Lifetime fracture risk: an approach to hip fracture risk assessment based on bone mineral density and age

Deep learning-based harmonization of trabecular bone microstructures between high- and low-resolution CT imaging

BACKGROUND

Osteoporosis is a bone disease related to increased bone loss and fracture-risk. The variability in bone strength is partially explained by bone mineral density (BMD), and the remainder is contributed by bone microstructure. Recently, clinical CT has emerged as a viable option for in vivo bone microstructural imaging. Wide variations in spatial-resolution and other imaging features among different CT scanners add inconsistency to derived bone microstructural metrics, urging the need for harmonization of image data from different scanners.

PURPOSE

This paper presents a new deep learning (DL) method for the harmonization of bone microstructural images derived from low- and high-resolution CT scanners and evaluates the method's performance at the levels of image data as well as derived microstructural metrics.

METHODS

We generalized a three-dimensional (3D) version of GAN-CIRCLE that applies two generative adversarial networks (GANs) constrained by the identical, residual, and cycle learning ensemble (CIRCLE). Two GAN modules simultaneously learn to map low-resolution CT (LRCT) to high-resolution CT (HRCT) and vice versa. Twenty volunteers were recruited. LRCT and HRCT scans of the distal tibia of their left legs were acquired. Five-hundred pairs of LRCT and HRCT image blocks of64 × 64 × 64 $64 \times 64 \times 64 $ voxels were sampled for each of the twelve volunteers and used for training in supervised as well as unsupervised setups. LRCT and HRCT images of the remaining eight volunteers were used for evaluation. LRCT blocks were sampled at 32 voxel intervals in each coordinate direction and predicted HRCT blocks were stitched to generate a predicted HRCT image.

RESULTS

Mean ± standard deviation of structural similarity (SSIM) values between predicted and true HRCT using both 3DGAN-CIRCLE-based supervised (0.84 ± 0.03) and unsupervised (0.83 ± 0.04) methods were significantly (p < 0.001) higher than the mean SSIM value between LRCT and true HRCT (0.75 ± 0.03). All Tb measures derived from predicted HRCT by the supervised 3DGAN-CIRCLE showed higher agreement (CCC  ∈ $ \in $ [0.956 0.991]) with the reference values from true HRCT as compared to LRCT-derived values (CCC  ∈ $ \in $ [0.732 0.989]). For all Tb measures, except Tb plate-width (CCC = 0.866), the unsupervised 3DGAN-CIRCLE showed high agreement (CCC  ∈ $ \in $ [0.920 0.964]) with the true HRCT-derived reference measures. Moreover, Bland-Altman plots showed that supervised 3DGAN-CIRCLE predicted HRCT reduces bias and variability in residual values of different Tb measures as compared to LRCT and unsupervised 3DGAN-CIRCLE predicted HRCT. The supervised 3DGAN-CIRCLE method produced significantly improved performance (p < 0.001) for all Tb measures as compared to the two DL-based supervised methods available in the literature.

CONCLUSIONS

3DGAN-CIRCLE, trained in either unsupervised or supervised fashion, generates HRCT images with high structural similarity to the reference true HRCT images. The supervised 3DGAN-CIRCLE improves agreements of computed Tb microstructural measures with their reference values and outperforms the unsupervised 3DGAN-CIRCLE. 3DGAN-CIRCLE offers a viable DL solution to retrospectively improve image resolution, which may aid in data harmonization in multi-site longitudinal studies where scanner mismatch is unavoidable.

Influence of a change in activity regime on femoral bone architecture and failure behaviour

The incidence and morbidity of femoral fractures increases drastically with age. Femoral architecture and associated fracture risk are strongly influenced by loading during physical activities and it has been shown that the rate of loss of bone mineral density is significantly lower for active individuals than inactive. The objective of this work is to evaluate the impact of a cessation of some physical activities on elderly femoral structure and fracture behaviour. The authors previously established a biofidelic finite element model of the femur considered as a structure optimised to loading associated with daily activities. The same structural optimisation algorithm was used here to quantify the changes in bone architecture following cessation of stair climbing and sit-to-stand. Side fall fracture simulations were run on the adapted bone structures using a damage elasticity formulation. Total cortical and trabecular bone volume and failure load reduced in all cases of activity cessation. Bone loss distribution was strongly heterogeneous, with some locations even showing increased bone volume. This work suggests that maintaining the physical activities involved in the daily routine of a young healthy adult would help reduce the risk of femoral fracture in the elderly population by preventing bone loss.

Finite element analysis of trabecular bone microstructure using CT imaging and continuum mechanical modelling

Purpose

Osteoporosis is a bone disease associated with enhanced bone loss, microstructural degeneration, and fracture‐risk. Finite element (FE) modeling is used to estimate trabecular bone (Tb) modulus from high‐resolution three‐dimensional (3‐D) imaging modalities including micro‐computed tomography (CT), magnetic resonance imaging (MRI), and high‐resolution peripheral quantitative CT (HR‐pQCT). This paper validates an application of voxel‐based continuum finite element analysis (FEA) to predict Tb modulus from clinical CT imaging under a condition similar to in vivo imaging by comparing with measures derived by micro‐CT and experimental approaches.

Method

Voxel‐based continuum FEA methods for CT imaging were implemented using linear and nonlinear models and applied on distal tibial scans under a condition similar to in vivo imaging. First, tibial axis in a CT scan was aligned with the coordinate z‐axis at 150 μm isotropic voxels. FEA was applied on an upright cylindrical volume of interests (VOI) with its axis coinciding with the tibial bone axis. Voxel volume, edge, and vertex elements and their connectivity were defined as per the isotropic image grid. A calibration phantom was used to calibrate CT numbers in Hounsfield unit to bone mineral density (BMD) values, which was then converted into calcium hydroxyapatite (CHA) density. Mechanical properties at each voxel volume element was defined using its ash‐density defined on CT‐derived CHA density. For FEA, the bottom surface of the cylindrical VOI was fixed and a constant displacement was applied along the z‐direction at each vertex element on the top surface to simulate a physical axial compressive loading condition. Finally, a Poisson's ratio of 0.3 was applied, and Tb modulus (MPa) was computed as the ratio of average von Mises stress (MPa) of volume elements on the top surface and the applied displacement. FEA parameters including mesh element size, substep number, and different tolerance values were optimized.

Results

CT‐derived Tb modulus values using continuum FEA showed high linear correlation with the micro‐CT‐derived reference values (r ∈ [0.87 0.90]) as well as experimentally measured values (r ∈ [0.80 0.87]). Linear correlation of computed modulus with their reference values using continuum FEA with linear modeling was comparable with that obtained by nonlinear modeling. Nonlinear continuum FEA‐based modulus values (mean of 1087.2 MPa) showed greater difference from their reference values (mean of 1498.9 MPa using micro‐CT‐based FEA) as compared with linear continuum methods. High repeat CT scan reproducibility (intra‐class correlation [ICC] = 0.98) was observed for computed modulus values using both linear and nonlinear continuum FEA. It was observed that high stress regions coincide with Tb microstructure as fuzzily characterized by BMD values. Distributions of von Mises stress over Tb microstructure and marrow regions were significantly different (p < 10^–8).

Conclusion

Voxel‐based continuum FEA offers surrogate measures of Tb modulus from CT imaging under a condition similar to in vivo imaging that alleviates the need for segmentation of Tb and marrow regions, while accounting for bone distribution at the microstructural level. This relaxation of binary segmentation will extend the scope of FEA application to assess mechanical properties of bone microstructure at relatively low‐resolution imaging.

Cosmetic use and serum level of lead (not cadmium) affect bone mineral density among young Iranian women

Bone mineral density is a crucially important index for skeletal health. A low amount of bone density (osteoporosis) is a common health problem among men and especially women. Among different parts of the body, women's face is the area on which many types of (facial) cosmetics are routinely applied. The aims of this study were to measure the association of cosmetic use with BMD of the lumbar spine and femoral neck among young female students. This is a cross-sectional study on 65 female students in the 2017 academic year. The study participants were students at Shiraz University of Medical Sciences who were selected randomly using phone directory sampling method. Based on the results of multiple linear regression, adjusted for several important covariates, cosmetic use is inversely associated with the BMD z-scores. Lead was significantly associated with trochanteric z-score (B = -0.002 to 95% CI = -0.004 to -0.0003, p = 0.02) and total lumbar z-score (B = -0.002 to 95% CI = -0.004 -0.0005, p = 0.01). In the present study, duration of using cosmetics was significantly associated with BMD of key skeletal regions. The big market of cosmetics in many countries especially those in the Middle East is highly a vastly neglected health issue. Many more observational prospective or interventional studies are required to understand the benefits and hazards caused by cosmetics in women.

Sex Difference in the Socioeconomic Burden of Osteoporosis among South Koreans

Background: The prevalence of osteoporosis is increasing with the aging of the population and the socioeconomic burden. The purpose of this study was to determine the socioeconomic burden of osteoporosis in Korea. Methods: The prevalence of osteoporosis was analyzed using 2017 National Patients Sample and Korea National Health and Nutrition Examination Survey data. Direct costs were divided into healthcare and non-healthcare costs, and indirect costs were calculated by assessing the cost of loss of productivity for labor loss due to disease. Results: The prevalence of osteoporosis diagnosis was 1.91% in total, which was 13 times higher in women than in men (3.57% vs. 0.26%). The socioeconomic cost of osteoporosis was 299.1 million USD based on main diagnosis, and the cost was 13 times higher in women than in men (277.6 vs. 21.5 million USD). The total cost based on main and secondary diagnosis was 981.8 million USD. Similarly, the cost was seven times higher in women than in men (862.4 vs. 119.4 million USD). Conclusions: Osteoporosis increases the socioeconomic burden of disease, and it is significantly higher in women than in men. The policy support for the implementation of prevention and management programs would be necessary to reduce the burden of osteoporosis.

Energy Metabolism and Ketogenic Diets: What about the Skeletal Health? A Narrative Review and a Prospective Vision for Planning Clinical Trials on this Issue

The existence of a common mesenchymal cell progenitor shared by bone, skeletal muscle, and adipocytes cell progenitors, makes the role of the skeleton in energy metabolism no longer surprising. Thus, bone fragility could also be seen as a consequence of a “poor” quality in nutrition. Ketogenic diet was originally proven to be effective in epilepsy, and long-term follow-up studies on epileptic children undergoing a ketogenic diet reported an increased incidence of bone fractures and decreased bone mineral density. However, the causes of such negative impacts on bone health have to be better defined. In these subjects, the concomitant use of antiepileptic drugs and the reduced mobilization may partly explain the negative effects on bone health, but little is known about the effects of diet itself, and/or generic alterations in vitamin D and/or impaired growth factor production. Despite these remarks, clinical studies were adequately designed to investigate bone health are scarce and bone health related aspects are not included among the various metabolic pathologies positively influenced by ketogenic diets. Here, we provide not only a narrative review on this issue, but also practical advice to design and implement clinical studies on ketogenic nutritional regimens and bone health outcomes. Perspectives on ketogenic regimens, microbiota, microRNAs, and bone health are also included.

Bone health in pediatric patients with neurological disorders

Patients with neurological disorders are at high risk of developing osteoporosis, as they possess multiple risk factors leading to low bone mineral density. Such factors include inactivity, decreased exposure to sunlight, poor nutrition, and the use of medication or treatment that can cause lower bone mineral density such as antiepileptic drugs, ketogenic diet, and glucocorticoids. In this article, mechanisms involved in altered bone health in children with neurological disorders and management for patients with epilepsy, cerebral palsy, and Duchenne muscular dystrophy regarding bone health are reviewed.

Neuron subset-specific Pten deletion induces abnormal skeletal activity in mice

Individuals with a history of epilepsy are at higher risk for bone fractures compared to the general population. Although clinical studies support an association between low bone mineral density (BMD) and anti-seizure medications, little is known on whether a history of seizures is linked to altered bone health. Therefore, in this study we tested the hypothesis that bone mass, morphology, and bone mineralization are altered by seizures in genetically epileptic animals and in animals subjected to an episode of status epilepticus. In this study, we used NS-Pten conditional knockout mice (a well-studied genetic model of epilepsy). We used microCT analysis to measure BMD, morphology, and mineralization in NS-Pten^+/+ (wildtype) and NS-Pten^-/- (knockout) mice at 4 and 8weeks, as well as adult Kv4.2^+/+ and Kv4.2^-/- mice. We measured BMD, bone morphology, and mineralization in adult NS-Pten^+/+ mice that received status epilepticus through kainic acid (20mg/kg intraperitoneal). Further, we measured locomotion for NS-Pten^+/+ and NS-Pten^-/- mice at 4 and 6weeks. We found that NS-Pten^-/- mice exhibited low BMD in the tibial metaphysis and midshaft compared to non-epileptic mice. Morphologically, NS-Pten^-/- mice exhibited decreased trabecular volume fraction, and endocortical expansion in both the metaphyeal and diaphyseal compartments. In the midshaft, NS-Pten^-/- mice exhibited reduced tissue mineral density, indicating impaired mineralization in addition to morphological deficits. NS-Pten^-/- mice exhibited hyperactivity in open field testing, suggesting low bone mass in NS-Pten^-/- mice was not attributable to hypoactivity. Differences in BMD were not observed following kainate-induced seizures or in the Kv4.2^-/- model of seizure susceptibility. Our findings suggest that deletion of Pten in the brain results in impaired bone mass and mineralization, which may contribute to weaker bones and thereby a higher fracture risk.

Risk factors for hip impact during real-life falls captured on video in long-term care

Hip fracture risk is increased by landing on the hip. We examined factors that contribute to hip impact during real-life falls in long-term care facilities. Our results indicate that hip impact is equally likely in falls initially directed forward as sideways and more common among individuals with dependent Activities of Daily Living (ADL) performance.

INTRODUCTION

The risk for hip fracture in older adults increases 30-fold by impacting the hip during a fall. This study examined biomechanical and health status factors that contribute to hip impact through the analysis of real-life falls captured on video in long-term care (LTC) facilities.

METHODS

Over a 7-year period, we captured 520 falls experienced by 160 residents who provided consent for releasing their health records. Each video was analyzed by a three-member team using a validated questionnaire to determine whether impact occurred to the hip or hand, the initial fall direction and landing configuration, attempts of stepping responses, and use of mobility aids. We also collected information related to resident physical and cognitive function, disease diagnoses, and use of medications from the Minimum Data Set.

RESULTS

Hip impact occurred in 40 % of falls. Falling forward or sideways was significantly associated with higher odds of hip impact, compared to falling backward (OR 4.2, 95 % CI 2.4-7.1) and straight down (7.9, 4.1-15.6). In 32 % of sideways falls, individuals rotated to land backward. This substantially reduced the odds for hip impact (0.1, 0.03-0.4). Tendency for body rotation was decreased for individuals with dependent ADL performance (0.43, 0.2-1.0).

CONCLUSIONS

Hip impact was equally likely in falls initially directed forward as sideways, due to the tendency for axial body rotation during descent. A rotation from sideways to backward decreased the odds of hip impact 10-fold. Our results may contribute to improvements in risk assessment and strategies to reduce risk for hip fracture in older adults.

Changes in bone mineral density may predict the risk of fracture differently in older adults according to fall history

OBJECTIVES

To determine whether the association between change in bone mass density (BMD) over 4 years and risk of hip and nonvertebral fracture differs according to an individual's history of falls.

DESIGN

Population-based cohort study.

SETTING

Framingham, Massachusetts.

PARTICIPANTS

Individuals with two measures of BMD at the femoral neck (mean age 78.8; 310 male, 492 female).

MEASUREMENTS

Cox proportional hazards models were used to estimate hazard ratios (HRs) for the association between percentage change in BMD (per sex-specific standard deviation) and risk of incident hip and nonvertebral fracture. Models were stratified based on history of falls (≥1 falls in the past year) and recurrent falls (≥2 falls) ascertained at the time of the second BMD test. Interactions were tested by including the term "fall history * change in BMD" in the models.

RESULTS

Mean change in BMD was -0.6%/year; 27.8% of participants reported falls, and 10.8% reported recurrent falls. Seventy-six incident hip and 175 incident nonvertebral fractures occurred over a median follow-up of 9.0 years. There was no difference in the association between change in BMD and hip fracture according to history of falls (P for interaction = .57). The HR associated with change in BMD and nonvertebral fracture was 1.31 (95% confidence interval (CI) = 1.10-1.56) in participants without a history of falls and 0.95 (95% CI 0.70-1.28) in those with a fall (interaction P = .07). Results for recurrent fallers were similar.

CONCLUSION

The effect of BMD loss on risk of nonvertebral fracture may be greater in persons without a history of falls. It is possible that change in BMD contributes less to fracture risk when a strong risk factor for fracture, such as falls, is present.

Raloxifene prevents skeletal fragility in adult female Zucker Diabetic Sprague-Dawley rats

Fracture risk in type 2 diabetes is increased despite normal or high bone mineral density, implicating poor bone quality as a risk factor. Raloxifene improves bone material and mechanical properties independent of bone mineral density. This study aimed to determine if raloxifene prevents the negative effects of diabetes on skeletal fragility in diabetes-prone rats. Adult Zucker Diabetic Sprague-Dawley (ZDSD) female rats (20-week-old, n = 24) were fed a diabetogenic high-fat diet and were randomized to receive daily subcutaneous injections of raloxifene or vehicle for 12 weeks. Blood glucose was measured weekly and glycated hemoglobin was measured at baseline and 12 weeks. At sacrifice, femora and lumbar vertebrae were harvested for imaging and mechanical testing. Raloxifene-treated rats had a lower incidence of type 2 diabetes compared with vehicle-treated rats. In addition, raloxifene-treated rats had blood glucose levels significantly lower than both diabetic vehicle-treated rats as well as vehicle-treated rats that did not become diabetic. Femoral toughness was greater in raloxifene-treated rats compared with both diabetic and non-diabetic vehicle-treated ZDSD rats, due to greater energy absorption in the post-yield region of the stress-strain curve. Similar differences between groups were observed for the structural (extrinsic) mechanical properties of energy-to-failure, post-yield energy-to-failure, and post-yield displacement. These results show that raloxifene is beneficial in preventing the onset of diabetes and improving bone material properties in the diabetes-prone ZDSD rat. This presents unique therapeutic potential for raloxifene in preserving bone quality in diabetes as well as in diabetes prevention, if these results can be supported by future experimental and clinical studies.

N-phenacylthiazolium bromide reduces bone fragility induced by nonenzymatic glycation

Nonenzymatic glycation (NEG) describes a series of post-translational modifications in the collagenous matrices of human tissues. These modifications, known as advanced glycation end-products (AGEs), result in an altered collagen crosslink profile which impacts the mechanical behavior of their constituent tissues. Bone, which has an organic phase consisting primarily of type I collagen, is significantly affected by NEG. Through constant remodeling by chemical resorption, deposition and mineralization, healthy bone naturally eliminates these impurities. Because bone remodeling slows with age, AGEs accumulate at a greater rate. An inverse correlation between AGE content and material-level properties, particularly in the post-yield region of deformation, has been observed and verified. Interested in reversing the negative effects of NEG, here we evaluate the ability of n-phenacylthiazolium bromide (PTB) to cleave AGE crosslinks in human cancellous bone. Cancellous bone cylinders were obtained from nine male donors, ages nineteen to eighty, and subjected to one of six PTB treatments. Following treatment, each specimen was mechanically tested under physiological conditions to failure and AGEs were quantified by fluorescence. Treatment with PTB showed a significant decrease in AGE content versus control NEG groups as well as a significant rebound in the post-yield material level properties (p<0.05). The data suggest that treatment with PTB could be an effective means to reduce AGE content and decrease bone fragility caused by NEG in human bone.

Osteoporosis onset differences between rural and metropolitan populations: correlation to fracture type, severity, and treatment efficacy

Osteoporosis is the prevalent cause of fractures in an ever-aging population, with an established correlation between daily activities and way of life. We aimed to delineate differences in onset of osteoporosis, T-score progression, quality of life, and correlation to prevalence, types, and severity of fractures in age-comparable populations of rural and metropolitan habitats in this multicenter, retrospective double-blind study. We evaluated data derived from the medical files of two comparable groups of osteoporotic patients: group A (n = 530, rural area) and group B (n = 171, metropolitan area). Both groups received comparable treatment for osteoporosis. Comparison was performed on the basis of osteoporosis onset, T-score in a maximum of 8 years follow-up, fracture types [American Academy of Orthopaedic Surgeons (AO) categorization], and type of treatment followed. Quality of life was assessed by use of specialized questionnaires. From the minimum 4-year follow-up of all patients included in the research, there was a statistically significant difference in favor of the rural population in all research parameters. Rural populations presented with osteoporosis at a later age than their metropolitan counterparts, exhibiting favorable T-scores with comparable treatments and simpler fractures (AO categorization). Metropolitan habitats and life therein have a deleterious effect on osteoporosis onset and response to treatment. Rural populations are diagnosed with osteoporosis on a later age, with better compliance and improved treatment outcome. Fracture categorization shows increased severity in the metropolitan populace and a suggested correlation between a poor-quality way of life and decreased activity levels.

Epidemiology of hip fracture in Tucuman, Argentina

The incidence of osteoporotic hip fracture was studied previously in a central area of Argentina. Studying Tucuman (north area) was very useful to compare results of the different areas and detect a similar incidence in women and a slightly higher incidence in men compared with previous data for the central region.

INTRODUCTION/METHODS

Epidemiology of hip fracture was studied over a 1-year period in the city of San Miguel de Tucumán (SMT) and in the whole province of Tucumán, located in the northeast of Argentina (latitudes 26° and 28° south). The results were compared with previous studies performed in the central region of Argentina.

RESULTS

Two hundred and eighty-three patients (208 women and 75 men) aged 50 years or over in SMT suffered a hip fracture. The incidence in females and males was 334.9 and 163.8 hip fractures per 100,000 inhabitants per year, respectively (female/male ratio 2.0). A total of 498 hip fractures were recorded in Tucuman province (367 in women and 131 in men). The results in females and males were 276.5 and 114.7 hip fractures per 100,000 inhabitants per year, respectively. Average age of the female and male population was 78±9 and 77±9 years, respectively.

CONCLUSIONS

These results showed that the incidence of hip fracture in female and male populations in SMT was similar to previous studies performed in the central area of the country. Further studies on the south area of Argentina should be conducted to complete the information on a large country extending from latitudes 22° to 55°S.

Changes in metacarpal bone mineral density with age and menopause using computed X-ray densitometry in Japanese women: Cross-sectional and longitudinal study

BACKGROUND

Bone mineral density (BMD) loss with age and menopause is widely accepted in elderly women. However, only a few studies have utilized a multiple regression model that includes physical characteristics to assess comprehensive lifetime changes in BMD.

OBJECTIVE

A prospective study was conducted to characterize the normal patterns in metacarpal BMD changes in Japanese women, and to assess the applicability of a fitting model using cross-sectional data compared with longitudinal variability.

SUBJECTS AND METHODS

The study consisted of 5422 healthy women in cross-sectional data and a 1-year follow-up of 359 women. The metacarpal BMD was measured by computed X-ray densitometry. Multiple linear and nonlinear regression analyses were performed in cross-sectional subjects. Nonparametric analysis was used to compare percentage rates of BMD changes between actual and estimated values.

RESULTS

The cross-sectional data showed that the best-fit equation was a nonlinear change model using the variables of age and height in premenopausal women, and years since menopause (YSM), age and height in postmenopausal women. The results of longitudinal data indicated the following. In premenopausal women, the actual BMD changes were greater in the 30-39 age group than the 20-29 age group and were less in the 50-59 group than the 40-49 group. The rates of annual change in BMD between the actual value and estimated value by change model were very similar. In postmenopausal women, the actual changes in BMD indicated that the rapid rate of reduction observed was over 3% at 0-5 YSM and 1.5% at 6-10 YSM, and thereafter showed a slower rate of decline at 11 YSM. The change model represented the trend of actual change in BMD for postmenopausal women, whereas the rates of estimated BMD loss underestimated the actual changes at 1-10 YSM.

CONCLUSION

The change model for premenopausal women using cross-sectional data is beneficial in evaluating the actual metacarpal BMD variability, whereas that for postmenopausal women is insufficient in estimating the longitudinal BMD variability.

Associations of genetic lactase non-persistence and sex with bone loss in young adulthood

Some studies have reported that after attainment of peak bone mass (PBM), slow bone loss may occur in both men and women; however, findings are inconsistent. Genetic factors play a significant role in bone loss, but the available evidence is conflicting. Genetic lactase non-persistence (lactase C/C(-13910) genotype) is suggested to increase risk for inadequate calcium intake predisposing to poorer bone health. We investigated whether this genotype is associated with PBM and bone loss in young Finnish adults. Subjects belong to the Cardiovascular Risk in Young Finns Study that is an ongoing multi-centre follow-up of atherosclerosis risk factors. From the original cohort, randomly selected subjects aged 20-29 participated in baseline bone mineral density (BMD) measurements (n=358), and in follow-up measurements 12 years later (n=157). Bone mineral content (BMC) and BMD at lumbar spine (LS) and femoral neck (FN) were measured at baseline and follow-up with dual energy X-ray absorptiometry (DXA). Lactase C/T(-13910) polymorphism was determined by PCR and allele-specific fluorogenic probes. Information on lifestyle was elicited with questionnaires. During the follow-up, bone loss at both bone sites was greater in males (LS BMD: -1.1%, FN BMD: -5.2%) than in females (LS BMD: +2.1%, FN BMD: -0.7%) (both bone sites p=0.001). Younger age predicted greater loss of FN BMC and BMD in females (p=0.013 and p=0.001, respectively). Increased calcium intake predicted FN BMD gain in both sexes (in females B=0.007 g/cm(2)/mg, p=0.002; in males B=0.006, p=0.045), and increased physical activity LS BMD gain in females (B=0.091 g/cm(2)/physical activity point, p=0.023). PBM did not differ between the lactase genotypes, but males with the CC(-13910) genotype seemed to be prone to greater bone loss during the follow-up (LS BMD: C/C vs. T/T p=0.081). In conclusion, bone loss in young adulthood was more common in males than in females and seemed to occur mainly at the femoral neck. Young males with the lactase CC(-13910) genotype may be more susceptible to bone loss; however, calcium intake predicts changes in bone mass more than the lactase genotype.

Efficacy and safety of pharmacological agents in managing osteoporosis in the old old: review of the evidence

INTRODUCTION

Osteoporosis and fracture risk increase exponentially in postmenopausal females. This places a significant burden in terms of morbidity, mortality and costs that are likely to increase with an ageing population. Despite this there is very limited data on pharmacological management of osteoporosis in this high risk group. OBJECTIVES OF THIS REVIEW: To review the published literature on the clinical efficacy and safety of specific anti osteoporosis treatments in the reduction in fracture risk in females >or=75 years of age. The following major endpoints were used in this review: SEARCH METHODS FOR IDENTIFICATION OF STUDIES: We performed an electronic search of Medline (1970 to June 2007) and the Cochrane Library (1996 to June 2007). Our search strategy included MeSH terms for osteoporosis and treatments. We reviewed the reference list of identified articles for additional relevant published trials.

RESULTS

Two hundred and fifty-two potentially relevant abstracts were identified. Only six publications were deemed to meet full eligibility criteria and one met most criteria. There is evidence for significant vertebral fracture relative risk reduction(RR) at 1 year for Risedronate (RR 81%; p<0.001), Teriparatide (RR 65%; p<0.05) and Strontium Ranelate (RR 59%; p=0.002) and 3 years for Risedronate (RR 44%; p=0.003), Alendronate (RR 38%; p<0.05) and Strontium Ranelate (RR 32%; p=0.013). There is evidence for significant non-vertebral fracture relative risk reduction at 1 year for Strontium Ranelate (RR 41%; p=0.027) but not Teriparatide (p=0.66) and 3 years for Strontium Ranelate (RR 31%; p=0.011) but not Risedronate (p=0.66). The only study to report a reduction in hip fracture at 3 years is the TROPOS study with Strontium Ranelate (RR 36%; p=0.046).

DISCUSSION

This review reinforces the irony that the least evidence is available for fragility fracture reduction in the group at greatest risk; the old old and those with non vertebral and hip fracture. Although there is good evidence for the benefit of the bisphosphonates (Alendronate and Risedronate), Teriparatide and Strontium Ranelate in vertebral fracture reduction, there are very limited data for non vertebral and hip fracture reduction. Strontium Ranelate is the only agent to date that has demonstrated a reduction in non vertebral and hip fracture events in this high risk elderly female population. Perhaps we need to adopt different strategies in managing older patients with osteoporosis as their fracture risks and treatment strategies may be quite different from younger populations.

Lifetime absolute risk of hip and other osteoporotic fracture in Belgian women

OBJECTIVES

To estimate the lifetime absolute risks of hip and other osteoporotic fracture in Belgian women aged 60 years and to examine the effect of changes in baseline population fracture risk and changes in life expectancy.

MATERIALS AND METHODS

Estimates were performed using a Markov microsimulation model and were based on the incidence of first fracture as well as life expectancy. Baseline scenario included projected mortality rates and increasing fracture incidence by 1% per year. Alternative scenarios were performed on age, life expectancy and trends in fracture incidence. Lifetime fracture risk for osteoporotic population (T-score <or= -2.5) was also estimated.

RESULTS

In the baseline scenario, lifetime absolute risks of hip fracture and of any major osteoporotic fracture (hip, clinical vertebral or wrist) were respectively 24.8% and 44.3%. Alternative scenarios showed that when assuming no change of age-specific fracture rates over time, these lifetime risks were 18.3% and 35.2%, while these values were 20.0% and 38.3% assuming no future mortality reductions. For osteoporotic women, these values were respectively 34.5% and 51.5%.

CONCLUSION

We conclude that absolute lifetime fracture risks are substantial and that trends in fracture incidence and changes in life expectancy have a marked impact on absolute lifetime fracture risks.

Sex hormones, their receptors and bone health

Sex steroids regulate skeletal maturation and preservation in both men and women, as already recognized in the 1940s by Albright and Reifenstein. The impact of gonadal insufficiency on skeletal integrity has been widely recognized in adult men and women ever since. In the context of their skeletal actions, androgens and estrogens are no longer considered as just male and female hormones, respectively. Androgens can be converted into estrogens within the gonads and peripheral tissues and both are present in men and women, albeit in different concentrations. In the late 1980s, sex steroid receptors were discovered in bone cells. However, the understanding of sex steroid receptor activation and translation into biological skeletal actions is still incomplete. Due to the complex metabolism, sex steroids may have not only endocrine but also paracrine and/or autocrine actions. Also, circulating sex steroid concentrations do not necessarily reflect their biological activity due to strong binding to sex hormone binding globulin (SHBG). Finally, sex steroid signaling may include genomic and non-genomic effects in bone and non-bone cells. This review will focus on our current understanding of gonadal steroid metabolism, receptor activation, and their most relevant cellular and biological actions on bone.

Osteoporotic fractures: a brain or bone disease?

Osteoporosis is a skeletal disorder that predisposes individuals to increased risk of fracture. However, most osteoporotic fractures occur in women who do not meet criteria for osteoporosis. Hence, bone density, by itself, is a relatively poor predictor of fracture. Age and age-related factors are now recognized as increasingly important in determining fracture risk. Osteoporotic fractures are associated with increased disability and mortality, suggesting that osteoporosis may be a clinical manifestation of an underlying disease process affecting multiple systems. The systems affected, the musculo-skeletal system and the central nervous system, are shared in many respects with the frailty syndrome. Vitamin D deficiency is a major contributor to the frailty syndrome, osteoporosis, and osteoporotic fractures. Its effects are mediated by the development of cerebrovascular disease, postural instability, muscle weakness, and bone fragility. Thus, osteoporotic fractures result from both a bone and brain disease.

Effect of pre-impact movement strategies on the impact forces resulting from a lateral fall

Approximately 90% of hip fractures in older adults result from falls, mostly from landing on or near the hip. A three-dimensional, 11-segment, forward dynamic biomechanical model was developed to investigate whether segment movement strategies prior to impact can affect the impact forces resulting from a lateral fall. Four different pre-impact movement strategies, with and without using the ipsilateral arm to break the fall, were implemented using paired actuators representing the agonist and antagonist muscles acting about each joint. Proportional-derivative feedback controller controlled joint angles and velocities so as to minimize risk of fracture at any of the impact sites. It was hypothesized that (a) the use of active knee, hip and arm joint torques during the pre-contact phase affects neither the whole body kinetic energy at impact nor the peak impact forces on the knee, hip or shoulder and (b) muscle strength and reaction time do not substantially affect peak impact forces. The results demonstrate that, compared with falling laterally as a rigid body, an arrest strategy that combines flexion of the lower extremities, ground contact with the side of the lower leg along with an axial rotation to progressively present the posterolateral aspects of the thigh, pelvis and then torso, can reduce the peak hip impact force by up to 56%. A 30% decline in muscle strength did not markedly affect the effectiveness of that fall strategy. However, a 300-ms delay in implementing the movement strategy inevitably caused hip impact forces consistent with fracture unless the arm was used to break the fall prior to the hip impact.

Bone consequences of epilepsy and antiepileptic medications

Childhood and adolescence are critical periods of skeletal mineralization. Peak bone mineral density achieved by the end of adolescence determines the risk for later pathological fractures and osteoporosis. Chronic disease and medication often adversely affect bone health. Epilepsy is one of the most common neurological conditions occurring in persons under the age of 21. Epilepsy may affect bone in a number of ways. Restrictions of physical activity imposed by seizures, cerebral palsy or other coexisting comorbidities adversely affect bone health. It has been observed that treatment with phenytoin and phenobarbital can be associated with rickets. More recently, established agents such as carbamazepine and valproate have been shown to be associated with decreased bone mineral density. The literature related to bone health in pediatric epilepsy is reviewed.

Osteoporosis and chronic kidney disease

Osteoporosis (OP), the most frequent bone disease affecting the general population, is associated with high fracture risk. Patients with impaired kidney function have bone and mineral disturbances leading to extraskeletal calcifications and complex changes in bone turnover that predispose them to increased fracture risk accompanied by increased morbidity and mortality. The combination of these two bone disorders seems to have an additive effect with regard to fracture risk and its outcome, so that appropriate diagnosis and treatment of this disorder should be of primary concern when approaching patients with kidney disease. Nevertheless, the clinical and laboratory diagnostic tools used to identify OP in the general population do not suit the requirement for detecting the complex bone and metabolic changes that occur with chronic kidney disease, leading to the lack of or the initiation of inappropriate therapy. This review will focus on the bone pathophysiologic processes involved in OP and renal osteodystrophy and address some of the problems associated with our current diagnostic tools and aspects of the therapeutic approaches.

Osteoporosis in a postpolio clinic population

OBJECTIVES

To determine (1) the frequency of osteoporosis at the hip and lumbar spine in a postpolio clinic population and (2) the association of lower-extremity muscle strength and other potential contributing factors to osteoporosis with bone density measured at the hip.

DESIGN

Cross-sectional study involving a chart review.

SETTING

A university-affiliated hospital postpolio clinic.

PARTICIPANTS

Patient charts (N=379) were reviewed; 164 (26%) were included, and 215 (74%) were not included primarily (74%) because of the unavailability of bone density results.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Bone density (in g/cm(2)) and T score were assessed at the femoral neck and lumbar spine. Muscle strength was evaluated by manual muscle testing in 7 bilateral lower-extremity muscles.

RESULTS

The occurrence of osteoporosis at the hip and lumbar spine was 20 (32%) of 62 and 6 (10%) of 61 in men, 3 (9%) of 33 and 2 (6%) of 32 in premenopausal women, and 18 (27%) of 67 and 7 (11%) of 65 in postmenopausal women, respectively. In a logistic regression model, the presence of osteoporosis at the hip was significantly associated with strength sum score in the same extremity in which the bone density was performed after adjusting for other important risk factors (age, body mass index, time since polio).

CONCLUSIONS

Osteoporosis occurred commonly at the hip in a postpolio clinic population. Hip bone density was associated with muscle strength in the same lower extremity.

Residual lifetime risk of fractures in women and men

In a sample of 1358 women and 858 men, > or = 60 yr of age who have been followed-up for up to 15 yr, it was estimated that the mortality-adjusted residual lifetime risk of fracture was 44% for women and 25% for men. Among those with BMD T-scores < or = -2.5, the risks increased to 65% in women and 42% in men.

INTRODUCTION

Risk assessment of osteoporotic fracture is shifting from relative risk to an absolute risk approach. Whereas BMD is a primary predictor of fracture risk, there has been no estimate of mortality-adjusted lifetime risk of fracture by BMD level. The aim of the study was to estimate the residual lifetime risk of fracture (RLRF) in elderly men and women.

MATERIALS AND METHODS

Data from 1358 women and 858 men > or = 60 yr of age as of 1989 of white background from the Dubbo Osteoporosis Epidemiology Study were analyzed. The participants have been followed for up to 15 yr. During the follow-up period, incidence of low-trauma, nonpathological fractures, confirmed by X-ray and personal interview, were recorded. Incidence of mortality was also recorded. BMD at the femoral neck was measured by DXA (GE-LUNAR) at baseline. Residual lifetime risk of fracture from the age of 60 was estimated by the survival analysis taking into account the competing risk of death.

RESULTS

After adjusting for competing risk of death, the RLRF for women and men from age 60 was 44% (95% CI, 40-48) and 25% (95% CI, 19-31), respectively. For individuals with osteoporosis (BMD T-scores < or = -2.5), the mortality-adjusted lifetime risk of any fracture was 65% (95% CI, 58-73) for women and 42% (95% CI, 24-71) for men. For the entire cohort, the lifetime risk of hip fracture was 8.5% (95% CI, 6-11%) for women and 4% (95% CI, 1.3-5.4%) for men; risk of symptomatic vertebral fracture was 18% (95% CI, 15-21%) for women and 11% (95% CI, 7-14%) for men.

CONCLUSIONS

These estimates provide a means to communicate the absolute risk of fracture to an individual patient and can help promote the identification and targeting of high-risk individuals for intervention.

Cost-effectiveness of the treatment and prevention of osteoporosis--a review of the literature and a reference model

OBJECTIVE

The purpose of the paper is to update and review the latest developments related to modelling and economic evaluation of osteoporosis in the period 2002-2005 and further to present a reference model for the assessment of the cost-effectiveness of the prevention and treatment of osteoporosis.

DISCUSSION

The reference model is intended to be used for fracture specific interventions affecting the risk of fracture. An interface version and an extensive description of the model is available on the internet ( http://www.healtheconomics.se ) and also accessible via the International Osteoporosis Foundation ( http://www.osteofound.org ). The purpose of the reference model is to improve the quality and comparability of cost-effectiveness analysis in the osteoporosis field and to serve as a tool for validation of present and future cost-effectiveness models. The reference model allows the cost-effectiveness analysis to be carried out from a societal perspective including intervention, morbidity and mortality costs. The model has been extensively tested and calibrated, and meets the properties of good decision analytic modelling. The model is a state transition Markov cohort model, which is characterised by a 50-year time horizon divided into one year cycle lengths. The following health states are included: "healthy", "hip fracture", "spine fracture", "wrist fracture", "other fracture", and "dead".

CONCLUSION

The model is flexible and allows for the estimation of the cost-effectiveness over different ranges for a selected number of variables (e.g., age, fracture risk, cost of intervention).

Pathological fractures in epilepsy

Fracture rates in epilepsy are two to three times that for the general population, although the influence of gender and age is not well defined. We examined, over a 7-year period at a single health care center, 750 patients with epilepsy who sustained the fractures. Among these patients, 293 (39%) had pathological fractures and 457 (61%) had traumatic/seizure-related fractures. Pathological fractures accounted for 71% of the 146 patients >60 years, a group traditionally at risk for pathological fractures (P<0.02). Fractures in epilepsy are distributed with bimodal peaks in the fifth and eighth decades of life, although pathological fractures are a significant contributor across the life span, accounting for 20 to 40% of patients traditionally thought not to be at risk for involutional osteoporotic fractures. Together these findings suggest that epilepsy, and/or its treatment, is a dominant influence in the pathogenesis of fractures and may exacerbate the effects of aging-related involutional osteoporosis.

Osteoporosis among male Saudi Arabs: a pilot study

BACKGROUND

Little attention has been paid to the problem of male osteoporosis in Saudi Arabia. In this prospective study we assessed the prevalence of male osteoporosis among Saudi Arabs.

SUBJECTS AND METHODS

We studied Saudi Arabian males >50 years of age attending outpatient clinics at King Fahd Hospital of the University, Al-Khobar, between 1 May 2005 and 30 January 2006. We determined body mass index (BMI) and tests were done to rule out secondary osteoporosis. All subjects had a bone mineral density (BMD) measurement of the hip area and the lumbar spine using dual energy X-ray absorptiometry (DEXA). A T-score of < or = -2.5 SD that of young, healthy adults was taken as osteoporotic and scores between -1 to -2.5 SD were taken as osteopenic.

RESULTS

One hundred fifteen patients (mean age, 61.8+/-0.75 years; range, 50 to 76 years) had a mean BMI of 24.7+/-0.35 (range, 18.5 to 31). Based on hip scans, the prevalence of osteoporosis was 24.3%. Sixty- four percent were osteopenic. Based on scans of the lumbar spine, the prevalence of osteoporosis was 37.4% and 33.9% were osteopenic. Spinal osteoporosis was more common than hip osteoporosis.

CONCLUSIONS

Our study indicates that the prevalence of osteoporosis among Saudi Arabian males is higher than among Western males. More studies are needed to determine the national prevalence of male osteoporosis. It is recommended that serious measures to be undertaken to prevent male osteoporosis to stop any future epidemic of catastrophic osteoporosis-related fractures.

Incidence and characteristics of falls leading to hip fracture in Iranian population

An estimated one in three adults aged 65 years or older falls each year, making falls a major health concern. Hip fractures are the most serious consequences of falls in elderly people. Identifying the characteristics of falls leading to hip fracture may provide information about high risk individuals, environment, and activities useful for the development of intervention strategies. Little is known, however, about the incidence and characteristics of falls leading to hip fracture in Middle Eastern countries. Therefore, the authors presented data from the Iranian Multicenter Study on Accidental Injuries, a prospective population-based study conducted in 9 provinces of Iran in 2003. All the hospitals serving about 9.5 million people in the study area were prospectively surveyed for any incident injury resulting from accidental events. A total of 2,186 patients (1,372 male, 814 female) were admitted due to any injurious fall events, where 572 (26.2%) of them suffered a hip fracture. Annual incidence rates of injurious fall events and related hip fractures were 116.3 and 30.4 per 100,000 person-years, respectively. These figures were 237.1 and 93.6 per 100,000 person-years for people over the age of 50 years, respectively. 71% of fall injuries and 76% of hip fractures occurred indoors. Among 450 patients with hip fractures >or=50 years of age, 61.8% arose from a fall from standing height or less. Only 1 in these 450 hip fractures occurred at the time of recreational activity. In multivariate logistic regression analysis, no factor was an independent predictor of hip fractures comparing to other fall-related injuries among younger participants (>or=20 and <50 years). For older patients, falls from standing height or loss (odds ratio (OR) = 2.67), falls during walking (OR = 1.71), and falls on stairs (OR = 1.73) were detected as risk factors of hip fracture. Married persons and those falling from a ladder or other elevations were less likely to fracture their hip in this age group. Our data suggest that modification of the factors external to the homes is less likely to prevent more than a small proportion of fall-related hip fractures in Iran. Further studies on this topic have potential applications for developing preventive strategies.

Selective estrogen receptor modulators: A possible new treatment of osteoporosis in males

More recently, osteoporosis in men has been recognized as an important public health problem. Bone loss begins in mid life and is associated with the decline of the sex steroids production. Although there is no equivalent of the menopause, gonadal function in men is affected in a slow progressive way leading to hypogonadism. Testosterone, the major androgen in men, exerts its effect on bone by local conversion to 5alpha-dihydrotestosterone or by aromatization to estrogens. Several studies have found that estrogen, rather than testosterone, levels are more closely correlated with BMD in elderly men. Selective estrogen receptor modulator (SERM) raloxifene binds to estrogen receptors and exhibit estrogenic effect in bone, but, contrary to estrogen, without feminizing effect. There are limited numbers of studies investigating the effects of SERMs in males. Animal studies demonstrated that SERMs inhibit bone turnover and prevent bone loss in orchidectomised adult male rats. Raloxifene has been shown to increase bone mineral density of the hip in men receiving androgen deprivation therapy for prostate cancer. Moreover, experimental data demonstrated dramatic increase in cell death in human prostate cancer cell lines after the treatment with raloxifene. All these observations suggest that SERMs may be useful for the prevention and treatment of osteoporosis not only in postmenopausal women but also in elderly men. However, our hypothesis should be tested in a proper designed clinical trial. Several important issues have to be addressed. Does the same drug dose that has been shown to be effective in postmenopausal women should be used in men, too? Does treatment with SERMs reduce the fracture risk in men and is it comparable to that observed in women? Does treatment with SERMs have any beneficial effect on cardiovascular system and prostate cancer? And finally, do men experience adverse events other than women treated with SERMs? Answering to these questions will have great impact in getting the decision of possible SERMs usage in the treatment of osteoporosis in elderly males.

Cost-effectiveness of inhaled steroids in asthma: impact of effect on bone mineral density

BACKGROUND

The effects of inhaled corticosteroid (ICS) preparations on bone health have been debated. Multiple analyses have been published examining the question, with mixed results.

OBJECTIVES

We examined how assumptions about the effect of ICS on bone mineral density (BMD) influence the cost-effectiveness of ICS in asthma.

METHODS

We developed a mathematical simulation model to estimate clinical outcomes and costs for a cohort with mild/moderate asthma. The analysis conformed to reference case recommendations of the US Panel on Cost-Effectiveness in Health and Medicine. Sensitivity analysis evaluated the stability of our results to uncertainty in treatment duration, age at treatment, and ICS dose.

RESULTS

Assuming a dose of 200 microg twice per day of ICS, a literature-based average effect of ICS on BMD and a 10-year time horizon, we observed a minimal increase in the costs attributed to hip fracture and incremental cost effectiveness ratio of $26,000 per quality-adjusted life-year and $14.00 per symptom-free day gained. Over an extended the time horizon (lifetime), the incremental cost effectiveness ratio increased to $42,000/quality-adjusted life-year. Only under a scenario of high-dose ICS, a lifetime horizon, and a large effect of ICS on BMD did the potential impact of ICS on BMD dramatically affect the economic attractiveness of therapy.

CONCLUSION

To minimize any potential impact, use of the lowest effective dose of ICS and measures to target and intervene in high-risk individuals are warranted. However, ICS therapy in mild/moderate asthma compares favorably with commonly accepted interventions over a wide range of assumptions regarding this treatment and its effects on BMD.

Geometry of the proximal femur in relation to age and sex: a cross-sectional study in healthy adult Danes

PURPOSE

To describe the natural variation in hip geometry in relation to Danish population characteristics, and to establish normal reference values.

MATERIAL AND METHODS

We included 249 healthy individuals (94 M and 155 F, aged 19-79 years) and measured hip-axis-length (HAL), neck-width (NW), neck-shaft-angle (NSA), and femoral head-radius (HR) on dual-energy X-ray absorptiometry (DXA) screen images.

RESULTS

HAL, NW, HR, and NSA were higher in men than in women (10.9 +/- 0.7 vs. 9.5 +/- 0.6 cm (P<0.001), 3.8 +/- 0.3 vs. 3.3 +/- 0.3 cm (P<0.01), 2.5 +/- 0.3 vs. 2.3 +/- 0.2 cm (P< 0.001), and 131 +/- 5 vs. 129 +/- 5 degrees (P< 0.01). NSA was higher in post-menopausal than in pre-menopausal women (130 +/- 4 vs. 128 +/- 5 degrees (P<0.001)). In multiple regression analysis, HAL, NW, and HR were positively related to body height in both sexes (R = 0.20 to 0.63, P<0.05 to P<0.001). In females, NSA was positively related to body height (R = 0.20, P<0.05) and negatively to body weight (R = -0.30, P<0.01). NW increased with age in men (R = 0.34, P<0.01) but not in women.

CONCLUSION

Hip dimensions differ between genders in the Danish population. HAL, NW, and HR depend on body height. Finally, NW increases with age in men but not in women.

[Physiopathology of osteoporosis]

PURPOSE

The pathophysiology of osteoporosis has seen many recent progress especially with the use of genetically modified animal models.

CURRENT KNOWLEDGE AND KEY POINTS

Among many discoveries, one can notice the crucial role of LRP5, GH, IGF-1 and the sex hormones receptors in the acquisition of the peak bone mass, the control of bone remodeling by the sympathetic nervous system and his implication as a transmitter of mechanical loading in bone. Also, the role of estrogen and androgen receptors as well as the aromatase is specified according to sexes. The role of growth plate's chondrocytes in the installation of the trabecular bone network is better and better demonstrated. The greater periosteal apposition in men, mediated by androgens receptor, seems to explain the greatest radial growth and so the greatest bone resistance to mechanical strains like a lower fracture rate in men compared to women. The bone microarchitecture and quality explain an important part of the mechanical properties of bones and why considering the same bone mass one bone is breaking and another one not.

FUTURE PROSPECTS AND PROJECTS

Many therapeutic applications should finalize the discovery of these new bone cells signalisation pathways.

Lebanese guidelines for osteoporosis assessment and treatment: who to test? What measures to use? When to treat?

With the demographic explosion of the population worldwide, the human, social, and economic costs of osteoporosis will continue to rise. It is estimated that the magnitude of the problem might be even larger in developing countries, including those in the Middle East. Although several organizations and countries have developed or adapted guidelines to their local needs, as of today there are no guidelines for osteoporosis assessment in the Middle East. In April 2002, a panel of osteoporosis experts met and discussed practice guidelines for osteoporosis assessment and treatment in Lebanon. The process, which involved an overview of international guidelines as well as local data on osteoporosis, resulted in a draft for Lebanese guidelines that addressed three main questions: "Who to test?" "What measures to use?" and "When to treat?". Representatives from five major Lebanese societies (Endocrinology, Rheumatology, Orthopedics, Obstetrics and Gynecology, and Radiology) subsequently reviewed, discussed, and officially endorsed the guidelines after revisions. The Lebanese guidelines were also endorsed by the Eastern Mediterranean branch of the World Health Organization.

Evidence from data searches and life-table analyses for gender-related differences in absolute risk of hip fracture after Colles' or spine fracture: Colles' fracture as an early and sensitive marker of skeletal fragility in white men

Based on data searches and life-table analyses, we determined the long-term (remaining lifetime) and short-term (10- and 5-year) absolute risks of hip fracture after sustaining a Colles' or spine fracture and searched for potential gender-related differences. In aging men, Colles' fractures carry a higher absolute risk for hip fracture than spinal fractures in contrast to women. These findings support the concept that forearm fracture is an early and sensitive marker of male skeletal fragility.

INTRODUCTION

Colles' fracture occurrence has been largely ignored in public health approaches to identify target populations at risk for hip fracture. The aim of this study was to estimate the long-term and short-term absolute risks of hip fracture after sustaining a Colles' or spine fracture and to search for potential gender-related differences in the relationship between fracture history and future fracture risk.

MATERIALS AND METHODS

To determine the long-term (remaining lifetime) and short-term (10- and 5-year) absolute risks of hip fracture, we applied life-table methods using U.S. age- and sex-specific hip fracture incidence rates, U.S. age-specific mortality rates for white women and men, pooled hazard ratios for mortality after Colles' and spine fracture, and pooled relative risks for hip fracture after Colles' and spine fracture, estimated from cohort studies by standard meta-analytic methods.

RESULTS

Our results indicate that the estimated remaining lifetime risks are dependent on age in both genders. In women, remaining lifetime risks increase until the age of 80 years, when they start to decline because of the competing probabilities of fracture and death. The same pattern is found in men until the age of 85 years, the increment in lifetime risk being even more pronounced. As expected, the risk of sustaining a hip fracture was found to be higher in postmenopausal women with a previous spine fracture compared with those with a history of Colles' fracture. In men, on the other hand, the prospective association between fracture history and subsequent hip fracture risk seemed to be strongest for Colles' fracture. At the age of 50, for example, the remaining lifetime risk was 13% in women with a previous Colles' fracture compared with 15% in the context of a previous spine fracture and 9% among women of the general population. In men at the age of 50 years, the corresponding risk estimates were 8%, 6%, and 3%, respectively. Similar trends were observed when calculating 5- and 10-year risks.

CONCLUSIONS

In aging men, Colles' fractures carry a higher absolute risk for hip fracture than spinal fractures in contrast to women. These findings support the concept that forearm fracture is an early and sensitive marker of male skeletal fragility. The gender-related differences reported in this analysis should be taken into account when designing screening and treatment strategies for prevention of hip fracture in men.

Exploring the effects of luteinizing hormone-releasing hormone agonist therapy on bone health: implications in the management of prostate cancer

Osteoporosis is a complication that may be associated with long-term androgen deprivation therapy (ADT) in men with prostate cancer. Androgen deprivation increases bone resorption, thereby leading to a more rapid decrease of bone mineral density (BMD) at multiple skeletal sites as compared with age-matched healthy men. ADT has been associated with an increased risk of skeletal fracture in several retrospective analyses. The role of androgens in maintaining bone health appears to be mediated indirectly through their conversion to estrogens, although testosterone may be an important factor in bone formation. Physicians need to be aware of the potential for osteoporosis and should inform patients of appropriate lifestyle and diet modifications, such as calcium and vitamin D supplementation, and exercise at the initiation of ADT. Evaluating BMD may become the accepted norm. Several studies suggest that bisphosphonates may be beneficial in preventing and treating osteoporosis in patients with prostate cancer. The overall benefit of ADT in men with prostate cancer will continue to improve as potential side effects, such as osteoporosis, are recognized and addressed successfully.

Relationship between age, renal function and bone mineral density in the US population

Bisphosphonate drugs for treating osteoporosis are excreted by the kidney. However, many of the major trials on efficacy and safety of the bisphophonates for treating osteoporosis excluded patients with significant renal compromise. Since both osteoporosis and renal insufficiency become more prevalent with age, it seems prudent for physicians to be aware of the prevalence of renal dysfunction in patients with osteoporosis who are candidates for treatment with bisphosphonates. Data on 13,831 men and women aged 20+ from the Third National Health and Nutrition Examination Survey, 1988-1994 (NHANES III) were used to study the occurrence of compromise in renal clearance function in men and women with osteopenia and osteoporosis. To estimate creatinine clearance (CCr), a measure of renal function, serum creatinine (sCr), weight and age were inserted into the Cockcoft-Gault (C-G) formula. The World Health Organization gender specific bone mineral density (BMD) cut-offs were used to define the populations with osteopenia and osteoporosis. For women ages 20-80+ with osteoporosis, the percent prevalence (95% CI) for mild to moderate compromise of CCr </=60 ml/min is estimated to be 85% (79%, 91%) and for severe renal compromise of CCr <35 ml/min to be 24% (19%, 29%). In women with osteoporosis and severe compromise, the age specific prevalence is negligible through ages 50-59 and then rises steeply to 54% (46%, 62%) for ages 80+. Similarly, in women with osteopenia and severe renal compromise, the age specific prevalence is also negligible through ages 50-59 and then rises to 37% (28%, 45%) for ages 80+. Lower prevalence estimates hold for men with about 11% of men with osteoporosis having severe renal compromise as compared to 24% for women. These data suggest that there is a substantial prevalence of candidates for treatment of osteoporosis and osteopenia who have significant renal compromise but for whom there is a dearth of clinical trial data on the impact of treatment.

Controversies in adolescent hormonal contraception

Unintended pregnancy and abortion rates among US adolescents remain high although hormonal contraception is safe and effective in this population. Controversies affecting the provision of hormonal contraception for adolescents include the side effects of oral contraceptives, the possibility that progestin-only injectables lead to decreased bone health, and debate as to whether emergency contraception should be available to teens without a prescription. Each of these issues is addressed with a review of relevant literature.

Hip fractures among the elderly: causes, consequences and control

This review examines all pertinent literature sources published in the English language between 1966 to the present concerning hip fracture epidemiology, hip fracture injury mechanisms, and hip fracture management strategies. These data reveal hip fractures have several causes, but among these, the impact of falls and muscle weakness, along with low physical activity levels seems to be the most likely explanation for the rising incidence of hip fracture injuries. Related determinants of suboptimal nutrition, drugs that increase fall risk and lower the safety threshold and comorbid conditions of the neuromuscular system may also contribute to hip fracture disability. A number of interventions may help to prevent hip fracture injuries, including, interventions that optimize bone mass and quality, interventions that help prevent falls and falls dampening interventions. Rehabilitation outcomes may be improved by comprehensive interventions, prolonged follow-up strategies and ensuring that all aging adults enjoy optimal health.

Identifying postmenopausal women at high risk of fracture in populations: a comparison of three strategies

OBJECTIVES

To describe the prevalence of risk factors for women at high risk of fracture in a population-based sample of postmenopausal women who were not using hormone replacement therapy (HRT), to demonstrate how the estimated prevalence of women at high risk of future fracture is affected by the different criteria used for classification, and to characterize the populations identified and missed by each of the criteria. A key study objective was to compare the proportion of postmenopausal women at high risk of fracture in a managed care population using several different definitions of who is at high risk.

DESIGN

The Osteoporosis Population-based Risk Assessment study, a randomized trial of three screening strategies.

SETTING

Conducted at Group Health Cooperative in western Washington state.

PARTICIPANTS

Women aged 60 to 79 who had not used HRT for at least 12 months were chosen at random.

MEASUREMENTS

In one of the trial arms, 428 women had their bone mineral density (BMD) measured at the hip and spine (L1-L4) using dual energy x-ray absorptiometry. Minimum t scores and z scores at all sites were used for classification. Risk factors for fractures were assessed at the time of the BMD scan.

RESULTS

Guidelines based on the Study of Osteoporotic Fractures classified 25.1% of the women as being at high risk of fracture, compared with 30.0% and 68.0% using World Health Organization (WHO) recommendations and National Osteoporosis Foundation guidelines, respectively. Classification based on low BMD alone (WHO) failed to include more than 50% of women who had already experienced a clinical fracture.

CONCLUSIONS

Prevalence of women at high risk of fracture not using HRT varies notably depending on the criteria used for identification. The criteria used to identify women to target for primary and secondary prevention of osteoporotic fractures has major implications for population-based prevention strategies.

Adolescent issues in epilepsy

Approximately one third of new cases of epilepsy have their onset before age 20 years. Many children will enter adolescence with epilepsy or have an onset of seizures during adolescence. Adolescence is a time of dramatic change in growth, hormonal, psychologic, and social situations. Seizure frequency, teenage pregnancy, driving, and alcohol and drug use often become major issues during the adolescent years. Furthermore, adolescents often have difficulty accepting the chronicity of epilepsy and complying with medications, which can result in physical injury and perceived or real obstacles to employment, thereby contributing to low morale. Both pediatricians and neurologists should be aware of adolescent issues in epilepsy.

A national random survey of bone mineral density reporting in the United States

The rapidly evolving technology of bone mineral density (BMD) testing has revolutionized the clinical care of osteoporosis; however, at present, there are no guidelines for BMD reporting. A survey was mailed to a random sample of bone densitometry centers in the United States registered in the National Osteoporosis Foundation database in order to evaluate the practice of BMD reporting in the United States. Of the 1200 questionnaires mailed, 22.5% were completed and returned. Spine and hip BMD were routinely measured at 71% of the centers and were expressed as T-scores by 90% of centers. The World Health Organization working group definition of osteoporosis was included in the report by 64% of the survey responders and was used as the sole criterion to make treatment recommendations by 34%. Fracture risk was reported by 70% of the centers and only the minority (<15%) applied appropriate age and gender restrictions. There were geographic and specialty variations in the practices of bone density reporting. Despite the established value of clinical densitometry in the care of patients at risk for osteoporosis, our survey revealed that clinical information, including fracture risk, was missing from many reports. A re-examination of the practice of clinical densitometry reporting is warranted.