Fluoride salts are no better at preventing new vertebral fractures than calcium-vitamin D in postmenopausal osteoporosis: the FAVOStudy

Refracture following vertebral fragility fracture when bone fragility is not recognized: summarizing findings from comparator arms of randomized clinical trials

PURPOSE

Since vertebral fragility fractures (VFFs) might increase the risk of subsequent fractures, we evaluated the incidence rate and the refracture risk of subsequent vertebral and non-vertebral fragility fractures (nVFFs) in untreated patients with a previous VFF.

METHODS

We systematically searched PubMed, Embase, and Cochrane Library up to February 2022 for randomized clinical trials (RCTs) that analyzed the occurrence of subsequent fractures in untreated patients with prior VFFs. Two authors independently extracted data and appraised the risk of bias in the selected studies. Primary outcomes were subsequent VFFs, while secondary outcomes were further nVFFs. The outcome of refracture within ≥ 2 years after the index fracture was measured as (i) rate, expressed per 100 person-years (PYs), and (ii) risk, expressed in percentage.

RESULTS

Forty RCTs met our inclusion criteria, ranging from medium to high quality. Among untreated patients with prior VFFs, the rate of subsequent VFFs and nVFFs was 12 [95% confidence interval (CI) 9-16] and 6 (95% CI 5-8%) per 100 PYs, respectively. The higher the number of previous VFFs, the higher the incidence. Moreover, the risk of VFFs and nVFFs increased within 2 (16.6% and 8%) and 4 years (35.1% and 17.4%) based on the index VFF.

CONCLUSION

The highest risk of subsequent VFFs or nVFFs was already detected within 2 years following the initial VFF. Thus, prompt interventions should be designed to improve the detection and treatment of VFFs, aiming to reduce the risk of future FFs and properly implement secondary preventive measures.

A Case of Fluorosis: Fluoride-Induced Osteopetrosis

There are multiple etiologies of increased bone density, including osteopetrosis and fluorosis. Osteopetrosis can either be a malignant autosomal recessive condition found in children or a benign autosomal dominant adult variant; both of which are characterized by decreased bone resorption. In contrast, fluorosis is characterized by increased bone formation secondary to chronic fluoride intoxication, but with a similar clinical manifestations to osteopetrosis.

A 70-year-old lady with generalized joint aches, stiffness as well as fatigue, was found to have high bone mineral density and alarmingly high fluoride levels. The patient was found to be drinking fluoride containing water from an untreated local well for many years.

Fluorosis results in increased bone mineral density and disease progression correlates with length of exposure. Fluorosis can result in reversible musculocutaneous symptoms and radiological findings. However, severe chronic cases may develop irreversible neurologic manifestations. Urinary fluoride testing is the screening modality of choice, and the key component of management is avoidance of the source of fluoride intoxication as well as monitoring of urinary fluoride levels.

Supplementation of Calcium and Fluoride-Free Water Mitigates Skeletal Fluorosis in Fluoride-Intoxicated Rats

Fluorosis is a public health concern in 25 countries around the globe. The present study is about the mitigation of fluoride (F) toxicity by giving F-free water (FFW) and calcium (Ca). A study was conducted by taking 76 Wistar rats in two phases, phase I (6 months), where rats were randomly divided into four groups: normal-Ca diet (NCD) 0.5%; low-Ca diet (LCD) 0.25%; NCD + 100 ppm F and LCD + 100 ppm F in groups 1, 2, 3 and 4, respectively. F and Ca were given through water and diet respectively. Phase II is the reversal of fluorosis for 3 months, where LCD group 2 was treated with NCD. Groups 3 and 4 were divided into two subgroups each: 3X and 3Y, and 4X and 4Y, respectively. Groups 3X and 4X received FFW with NCD. Group 3Y continued as phase I and 4Y NCD and F. The biochemical expression, gene expression, biomechanical properties and DXA were studied by standard methods. The results revealed that in phase I, bone turnover was significantly increased whereas bone mineral content and biomechanical properties of group 4 were significantly decreased (p ≤ 0.05) as compared with that of all other groups. Trabecular separation and total porosity increased in groups 2 and 4. Expression of osteocalcin, osteonectin and osteopontin genes was significantly downregulated in group 4. Bone turnover in group 4X was normalised. Expressions of osteocalcin, osteonectin and osteopontin were upregulated after providing NCD and FFW. In conclusion, low calcium aggravates skeletal fluorosis which could be mitigated on supplementation of Ca and FFW.

A New 1,25 Dihydroxy Vitamin D Analog with Strong Bone Anabolic Activity in OVX Rats with Little or no Bone Resorptive Activity

A new 1α,25-dihydroxy vitamin D₃ analog (2-methylene-22(E)-(24R)-22-dehydro-1α,24,25-trihydroxy-19-norvitamin D₃ or WT-51) has been tested as a possible therapeutic for osteoporosis. It is 1/10th as active as 1,25(OH)₂ D₃ in binding affinity for the vitamin D receptor but is at least 200 times more active than 1,25(OH)₂ D₃ and equal to that of 2MD (2-methylene-19-nor-(20S)-1α,25(OH)₂ D₃ , an analog previously tested in postmenopausal women), in supporting bone formation by isolated osteoblasts in culture. However, in contrast to 2MD, it is virtually inactive on bone resorption in vivo. WT-51 markedly increased bone mass (lumbar and femur) in ovariectomized (OVX) female rats. Further, bone strength tested by the three-point bending system is significantly increased by WT-51. Thus, WT-51 is an attractive candidate for the treatment of postmenopausal osteoporosis. © 2019 American Society for Bone and Mineral Research.

Health state utility values of osteoporotic fractures among Korean women

Objectives: This study aimed to investigate health state utility values in eight health states related to osteoporosis and osteoporotic fractures using time trade-off (TTO) technique among postmenopausal Korean women.Methods: Scenarios describing eight health states including osteoporosis and hip, vertebral, post-hip, post-vertebral, ankle, humerus, and wrist fractures were developed and presented to 500 female participants aged 45 to 59 years who were selected with probability proportionate to age group and region for this investigation. Each health states valuation was derived using the trade-off (TTO) technique. Ten years of a given health state was traded off with a shorter length of time in full health.Results: Mean scores of each state were calculated. Osteoporosis scored the highest (0.669 ± 0.155), followed by wrist fracture (0.656 ± 0.151). Hip (0.298 ± 0.158) and vertebral (0.298 ± 0.160) fractures were found to be the worst health states. Post-hip (0.446 ± 0.159) and post-vertebral fractures (0.455 ± 0.160) were also considered undesirable states. All fractures were associated with disutilities, ranging from a mean of -0.013 to -0.371. These values were statistically significant (p < 0.0001). Hip and vertebral fractures are among the most serious consequences of osteoporotic fractures.Conclusions: The vertebral and hip fractures marked the lowest utility scores among post-menopausal women in Korea.

The Fluoride Debate: The Pros and Cons of Fluoridation

Fluoride is one of the most abundant elements found in nature. Water is the major dietary source of fluoride. The only known association with low fluoride intake is the risk of dental caries. Initially, fluoride was considered beneficial when given systemically during tooth development, but later research has shown the importance and the advantages of its topical effects in the prevention or treatment of dental caries and tooth decay. Water fluoridation was once heralded as one of the best public health achievements in the twentieth century. Since this practice is not feasible or cost effective in many regions, especially rural areas, researchers and policy makers have explored other methods of introducing fluoride to the general population such as adding fluoride to milk and table salt. Lately, major concerns about excessive fluoride intake and related toxicity were raised worldwide, leading several countries to ban fluoridation. Health-care professionals and the public need guidance regarding the debate around fluoridation. This paper reviews the different aspects of fluoridation, their effectiveness in dental caries prevention and their risks. It was performed in the PubMed and the Google Scholar databases in January 2018 without limitation as to the publication period.

The Robustness of Trials That Guide Evidence-Based Orthopaedic Surgery

BACKGROUND

The fragility index (FI) may prove to be a powerful metric of trial robustness. The FI is the minimum number of patient events that would need to become nonevents in order to nullify a significant result. The fragility quotient (FQ) is the FI divided by the total sample size. This study evaluates the robustness of the 20% of orthopaedic clinical trials that were cited as having strong evidence in the American Academy of Orthopaedic Surgeons (AAOS) Clinical Practice Guidelines and that could be analyzed with these indices.

METHODS

From the AAOS recommendations with strong evidence, we extracted the randomized controlled trials that were cited as having supporting evidence that could be analyzed with the FI. Each trial's FI was calculated using the fragility calculator (http://www.fragilityindex.com). With use of the Cochrane Risk of Bias Tool 2.0, we evaluated the likelihood of bias. We also performed a post hoc power analysis of eligible studies.

RESULTS

The median FI for the 72 trials was 2 events, and the median FQ was 0.022. Of the 72 trials, only 3 (4.2%) were at a low risk of bias, and 35 (48.6%) were at a high risk of bias. Thirty-eight (53%) of the trials were underpowered. We identified a strong correlation between a trial's FI or FQ and the trial's power.

CONCLUSIONS

Our study found that trials that provided strong evidence for orthopaedic surgery guidelines were largely fragile, underpowered, and at risk of bias.

Intermittent Nitrate Use and Risk of Hip Fracture

PURPOSE

Nitrates, commonly used antianginal medications, also have a beneficial effect on bone remodeling and bone density, particularly with intermittent use. However, their effect on fracture risk is not clear. We examined the relation of short-acting nitrate use (proxy for intermittent use) with the risk of hip fracture in a large cohort of older adults with ischemic heart disease.

METHODS

Participants aged 60 years or more with ischemic heart disease and without a history of hip fracture from The Health Improvement Network, an electronic medical records database in the United Kingdom, were included. The association of incident (new) use of short-acting nitrate formulations (nitroglycerin sublingual/spray/ointment or isosorbide dinitrate injection/sprays) with incident (new-onset) hip fracture risk was examined by plotting Kaplan-Maier curves and calculating hazard ratios using Cox proportional hazards regression models. Competing risk by death was analyzed in separate analyses.

RESULTS

Among 14,451 pairs of matched nitrate users and nonusers (mean age, 72 ± 7.6 years, 41% women for each cohort), 573 fractures occurred during follow-up (257 nitrate users; 316 nonusers). Hip fracture risk was 33% lower among short-acting nitrate users compared with nonusers (hazard ratio, 0.67; 95% confidence interval, 0.53-0.85; P = .0008). Competing risk analysis by death did not change effect estimates.

CONCLUSIONS

In this large population-based cohort of older adults with ischemic heart disease, we found a significant reduction in hip fracture risk with the use of short-acting nitrates (intermittent use). Future studies are warranted given the potential for nitrates to be potent, inexpensive, and readily available antiosteoporotic agents.

Bone quality: the determinants of bone strength and fragility

Bone fragility is a major health concern, as the increased risk of bone fractures has devastating outcomes in terms of mortality, decreased autonomy, and healthcare costs. Efforts made to address this problem have considerably increased our knowledge about the mechanisms that regulate bone formation and resorption. In particular, we now have a much better understanding of the cellular events that are triggered when bones are mechanically stimulated and how these events can lead to improvements in bone mass. Despite these findings at the molecular level, most exercise intervention studies reveal either no effects or only minor benefits of exercise programs in improving bone mineral density (BMD) in osteoporotic patients. Nevertheless, and despite that BMD is the gold standard for diagnosing osteoporosis, this measure is only able to provide insights regarding the quantity of bone tissue. In this article, we review the complex structure of bone tissue and highlight the concept that its mechanical strength stems from the interaction of several different features. We revisited the available data showing that bone mineralization degree, hydroxyapatite crystal size and heterogeneity, collagen properties, osteocyte density, trabecular and cortical microarchitecture, as well as whole bone geometry, are determinants of bone strength and that each one of these properties may independently contribute to the increased or decreased risk of fracture, even without meaningful changes in aBMD. Based on these findings, we emphasize that while osteoporosis (almost) always causes bone fragility, bone fragility is not always caused just by osteoporosis, as other important variables also play a major role in this etiology. Furthermore, the results of several studies showing compelling data that physical exercise has the potential to improve bone quality and to decrease fracture risk by influencing each one of these determinants are also reviewed. These findings have meaningful clinical repercussions as they emphasize the fact that, even without leading to improvements in BMD, exercise interventions in patients with osteoporosis may be beneficial by improving other determinants of bone strength.

Changes in the degree of mineralization with osteoporosis and its treatment

The diagnosis of osteoporosis is based on low bone mineral density (BMD) and/or the occurrence of fragility fractures. The majority of patients, however, have also abnormally low bone matrix mineralization. The latter is indicative of alterations in bone turnover rates and/or in kinetics of mineral accumulation within the newly formed bone matrix. Osteoporosis therapies can alter the bone matrix mineralization according to their action on bone turnover and/or mineralization kinetics. Antiresorptives, including the most widely used bisphosphonates, reduce the bone turnover rate resulting in a decrease in heterogeneity and an increase in the degree of mineralization toward to or even beyond normal values. Anabolic agents increase the bone volume and the amount of newly formed bone resulting in a likely transient decrease in mean degree and homogeneity of mineralization. Hence, the measurement of bone matrix mineralization is a sensitive tool to evaluate the response to therapy.

Bone mineralization: from tissue to crystal in normal and pathological contexts

Bone is a complex and structured material; its mechanical behavior results from an interaction between the properties of each level of its structural hierarchy. The degree of mineralization of bone (bone density measured at tissue level) and the characteristics of the mineral deposited (apatite crystals) are major determinants of bone strength. Bone remodeling activity acts as a regulator of the degree of mineralization and of the distribution of mineral at the tissue level, directly impacting bone mechanical properties. Recent findings have highlighted the need to understand the underlying process occurring at the nanostructure level that may be independent of bone remodeling itself. A more global comprehension of bone qualities will need further works designed to characterize what are the consequences on whole bone strength of changes at nano- or microstructure levels relative to each other.

Low-dose fluoride in postmenopausal women: a randomized controlled trial

CONTEXT

Trials of high-dose fluoride have reported increased bone formation and bone mineral density (BMD), but impaired bone mineralization and either adverse or neutral effects on fracture risk. Meta-analysis of a heterogeneous dataset of small trials suggests that daily doses of <20 mg fluoride might reduce fracture risk, but it is not known whether low doses of fluoride are safely anabolic to bone.

OBJECTIVE

We set out to investigate the skeletal effects of low doses of fluoride.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a double-blind, placebo-controlled randomized trial over 1 year at an academic research center, in 180 postmenopausal women with osteopenia.

INTERVENTION

Participants received daily treatment with tablets containing placebo, 2.5 mg fluoride, 5 mg fluoride, or 10 mg fluoride.

MAIN OUTCOME MEASURES

The primary endpoint was a change in lumbar spine BMD at 1 year; secondary endpoints were hip and forearm BMD, and markers of bone turnover. Safety was assessed by histomorphometric analysis of transiliac bone biopsies from a subset of participants.

RESULTS

Compared to placebo, none of the doses of fluoride altered BMD at any site. The bone formation marker, procollagen type I N-terminal propeptide, increased significantly in the 5 mg and 10 mg fluoride groups compared to placebo (P = .04 and .005, respectively). No differences were observed between placebo and any of the fluoride groups in levels of β-C-terminal telopeptide of type I collagen.

CONCLUSIONS

Low-dose fluoride does not induce substantial effects on surrogates of skeletal health and is unlikely to be an effective therapy for osteoporosis.

Surface properties and ion release from fluoride-containing bioactive glasses promote osteoblast differentiation and mineralization in vitro

Bioactive glasses (BG) are suitable for bone regeneration applications as they bond with bone and can be tailored to release therapeutic ions. Fluoride, which is widely recognized to prevent dental caries, is efficacious in promoting bone formation and preventing osteoporosis-related fractures when administered at appropriate doses. To take advantage of these properties, we created BG incorporating increasing levels of fluoride whilst holding their silicate structure constant, and tested their effects on human osteoblasts in vitro. Our results demonstrate that, whilst cell proliferation was highest on low-fluoride-containing BG, markers for differentiation and mineralization were highest on BG with the highest fluoride contents, a likely effect of a combination of surface effects and ion release. Furthermore, osteoblasts exposed to the dissolution products of fluoride-containing BG or early doses of sodium fluoride showed increased alkaline phosphatase activity, a marker for bone mineralization, suggesting that fluoride can direct osteoblast differentiation. Taken together, these results suggest that BG that can release therapeutic levels of fluoride may find use in a range of bone regeneration applications.

Improved prediction of rat cortical bone mechanical behavior using composite beam theory to integrate tissue level properties

Tissue level characteristics of bone can be measured by nanoindentation and microspectroscopy, but are challenging to translate to whole bone mechanical behavior in this hierarchically structured material. The current study calculated weighted section moduli from microCT attenuation values based on tissue level relationships (Z(lin,a) and Z(lin,b)) between mineralization and material properties to predict whole bone mechanical behavior. Z(lin,a) was determined using the equation of the best fit linear regression between indentation modulus from nanoindentation and mineral:matrix ratio from Raman spectroscopy. To better represent the modulus of unmineralized tissue, a second linear regression with the intercept fixed at 0 was used to calculate Z(lin,b). The predictive capability of the weighted section moduli calculated using a tissue level relationship was compared with average tissue level properties and weighted section moduli calculated using an apparent level relationship (Z(exp)) between Young's Modulus and mineralization. A range of bone mineralization was created using vitamin D deficiency in growing rats. After 10 weeks, left femurs were scanned using microCT and tested to failure in 3 point bending. Contralateral limbs were used for co-localized tissue level mechanical properties by nanoindentation and compositional measurements by Raman microspectroscopy. Vitamin D deficiency reduced whole bone stiffness and strength by ∼35% and ∼30%, respectively, but only reduced tissue mineral density by ∼10% compared with Controls. Average tissue level properties did not correlate with whole bone mechanical behavior while Z(lin,a), Z(lin,b), and Z(exp) predicted 54%, 66%, and 80% of the failure moment respectively. This study demonstrated that in a model for varying mineralization, the composite beam model in this paper is an improved method to extrapolate tissue level data to macro-scale mechanical behavior.

The effect of the microscopic and nanoscale structure on bone fragility

Bone mineral density is the gold-standard for assessing bone quantity and diagnosing osteoporosis. Although bone mineral density measurements assess the quantity of bone, the quality of the tissue is an important predictor of fragility. Understanding the macro- and nanoscale properties of bone is critical to understanding bone fragility in osteoporosis. Osteoporosis is a disease that affects more than 75 million people worldwide. The gold standard for osteoporosis prognosis, bone mineral density, primarily measures the quantity of bone in the skeleton, overlooking more subtle aspects of bone's properties. Bone quality, a measure of bone's architecture, geometry and material properties, is evaluated via mechanical, structural and chemical testing. Although decreased BMD indicates tissue fragility at the clinical level, changes in the substructure of bone can help indicate how bone quality is altered in osteoporosis. Additionally, mechanical properties which can quantify fragility, or bone's inability to resist fracture, can be changed due to alterations in bone architecture and composition. Recent studies have focused on examination of bone on the nanoscale, suggesting the importance of understanding the interactions of the mineral crystals and collagen fibrils and how they can alter bone quality. It is therefore important to understand alterations in bone that occur at the macro-, micro- and nanoscopic levels to determine what parameters contribute to decreased bone quality in diseased tissue.

Effects of treatment with fluoride on bone mineral density and fracture risk--a meta-analysis

Fluoride has fallen into discredit due to the absence of an anti-fracture effect. However, in this meta-analysis, a fracture reducing potential was seen at low fluoride doses [< or =20 mg fluoride equivalents (152 mg monofluorophosphate/44 mg sodium fluoride)]: OR = 0.3, 95% CI: 0.1-0.9 for vertebral and OR = 0.5, 95% CI: 0.3-0.8 for non-vertebral fractures.

INTRODUCTION

Fluoride is incorporated into bone mineral and has an anabolic effect. However, the biomechanical competence of the newly formed bone may be reduced.

METHODS

A systematic search of PubMed, Embase, and ISI web of science yielded 2,028 references.

RESULTS

Twenty-five eligible studies were identified. Spine BMD increased 7.9%, 95% CI: 5.4-10.5%, and hip BMD 2.1%, 95% CI: 0.9-3.4%. A meta-regression showed increasing spine BMD with increasing treatment duration (5.04 +/- 2.16%/year of treatment). Overall there was no significant effect on the risk of vertebral (OR = 0.8, 95% CI: 0.5-1.5) or non-vertebral fracture (OR = 0.8, 95% CI: 0.5-1.4). With a daily dose of < or =20 mg fluoride equivalents (152 mg monofluorophosphate/44 mg sodium fluoride), there was a statistically significant reduction in vertebral (OR = 0.3, 95% CI: 0.1-0.9) and non-vertebral (OR = 0.5, 95% CI: 0.3-0.8) fracture risk. With a daily dose >20 mg fluoride equivalents, there was no significant reduction in vertebral (OR = 1.3, 95% CI: 0.8-2.0) and non-vertebral (OR = 1.5, 95% CI: 0.8-2.8) fracture risk.

CONCLUSIONS

Fluoride treatment increases spine and hip BMD, depending on treatment duration. Overall there was no effect on hip or spine fracture risk. However, in subgroup analyses a low fluoride dose (< or =20 mg/day of fluoride equivalents) was associated with a significant reduction in fracture risk.

WITHDRAWN: Calcium supplementation on bone loss in postmenopausal women

BACKGROUND

Although calcium is one the simplest and least expensive strategies for preventing osteoporotic fractures calcium supplementation is nevertheless not without controversy (Kanis 1989; Nordin 1990). The Food and Drug Administration in the US has permitted a bone health claim for calcium-rich foods, and the NIH in its Consensus Development Process approved a statement that high calcium intake reduces the risk of osteoporosis.

OBJECTIVES

To assess the effects of calcium on bone density and fractures in postmenopausal women.

SEARCH STRATEGY

We searched Cochrane Controlled Register, MEDLINE and EMBASE up to 2001, and examined citations of relevant articles and proceedings of international meetings.

SELECTION CRITERIA

Trials that randomized postmenopausal women to calcium supplementation or usual calcium intake in the diet and reported bone mineral density of the total body, vertebral spine, hip, or forearm or recorded the number of fractures, and followed patients for at least one year were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Three independent reviewers assessed the methodologic quality and extracted data for each trial. For each bone density site (lumbar spine, total body, combined hip and combined forearm), we calculated the weighted mean difference in bone density between treatment and control groups using the percentage change from baseline. We constructed regression models in which the independent variables were year and dose, and the dependent variable was the effect size. This regression was used to determine the years across which pooling was appropriate. Heterogeneity was assessed. For each fracture analysis we calculated a risk ratio.

MAIN RESULTS

Fifteen trials, representing 1806 participants, were included. Calcium was more effective than placebo in reducing rates of bone loss after two or more years of treatment. The pooled difference in percentage change from baseline was 2.05% (95% CI 0.24 to 3.86) for total body bone density, 1.66% (95% CI 0.92 to 2.39) for the lumbar spine at 2 years, 1.60% (95% CI 0.78 to 2.41) for the hip, and 1.91% (95% CI 0.33 to 3.50) for the distal radius. The relative risk of fractures of the vertebrae was 0.79 (95% CI 0.54 to 1.09); the relative risk for non-vertebral fractures was 0.86 (95% CI 0.43 to 1.72).

AUTHORS' CONCLUSIONS

Calcium supplementation alone has a small positive effect on bone density. The data show a trend toward reduction in vertebral fractures, but it is unclear if calcium reduces the incidence of non vertebral fractures.

Addition of monofluorophosphate to estrogen therapy in postmenopausal osteoporosis: a randomized controlled trial

INTRODUCTION

Treatment of osteoporosis with high-dose fluoride alone does not reduce fracture risk. We hypothesized that the antifracture efficacy of fluoride could be optimized by its use in low doses combined with an antiresorptive agent.

EXPERIMENTAL SUBJECTS

Subjects included 80 women with postmenopausal osteoporosis who had been taking estrogen for at least 1 yr.

METHODS

Subjects were randomized to receive monofluorophosphate (MFP) (fluoride content of 20 mg/d) or placebo over 4 yr in a double-blind trial.

RESULTS AND DISCUSSION

There were progressive increases in lumbar spine bone density over the duration of the study (MFP, 22%; placebo, 6%; P < 0.0001). In the trabecular bone of L3, these increases were even greater (MFP, 49%; placebo, 2.5%; P < 0.0001). In the proximal femur, there were smaller but significant treatment effects (P = 0.015). Total body scans and their subregions also showed significantly greater increases in the MFP group. Bone formation markers increased significantly in the MFP group at yr 1. Hyperosteoidosis was present in biopsies from five of seven MFP subjects, with osteomalacia in two of seven. The hazards ratio for vertebral fractures was 0.20 (95% confidence interval, 0.05-1.30), and the incidence rate ratio was 0.12 (95% confidence interval, 0.06-0.23; P < 0.01). The hazards ratio for nonvertebral fractures was 3.3 (95% confidence interval, 0.8-12.0).

CONCLUSIONS

We conclude that fluoride at 20 mg/d produces substantial increases in bone mineral density but still interferes with bone mineralization. This indicates that most previous studies with this ion have used toxic doses and that much lower doses should be assessed to find a safe dose window for the use of this powerful anabolic agent.

Alcohol consumption, bone density, and hip fracture among older adults: the cardiovascular health study

INTRODUCTION

Previous studies have found inconsistent relationships of alcohol consumption with risk of hip fracture, and the importance of bone mineral density and risk of falls in mediating such a relationship has not been determined.

METHODS

As part of the Cardiovascular Health Study, a population-based cohort study of adults aged 65 years and older from four U.S. communities, 5,865 participants reported their use of beer, wine, and liquor yearly. We identified cases of hip fracture unrelated to malignancy or motor vehicle accidents using hospitalization discharge diagnoses. A subgroup of 1,567 participants in two communities underwent dual-energy x-ray absorptiometry scans to assess bone mineral density.

RESULTS

A total of 412 cases of hip fracture occurred during an average of 12 years of follow-up. There was a significant U-shaped relationship between alcohol intake and risk of hip fracture (p quadratic 0.02). Compared with long-term abstainers, the adjusted hazard ratios for hip fracture were 0.78 (95% confidence interval [CI], 0.61-1.00) among consumers of up to 14 drinks per week and 1.18 (95% CI, 0.77-1.81) among consumers of 14 or more drinks per week. Alcohol intake was associated with bone mineral density of the total hip and femoral neck in a stepwise manner, with approximately 5% (95% CI, 1%-9%) higher bone density among consumers of 14 or more drinks per week than among abstainers. These relationships were all similar among men and women.

CONCLUSIONS

Among older adults, moderate alcohol consumption has a U-shaped relationship with risk of hip fracture, but a graded positive relationship with bone mineral density at the hip.

Insights into material and structural basis of bone fragility from diseases associated with fractures: how determinants of the biomechanical properties of bone are compromised by disease

Minimal trauma fractures in bone diseases are the result of bone fragility. Rather than considering bone fragility as being the result of a reduced amount of bone, we recognize that bone fragility is the result of changes in the material and structural properties of bone. A better understanding of the contribution of each component of the material composition and structure and how these interact to maintain whole bone strength is obtained by the study of metabolic bone diseases. Disorders of collagen (osteogenesis imperfecta and Paget's disease of bone), mineral content, composition and distribution (fluorosis and osteomalacia); diseases of high remodeling (postmenopausal osteoporosis, hyperparathyroidism, and hyperthyroidism) and low remodeling (osteopetrosis, pycnodysostosis); and other diseases (idiopathic male osteoporosis, corticosteroid-induced osteoporosis) produce abnormalities in the material composition and structure that lead to bone fragility. Observations in patients and in animal models provide insights on the biomechanical consequences of these illnesses and the nature of the qualities of bone that determine its strength.

The role of nutrients in bone health, from A to Z

Osteoporosis is a major public health problem, affecting millions of individuals. Dietary intake is an important modifiable factor for bone health. Inadequate intake of nutrients important to bone increases the risk for bone loss and subsequent osteoporosis. The process of bone formation requires an adequate and constant supply of nutrients, such as calcium, protein, magnesium, phosphorus, vitamin D, potassium, and fluoride. However, there are several other vitamins and minerals needed for metabolic processes related to bone, including manganese, copper, boron, iron, zinc, vitamin A, vitamin K, vitamin C, and the B vitamins. Although the recommended levels of nutrients traditionally related to bone were aimed to promote bone mass and strength, the recommended levels of the other nutrients that also influence bone were set on different parameters, and may not be optimal for bone health, in view of recent epidemiological studies and clinical trials.

Physical properties of root cementum: Part 9. Effect of systemic fluoride intake on root resorption in rats

INTRODUCTION

Orthodontically induced inflammatory root resorption is a common complication in orthodontic treatment. Fluoride has been reported to have a beneficial effect against root resorption in dental traumatology. The effect of fluoride on orthodontically induced inflammatory root resorption has not been investigated. This study was undertaken to investigate the effect of fluoride on the incidence of root resorption.

METHODS

Thirty-two female 8-week-old Wistar rats were separated into 4 groups. Two groups (6 rats per group) were controls; they did not undergo orthodontic tooth movement. The other 2 groups (10 rats per group) had orthodontic tooth movement consisting of activated 100-g closing nickel-titanium coils (NiTi 10-000-06, GAC International, Bohemia, NY) connecting the mandibular first molar to the incisors. Fluoridated water (100 ppm) was given ad libitum to 1 control and 1 experimental group. The other 2 groups received deionized water. After 2 weeks, the animals were killed, and the samples were harvested. Resorption craters were scanned with a Micro CT (SkyScan 1072, Aartselaar, Belgium). Software analysis of the scanned samples provided a volumetric measurement of the resorption craters on the mandibular molar cementum surface.

RESULTS

Resorption sites were found in the control samples, especially on the distal surfaces; this could be attributed to normal physiological tooth drift. Resorption sites were significantly (P <.05) increased in the groups receiving orthodontic tooth movement.

CONCLUSIONS

Fluoride reduces the size of resorption craters, but the effect is variable and not statistically significant (P >.05).

The effects of antifracture therapies on the components of bone strength: assessment of fracture risk today and in the future

OBJECTIVE

To summarize the current knowledge regarding the impact of the most common antifracture medications on the various determinants of bone strength.

METHODS

Relevant English-language articles acquired from Medline from 1966 to January 2005 were reviewed. Searches included the keywords bone AND 1 of the following: strength, remodeling, microcrack, structure, mineralization, collagen, organic, crystallinity, osteocyte, porosity, diameter, anisotropy, stress risers, or connectivity AND alendronate, estrogen, etidronate, hormone replacement therapy, parathyroid hormone, risedronate, OR teriparatide. Abstracts from relevant conference proceedings were also reviewed for pertinent information.

RESULTS

Antiresorptive therapies increase bone strength through decreasing bone turnover. This lower bone turnover results in a higher mean mineralization and decreases the number of active resorption pits within bone at any given time. These resorption pits are speculated to be areas of focal weakness and a higher number of them would, if all other things were equal, result in greater fragility. Parathyroid hormone therapy increases the rate of bone remodeling, which introduces many resorption pits, but this source of strength loss is thought to be compensated by rapid increases in bone mass.

CONCLUSIONS

Both the antiresorptives, particularly bisphosphonates, and the parathyroid hormone therapy increase bone strength; however, the changes that are elicited to achieve this differ significantly.

Fluoride exposure and bone status in patients with chronic intestinal failure who are receiving home parenteral nutrition

BACKGROUND AND OBJECTIVE

Metabolic bone disease is frequent in chronic intestinal failure. Because fluoride has a major effect on bones, the status of both fluoride and bone was studied in long-term home parenteral nutrition (HPN) patients.

DESIGN

We studied 31 adults aged (x +/- SD) 56.3 +/- 15.1 y, mainly patients with short-bowel syndrome, who had been receiving HPN for >1 y. Bone mineral density (BMD) was measured by absorptiometry, and serum fluoride was measured by using a fluoride-sensitive electrode. All patients ate and drank ad libitum. HPN (3.4 +/- 1.2 times/wk) complemented oral nutrition. Potential explicative factors were estimated by using a linear regression model (mixed-effects model).

RESULTS

Of 120 fluoride dosages (2-6/patient), 102 were above the upper normal limit (1.58 micromol/L) at the laboratory. Mean (+/- SD) daily fluoride supply was 8.03 +/- 7.71 mg (US adequate intake: 3.1 mg/d for women and 3.8 for men; tolerable upper normal limit: 10 mg/d); intravenous fluoride varied from 0.06 to 1.45 mg, and oral fluoride varied from 0.09 to 27.8 mg. Serum fluoride concentrations were correlated with creatinine clearance and fluoride supply. BMD was significantly lower in the femoral neck than in the spinal area. After adjustment for sex and the duration of HPN, only the effect of serum fluoride on spinal BMD was significant. Two patients had symptoms of fluorosis, eg, calcaneum fissures, interosseous calcifications, or femoral neck osteoporosis.

CONCLUSIONS

In chronic intestinal failure, high intakes of fluoride are frequent because of the beverages ingested to compensate for stool losses. Hyperfluoremia has an effect on bone metabolism and may increase skeletal fragility. The consumption of fluoride-rich beverages for extended periods is therefore not advisable.

Important Determinants of Bone Strength

Osteoporosis is a systemic skeletal disorder characterized by compromised bone strength that predisposes individuals to increased fracture risk. Bone strength is determined by its material and structural properties. Bone mineral density (BMD) is a useful tool for diagnosis; however, this parameter provides information regarding only the quantity of mineral in bone, which is only one component of bone strength. Osteoporosis treatments have been shown to have beneficial effects on bone turnover, microarchitecture, and/or mineralization, all of which can help account for the reductions in fracture risk above and beyond changes in BMD. Newer noninvasive imaging methods are being developed that assess bone strength independent of BMD, and these methods should improve the assessment of fracture risk and response to treatment. These imaging methods are not currently available for routine clinical use, and therefore, clinicians need to continue for now to rely on surrogate markers of bone fragility, including BMD, prevalent fracture, and other important risk factors for fracture.

Statins and osteoporosis: new role for old drugs

Osteoporosis is the most common bone disease, affecting millions of people worldwide and leading to significant morbidity and high expenditure. Most of the current therapies available for its treatment are limited to the prevention or slowing down of bone loss rather than enhancing bone formation. Recent discovery of statins (HMG-CoA reductase inhibitors) as bone anabolic agents has spurred a great deal of interest among both basic and clinical bone researchers. In-vitro and some animal studies suggest that statins increase the bone mass by enhancing bone morphogenetic protein-2 (BMP-2)-mediated osteoblast expression. Although a limited number of case-control studies suggest that statins may have the potential to reduce the risk of fractures by increasing bone formation, other studies have failed to show a benefit in fracture reduction. Randomized, controlled clinical trials are needed to resolve this conflict. One possible reason for the discrepancy in the results of preclinical, as well as clinical, studies is the liver-specific nature of statins. Considering their high liver specificity and low oral bioavailability, distribution of statins to the bone microenvironment in optimum concentration is questionable. To unravel their exact mechanism and confirm beneficial action on bone, statins should reach the bone microenvironment in optimum concentration. Dose optimization and use of novel controlled drug delivery systems may help in increasing the bioavailability and distribution of statins to the bone microenvironment. Discovery of bone-specific statins or their bone-targeted delivery offers great potential in the treatment of osteoporosis. In this review, we have summarized various preclinical and clinical studies of statins and their action on bone. We have also discussed the possible mechanism of action of statins on bone. Finally, the role of drug delivery systems in confirming and assessing the actual potential of statins as anti-osteoporotic agents is highlighted.

Anabolic Agents: A New Chapter in the Management of Osteoporosis

Osteoporosis in postmenopausal women has until now been treated with antiresorptive agents, reducing the incidence of fragility fracture by approximately 50%. Clinical research has led to the development of new anabolic therapies capable of increasing the production of bone matrix by osteoblasts and reversing microarchitectural deterioration, resulting in major improvements in both bone quality and bone quantity. Teriparatide, a recombinant human parathyroid hormone consisting of the first 34 of 84 amino acids in human parathyroid hormone, has been shown to reduce significantly the risk of both vertebral and non-vertebral fractures in postmenopausal women. This agent was recently approved for use in Canada. Strontium ranelate is a new oral agent capable of uncoupling bone resorption from bone formation, which results in increases in bone formation with reductions in bone resorption. This agent has also been shown to reduce the risk of both vertebral and non-vertebral fracture while improving bone structure. Anabolic therapies represent a major advance in the management of postmenopausal osteoporosis, and they may provide significant benefit to those patients with severe osteoporosis in whom antiresorptive therapy has proven insufficient. Anabolic therapies should complement the antiresorptive treatments currently available for use in women with postmenopausal osteoporosis.

Fluoridosteopathie — eine vergessene Entität

The clinical manifestation of fluorosis has become rare over the past years. Although the use of fluoride medication in osteoporosis therapy remains controversial, past study results have led to a reduction in fluoride prescriptions. Several studies have shown minor biomechanical properties of newly built woven bone compared to original bone. Despite new prescription protocols, fluoride therapy should not be disregarded in the anamnesis of osteoporosis patients. In addition to conventional diagnostics in fluorosis, new techniques such as microanalysis and micro-CT-analysis show a diagnostic benefit. In this case, the edx-microanalysis results show an F concentration of over 1.0 wt% in bone. The ratio of bone to tissue volume, evaluated by micro-CT, is clearly elevated at 46% BV/TV. The histopathological preparation of the femoral head has made the possible effects of fluoride medication on bone visible and quantifiable. A direct causal relationship between coxarthrosis and fluoride medication, found both in our patient as well as in the literature, has not been demonstrated. In order to better understand the broad effects of fluoride medication in combination with coxarthrosis more studies are needed.

Tratamiento de la pérdida de masa ósea en la mujer postmenopáusica

In this revision, the results of different controlled clinical trials and metaanalyses on the efficacy in the increase of bone mineral density (BMD) and reduction of risk of fracture on postmenopausal osteoporosis treatments are summarized. Most of the drugs studied produce significant BMD increases but with significant differences regarding fracture risk reduction, especially regarding extravertebral fractures. Bisphosphonates and selective estrogen receptor modulators would constitute the first line of treatment of postmenopausal osteoporosis with previous fractures. Head to head studies would be necessary to know its true efficacy since some results are based on post hoc analysis. Possible side effects, risks, treatment comfort and price in addition to the demonstrated efficacy in fracture prevention must be considered in the selection of treatment.

Strontium ranelate: a novel mode of action leading to renewed bone quality

Various bone resorption inhibitors and bone stimulators have been shown to decrease the risk of osteoporotic fractures. However, there is still a need for agents promoting bone formation by inducing positive uncoupling between bone formation and bone resorption. In vitro studies have suggested that strontium ranelate enhances osteoblast cell replication and activity. Simultaneously, strontium ranelate dose-dependently inhibits osteoclast activity. In vivo studies indicate that strontium ranelate stimulates bone formation and inhibits bone resorption and prevents bone loss and/or promotes bone gain. This positive uncoupling between bone formation and bone resorption results in bone gain and improvement in bone geometry and microarchitecture, without affecting the intrinsic bone tissue quality. Thus, all the determinants of bone strength are positively influenced. In conclusion, strontium ranelate, a new treatment of postmenopausal osteoporosis, acts through an innovative mode of action, both stimulating bone formation and inhibiting bone resorption, resulting in the rebalancing of bone turnover in favor of bone formation. Strontium ranelate increases bone mass while preserving the bone mineralization process, resulting in improvement in bone strength and bone quality.

Combination/sequential therapy in osteoporosis

Combination therapy includes the concomitant or sequential use of compounds sharing the same mode of action (eg, two or more inhibitors of bone resorption) or with distinct pathways of activity (eg, an inhibitor of resorption plus an anabolic agent). Combination use of antiresorptive agents may generate concerns, because of the risk of inducing oversuppression of bone turnover. However, if low doses of estrogen, used for the management of climacteric symptoms, are insufficient to normalize bone turnover, the addition of a bisphosphonate to hormone therapy may prove to be useful to achieve this objective. Patients pretreated with inhibitors of resorption, who have not achieved a full therapeutic response, are good candidates for treatment with anabolic agents. The increase in bone turnover that comes after the introduction of parathyroid hormone (PTH) in patients treated with an antiresorptive agent is similar to that observed in treatment-naïve patients and the pattern of bone mineral density (BMD) increase is also identical, with the exception of a 6 month delay in the spine and hip BMD changes observed in prior alendronate-treated subjects. Current data discourage the concomitant use of alendronate and PTH since the bisphosphonate appears to blunt (in men and women) the anabolic action of PTH. Whether this applies to other bisphosphonates or inhibitors of resorption, remains unknown. The use of an inhibitor of bone resorption after completion of PTH treatment seems an appropriate way to maintain the skeletal benefits gained during therapy. Long-term clinical studies, using fractures as an endpoint should be initiated to better understand the clinical and pharmaco-economic interest of combination therapies in the management of osteoporosis.

Calcium supplementation on bone loss in postmenopausal women

BACKGROUND

Although calcium is one the simplest and least expensive strategies for preventing osteoporotic fractures calcium supplementation is nevertheless not without controversy (Kanis 1989; Nordin 1990). The Food and Drug Administration in the US has permitted a bone health claim for calcium-rich foods, and the NIH in its Consensus Development Process approved a statement that high calcium intake reduces the risk of osteoporosis.

OBJECTIVES

To assess the effects of calcium on bone density and fractures in postmenopausal women.

SEARCH STRATEGY

We searched Cochrane Controlled Register, MEDLINE and EMBASE up to 2001, and examined citations of relevant articles and proceedings of international meetings.

SELECTION CRITERIA

Trials that randomized postmenopausal women to calcium supplementation or usual calcium intake in the diet and reported bone mineral density of the total body, vertebral spine, hip, or forearm or recorded the number of fractures, and followed patients for at least one year were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Three independent reviewers assessed the methodologic quality and extracted data for each trial. For each bone density site (lumbar spine, total body, combined hip and combined forearm), we calculated the weighted mean difference in bone density between treatment and control groups using the percentage change from baseline. We constructed regression models in which the independent variables were year and dose, and the dependent variable was the effect size. This regression was used to determine the years across which pooling was appropriate. Heterogeneity was assessed. For each fracture analysis we calculated a risk ratio.

MAIN RESULTS

Fifteen trials, representing 1806 participants, were included. Calcium was more effective than placebo in reducing rates of bone loss after two or more years of treatment. The pooled difference in percentage change from baseline was 2.05% (95% CI 0.24 to 3.86) for total body bone density, 1.66% (95% CI 0.92 to 2.39) for the lumbar spine at 2 years, 1.60% (95% CI 0.78 to 2.41) for the hip, and 1.91% (95% CI 0.33 to 3.50) for the distal radius. The relative risk of fractures of the vertebrae was 0.79 (95% CI 0.54 to 1.09); the relative risk for non-vertebral fractures was 0.86 (95% CI 0.43 to 1.72).

REVIEWER'S CONCLUSIONS

Calcium supplementation alone has a small positive effect on bone density. The data show a trend toward reduction in vertebral fractures, but it is unclear if calcium reduces the incidence of non vertebral fractures.

Idiopathic or Hypogonadal Osteoporosis in Men

Osteoporosis is being recognized increasingly in men, and represents a substantial public health problem. As the male population ages and lives longer, the incidence of osteoporotic fractures is expected to increase. The current lifetime risk for a fragility fracture is approximately 27% in men aged 50 years or more, and will increase further over the next 20 years. A major problem with osteoporosis in men is that it continues to be unrecognized, and the majority of men with fragility fractures due to osteoporosis are not being treated. A higher level of awareness is required amongst both general practitioners and the general public that osteoporosis is a treatable condition that can affect men. Secondary causes for osteoporosis are more common in men than in women, and require rigorous exclusion and treatment. Undiagnosed clinical hypogonadism is a common cause of osteoporosis in men, and is readily treatable. The cause of primary osteoporosis in men is unknown, but it results in an osteoblast defect. Genetic factors are likely to be important. In some but not all men, relative estrogen deficiency contributes to rapid rates of age-related bone loss and fractures. An adequate calcium intake, regular weight-bearing exercise, and normal vitamin D status are all very important, particularly with increasing age. The role of testosterone in treating eugonadal men with osteoporosis is currently unclear, and larger prospective studies will be required to carefully evaluate the benefits and risks of therapy. First-line treatment of osteoporosis in hypogonadal or eugonadal men is with bisphosphonates. Alendronate increases bone density and reduces vertebral fractures measured using a semiquantitative method in eugonadal or hypogonadal men with osteoporosis. In the near future, it is likely that subcutaneous human parathyroid hormone (1-34) or teriparatide will also be available as an important new anabolic treatment for men with osteoporosis. Teriparatide treatment also increases bone density in men. Selective estrogen receptor modulating drugs require further evaluation in men, but would appear to theoretically benefit men, especially those with low estradiol levels. In the future, selective androgen receptor modulating drugs may be useful in the prevention and treatment of osteoporosis, and in increasing lean body mass in men, without having adverse effects on prostate and breast tissue.

Bone as an effect compartment : models for uptake and release of drugs

"Bone-seeking agents" are drugs characterised by high affinity for bone, and are disposed in bone for prolonged periods of time while maintaining remarkably low systemic concentrations. As a consequence, the bone becomes a reservoir for bone-seeking agents, and a site of both desirable and adverse effects, depending on the pharmacological activities of the specific agent. For some agents, significant systemic effects may also be produced following their prolonged release from bone, a process that is governed mostly by the rate of bone remodelling. This review covers the pharmacokinetic and pharmacodynamic features of bone-seeking agents with different pharmacological properties, including drugs (bisphosphonates, drug-bisphosphonate conjugates, radiopharmaceuticals and fluoride), bone markers (tetracycline, bone imaging agents) and toxins (lead, chromium, aluminium). In addition, drugs that do not possess bone-seeking properties but are used for therapy of bone diseases (such as antibacterials for treatment of osteomyelitis) are discussed, along with targeting of these drugs to the bone by conjugation to bone-seeking agents, local delivery systems, and other approaches. The pharmacokinetic and pharmacodynamic behaviour of bone-seeking agents is extremely complex due to heterogeneity in bone morphology and physiology. This complexity, accompanied by difficulties in human bone research caused by ethical and other limitations, gave rise to modelling approaches to study bone drug disposition. This review describes the pharmacokinetic models that have been proposed to describe the pharmacokinetic behaviour of bone-seeking agents and predict bone concentrations of these agents for different doses and patient populations. Models of different types (compartmental and physiologically based) and of different complexity have been applied, but their relevance to drug effects in the bone tissue is limited since they describe the behaviour of the "average" drug molecule. Understanding of the cellular and molecular processes responsible for the heterogeneity of bone tissue will provide better comprehension of the influence of microenvironment on drug bone disposition and the resulting pharmacological response.

Management of osteoporosis in patients with gastrointestinal diseases

Osteoporosis is a frequent complication in the course of various gastrointestinal disorders. Since its pathogenesis is complex, and incompletely understood in comparison to the well-known pathomechanism of postmenopausal osteoporosis, adequate management is difficult. We first summarize those therapeutic options which have strong evidence in postmenopausal osteoporosis and, thereafter, we review those in the context of different gastrointestinal diseases. Treatment of the underlying intestinal disorder seems to be most important to normalise altered bone metabolism and to prevent osteoporosis in patients with coeliac disease. In patients with osteoporosis associated with Crohn's disease, various treatment strategies (such as vitamin D, sodium fluoride, bisphosphonates) are discussed. In contrast to postmenopausal osteoporosis, interventional studies in secondary osteoporosis are often limited by the small study population and data about the efficacy of any treatment in prevention of fractures are therefore lacking. Well-conducted, controlled studies with the endpoint of preventing fractures are therefore required to optimise the treatment of osteoporosis in these patients.

Bone strength and its determinants

Osteoporosis is a disease defined by decreased bone mass and alteration of microarchitecture which results in increased bone fragility and increased risk of fracture. The major complication of osteoporosis, i.e., fracture, is due to a lower bone strength. Thus, any treatment of osteoporosis implies an improvement in bone strength. Bone strength is determined by bone geometry, cortical thickness and porosity, trabecular bone morphology, and intrinsic properties of bony tissue. Bone strength is indirectly estimated by bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA). Since DXA-measured BMD accounts for 60-70% of the variation in bone strength, some important factors are not captured by DXA in the progression of osteoporosis and the effects of antiosteoporotic treatment. Geometry and trabecular microarchitecture have also to be taken into account. Thus, the assessment of intrinsic mechanical quality of bony tissue should provide a better understanding of the role of tissue quality in determining bone strength. The careful investigation of all the determinants of bone strength (bone tissue included) should be considered in the pathophysiology of osteoporosis and in the mechanisms of action of antiosteoporotic drugs.

[New osteoformative agents for osteoporosis]

PURPOSE

Antiresorptive therapy are usual treatment of osteoporosis, but they prevent no more than 40 or 60% of osteoporotic fracture. Thus, there is a need for osteoformative agents that can further augment bone mass and reduce risk fracture more substantially. CURRENT KNOWLEDGER AND KEYPOINTS: Daily injections of 1-34 aminoterminal fragment of PTH increase bone formation and bone mass. A randomized study recently demonstrated that PTH 1-34 decrease the risk of vertebral and non vertebral fracture, and the place of this treatment in the strategy of osteoporosis treatment is to demonstrate. Oral administration of strontium salt at low dosage level stimulate bone formation and decrease bone resorption. Preliminary data needs to be confirmed by a multicenter antifracture study. Retrospective results with statins in three international studies have not be confirmed by the only randomized clinical trial. Use of low dose intermittent fluoride therapy are still recommended by some authors. FUTURES PROSPECTS AND PROJECTS: Effects of insuline like growth factor I and other growing factor on bone turnover have to be confirmed in human, and pharmacological and tolerance problems have to be solved.

Treatment of postmenopausal osteoporosis

The aim of treatment of postmenopausal osteoporosis is to reduce the frequency of vertebral and non-vertebral fractures (especially at the hip), which are responsible for morbidity associated with the disease. Results of large placebo controlled trials have shown that alendronate, raloxifene, risedronate, the 1-34 fragment of parathyroid hormone, and nasal calcitonin, greatly reduce the risk of vertebral fractures. Furthermore, a large reduction of non-vertebral fractures has been shown for alendronate, risedronate, and the 1-34 fragment of parathyroid hormone. Calcium and vitamin D supplementation is not sufficient to treat individuals with osteoporosis but is useful, especially in elderly women in care homes. Hormone replacement therapy remains a valuable option for the prevention of osteoporosis in early postmenopausal women. Choice of treatment depends on age, the presence or absence of prevalent fractures, especially at the spine, and the degree of bone mineral density measured at the spine and hip. Non-pharmacological interventions include adequate calcium intake and diet, selected exercise programmes, reduction of other risk factors for osteoporotic fractures, and reduction of the risk of falls in elderly individuals.

Pharmacotherapy of osteoporosis in postmenopausal women: focus on safety

The therapy of osteoporosis has made enormous strides in the last decade. There is now a range of interventions, each with its pros and cons. Calcium and vitamin D supplementation remain the foundation and have few safety issues. Bisphosphonates are widely used, though gastrointestinal tolerance is a problem with some oral preparations. Intravenous administration may circumvent this, although this introduces the smaller problem of acute phase reactions. The side effect profile of hormone replacement therapy (HRT) is still being delineated after 40 years of use, with substantial new information expected in the next few years. This will clarify its place in the medical management of the menopause. Raloxifene appears to have a superior safety profile to HRT, though its efficacy on bone may be less. While none of these options is suitable for everyone, the range of available therapies does mean that most patients can find an intervention that is effective and acceptable.