An evaluation of the United Kingdom National Osteoporosis Society position statement on the use of peripheral dual-energy X-ray absorptiometry

A recent position statement issued by the UK National Osteoporosis Society recommends a triage approach to the use of peripheral dual-energy X-ray absorptiometry (pDXA) devices. Patients with a forearm T-score greater than –1 or less than –2.5 are regarded as normal or osteoporotic, respectively, while those with a T-score between –1 and –2.5 are sent for further assessment with spine and hip DXA. We have evaluated the NOS pDXA algorithm by comparing it with the alternative strategies of relying on forearm BMD alone, or performing spine and hip DXA in every patient. The evaluation was carried out using a mathematical model, and the predictions were compared with in vivo data obtained in patients referred for investigation by their general practitioner. In the model the population distribution of spine, hip, and forearm BMD was described by a trivariant Gaussian function. Relative risks of fracture were taken from a meta-analysis. The three strategies were compared using receiver operating characteristic (ROC) curves in which the percentage of future fracture cases identified was plotted against the percentage of the whole population found to have osteoporosis. ROC curves plotted for the discrimination of hip, vertebral, and Colles fracture risk and the risk of a fracture at any skeletal site were similar for all three strategies, with the curves for the NOS pDXA algorithm nearly identical to those for spine and hip DXA. For the case of hip fracture, vertebral fracture, or a fracture at any site, forearm BMD was slightly inferior to the NOS algorithm, but the reverse was true for Colles fracture. The small difference between the ROC curves suggests that forearm BMD used alone can reproduce clinical decision-making with the NOS pDXA algorithm provided that a T-score threshold of T=–2.1 is used for the diagnosis of osteoporosis, instead of the conventional figure of T=–2.5. Results from the in vivo study were in good agreement with the predictions of the model, although some differences were observed that were explained by inaccuracies in the forearm reference data. We conclude that use of forearm BMD alone with a modified T-score threshold of –2.1 would save the need for spine and hip DXA scans and identify only slightly fewer fracture cases for treatment.     

Efficient patient identification strategies for women with osteoporosis.

The purpose of this analysis was to identify efficient (highest sensitivity at each level of cost) strategies to detect osteoporosis in postmenopausal women. Our study sample consisted of 392 women (age >/=50 yr) who were retirees or active employees of a corporation. The Simple Calculated Osteoporosis Risk Estimation (SCORE) questionnaire was completed, and bone mineral density levels were collected at the forearm using peripheral dual X-ray absorptiometry (pDXA), and at the femoral neck and lumbar spine using central DXA. Osteoporotic women were those with a T-score of -2.5 or less at any one of the three skeletal sites tested. Assumed costs were $5 for SCORE, $35 for pDXA, $120 for DXA at either the hip or spine, and $200 for DXA at both the hip and spine. The analysis indicated that the current "gold standard" is inefficient relative to other strategies investigated. By comparison, a tiered strategy consisting of SCORE, pDXA, and then selective use of DXA at both the hip and spine identified 90% of the women with osteoporosis at a cost of only $106 per woman tested. In choosing among the efficient strategies, decision makers must determine the extent to which they are willing to trade off higher program cost for greater sensitivity.     

Ability of Peripheral DXA Measurements of the Forearm to Predict Low Axial Bone Mineral Density at Menopause

The aim of this study was to evaluate the ability of peripheral dual-energy X-ray absorptiometry (pDXA) measurement of the forearm to predict low axial bone mineral density (BMD) as defined according to the WHO classification. Two hundred and thirty-four healthy women aged 45-60 years were investigated. BMD was measured at the proximal and distal radius + ulna by pDXA and at the lumbar spine and femoral neck by DXA. There was a significant but moderate correlation between peripheral and axial BMD measurements, with r values ranging from 0.4 to 0.6 (SEE: 13.5-17%). The cutoff values for the proximal and distal radius BMD that allow the identification with 95% sensitivity of postmenopausal women with either a lumbar spine or femoral neck T-score < -1, corresponded to a T-score of +0.5 (proximal radius) and +1 (distal radius). More than 90% of the whole population had a peripheral T-score below these thresholds. Using an axial T-score < or = -2.5 as the definition of abnormality reduced to 48% (proximal radius) to 66% (distal radius) the number of women who would have required DXA axial measurements (i.e., with a pDXA T-score below the cutoff value of -0.7). Of the 33 women (14%) with a proximal radius T-score < or = -2.5 (osteoporosis), only 1 had a lumbar spine and femoral neck T-score > or = -1 (normal). Conversely, of the 50% (proximal radius) to 65% (distal radius) of the women with normal forearm measurement, 5% (proximal radius) to 9% (distal radius) were found to be osteoporotic and an additional 57% (proximal radius) to 59% (distal radius) could be classified as osteopenic (T-score between -1 and -2.5) at either the lumbar spine or femoral neck. In conclusion, use of pDXA forearm measurement as a prescreening tool in early postmenopausal women should allow the direct identification of about 50% of the women with no axial osteoporosis. However, this study highlights the difficulties in using a unique T-score that could be applied to different sites to diagnose osteoporosis.     

Bone Density Reduction in Various Measurement Sites in Men and Women with Osteoporotic Fractures of Spine and Hip: The European Quantitation of Osteoporosis Study

We have measured bone mineral density (BMD) using dual X-ray absorptiometry (DXA) of the spine and hip, spinal quantitative computed tomography (QCTspi), and peripheral radial quantitative computed tomography (pQCTrad) in 334 spine and 51 hip fracture patients. The standardized hip and spine BMD for each patient was calculated and compared with the combined reference ranges published previously, each densitometer having been cross-calibrated with the prototype European Spine Phantom (ESPp) or the European Forearm Phantom (EFP). Male and female fracture cases had similar BMD values after adjusting for body size, where appropriate. This suggests that the relationship between bone density (mass per unit volume) and fracture risk is similar between men and women. However, compared with age-matched controls, mean decreases in BMD ranged from 0.78 SD units (women with hip fracture, DXAspi) to 2.57 SD units (men with spine fractures, QCTspi). The proportion of spine and hip fracture patients falling below the cutoff for osteoporosis (T-score <−2.5 SD) proposed by the World Health Organization (WHO) study group varied according to different BMD measurement procedures (range 18–94%). This finding suggests that the WHO definition requires different thresholds when used with non-DXA BMD measurement techniques. Receiver operator characteristic (ROC) analysis was used to compare measurement techniques for their ability to discriminate between cases and controls. Among DXA sites, the proximal femur was preferred when evaluating generalized bone loss, particularly in elderly people. An additional spinal BMD measurement may add clinical value if spine fracture risk assessment has a high priority. Both axial and peripheral QCT techniques performed comparably to DXA in spinal osteoporosis, so investigators and clinicians may use any of the three technologies with similar degrees of confidence for the diagnosis of generalized or site-specific bone loss providing straightforward clinical guidelines are followed. Received: 21 May 1997 / Accepted: 24 June 1998     

Use of pharmacologic agents for the primary prevention of osteoporosis among older women with low bone mass

Summary

We examined the use of pharmacologic agents for the primary prevention of osteoporosis among older women with osteopenia. We found that these individuals were not managed in concordance with the National Osteoporosis Foundation (NOF) guidelines and that self-perceived osteoporosis risk and lower bone density were strongly associated with receipt of treatment.

Introduction

Although osteoporosis medications are used for the primary prevention of osteoporosis among persons with low bone mass (osteopenia), their use may be discordant with clinical practice guidelines.

Methods

We studied women 55 years and older participating in the Global Longitudinal Study of Osteoporosis in Women (GLOW). Eligible participants had a dual energy x-ray absorptiometry (DXA) test performed at the University of Alabama at Birmingham hospital and had an osteopenia diagnosis based on their DXA test results. Participants' demographics, fracture risk factors, and exposure to osteoporosis medications were determined from the GLOW survey. We examined the proportions of women managed in concordance with the National Osteoporosis Foundation 2008 guidelines, and we assessed factors independently associated with osteoporosis treatment decisions. Women with a prior spine or hip fracture were excluded.

Results

Among 597 eligible women from GLOW, the mean age ± standard deviation (SD) was 70?±?7 years. Among all subjects, 309 (52 %) were treated in concordance with the NOF 2008 guidelines. Greater self-perceived osteoporosis risk and lower bone mineral density were significantly and consistently associated with receipt of osteoporosis treatment, both for those considered appropriate and for those considered inappropriate for treatment based on the NOF guidelines.

Conclusions

We found significant discordance between NOF 2008 guidelines and pharmacologic management of women with osteopenia. A person's self-perceived osteoporosis risk and bone mineral density were most strongly associated with receipt of osteoporosis medication use among women with low bone mass.     

Bone Mineral Density Measurement at Both Spine and Hip for Diagnosing Osteoporosis in Japanese Patients

In Japan, spinal dual-energy X-ray absorptiometry (DXA) has been commonly performed for diagnosing osteoporosis but scanning the proximal femur is not done widely. The latest Japanese guidelines for prevention and treatment of osteoporosis, revised in 2006, recommend bone mineral density (BMD) measurement at both spine and hip for diagnosing osteoporosis, although there have been no reports that proved the necessity of those measurements. One thousand forty-one women and 485 men with clinical suspicion of osteoporosis were enrolled in this study, and DXA was performed at both spine and hip. The proportions of the patients who had inconsistency between diagnosis of osteoporosis from spinal DXA and that of hip were estimated. As a result, 22% of women and 15% of men had an inconsistency with the diagnosis of osteoporosis using DXA at each measurement site. There was inconsistency in diagnosing osteoporosis using DXA at the spine and proximal femur measurement sites. Because spine and femoral DXA measurements complement each other in the diagnosis of osteoporosis, BMD measurement at both spine and hip should be performed for all Japanese patients who are suspected osteoporosis, regardless of age and sex.     

Device-specific thresholds to diagnose osteoporosis at the proximal femur: an approach to interpreting peripheral bone measurements in clinical practice

INTRODUCTION: A single T score criterion cannot be universally applied to different peripheral bone measurement devices, since measurements in an identical population result in a tenfold difference in the prevalence of osteoporosis. The use of peripheral devices is increasing in clinical practice, despite the difficulties in interpreting results. We propose the use of two thresholds, which have either 95% sensitivity or 95% specificity, to identify (1) individuals who require treatment or (2) individuals who require no treatment, both based on a peripheral measurement alone, or (3) individuals who require additional central densitometry measurements. METHODS: We recruited 500 postmenopausal women, 100 premenopausal women and 279 women with proximal femoral, vertebral, distal forearm or proximal humeral fractures. All subjects underwent dual energy X-ray absorptiometry (DXA) measurements of the lumbar spine, total hip and distal forearm, quantitative computed tomography (QCT) of the distal forearm and quantitative ultrasound (QUS) of the heel (four devices), finger (two devices), radius and metatarsal. We identified the threshold for each device that identified women without osteoporosis with the same sensitivity (upper threshold set at 95%) as total hip DXA and women with osteoporosis with the same specificity (lower threshold set at 95%) as total hip DXA. Individuals between the two thresholds required additional examination by central densitometry. RESULTS: The correlation between devices varied from 0.173 (QUS finger) to 0.686 (DXA forearm) compared with total hip DXA (P<0.0001). The area under the curve (AUC) between devices varied from 0.604 (QUS finger) to 0.896 (DXA forearm) compared with total hip DXA (P<0.0001). In a population-based cohort (prevalence of osteoporosis 9.8%) the threshold approach appropriately identified between 26% (QUS heel) and 68% (DXA forearm) of subjects in whom a treatment decision could be made without additional central DXA with 95% certainty. In a fracture cohort (prevalence of osteoporosis 36%) between 16% (QUS finger) and 37% (QCT forearm) of subjects were appropriately identified. CONCLUSION: The threshold approach to interpreting peripheral bone measurements enables a substantial number of individuals with either normal bone mineral density (BMD) or osteoporosis to be selected and treated appropriately.     

An audit of bone densitometry practice with reference to ISCD, IOF and NOF guidelines

Introduction The impact of osteoporosis guidelines on clinical practice has not been fully evaluated. Objectives To estimate the positive predictive value (PPV) of the National Osteoporosis Foundation (NOF), the International Osteoporosis Foundation (IOF) and the International Society for Clinical Densitometry (ISCD) guidelines for osteoporosis and compare it to the PPV of clinical judgement alone. Methods All subjects tested for bone mineral density during the fall of 2001 in three teaching hospitals in Beirut were invited to participate. The reference databases used for the calculation of the T-score were the NHANES database for the hip and the manufacturer’s database for the spine. The impact of using guidelines was measured by the increment in PPV. Osteoporosis was defined as a T-score ≤−2.5 at either the spine or hip. Results A total of 307 post-menopausal women were tested with dual-energy X-ray absorptiometry (DXA). In current practice (clinical judgement alone), the PPV for osteoporosis was 42.4%; using NOF guidelines, 236 women would have been tested, and the PPV would have been 46.2%. Similarly, using IOF or ISCD guidelines, 236 women would have been tested, and the PPV would have been 47.1%. Conclusion Compared to current clinical practice, application of the ISCD, IOF and NOF guidelines may increase the predictive value of a central DXA for osteoporosis.     

Validation and comparative evaluation of four osteoporosis risk indexes in Moroccan menopausal women

Introduction Measuring bone mineral density (BMD) is a widely accepted strategy for identifying subjects with an increased risk of fracture. However, because of limited availability of BMD technology in some communities and cost considerations, it has been proposed that BMD measurements be targeted to subjects with risk factors for osteoporosis. Recently, many risk assessment indices have been developed to identify women who are more likely to have low BMD and thus undergo BMD testing. The objective of this study was to compare the performance of four risk indices for osteoporosis in white women in Morocco. Methods We analysed in an epidemiological cross-sectional study the records for 986 postmenopausal white Moroccan women seen at an out-patient rheumatology centre. Four osteoporosis risk index scores were compared to bone density T-scores. The ability of each risk index to identify women with low BMD (T-score<−2.0) or osteoporosis (T<−2.5) was evaluated. Results Using an Osteoporosis Self-Assessment Tool (OST) score<2 to recommend DXA referral, we found that sensitivity ranged from 61% at the lumbar spine to 85% at the total hip to detect BMD T-scores of −2.5, and specificity ranged from 62% at the lumbar spine to 67% at the total hip. The negative predictive value was high at all skeletal sites (79–98%), demonstrating the usefulness of the OST to identify patients who have normal BMD and should not receive DXA testing. All risk indices performed similarly and showed better results in identifying women with osteoporosis or low BMD based on hip measurement. Conclusions This is the first study that validated several risk osteoporosis indexes in Moroccan women. The performance of these risk indices among women in Morocco was similar to that reported earlier for other samples in Asian countries, the US, and Belgium. The OST and other risk indices are effective and efficient tools to help target high-risk women for DXA measurement.     

A Comparison of Calcaneal Dual-Energy X-Ray Absorptiometry and Calcaneal Ultrasound for Predicting the Diagnosis of Osteoporosis From Hip and Spine Bone Densitometry

Peripheral densitometry is increasingly being used in the management of osteoporosis, but the optimal diagnostic thresholds have not been defined. The aim of this study was to determine the optimal T-score for peripheral dual-energy X-ray absorptiometry (pDXA) of the heel using a GE Lunar PIXI and quantitative ultrasound (QUS) of the heel using a GE Lunar Achilles Plus when compared with dual-energy X-ray absorptiometry (DXA) of central sites (spine, femoral neck, or total hip). Ninety-nine women (mean age 69 +/- 8, range 33-86 yr) referred from the metabolic bone clinic were studied. The optimal T-score for pDXA from ROC analysis was -1.7 and for QUS was -2.5. The pDXA T-score that defined the same prevalence of osteoporosis at any central site was also -1.7 and for QUS was -2.4. These results are similar to the manufacturer's recommendations. There is no significant difference in performance between the PIXI and QUS.     

33% radius evaluation to assess bone mineral density in prostate cancer patients

Purpose

Dual-energy X-ray absorptiometry (DXA) is the standard method to assess bone mineral density (BMD). The International Society for Clinical Densitometry recommends the measurement of BMD at lumbar spine, total hip and femoral neck, but in certain circumstances the 33% radius may be the recommended area to measure BMD. The aim of this study has been to analyze whether 33% radius should be considered the recommended area to assess BMD in prostate cancer patients.

Methods

This is a retrospective study where BMD was assessed by DXA at 33% radius, lumbar spine, total hip, and femoral neck (cDXA) in 141 prostate cancer patients. Twenty-eight patients were hormone na?ve while 113 were subjected to androgen suppression (AS) during the mean period of 29?months. Osteoporosis was diagnosed when T-score was lower than ?2.5 and osteopenia when it ranged between ?1 and ?2.5.

Results

The osteoporosis rate was 29.8% at 33% radius, 23.4% at femoral neck, 19.9% at lumbar spine, and 12.8% at total hip. The overall osteoporosis rate at cDXA was 29.1%. Osteoporosis was detected in 52.2% at 33% radius and 36.2% at cDXA. Normal BMD was found in 17.7% at 33% radius and 34.8% at cDXA. The 33% radius was the only site where a significant increase in the osteoporosis rate was detected in patients subjected to AS compared to those hormone na?ve (33 and 13.8%).

Conclusions

The 33% radius seems more sensible than the central skeleton areas to detect bone mass loss in patients with prostate cancer.     

Osteoporosis case finding in the general practice: phalangeal radiographic absorptiometry with and without risk factors for osteoporosis to select postmenopausal women eligible for lumbar spine and hip densitometry

Mass screening for osteoporosis using DXA measurements at the spine and hip is presently not recommended by health authorities. Instead, risk factor questionnaires and peripheral bone measurements may facilitate the selection of women eligible for axial bone densitometry. The aim of this study was to validate a case finding strategy for postmenopausal women who would benefit most from subsequent DXA measurement by using phalangeal radiographic absorptiometry (RA) alone or in combination with risk factors in a general practice setting. The sensitivity and specificity of this strategy in detecting osteoporosis (T-score 2.5 SD at the spine and/or the hip) were compared with those of the current reimbursement criteria for DXA measurements in Switzerland. Four hundred and twenty-three postmenopausal women with one or more risk factors for osteoporosis were recruited by 90 primary care physicians who also performed the phalangeal RA measurements. All women underwent subsequent DXA measurement of the spine and the hip at the Osteoporosis Policlinic of the University Hospital of Berne. They were allocated to one of two groups depending on whether they matched with the Swiss reimbursement conditions for DXA measurement or not. Logistic regression models were used to predict the likelihood of osteoporosis versus no osteoporosis and to derive ROC curves for the various strategies. Differences in the areas under the ROC curves (AUC) were tested for significance. In women lacking reimbursement criteria, RA achieved a significantly larger AUC (0.81; 95% CI 0.72–0.89) than the risk factors associated with patients age, height and weight (0.71; 95% C.I. 0.62–0.80). Furthermore, in this study, RA provided a better sensitivity and specificity in identifying women with underlying osteoporosis than the currently accepted criteria for reimbursement of DXA measurement. In the Swiss environment, RA is a valid case finding tool for patients with risk factors for osteoporosis, especially for those who do not qualify for DXA reimbursement.     

Effect of bone strontium on BMD measurements.

Strontium ranelate is a new treatment for osteoporosis that is of interest for, among other reasons, its unusual effect on measurements of bone mineral density (BMD). When some of the calcium in bone is replaced by strontium, X-ray absorptiometry measurements of BMD are overestimated because strontium attenuates X-rays more strongly than calcium. In this study, we report the first theoretical estimation of this effect for measurements made using axial (spine and hip) dual-energy X-ray absorptiometry (DXA), peripheral DXA (pDXA), and single-energy quantitative computed tomography (SEQCT). Tables of X-ray attenuation coefficients were used to calculate values of the strontium ratio defined as the ratio of the percentage overestimation of BMD to the molar percentage of strontium (%Sr/[Ca+Sr]) in bone. For DXA measurements, the theoretical value of the strontium ratio increased slightly with increasing effective photon energy of the X-ray beam with figures of 9.0 for Osteometer DTX200 and G4 pDXA devices (Osteometer Meditech Inc., Hawthorne, CA), 10.0 for GE-Lunar DPX and Prodigy DXA systems (GE-Lunar, Madison, WI), 10.4 for Hologic QDR1000 and QDR2000, and 10.8 for Hologic QDR4500 and Discovery (Hologic Inc., Bedford, MA). Results for SEQCT also varied with the effective photon energy with strontium ratios of 6.2 at 60 keV and 4.4 at 80 keV. The results of the theoretical study are in good agreement with the experimental value of 10 reported by Pors Nielsen and colleagues for a variety of different axial DXA systems. A reliable figure for the strontium ratio is important for adjusting BMD measurements in strontium ranelate treated patients for the effect of bone strontium content. This latter correction will be required for the interpretation of future DXA scans in patients who have discontinued strontium ranelate treatment.     

Spine radiographs to improve the identification of women at high risk for fractures

Summary

In women older than 60 years with clinical risk factors for osteoporosis but without osteoporosis based on bone mineral density (T-score?≥??2.5), a systematic survey with X-rays of the spine identified previously unknown vertebral deformities in 21% of women.

Introduction

This study determines the prevalence of vertebral deformities in elderly women with clinical risk factors for osteoporosis but with BMD values above the threshold for osteoporosis (T-score?≥??2.5).

Methods

Bisphosphonate naïve women older than 60 years attending 35 general practices in the Netherlands with ≥2 clinical risk factors for osteoporosis were invited for BMD measurement (DXA). In women with T-score?≥??2.5 at both spine and the hips, lateral radiographs of the thoracic and lumbar spine were performed.

Results

Of 631 women with a DXA measurement, 187 (30%) had osteoporosis (T-score?T-score?≥??2.5 at both spine and hip, 387 had additional spine radiographs, of whom 80 (21%) had at least one vertebral deformity.

Conclusion

In elderly women with clinical risk factors for osteoporosis but BMD T-score?≥??2.5, addition of spine radiographs identified vertebral deformities in 21% (95% CI: 17–25). Since these women are at risk of future fractures, antiosteoporotic treatment should be considered.     

The Utility of Portable Dual-Energy X-Ray Absorptiometry of the Wrist in Patients Referred to a Bone Health Clinic: A Pilot Study

Fifty white female patients referred to a bone health care clinic were studied. Patients with a history of fracture were excluded. At the time of hip and spine dual-energy X-ray absorptiometry (DXA), those willing underwent portable dual-energy X-ray absorptiometry (pDXA) of the wrist. The mean age of the patients was 57 yr. Bone mineral density (BMD) assessment was performed on each patient at four different sites: posterior-anterior lumbar spine, nondominant hip, the distal radius and ulna, and the proximal radius and ulna of the nondominant arm. Comparison of the pDXA results with that of the conventional DXA results showed the highest correlation between pDXA of the distal radius and ulna (DR + U) and the DXA of the femoral neck and lumbar spine. By defining a pDXA (DR + U) T-score 相似文献   

Effect of osteoarthritis in the lumbar spine and hip on bone mineral density and diagnosis of osteoporosis in elderly men and women

To determine in the elderly the effect of osteoarthritis on bone mineral density (BMD) and on diagnosis of osteoporosis, lumbar spine and hip were radiographed and BMD measured by dual-energy X-ray absorptiometry (DXA) in 120 men and 314 women, aged 60–99 years. Prevalence and severity of osteoarthritis were scored on osteophytes, joint space narrowing and bone sclerosis. Ultrasound measurements were also made at the heel to examine whether osteoarthritis at hip or lumbar spine influence bone at this remote site. Osteophytes were the commonest feature, with men having a higher prevalence than women, and lumbar spine having more disease than hip. Lumbar spine osteophytes affected 75% of men and 61.1% of women, and hip osteophytes affected 31.7% of men and 27.4% of women. Stepwise multiple regression analysis using age, weight, height, osteophytes, sclerosis and joint space narrowing indicated that lumbar osteophytes explained 16.6% of variation in lumbar spine BMD in women, and 22.4% in men. Hip osteophytes had a minimal effect on hip BMD, accounting for only 2.2% of variation in women, and none in men. Sclerosis and joint narrowing had little effect on BMD at lumbar spine or hip. Indirect effects of osteoarthritis on BMD were small and inconsistent across genders. Lumbar spine osteophytes in men explained 3.1% of hip BMD variation and 6% of variation in speed of sound at the heel, whereas hip osteophytes in women explained 2.2% of lumbar spine BMD variation. Osteoporosis at the hip, defined as BMD <2.5 SD of the young normal mean, was present in 33.1% of women and 25.8% of men, whereas, at the lumbar spine it was present in only 24.2% of women and 4.2% of men. However, in women and men free of spinal osteoarthritis, 37.7% of women and 10% of men had osteoporosis. We conclude that lumbar spine ostoephytes affect most subjects over the age of 60 years, and contribute substantially to lumbar spine BMD measured in the anteroposterior position by DXA. The effect is largely direct by virtue of osteophytes being included in the BMD measurement. However, a small indirect effect on remote skeletal sites is also present. Diagnosis of osteoporosis and assessment of osteoporotic fracture risk in the elderly should be based on hip BMD and not on anteroposterior lumbar spine, unless spinal osteoarthritis has been excluded.     

Prediction of fracture risk in postmenopausal white women with peripheral bone densitometry: evidence from the National Osteoporosis Risk Assessment.

Low bone mineral density (BMD) is a risk factor for fracture. Although the current "gold standard" test is DXA of the hip and spine, this method is not universally available. No large studies have evaluated the ability of new, less expensive peripheral technologies to predict fracture. We studied the association between BMD measurements at peripheral sites and subsequent fracture risk at the hip, wrist/forearm, spine, and rib in 149,524 postmenopausal white women, without prior diagnosis of osteoporosis. At enrollment, each participant completed a risk assessment questionnaire and had BMD testing at the heel, forearm, or finger. Main outcomes were new fractures of the hip, wrist/forearm, spine, or rib within the first 12 months after testing. After 1 year, 2259 women reported 2340 new fractures. Based on manufacturers' normative data and multivariable adjusted analyses, women who had T scores < or = -2.5 SD were 2.15 (finger) to 3.94 (heel ultrasound [US]) times more likely to fracture than women with normal BMD. All measurement sites/devices predicted fracture equally well, and risk prediction was similar whether calculated from the manufacturers' young normal values (T scores) or using SDs from the mean age of the National Osteoporosis Risk Assessment (NORA) population. The areas under receiver operating characteristic (ROC) curves for hip fracture were comparable with those published using measurements at hip sites. We conclude that low BMD found by peripheral technologies, regardless of the site measured, is associated with at least a twofold increased risk of fracture within 1 year, even at skeletal sites other than the one measured.     

New method for point-of-care osteoporosis screening and diagnostics

Summary

Due to the lack of diagnostics in primary health care, over 75 % of osteoporotic patients are not diagnosed. A new ultrasound method for primary health care is proposed. Results suggest applicability of ultrasound method for osteoporosis diagnostics at primary health care.

Introduction

We lack effective screening and diagnostics of osteoporosis at primary health care. In this study, a new ultrasound (US) method is proposed for osteoporosis diagnostics.

Methods

A total of 572 Caucasian women (age 20 to 91 years) were examined using pulse-echo US measurements in the tibia and radius. This method provides an estimate of bone mineral density (BMD), i.e. density index (DI). Areal BMD measurements at the femoral neck (BMD_neck) and total hip (BMD_total) were determined by using axial dual-energy X-ray absorptiometry (DXA) for women older than 50 years of age (n?=?445, age?=?68.8?±?8.5 years). The osteoporosis thresholds for the DI were determined according to the International Society for Clinical Densitometry (ISCD). Finally, the FRAX questionnaire was completed by 425 participants.

Results

Osteoporosis was diagnosed in individuals with a T-score ?2.5 or less in the total hip or femoral neck (n?=?75). By using the ISCD approach for the DI, only 28.7 % of the subjects were found to require an additional DXA measurement. Our results suggest that combination of US measurement and FRAX in osteoporosis management pathways would decrease the number of DXA measurements to 16 % and the same treatment decisions would be reached at 85.4 % sensitivity and 78.5 % specificity levels.

Conclusions

The present results demonstrate a significant correlation between the ultrasound and DXA measurements at the proximal femur. The thresholds presented here with the application to current osteoporosis management pathways show promise for the technique to significantly decrease the amount of DXA referrals and increase diagnostic coverage; however, these results need to be confirmed in future studies.

     

Clinical utility of spine bone density in elderly women.

It is common clinical practice to obtain a bone density measurement at both the hip and spine to evaluate osteoporosis. With aging, degenerative changes in the lumbar spine may elevate the bone mineral density (BMD) results giving false assurances that the fracture risk at the spine is low. We examined the association of spine osteoarthritis and bone mineral density in 1082 community-dwelling ambulatory older women aged 50-96 years who participated in a 1992-1996 osteoporosis research clinic visit. The BMD was measured at the hip and posteroanterior (PA) and lateral lumbar spine using dual energy X-ray absorptiometry (DXA). Spine osteoarthritis was identified on the PA lumbar spine DXA images by a musculoskeletal radiologist. Forty percent of women had evidence of spine osteoarthritis (OA). Women with spine OA had a mean age of 77.4 yr (95% confidence interval [CI]: 76.5-78.2), were significantly older than women without spine OA (mean age, 66.8 yr; 95% CI: 65.9-67.7), and were more likely to have prevalent radiographic fractures (14.2% vs. 9.5%; p<0.05). Age-adjusted BMD at the femoral neck, total hip, PA spine, and lateral spine was significantly higher in women with spine OA. Women with spine OA were more likely to have osteoporosis by the World Health Organization classification at the femoral neck and total hip than those without spine OA, but less likely based on the PA spine (14.4% vs. 24.5%). Despite higher BMD levels, women with OA of the lumbar spine had higher prevalence of osteoporosis at the hip and more radiographic vertebral fractures. In elderly women 65 yr and older who are likely to have spine OA, the DXA measurement of the spine may not be useful in assessing fracture risk, and DXA of the hip is recommended for identification of osteoporosis.     

Role of dual-energy X-ray absorptiometry in the diagnosis and treatment of osteoporosis.

Dual energy X-ray absorptiometry (DXA) measurements of spine and hip bone mineral density (BMD) (referred to here as central DXA) have an important role as a clinical tool for the evaluation of individuals at risk of osteoporosis, and in helping clinicians give advice to patients about the appropriate use of antifracture treatment. Compared with alternative bone densitometry techniques such quantitative computed tomography (QCT), peripheral DXA (pDXA) and quantitative ultrasound (QUS), central DXA has a number of significant advantages that include a consensus that BMD results can be interpreted using the World Health Organization (WHO) T-score definition of osteoporosis, a proven ability to predict fracture risk, and proven effectiveness at targeting antifracture treatments. This review article discusses the evidence for these and other advantages of central DXA, including its role in the new WHO algorithm for treating patients on the basis of individual fracture risk.