a significantly decreased risk for new clinical fractures versus placebo in patients with recent low-trauma hip fracture. Both agents have favorable safety and tolerability profiles.ConclusionIntravenously administered bisphosphonates have the potential to increase compliance and persistence with therapy in patients with osteoporosis and to improve patient outcomes. (Endocr Pract. 2009;15:483-493)     

Osteoporosis: pathogenesis and clinical intervention

Osteoporosis is a very common disorder and much has been learnt in recent years about the many pathogenic processes that contribute to bone loss and fragility. Drug treatments are now available to prevent bone loss and reduce fracture, and there are prospects for modifying some of the pathogenic processes themselves. In common with other structures, the tissues of the musculoskeletal system undergo many changes with aging, and some of the commonest skeletal disorders are seen in the elderly. The changes in bone lead to osteoporosis and fractures, whereas muscle changes (sarcopenia) contribute to frailty, and changes in cartilage lead to osteoarthritis.     

Efficacy,cost, and aspects to take into account in the treatment of osteoporosis in the elderly

Age is one of the principal risk factors for development of frailty fractures. Age pyramids show a population that is becoming increasingly more elderly, with an increasing incidence of fractures, and the forecasts for the future are truly alarming. Adequate handling of these patients who are especially at risk, at both the preventive and care levels, with a well-defined orthogeriatric model is necessary to respond to this clinical challenge. The objective of this review is to analyze the efficacy of the different strategies for the handling of geriatric patients with fracture risk.     

Stéroides sexuels et ostéoporose chez l'homme

Several epidemiological studies have shown that about 25 per cent of hip fractures and 20 per cent of symptomatic vertebral fractures occur in men. The lifetime risk of hip fracture was estimated to be about 6 to 8 per cent and the risk of any osteoporotic fracture was estimated to be about 18 per cent in 50-year-old white men. In about 60% of cases in men, bone loss is secondary to several pathological conditions, such as long-term steroid therapy, severe hypogonadism, smoking or alcohol abuse or gastrointestinal disorders. In 40% of cases, osteoporosis is primary or idiopathic in men between the ages of 40 and 60 years. Genetic factors, a defect of boneforming cells or abnormal serum levels of bioavailable sex steroids could explain bone loss and fragility fractures in these men. It has been shown that hypogonadism is associated with a marked increase in bone remodelling and particularly in bone resorption with a dramatic loss in trabecular bone. It is now known that testosterone is partly transformed into estradiol by aromatase. Testosterone may therefore act on bone in two ways: it directly stimulates bone formation and estradiol regulates bone remodelling and inhibits bone resorption. Finally, in men over the age of 60 without hypogonadism, it has been shown that bone mineral density and fracture risk were better correlated with serum levels of bioavailable estradiol and Sex Hormone Binding Globulin than with serum testosterone levels.     

老年髋部骨折患者抗骨质疏松的治疗

髋部骨折往往与高发病率、死亡率以及沉重的经济负担相联系,也是再次骨折的一个主要危险因素。因此加强老年髋部骨折患者的抗骨质疏松治疗及预防再次骨折成为提高该类人群生活质量的必要和关键,其中均衡的营养、补充钙和维生素D是基础,及早进行抗骨质疏松药物治疗是关键,而消除骨质疏松的继发原因、治疗并存疾病、适当的锻炼及防止跌倒则是重要的补充。总之,加强老年骨质疏松的多学科综合管理能够获得很好的临床效果。本文就抗骨质疏松药物在老年髋部患者和那些具有跌倒高风险人群中的疗效予以综述,以期为老年骨质疏松的管理提供借鉴。     

Evidence for efficacy of drugs affecting bone metabolism in preventing hip fracture.

OBJECTIVE--To examine the effects of taking drugs affecting bone metabolism on the risk of hip fracture in women aged over 50 years. DESIGN--Retrospective, population based, case-control study by questionnaire. SETTING--14 centres in six countries in southern Europe. SUBJECTS--2086 women with hip fracture and 3532 control women matched for age. MAIN OUTCOME MEASURES--Number of drugs affecting bone metabolism taken and length taken for. RESULTS--Women taking drugs affecting bone metabolism had a significantly decreased risk of hip fracture. After adjustment for differences in other risk factors, the relative risk of hip fractures was 0.55 (95% confidence interval 0.31 to 0.85) in women taking oestrogens, 0.75 (0.60 to 0.94) in those taking calcium, and 0.69 (0.51 to 0.92) in those taking calcitonin. The fall in risk was not significant for anabolic steroids (0.6 (0.29 to 1.22)). Neither vitamin D nor fluorides were associated with a significant decrease in the risk of hip fracture. The effect on hip fracture risk increased significantly with increasing duration of exposure (risk ratio 0.8 (0.61 to 1.05) for less than median exposure v 0.66 (0.5 to 0.88) for greater than median exposure). Drugs were equally effective in older and younger women, with the exception of oestrogen. CONCLUSIONS--Oestrogen, calcium, and calcitonins significantly decrease the risk of hip fracture. Short term intervention late in the natural course of osteoporosis may have significant effects on the incidence of hip fracture.     

Iatrogenic Osteoporosis,Bilateral Hip Osteonecrosis,and Secondary Adrenal Suppression in an Hiv-Infected Man Receiving Inhaled Corticosteroids and Ritonavir-Boosted Highly Active Antiretroviral Therapy

ObjectiveTo report the first case of severe osteoporosis associated with a vertebral pathologic fracture and osteonecrosis of femoral heads in an HIV-infected man receiving inhaled corticosteroids and ritonavir-boosted antiretroviral therapy.MethodsWe describe an HIV-infected man with severe osteoporosis, bilateral hip osteonecrosis, and secondary adrenal suppression, including detailed clinical, laboratory, and radiographic data, and review the related literature.ResultsA 60-year-old man with a 15-year history of HIV infection and a medical history of long-standing bronchiectasis treated with inhaled corticosteroids and hypogonadism treated with testosterone was referred to the endocrinology clinic after experiencing an osteoporotic vertebral fracture. He was taking ritonavir-boosted antiretroviral therapy. Osteonecrosis of both hips was also diagnosed, which required total hip replacement therapy.Laboratory evaluation revealed adrenal insufficiency due to increased effect of exogenous inhaled steroids and no other secondary causes of osteoporosis. A bone densitometry study showed osteoporosis of both hips and the lumbar spine. He was treated with intravenous pamidronate. During treatment, he developed bilateral femoral fractures after minor trauma.ConclusionsGiven the potential for increased serum levels of inhaled corticosteroids in patients taking ritonavirboosted highly active antiretroviral therapy, attention must be paid to the risk of bone loss in HIV-infected patients taking inhaled corticosteroids. Prescribing calcium and vitamin D supplementation and considering early osteoporosis screening are reasonable measures for this patient population. Interaction between inhaled corticosteroids and ritonavir may increase risk of hypothalamus-pituitary-adrenal axis suppression. (Endocr Pract. 2011;17:74-78)     

Meta-analysis of how well measures of bone mineral density predict occurrence of osteoporotic fractures.

OBJECTIVE--To determine the ability of measurements of bone density in women to predict later fractures. DESIGN-- Meta-analysis of prospective cohort studies published between 1985 and end of 1994 with a baseline measurement of bone density in women and subsequent follow up for fractures. For comparative purposes, we also reviewed case control studies of hip fractures published between 1990 and 1994. SUBJECTS--Eleven separate study populations with about 90,000 person years of observation time and over 2000 fractures. MAIN OUTCOME MEASURES--Relative risk of fracture for a decrease in bone mineral density of one standard deviation below age adjusted mean. RESULTS--All measuring sites had similar predictive abilities (relative risk 1.5 (95% confidence interval 1.4 to 1.6)) for decrease in bone mineral density except for measurement at spine for predicting vertebral fractures (relative risk 2.3 (1.9 to 2.8)) and measurement at hip for hip fractures (2.6 (2.0 to 3.5)). These results are in accordance with results of case-control studies. Predictive ability of decrease in bone mass was roughly similar to (or, for hip or spine measurements, better than) that of a 1 SD increase in blood pressure for stroke and better than a 1 SD increase in serum cholesterol concentration for cardiovascular disease. CONCLUSIONS--Measurements of bone mineral density can predict fracture risk but cannot identify individuals who will have a fracture. We do not recommend a programme of screening menopausal women for osteoporosis by measuring bone density.     

The determinants of fracture in men

Osteoporosis represents an increasingly important clinical and public health problem among older men. Estimates indicated that 1-2 million (3-6%) men aged 50 years and over in the United States have osteoporosis and 8-13 million (28- 47%) have osteopenia. The lifetime risk of suffering a hip, spine or forearm fracture for a 50-year-old man is 13%, similar to the risk for prostate cancer. The number of osteoporotic fractures in men is expected to increase dramatically due to aging of the population and secular increases in fracture rates. Identification of men who are at greatest risk of osteoporosis and the risk factors, which predispose men to fracture, are essential so that preventive steps can be taken. Data on risk factors are emerging but many questions remain. Men may fracture at a higher bone mineral density (BMD) level than women. However, estimates of volumetric BMD, which correct in part for gender differences in bone size, and risk of fracture, may actually show similar relationships in men and women. Fracture rates are similar in older African American women and Caucasian men. Improved understanding of ethnic differences in fracture could identify potential reasons for gender differences. Family history and genetic factors are also important risk factors for fractures but the specific candidate genes are not known and whether gender modifies the effects of these genetic polymorphisms on BMD and the risk of fracture is also not known. In general, lifestyle factors and anthropometric measurements show similar relationships with fractures in men and women although few comprehensive prospective studies have been conducted. Current data will be reviewed on the relationships between markers of skeletal health, genetic polymorphisms, lifestyle and anthropometric factors and fracture.     

Osteoporosis in Men

ObjectiveTo review information pertinent to bone health and osteoporosis in men.MethodsA review of pertinent literature was conducted.ResultsOsteoporosis affects approximately 2 million men in the US and accounts for an estimated 600,000 fractures each year. There are significant differences in skeletal size and structure between men and women that account for differences in fracture incidence, location, and outcomes. Bone density testing is appropriate for men age 70 and older and younger men (50-69) who have risk factors for osteoporosis. Lifestyle management, including adequate calcium and vitamin D intake, appropriate physical activity, and avoidance of tobacco and heavy alcohol use, is appropriate for all men. Pharmacologic therapy to reduce fracture risk is advisable for men with a clinical diagnosis of osteoporosis (a spine or hip fracture) or a T-score of −2.5 or below in the spine, femoral neck, total hip or 1/3 radius; however, the majority of men at high risk will only be identified using a fracture risk assessment tool, such as FRAX. Alendronate, risedronate, zoledronic acid, denosumab, and teriparatide are Food and Drug Administration (FDA)-approved therapeutic options.ConclusionOsteoporosis in men presents an important public health problem with significant morbidity and mortality. There are recommended strategies for identifying men at high risk of fracture, and effective agents are available for treatment. (Endocr Pract. 2013;19:834-838)     

Osteoporosis Treatment After Osteoporotic Fractures: Data From a Single Medical Center

ObjectiveMost patients do not receive osteoporosis treatment after osteoporotic fracture. This study reviewed osteoporosis treatment after osteoporotic fractures in a center without a Fracture Liaison Service.MethodsWe identified all patients with hip, vertebral, humeral or radial fractures, evaluated in Meir Medical Center, in 2017. The exclusion criteria were not a Clalit Health Services member, high-energy fracture or 30-day postoperative mortality. The primary endpoint was osteoporosis drugs issued within 12 months of fracture. Secondary endpoints included bone densitometry and 1-year mortality.ResultsFive-hundred-eighty-two patients (average age 78.6 ± 11.1 years, 75.8% women) were included. There were 321 (55.5%) hip, 84 (14.1%) humeral, 33 (5.6%) vertebral, and 144 (24.7%) radial fractures. Osteoporosis drugs were issued to 26.5% of the patients; those with humeral fractures received the least (21.4%) and vertebral, the most (30.3%; P = .51). Bone densitometry was performed in 23.2% of patients. One-year mortality after hip fracture was 12.1%, followed by humeral (3.6%; P < .05). Logistic regression showed that previous treatment (odds ratio [OR] = 7.4; 95% confidence interval [CI] 3.6–15.2), bone densitometry (OR = 4.4; 95% CI 2.6–7.4) and endocrinology visit (OR = 2.6; 95% CI, 1.4–4.6) were the most important factors associated with treatment.ConclusionFewer than one third of patients received pharmacotherapy within 1 year after fracture. Because pharmacotherapy reduces future fractures and mortality, we recommend that medical staff who care for patients with fracture adopt practical and effective strategies to increase treatment rates among patients with osteoporotic fractures.     

Association between Frailty,Osteoporosis, Falls and Hip Fractures among Community-Dwelling People Aged 50 Years and Older in Taiwan: Results from I-Lan Longitudinal Aging Study

Background

Association of frailty with adverse clinical outcomes has been reported in Western countries, but data from the Asian population are scarce. This study aimed to evaluate the epidemiology of frailty among community-dwelling middle-aged and elderly population and to explore its association with musculoskeletal health in Taiwan.

Methods

I-Lan Longitudinal Aging Study (ILAS) data were retrieved for this study. Frailty was defined by the Fried’s criteria; a comparison of demographic characteristics, physical performance, and body composition, including skeletal muscle mass and bone mineral density (BMD), as well as recent falls, history of hip fractures and the functional status of subjects with different frailty statuses were accomplished.

Results

Overall, the data of 1,839 participants (mean age: 63.9±9.3 years, male 47.5%) were obtained for analysis. The prevalence of pre-frailty was 42.3% in men and 38.8% in women, whereas the prevalence of frailty was 6.9% and 6.7% in men and women, respectively. Frailty was significantly associated with older age, the male gender, larger waist circumference, lower skeletal muscle index, lower hip BMD, poorer physical function, poorer nutritional status, and poorer cognitive function. Also, frailty was significantly associated with osteoporosis (OR: 7.73, 95% CI: 5.01–11.90, p<0.001), history of hip fractures (OR: 8.66, 95% CI: 2.47–30.40, p = 0.001), and recent falls (O.R: 2.53, 95% CI: 1.35–4.76, p = 0.004).

Conclusions

Frailty and pre-frailty, in Taiwan, was closely associated with recent falls, history of hip fractures and osteoporosis among community-dwelling people 50 years of age and older. Furthermore, frailty intervention programs should take an integrated approach towards strengthening both and muscle mass, as well as prevention of falls.     

Bone diseases associated with human immunodeficiency virus infection: pathogenesis, risk factors and clinical management

Bone disorders such as osteopenia and osteoporosis have been recently reported in patients infected with the human immunodeficiency virus (HIV), but their etiology remains still unknown. The prevalence estimates vary widely among the different studies and can be affected by concomitant factors such as the overlapping of other possible conditions inducing bone loss as lypodystrophy, advanced HIV-disease, advanced age, low body weight or concomitant use of other drugs. All the reports at the moment available in the literature showed a higher than expected prevalence of reduced bone mineral density (BMD) in HIV-infected subjects both na?ve and receiving potent antiretroviral therapy compared to healthy controls. This controversial can suggest a double role played by both antiretroviral drugs and HIV itself due to immune activation and/or cytokines disregulation. An improved understanding of the pathogenesis of bone disorders can result in better preventative and therapeutic measures. However, the clinical relevance and the risk of fractures remains undefined in HIV-population. The clinical management of osteopenia and osteoporosis in HIV-infected subjects is still being evaluated. Addressing potential underlying bone disease risk factors (e.g., smoking and alcohol intake, use of corticosteroids, advanced age, low body weight), evaluating calcium and vitamin D intake, and performing dual x-ray absorptiometry in HIV-infected individuals who have risk factors for bone disease can be important strategies to prevent osteopenia and osteoporosis in this population. The administration of bisphosphonates (e.g., alendronate), with calcium and vitamin D supplementation, may be a reasonable and effective option to treat osteoporosis in these subjects.     

Prevalence of Sarcopenia and Its Relationship with Sites of Fragility Fractures in Elderly Chinese Men and Women

Objective

Sarcopenia might be associated with bone fragility in elderly individuals. This study aimed to investigate the prevalence of sarcopenia and its association with fragility fracture sites in elderly Chinese patients.

Methods

Patients (322 men and 435 women) aged 65–94 years and with a history of fragility fractures in the ankle, wrist, vertebrae or hip, and healthy men (n = 1263) and women (n = 1057) aged 65–92 years without a history of fractures were enrolled. Whole-body dual energy X-ray absorptiometry was used to analyze skeletal muscle mass index (SMI), fat mass and bone mineral density. Sarcopenia was defined as SMI less than two standard deviations below the mean of a young reference group.

Results

Sarcopenia occurrence varied with fracture location. Sarcopenia was more common in females with vertebral and hip fractures and in men with hip and ankle fractures than in the non-fracture group). Sarcopenia was significantly more prevalent in men with wrist, hip and ankle fractures than in women. SMI was correlated with BMD in different fracture groups. Logistic regression analyses revealed that lower SMI was associated with an increased risk of hip fracture both in men and women and ankle fracture in men.

Discussion

Sarcopenia may be an independent risk factor for hip and ankle fractures in men, and for hip fractures in women.     

Vitamin D in the aging musculoskeletal system: an authentic strength preserving hormone

Until recently, vitamin D was only considered as one of the calciotrophic hormones without major significance in other metabolic processes in the body. Several recent findings have demonstrated that vitamin D plays also a role as a factor for cell differentiation, function and survival. Two organs, muscle and bone, are significantly affected by the presence, or absence, of vitamin D. In bone, vitamin D stimulates bone turnover while protecting osteoblasts of dying by apoptosis whereas in muscle vitamin D maintains the function of type II fibers preserving muscle strength and preventing falls. Furthermore, two major changes associated to aging: osteoporosis and sarcopenia, have been also linked to the development of frailty in elderly patients. In both cases vitamin D plays an important role since the low levels of this vitamin seen in senior people may be associated to a deficit in bone formation and muscle function. In this review, the interaction between vitamin D and the musculoskeletal components of frailty are considered from the basic mechanisms to the potential therapeutic approach. We expect that these new considerations about the importance of vitamin D in the elderly will stimulate an innovative approach to the problem of falls and fractures which constitutes a significant burden to public health budgets worldwide.     

Contribution of bone mineral density and bone turnover markers to the estimation of risk of osteoporotic fracture in postmenopausal women

In osteoporosis, the main cause for concern is the increase in the risk of fractures. The level of bone mineral density (BMD) measured by various techniques has been shown to be a strong predictor of fracture risk in postmenopausal women. However, half of patients with incident fractures have BMD value above the diagnostic threshold of osteoporosis defined as a T-score of -2.5 SD or more below the average value of young healthy women. Clearly there is a need for improvement in the identification of patients at risk for fracture. Several prospective studies have shown that an increased bone resorption evaluated by specific biochemical markers was associated with increased risk of the hip, spine and non-vertebral fractures independently of BMD. The use of bone markers in individual patients may be appropriate in some situations, especially in women who are not detected at risk by BMD measurements. For example, in the OFELY study including 668 postmenopausal women followed prospectively over 9 years, we found that among the 115 incident fractures, 54 (47%) actually occurred in non-osteoporotic women. Among these women, the combination of bone markers and history of previous fracture was highly predictive of fracture risk. Thus, bone markers may be used in the assessment of fracture risk in selected cases in which BMD and clinical risk factors are not enough to take a treatment decision. Advances in our knowledge of bone matrix biochemistry, most notably of post-translational modifications in type I collagen, may allow identification of biochemical markers that reflect changes in the material property of bone, which is an important determinant of bone strength. Preliminary in vitro studies indicate that the extent of post-translational modifications of collagen--which can be reflected in vivo by the measurement of the urinary ratio between native and isomerised type I collagen--play a role in determining the mechanical competence of cortical bone, independently of BMD. Further studies in osteoporosis should explore the changes in these biochemical parameters of bone matrix as they may represent a key component of bone quality.