Executive summary International Society for Clinical Densitometry position development conference Denver, Colorado July 20-22, 2001

Assessing Change in Spine Bone Density from Different Numbers and Combinations of Lumbar Vertebrae: The Manitoba BMD Registry

INTRODUCTION

Change in bone mineral density (BMD) is considered significant when it exceeds the 95 % least significant change (LSC) derived from that facility's precision study. The lumbar spine is often affected by structural artifact such that not all four lumbar vertebrae are evaluable. Guidelines suggest using a site-matched LSC when omitting vertebrae from the BMD measurement. The current study describes significant BMD change related to intervening anti-osteoporosis treatment for different numbers and combinations of lumbar vertebrae using site-matched LSC values.

METHODOLOGY

We identified 10,526 untreated adult women mean age 59.6 years with baseline and repeat spine BMD testing (mean interval 4.7 years) where all 4 lumbar vertebrae were evaluable. Change in spine BMD for different combinations of lumbar vertebrae was assessed in relation to intervening anti-resorptive treatment, contrasting women with high treatment exposure (medication possession ratio, MPR ≥ 0.8) versus women who remained untreated. Site-matched LSC values were derived from 879 test-retest precision measurements.

RESULTS

There was consistent linear trend between increasing MPR and BMD change exceeding the LSC for all lumbar vertebral combinations, positive with BMD increase and negative with BMD decrease (all p-trend <0.001). In the high treatment exposure group, mean percent increases in spine BMD were similar for all vertebral combinations, from L1-4 to a single vertebra. In untreated women, mean percent decreases in spine BMD were also similar for all vertebral combinations. The net treatment response (proportion of women with treatment-concordant changes minus proportion with treatment-discordant changes exceeding the LSC) was 29.7 % for 4 vertebrae, 27.5-30.0 % for 3 vertebrae, 22.4-28.5 % for 2 vertebrae, and 18.1-21.9 % for a single vertebra.

CONCLUSIONS

All numbers and combinations of lumbar vertebrae, when used in conjunction with site-matched LSC values, can provide clinically meaningful follow-up in treated and untreated patients, even when spine BMD is based on a single vertebral body.

Estimating Lumbar Spine Least Significant Change for Fewer than Four Vertebrae: The Manitoba BMD Registry

INTRODUCTION

The International Society of Clinical Densitometry recommends omitting lumbar vertebrae affected by structural artifact from spine BMD measurement. Since reporting fewer than 4 vertebrae reduces spine BMD precision, least significant change (LSC) needs to be adjusted upwards when reporting spine BMD change based on fewer than 4 vertebrae.

METHODOLOGY

In order to simplify estimating LSC from combinations of vertebrae other than L1-L4 (denoted LSCL1-4 ), we analyzed 879 DXA spine scan-pairs from the Manitoba BMD Program's ongoing precision evaluation. The additional impact on the LSC of performing the second scan on the same day vs different day was also assessed.

RESULTS

LSC progressively increased when fewer vertebrae were included, and also increased when the scans were performed on different days. We estimated that the LSCL1-4 should be adjusted upwards by 7 %, 24 % and 65 % to approximate the LSC for 3, 2, or 1 vertebral body, respectively. To additionally capture the greater LSC when the precision study was done on different days, LSCL1-4 derived from a precision study where scans were done on the same day should be adjusted upwards by 39 %, 60 % and 112 % for 3, 2, or 1 vertebral body, respectively.

CONCLUSION

LSCL1-4 derived from a precision study where scans are performed on the same day can be used to estimate LSC for fewer than 4 vertebrae and for scans performed on different days.

Adjusting Trabecular Bone Score (TBS) for Level-Specific Differences Reduces FRAX®-Based Treatment Reclassification in Patients with Vertebral Exclusions: The Manitoba BMD Registry

Trabecular bone score (TBS) is a FRAX®-independent risk factor for fracture prediction. TBS values increase from cranial to caudal, with the following mean differences between TBSL1-L4 and individual lumbar vertebrae: L1 -0.093, L2 -0.008, L3 +0.055 and L4 +0.046. Excluding vertebral levels can affect FRAX-based treatment recommendations close to the intervention threshold. We examined the effect of adjusting for level-specific TBS differences in individuals with vertebral exclusions due to structural artifact on TBS-adjusted FRAX-based treatment recommendations. We identified 71,209 individuals aged ≥40 years with TBS and FRAX calculations through the Manitoba Bone Density Program. In the 24,428 individuals with vertebral exclusions, adjusting TBS using these level-specific factors agreed with TBSL1-L4 (mean difference -0.001). We compared FRAX-based treatment recommendations for TBSL1-L4 and for non-excluded vertebral levels before and after adjusting for level-specific TBS differences. Among those with baseline major osteoporotic fracture risk ≥15 %, TBS with vertebral exclusions reclassified FRAX-based treatment in 10.6 % of individuals compared with TBSL1-L4, and was reduced to 7.2 % after adjusting for level-specific differences. In 11,131 patients where L1-L2 was used for BMD reporting (the most common exclusion pattern with the largest TBS effect), treatment reclassification was reduced from 13.9 % to 2.4 %, respectively. Among individuals with baseline hip fracture risk ≥2 %, TBS vertebral exclusions reclassified 7.1 % compared with TBSL1-L4, but only 4.5 % after adjusting for level-specific differences. When L1-L2 was used for BMD reporting, treatment reclassification from hip fracture risk was reduced from 9.2 % to 5.2 %. In conclusion, TBS and TBS-adjusted FRAX-based treatment recommendations are affected by vertebral level exclusions for structural artifact. Adjusting for level-specific differences in TBS reduces reclassification in FRAX-based treatment recommendations.

Effects of Severe Lumbar Spine Structural Artifact on Trabecular Bone Score (TBS): The Manitoba BMD Registry

Trabecular bone score (TBS) is a bone mineral density (BMD)-independent risk factor for fracture. During DXA analysis and BMD reporting, it is standard practice to exclude lumbar vertebral levels affected by structural artifact. Although TBS is relatively insensitive to degenerative artifact, it is uncertain whether TBS is still useful in the presence extreme structural artifact that precludes reliable spine BMD measurement even after vertebral exclusions. Among individuals aged 40 years and older undergoing baseline DXA assessment from September 2012 to March 2018 we identified three mutually exclusive groups: spine BMD reporting performed without exclusions (Group 1, N=12,865), spine BMD reporting performed with vertebral exclusions (Group 2, N=4867), and spine BMD reporting not performed due to severe structural artifact (Group 3, N=1541). No significant TBS difference was seen for Group 2 versus Group 1 (referent), whereas TBS was significantly greater in Group 3 (+0.041 partially adjusted, +0.043 fully adjusted). When analyzed by the reason for vertebral exclusion, multilevel degenerative changes significantly increased TBS (+0.041 partially adjusted, +0.042 fully adjusted), while instrumentation significantly reduced TBS (-0.059 partially adjusted, -0.051 fully adjusted). Similar results were seen when analyses were restricted to those in Group 3 with a single reason for vertebral exclusions, and when follow up scans were also included. During mean follow-up of 2.5 years there were 802 (4.2 %) individuals with one or more incident fractures. L1-L4 TBS showed significant fracture risk stratification in all groups including Group 3 (P-interaction >0.4). In conclusion, lumbar spine TBS can be reliably measured in the majority of lumbar spine DXA scans, including those with artifact affecting up to two vertebral levels. However, TBS is significantly affected by the presence of extreme structural artifact in the lumbar spine, especially those with multilevel degenerative disc changes and/or instrumentation that precludes reliable BMD reporting.

Prevalence of Low Bone Mass and Osteoporosis in Ireland: the Dual-Energy X-Ray Absorptiometry (DXA) Health Informatics Prediction (HIP) Project

Osteoporosis is a common disease that has a significant impact on patients, healthcare systems, and society. World Health Organization (WHO) diagnostic criteria for postmenopausal women were established in 1994 to diagnose low bone mass (osteopenia) and osteoporosis using dual-energy X-ray absorptiometry (DXA)-measured bone mineral density (BMD) to help understand the epidemiology of osteoporosis, and identify those at risk for fracture. These criteria may also apply to men ≥50 years, perimenopausal women, and people of different ethnicity. The DXA Health Informatics Prediction (HIP) project is an established convenience cohort of more than 36,000 patients who had a DXA scan to explore the epidemiology of osteoporosis and its management in the Republic of Ireland where the prevalence of osteoporosis remains unknown. In this article we compare the prevalence of a DXA classification low bone mass (T-score < -1.0) and of osteoporosis (T-score ≤ -2.5) among adults aged ≥40 years without major risk factors or fractures, with one or more major risk factors, and with one or more major osteoporotic fractures. A total of 33,344 subjects met our study inclusion criteria, including 28,933 (86.8%) women; 9362 had no fractures or major risk factors, 14,932 had one or more major clinical risk factors, and 9050 had one or more major osteoporotic fractures. The prevalence of low bone mass and osteoporosis increased significantly with age overall. The prevalence of low bone mass and osteoporosis was significantly greater among men and women with major osteoporotic fractures than healthy controls or those with clinical risk factors. Applying our results to the national population census figure of 5,123,536 in 2022 we estimate between 1,039,348 and 1,240,807 men and women aged ≥50 years have low bone mass, whereas between 308,474 and 498,104 have osteoporosis. These data are important for the diagnosis of osteoporosis in clinical practice, and national policy to reduce the illness burden of osteoporosis. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Trabecular Bone Score Vertebral Exclusions Affect Risk Classification and Treatment Recommendations: The Manitoba Bmd Registry

Lumbar spine trabecular bone score (TBS), a texture measure derived from spine dual-energy x-ray absorptiometry (DXA) images, is a bone mineral density (BMD)-independent risk factor for fracture. Lumbar vertebral levels that show structural artifact are excluded from BMD measurement. TBS is relatively unaffected by degenerative artifact, and it is uncertain whether the same exclusions should be applied to TBS reporting. To gain insight into the clinical impact of vertebral exclusion on TBS, we examined the effect of lumbar vertebral exclusions in routine clinical practice on tertile-based TBS categorization and TBS adjusted FRAX-based treatment recommendations. The study population consisted of 71,209 individuals aged 40 years and older with narrow fan-beam spine DXA examinations and retrospectively-derived TBS. During BMD reporting, 34.3% of the scans had one or more vertebral exclusions for structural artifact. When TBS was derived from the same vertebral levels used for BMD reporting, using fixed L1-L4 tertile cutoffs (1.23 and 1.31 from the McCloskey meta-analysis) reclassified 17.9% to a lower and 6.5% to a higher TBS category, with 75.6% unchanged. Reclassification was reduced from 24.4% overall to 17.2% when level-specific tertile cutoffs from the software manufacturer were used. Treatment reclassification based upon FRAX major osteoporotic fracture probability occurred in 2.9% overall, but in 9.6% of those with baseline risk ≥15%. For treatment based upon FRAX hip fracture probability, reclassification occurred in 3.4% overall, but in 10.4% in those with baseline risk ≥2%. In summary, lumbar spine TBS measurements based upon vertebral levels other than L1-L4 can alter the tertile category and treatment recommendations based upon TBS-adjusted FRAX calculation, especially for those close to or exceeding the treatment cut-off. Manufacturer level-specific tertile cut-offs should be used if vertebral exclusions are applied.

Positions of The International Society for Clinical Densitometry and Their Etiology: A Scoping Review

The International Society for Clinical Densitometry convenes a Position Development Conference (PDC) every 2 to 3 years to make recommendations for guidelines and standards in the field of musculoskeletal measurement and assessment. The recommendations pertain to clinically relevant issues regarding the acquisition, quality control, interpretation, and reporting of measures of various aspects of musculoskeletal health. These PDCs have been meeting since 2002 and have generated 214 Adult, 26 FRAX, 41 pediatric, and 9 general nomenclature consideration positions, for a total of 290 positions. All positions are justified by detailed documents that present the background and rationale for each position. However, the linkage to these publications is not maintained by the ISCD or any other publication such that physicians cannot easily understand the etiology of the positions. Further, the wording of many positions has changed over the years after being reviewed by subsequent PDCs. This scoping review captures the references, changes, and timeline associated with each position through the 2019 PDC. It is meant to serve as a guide to clinicians and researchers for intelligent use and application of the positions.

Older Women who are Overweight or Obese Have Vertebral Abnormalities, Partially Degraded TBS, and BMD that Worsen with Weight Loss

Obesity is a risk factor for chronic diseases and moderate weight loss is generally recommended. Energy restriction results in the loss of hip bone mineral density (BMD) in older adults, but there is no consistent decline at the lumbar spine (LS), possibly due to vertebral abnormalities although this may also be dependent on the amount of weight loss. In this secondary analysis of weight loss trials investigating BMD and trabecular bone score (TBS) changes over 12-18 months, 92 postmenopausal women (60.8 ± 5.8 years; body mass index 32.7 ± 4.4 kg/m²) without osteoporosis, were divided into two groups: those who lost < 5% body weight (minimal) or ≥ 5% (moderate). Hip and LS-BMD and TBS were measured at baseline, 6 and 12-18 months. Exclusion of vertebral abnormalities (VE) was used to calculate BMD at the spine (LS-BMD-VE) using standard guidelines. Women lost 2.3 ± 2.4% and 8.5 ± 4.7% weight in the minimal and moderate weight loss groups, respectively. Over one third of the women had at least one vertebral abnormality or partially degraded TBS at baseline that worsened after weight loss, increasing to over 50% in this population (p < 0.05). TBS and hip BMD decreased with weight loss (p < 0.05), but LS-BMD did not decrease significantly. However, after excluding vertebral abnormalities, the LS-BMD-VE decreased in the entire population (p < 0.01), and by 1.7 ± 4.3% in the moderate weight loss group. This study suggests that older women without osteoporosis have vertebral abnormalities that obfuscated declines in BMD with weight loss, indicating that bone at the spine is further compromised.

Executive Summary of the 2019 ISCD Position Development Conference on Monitoring Treatment, DXA Cross-calibration and Least Significant Change, Spinal Cord Injury, Peri-prosthetic and Orthopedic Bone Health, Transgender Medicine, and Pediatrics

To answer important questions in the fields of monitoring with densitometry, dual-energy X-ray absorptiometry machine cross-calibration, monitoring, spinal cord injury, periprosthetic and orthopedic bone health, transgender medicine, and pediatric bone health, the International Society for Clinical Densitometry (ISCD) held a Position Development Conference from March 20 to 23, 2019. Potential topics requiring guidance were solicited from ISCD members in 2017. Following that, a steering committee selected, prioritized, and grouped topics into Task Forces. Chairs for each Task Force were appointed and the members were co-opted from suggestions by the Steering Committee and Task Force Chairs. The Task Forces developed key questions, performed literature searches, and came up with proposed initial positions with substantiating draft publications, with support from the Steering Committee. An invited Panel of Experts first performed a review of draft positions using a modified RAND Appropriateness Method with voting for appropriateness. Draft positions deemed appropriate were further edited and presented at the Position Development Conference meeting in an open forum. A second round of voting occurred after discussions to approve or reject the positions. Finally, a face-to-face closed session with experts and Task Force Chairs, and subsequent electronic follow-up resulted in 34 Official Positions of the ISCD approved by the ISCD Board on May 28, 2019. The Official Positions and the supporting evidence were submitted for publication on July 1, 2019. This paper provides a summary of the all the ISCD Adult and Pediatric Official Positions, with the new 2019 positions highlighted in bold.

Association between liver enzymes and bone mineral density in Koreans: a cross-sectional study

Background

Osteoporosis is a major health concern for both men and women, and associated fractures incur substantial economic burden. While there are a multitude of studies on bone mineral density (BMD) and liver diseases, not many studies have assessed the association between liver enzyme levels and BMD in homogeneous populations.

Methods

The current study investigated the association between serum liver enzyme levels and BMD at various sites in Koreans. Out of 21,517 surveyees of the 5th Korean National Health and Nutrition Examination Survey (2010–2012), 7160 participants’ data on BMD, serum liver enzymes, and full covariate data were included for cross-sectional analysis. BMD at the femoral neck, lumbar spine, entire femur, and whole body was assessed using dual energy X-ray absorptiometry (DEXA), and liver enzymes included aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma(γ)-glutamyl transferase (GGT) levels. Differences in participant characteristics by BMD and liver enzyme levels were analyzed, and complex sample design regression analysis adjusted for multiple covariates was performed to assess the relationship between liver enzymes and BMD.

Results

Negative associations were seen with GGT and BMD at all sites (P ≤ 0.02), ALT with lumbar spine (P = 0.0013), and AST with lumbar BMD (P = 0.0009). In particular, GGT presented strong negative associations with BMD in postmenopausal women and elder men.

Conclusions

This study demonstrates a negative relationship between liver enzyme levels and BMD, and suggests that a significant association exists between osteoporosis/decreased BMD and liver disorders.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2322-1) contains supplementary material, which is available to authorized users.

Opportunistic Screening for Osteoporosis Using Computed Tomography: State of the Art and Argument for Paradigm Shift

PURPOSE OF REVIEW

Osteoporosis is disproportionately common in rheumatology patients. For the past three decades, the diagnosis of osteoporosis has benefited from well-established practice guidelines that emphasized the use of dual x-ray absorptiometry (DXA). Despite these guidelines and the wide availability of DXA, approximately two thirds of eligible patients do not undergo testing. One strategy to improve osteoporosis testing is to employ computed tomography (CT) examinations obtained as part of routine patient care to "opportunistically" screen for osteoporosis, without additional cost or radiation exposure to patients. This review examines the role of opportunistic CT in the evaluation of osteoporosis.

RECENT FINDINGS

Recent evidence suggests that opportunistic measurement of bone attenuation (radiodensity) using CT has sensitivity comparable to DXA. More importantly, such an approach has been shown to predict osteoporotic fractures. The paradigm shift of using CTs obtained for other reasons to opportunistically screen for osteoporosis promises to substantially improve patient care.

The history of bone densitometry

Bone densitometry (dual energy x-ray absorptiometry-DXA) is a vital medical tool needed for the diagnosis of osteoporosis in non-fractured patients; predicting future fracture risk; and monitoring bone mineral density (BMD) in untreated or treated patients. The history of the pivotal international society involved in the science and clinical interpretation of DXA, the International Society for Clinical Densitometry (ISCD) is defined in this manuscript. Since DXA and Osteoporosis management are intimately linked, the ISCD has over the years developed strong bonds with both the National Osteoporosis Foundation (NOF) and the International Osteoporosis Foundation (IOF). The positive impact that ISCD has led in the proper performance and clinical interpretation of bone mass measurements has been enormous worldwide.

Best Practices for Dual-Energy X-ray Absorptiometry Measurement and Reporting: International Society for Clinical Densitometry Guidance

Dual-energy X-ray absorptiometry (DXA) is a technology that is widely used to diagnose osteoporosis, assess fracture risk, and monitor changes in bone mineral density (BMD). The clinical utility of DXA is highly dependent on the quality of the scan acquisition, analysis, and interpretation. Clinicians are best equipped to manage patients when BMD measurements are correct and interpretation follows well-established standards. Poor-quality acquisition, analysis, or interpretation of DXA data may mislead referring clinicians, resulting in unnecessary diagnostic evaluations, failure to evaluate when needed, inappropriate treatment, or failure to provide medical treatment, with potentially ineffective, harmful, or costly consequences. Misallocation of limited healthcare resources and poor treatment decisions can be minimized, and patient care optimized, through meticulous attention to DXA instrument calibration, data acquisition and analysis, interpretation, and reporting. This document from the International Society for Clinical Densitometry describes quality standards for BMD testing at DXA facilities worldwide to provide guidance for DXA supervisors, technologists, interpreters, and clinicians. High-quality DXA testing is necessary for correct diagnostic classification and optimal fracture risk assessment, and is essential for BMD monitoring.

Executive Summary of the 2015 ISCD Position Development Conference on Advanced Measures From DXA and QCT: Fracture Prediction Beyond BMD

There have been many scientific advances in fracture risk prediction beyond bone density. The International Society for Clinical Densitometry (ISCD) convened a Position Development Conference (PDC) on the use of dual-energy X-ray absorptiometry beyond measurement of bone mineral density for fracture risk assessment, including trabecular bone score and hip geometry measures. Previously, no guidelines for nonbone mineral density DXA measures existed. Furthermore, there have been advances in the analysis of quantitative computed tomography (QCT) including finite element analysis, QCT of the hip, DXA-equivalent hip measurements, and opportunistic screening that were not included in the previous ISCD positions. The topics and questions for consideration were developed by the ISCD Board of Directors and the Scientific Advisory Committee and were designed to address the needs of clinical practitioners. Three task forces were created and asked to conduct comprehensive literature reviews to address specific questions. The task forces included participants from many countries and a variety of interests including academic institutions and private health care delivery organizations. Representatives from industry participated as consultants to the task forces. Task force reports with proposed position statements were then presented to an international panel of experts with backgrounds in bone densitometry. The PDC was held in Chicago, Illinois, USA, contemporaneously with the Annual Meeting of the ISCD, February 26 through February 28, 2015. This Executive Summary describes the methodology of the 2015 PDC on advanced measures from DXA and QCT and summarizes the approved official positions. Six separate articles in this issue will detail the rationale, discussion, and additional research topics for each question the task forces addressed.

Could the bone mineral density (T-score) be correlated with the Raman spectral features of keratin from women's nails and be used to predict osteoporosis?

Osteoporosis is a disease with great importance in current public health due to the associated risk of fracture; therefore, a rapid and accurate diagnosis becomes increasingly important. Recent literature has described a possible relationship between the changes in the organic phase of bone and the changes in nail keratin measured through Raman spectroscopy, aiming at the development of a standard for measuring bone quality and fracture risk both rapid and accurately. This work evaluated the correlation between the bone mineral density (BMD) scores of women with and without osteoporotic disease with the changes in the Raman spectra of the nail keratin, by assessing the intensity of the peak at 510 cm(-1) (S-S bridge) and the scores of principal component analysis (PCA), correlated with the values of BMD measured at the lumbar and hip. Raman spectra of ex vivo fingernails of 213 women were obtained by means of a dispersive Raman spectrometer (830 nm, 300 mW, in the spectral range between 400 and 1,800 cm(-1)). Peak intensities at ∼510 cm(-1) (assigned to the keratin S-S bridge) were measured, and the scores of first principal component loading vectors were calculated. Results showed no differences in the mean Raman spectra of nails of groups with and without osteoporosis. No correlation was found between the BMD scores and both the intensities of the 510 cm(-1) peak and the scores of the first four principal component vectors. Results suggest that BMD and fracture risk could not be assessed by the nail keratin features.

Factor analysis of biochemical markers associated with bone mineral density in adults

[Purpose] The aim of this study was to find biochemical markers related to low bone mineral density in Korean adults. [Subjects and Methods] From August 1 to September 15, 2013, subjects receiving medical checkups were classified as lumbar spine bone normal, osteopenic, or osteoporotic using a bone mineral densitometer. Next, age, body mass index, and biochemical parameter differences were compared among the three groups. [Results] The results revealed that, the relevant factors were maximum blood pressure, minimum blood pressure, bone mineral density, total bilirubin, alkaline phosphatase (ALP), fasting blood glucose, iron, neutrophils, monocytes, and eosinophils. The bone mineral density of patients with osteoporosis was 0.763 times lower than that of normal subjects. The total bilirubin level of patients with osteoporosis was 0.45 times lower than that of normal subjects. The alkaline phosphatase level of patients with osteopenia was 1.059 times higher than that of normal subjects, and that in patients with osteoporosis was 1.088 times higher than that in normal subjects. The fasting blood glucose level of patients with osteoporosis was 0.963 times lower than that of normal subjects. The iron level of patients with osteoporosis was 0.986 times lower than that of normal subjects. [Conclusion] In conclusion, osteoporosis is a representative disease in elderly women due to aging and menopause, and more active interest should be taken for prevention and treatment.

Quality Control of DXA System and Precision Test of Radio-technologists

The image quality management of bone mineral density (BMD) is the responsibility and duty of radio-technologists who carry out examinations. However, inaccurate conclusions due to the lack of understanding and ignorance regarding the methodology of image quality management can be a fatal error to patients. The accuracy and precision of BMD measurement must be maintained at the highest level so that actual biological changes can be detected with even slight changes in BMD. Accuracy and precision should be continuously preserved for image quality of machines. Those factors will contribute to ensure the reliability of BMD examination. The enforcement of proper quality control of radiologists performing BMD inspections which brings about the durability extensions of equipment and accurate results of calculations will help the assurance of reliable inspections.

Executive summary of the 2013 International Society for Clinical Densitometry Position Development Conference on bone densitometry

The International Society for Clinical Densitometry (ISCD) convenes a Position Development Conference (PDC) every 2-3 yr to make recommendations for guidelines and standards in the field of musculoskeletal measurement and assessment. The recommendations pertain to clinically relevant issues regarding the acquisition, quality control, interpretation, and reporting of various aspects of musculoskeletal health metrics. Topics for consideration are developed by the ISCD Board of Directors and the Scientific Advisory Committee. For the 2013 PDC, body composition analysis was a central topic area for the first time and considered timely because of the scientific advances in measurement of fat and lean body mass by dual-energy X-ray absorptiometry (DXA). Indications for DXA and vertebral fracture assessment and use of reference data to calculate bone mineral density T-scores were also updated. Task Forces for each of these areas were assigned questions of relevance to a clinical audience and asked to conduct comprehensive literature reviews. Reports with proposed Position Statements were then presented to an international panel of experts. The Expert Panel included representatives of the International Osteoporosis Foundation, the American Society for Bone and Mineral Research, the National Osteoporosis Foundation, Osteoporosis Canada, and the North American Menopause Society. The PDC was held in Tampa, FL, contemporaneously with the Annual Meeting of the ISCD, March 21 through March 23, 2013. This report describes the methodology of the 2013 ISCD PDC and summarizes the results of the 2013 ISCD PDC for vertebral fracture assessment/DXA and National Health and Nutrition Survey (NHANES) Reference Database Task Forces. A separate article in this issue will summarize the results of the Body Composition Analysis Task Forces.

Executive summary of the 2013 International Society for Clinical Densitometry Position Development Conference on Body Composition

There have been many scientific advances in measurement of fat and lean body mass as determined by dual-energy X-ray absorptiometry (DXA). The International Society for Clinical Densitometry (ISCD) convened a Position Development Conference (PDC) on the use of DXA for body composition measurement. Previously, no guidelines to the use of DXA for body composition existed. The recommendations pertain to clinically relevant issues regarding DXA indications of use, acquisition, analysis, quality control, interpretation, and reporting were addressed. The topics and questions for consideration were developed by the ISCD Board of Directors and the Scientific Advisory Committee and were designed to address the needs of clinical practitioners. Three Task Forces were created and assigned these questions and asked to conduct comprehensive literature reviews. The Task Forces included participants from 6 countries and a variety of interests including academic institutions, private clinics, and industry. Reports with proposed Position Statements were then presented to an international panel of experts with backgrounds in DXA and bone densitometry and a variety of fields that use body composition measures. The PDC was held in Tampa, FL, contemporaneously with the Annual Meeting of the ISCD, March 21 through March 23, 2013. This report describes the methodology of the 2013 ISCD Body Composition PDC and summarizes the results. Three separate articles in this issue will detail the rationale, discussion, and additional research topics for each question the Task Forces addressed.

Goal-directed treatment of osteoporosis

Drug treatment for osteoporosis typically begins with an oral bisphosphonate, regardless of initial bone mineral density (BMD) or fracture risk, and decisions to continue or change treatment are often based on evidence of response to treatment based on changes in BMD, bone turnover markers, and occurrence of fractures. This pattern differs from preventive therapy for other conditions, such as hypertension, where treatment is based on achieving a goal. We propose that a goal be established to guide treatments to reduce fracture risk. The goal could be a certain risk of fracture or level of BMD. Goal-directed treatment would individualize the initial choice of treatment based on the probability that alternatives would achieve the patient's goal. In contrast to changing treatments based on years of use or failure to respond, the patient's BMD and risk would be reassessed periodically and decisions to stop or change treatment would be based on achieving or maximizing the chance of reaching an acceptable level of fracture risk or BMD. The acceptance of goal-directed treatment and application to practice will require a consensus on a number of issues about goals along with models of fracture risk while on treatment and probabilities of achieving goals. The result could be more rational and effective use of the expanding array of treatments for osteoporosis.

Joint Official Positions of the International Society for Clinical Densitometry and International Osteoporosis Foundation on FRAX(®). Executive Summary of the 2010 Position Development Conference on Interpretation and use of FRAX® in clinical practice

The International Society for Clinical Densitometry (ISCD) and the International Osteoporosis Foundation (IOF) convened the FRAX(®) Position Development Conference (PDC) in Bucharest, Romania, on November 14, 2010, following a two-day joint meeting of the ISCD and IOF on the "Interpretation and Use of FRAX(®) in Clinical Practice." These three days of critical discussion and debate, led by a panel of international experts from the ISCD, IOF and dedicated task forces, have clarified a number of important issues pertaining to the interpretation and implementation of FRAX(®) in clinical practice. The Official Positions resulting from the PDC are intended to enhance the quality and clinical utility of fracture risk assessment worldwide. Since the field of skeletal assessment is still evolving rapidly, some clinically important issues addressed at the PDCs are not associated with robust medical evidence. Accordingly, some Official Positions are based largely on expert opinion. Despite limitations inherent in such a process, the ISCD and IOF believe it is important to provide clinicians and technologists with the best distillation of current knowledge in the discipline of bone densitometry and provide an important focus for the scientific community to consider. This report describes the methodology and results of the ISCD-IOF PDC dedicated to FRAX(®).

2008 Santa Fe Bone Symposium: update on osteoporosis

The Ninth Annual Santa Fe Bone Symposium was held on August 1-2, 2008, in Santa Fe, New Mexico, USA. The symposium faculty presented the current best evidence on selected topics of clinical relevance in the fields of osteoporosis, metabolic bone disease, and assessment of skeletal health. The educational venues were in the form of didactic presentations, panel discussions, challenging cases, and numerous interactive discussions. Knowledge of basic science and clinical trials was applied to real-world patient scenarios that were discussed by faculty experts and clinician participants. Topics included an update on the rationale and development of new agents for the treatment of osteoporosis, the use of bone turnover markers in clinical practice, hospital-based pathways for the management of hip fracture patients, injectable bisphosphonates for the treatment of osteoporosis, combination therapy with anabolic and antiresorptive agents, and assessment of skeletal health with devices other than central dual-energy X-ray absorptiometry. This is a collection of scientific essays based on presentations and discussions at the 2008 Santa Fe Bone Symposium.

Report of the International Society for Clinical Densitometry 2007 Adult Position Development Conference and Official Positions

The International Society for Clinical Densitometry (ISCD) periodically holds Position Development Conferences (PDCs) for the purpose of establishing standards and guidelines for the assessment of skeletal health -- the nomenclature, indications, acquisition, analysis, quality control, interpretation, and reporting of bone density tests. Topics are selected for consideration according to criteria that include clinical relevancy, uncertainty in the application of medical evidence to clinical practice, and the likelihood of the expert panel achieving agreement. The most recent Adult PDC was held July 20 to 22, 2007, in Lansdowne, Virginia. Topics included technical and clinical issues relevant to dual-energy x-ray absorptiometry (DXA), vertebral fracture assessment, and bone densitometry technologies other than central DXA. This report describes the methodology and presents the results of this PDC. The first ISCD Pediatric PDC was held June 20 to 21, 2007 in Montreal, Quebec, Canada, and is reported separately.

International Society for Clinical Densitometry 2007 Adult and Pediatric Official Positions

The International Society for Clinical Densitometry (ISCD) periodically convenes Position Development Conferences (PDCs) in order to establish standards and guidelines for the assessment of skeletal health. The most recent Adult PDC was held July 20-22, 2007, in Lansdowne, Virginia, USA; the first Pediatric PDC was June 20-21, 2007 in Montreal, Quebec, Canada. PDC topics were selected according to clinical relevancy, perceived need for standardization, and likelihood of achieving agreement. Each topic area was assigned to a task force for a comprehensive review of the scientific literature. The findings of the review and recommendations were presented to adult and pediatric international panels of experts. The panels voted on the appropriateness, necessity, quality of the evidence, strength, and applicability (worldwide or variable according to local requirements) of each recommendation. Those recommendations that were approved by the ISCD Board of Directors become Official Positions. This is a review of the methodology of the PDCs and selected ISCD Official Positions.

Special report on the 2007 adult and pediatric Position Development Conferences of the International Society for Clinical Densitometry

The International Society for Clinical Densitometry (ISCD) conducts Position Development Conferences (PDCs) for the purpose of establishing standards and guidelines in the field of bone densitometry. Topics for consideration are selected according to clinical relevance, a perceived need for standardization, and the likelihood of achieving agreement. Questions regarding nomenclature, indications, acquisition, analysis, quality control, interpretation, and reporting of bone density tests for each topic area are assigned to task forces for a comprehensive review of the scientific literature. The findings of the review and recommendations are then presented to an international panel of experts at the PDC. The expert panel votes on potential Official Positions for appropriateness, necessity, quality of the evidence, strength of the recommendation, and applicability (worldwide or variable according to local requirements). Recommendations that are approved by the ISCD Board of Directors become Official Positions. The first Pediatric PDC was 20-21 June 2007 in Montreal, QC, Canada. The most recent Adult PDC was held 20-22 July 2007, in Lansdowne, VA, USA. This Special Report summarizes the methodology of the ISCD PDCs and presents selected Official Positions of general interest.

Official Positions of the International Society for Clinical Densitometry and executive summary of the 2007 ISCD Position Development Conference

The International Society for Clinical Densitometry (ISCD) convenes a Position Development Conference (PDC) every 2 yr to make recommendations for standards in the field of bone densitometry. The recommendations are based on clinically relevant issues in bone densitometry such as quality control, acquisition, analysis, interpretation and reporting. Topics for consideration are developed by the ISCD Board of Directors and its Scientific Advisory Committee. Clinically relevant questions related to each topic area are assigned to task forces for a comprehensive review of the medical literature and subsequent presentation of the reports to an international panel of experts. For this PDC, the Expert Panel included representatives of the American Society for Bone and Mineral Research, International Bone and Mineral Society and the National Osteoporosis Foundation. The recommendations of the PDC Expert Panel are then reviewed by the ISCD Board of Directors. Recommendations that are approved become Official Positions of the ISCD. The most recent PDC was held July 20-22, 2007, in Lansdowne, Virginia, USA. Topics considered included vertebral fracture assessment, technical and clinical issues relevant to dual-energy X-ray absorptiometry (DXA), and bone densitometry technologies other than central DXA. This report describes the methodology and the results of the Lansdowne, Virginia, USA 2007 PDC, and a summary of all ISCD Official Positions, including the ones recently adopted by this PDC and the 2007 Pediatric PDC held in Montreal, Quebec, Canada.

First update of the Lebanese guidelines for osteoporosis assessment and treatment

With the demographic explosion, the human, social, and economic costs of osteoporosis in developing countries, including the Middle East, will continue to rise. In 2002, the Lebanese Guidelines for Osteoporosis Assessment and Treatment were developed to optimize quality of osteoporosis care in Lebanon and the region. They were endorsed by 5 Lebanese medical scientific societies, and by the Eastern Mediterranean Regional Office branch of the World Health Organization (WHO). In April 2006, the Lebanese Society for Osteoporosis and Metabolic Bone Disorders (OSTEOS) led an initiative to update several recommendations detailed in the original document, based on relevant new local and international data. Data from a population-based sample of elderly Lebanese validated the following recommendations: fracture risk assessment, expressed as relative risk per standard deviation (RR/SD) decrease, was comparable in Lebanese subjects to similarly derived estimates from Western studies; the use of the NHANES database (hip), and the densitometer American database (spine) was as good, if not superior to the use of a Lebanese database for identifying subjects with prevalent vertebral fractures. The original recommendation regarding the use of a gender-specific western database, densitometer for spine and NHANES for T-score derivation for men, remains unchanged. For skeletal site selection, the update recommends measuring the spine and hip for women < or =65 yr, hip only for subjects >65 yr, and adding the forearm in conditions associated with cortical bone loss or in the case of inability to measure axial sites. The original recommendations for conservative management in premenopausal women were reiterated. This First Update of the Lebanese Osteoporosis Guidelines validates previous recommendations using evidence from a population-based sample of elderly Lebanese, and lays the ground for transitioning the Lebanese Osteoporosis Guidelines to the WHO global fracture risk assessment model.

Vertebral fracture risk and impact of database selection on identifying elderly Lebanese with osteoporosis

The International Osteoporosis Foundation recommends using a universal database i.e. the NHANES database for the diagnosis of osteoporosis. Population-based databases for T-score calculation are still debated in terms of clinical and public health relevance. The current study aimed at estimating the prevalence of vertebral fractures in the Lebanese elderly, determining BMD-fracture relationship, and assessing the effect of database selection on osteoporosis prevalence and fracture risk assessment. Apparently healthy subjects were randomly selected from the Greater Beirut area - one-third of the Lebanese population at large - using a multilevel cluster technique. Subjects with medical conditions likely to affect bone metabolism i.e. history of major chronic disease, intake of medications that affect bone metabolism were excluded. Presence of vertebral fracture was estimated by a semi-quantitative assessment. Bone density was measured by central DXA. Clinical risk factors included age, gender, height, weight, body mass index, smoking, exercise, falls, previous fragility fracture and family history of fragility fracture. Impact of database selection was assessed by: (1) Comparison of sensitivity and specificity for prevalent vertebral fractures of the T-score <or= - 2.5 threshold using local versus NHANES database. (2) Comparison of estimates for fracture risk (RR/SD decrease in BMD) using local versus NHANES database. Prevalence of vertebral fractures was estimated at 19.9% [15.4-25.0] in women and at 12.0% [7.3-18.3] in men. Prevalence of osteoporosis by DXA using total hip was 33.0% [27.5-38.8] in women and 22.7% [16.2-30.2] in men. The NHANES database provided higher sensitivity for vertebral fracture than our population-specific database. RR of vertebral fracture per SD decrease in BMD remained unchanged across the two databases. In women, RR/SD were 1.61 [1.17-2.23] and 1.49 [1.14-1.95] in the NHANES and the local database, respectively, and in men 1.59 [0.94-2.72] and 1.43 [0.95-2.16]. In conclusion, our findings were in concordance with the IOF recommendations for the use of a universal database and could be used for the implementation of a unified fracture risk assessment paradigm along with the WHO initiative.

Monitoring osteoporosis therapies

Postmenopausal osteoporosis (PMO) is a progressive disease of bone loss, fractures, or both. The progression of osteoporosis leads to increased mortality and morbidity and impairs quality of life. There are effective treatments that prevent bone loss, increase bone strength, and reduce fracture risk. Improvement in persistence and adherence to therapy leads to better clinical outcomes. The management of PMO is facilitated by measuring surrogate markers of the efficacy of PMO treatments: 1) bone mineral density, 2) bone turnover markers, and 3) assessment of spinal integrity by vertebral fracture assessment by dual-energy x-ray absorptiometry. Appropriate use of markers measures the patient's baseline fracture risk and monitors response to treatments. Clinicians must interpret markers in the context of a patient's fracture risk and determine the effectiveness of therapy. Integrating these markers enhances overall patient care. The surrogate markers help the clinician to achieve the goal of managing PMO; attempting to manage PMO without markers reduces the clinical management to guesswork.

Race/ethnicity and fracture risk assessment: an issue that is more than skin deep

The study of race/ethnicity in relation to health outcomes and health disparities is of great importance in medicine. This is as true in the field of osteoporosis as it is in others, and it comes into sharp focus when the question of population-specific reference data for bone densitometry arises. Race/ethnicity can be viewed as both an ecosocial construct and as a biomedical concept. Whether or not, and how, to use race/ethnicity in fracture assessment potentially places these two paradigms in opposition. In this article, some of the issues that need to be considered to develop a rational approach to reference data selection and a globally acceptable measure of fracture risk are reviewed. Race/ethnicity is often a proxy for other disease-related risk factors. Understanding fundamental risk factors goes beyond the language of race/ethnicity.

Nonprogression of vertebral area or bone mineral content on DXA does not predict compression fractures

The 2003 International Society for Clinical Densitometry consensus guidelines recommend exclusion of vertebral bodies for lack of increase in bone area (BA) or bone mineral content (BMC), or an unusual T-score discrepancy (>1 standard deviation [SD]) between adjacent vertebrae. It is unclear how often nonprogression in BA, BMC, and T-score discrepancies predicts abnormal vertebral morphology, such as compression fractures. We prospectively studied 101 individuals sent for clinical dual-energy X-ray absorptiometry (DXA) scanning, including 20.8% males and 79.2% females. The population was 85% Caucasian, 13% African-American, and 3% Hispanic. The mean age was 65.6 yr; 20.2% were currently on steroids and 22.7% were taking drugs for osteoporosis. All subjects underwent the usual posteroanterior (PA) spine DXA scan PA and lateral vertebral fracture analysis (VFA). The presence of vertebral compression fractures and/or scoliosis of the lumbar spine by VFA were correlated with nonprogression of area or BMC, and/or a difference of >1 SD in T-scores using Fisher's exact test. By VFA, we detected 22 lumbar compression fractures among 101 subjects, which was 16% of the population. Nonprogression of BA, BMC, and T-score discrepancy were not statistically associated with the presence of vertebral compression fracture as assessed by VFA. Thirty percent of subjects had lumbar spine scoliosis. The presence of scoliosis was significantly related to a T-score discrepancy at L1-L4.

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.

Photon absorptiometry, bone densitometry and the challenge of osteoporosis

During the lifetime of Physics in Medicine and Biology, osteoporosis has been recognized as the cause of a major health burden for societies, particularly within developed countries. The health detriment is associated with the consequences of bone fractures and the subsequent increases in morbidity and mortality. Much of the credit for the current availability of means for identifying groups of subjects at risk of fracture and the provision of means for the effective treatment of excessive bone loss can be attributed to the technique of dual photon absorptiometry. In this review, the history of the development of techniques based on the interactions of x- and gamma-rays with bone is considered and the ultimate dominance of x-ray based absorptiometry is described. The advantages and disadvantages of current absorptiometric techniques are presented and the likely future path for bone measurement is outlined.

Application of the 1994 WHO classification to populations other than postmenopausal Caucasian women: the 2005 ISCD Official Positions

In 2003, the International Society for Clinical Densitometry (ISCD) developed Official Positions regarding the applicability of the World Health Organization (WHO) classification of bone mineral density to populations other than postmenopausal women. However, these prior Official Positions do not fully address bone mineral density reporting in females prior to menopause, men, and non-whites. During the 2005 ISCD Position Development Conference, members of the ISCD Expert Panel in conjunction with the ISCD Scientific Advisory Committee re-addressed these topics and, based upon stringent reviews of best available data, developed ISCD Official Positions that provide greater specificity and clarification with respect to the following: (1) the utility of the term 'osteopenia'; (2) utilization of T- and Z-scores for bone mineral density reporting; (3) when to apply the WHO densitometric classification; and (4) which normative database(s) should be used for non-white individuals. Briefly, the term "osteopenia" is retained, but 'low bone mass' or 'low bone density' is preferred. Z-scores, not T-scores, are preferred in females prior to menopause and males under age 50. In these individuals, a Z-score of -2.0 or lower is defined as "below the expected range for age" and a Z-score above -2.0 is "within the expected range for age." T-scores are preferred and the WHO classification is applicable for postmenopausal women and men age 50 and older. These Official Positions, rationale and evidence are discussed in the following report.

Does vertebral height restoration achieved at vertebroplasty matter?

PURPOSE

Altered vertebral and spinal configuration after osteoporotic vertebral compression fracture (VCF) is believed to contribute to postfracture morbidity. The objective of this study was to determine whether patients in whom partial vertebral height restoration (VHR) was achieved at percutaneous vertebroplasty had greater pain relief or improved quality of life compared with patients in whom no anatomic restoration was achieved.

MATERIALS AND METHODS

Consecutive subjects undergoing percutaneous vertebroplasty for painful osteoporotic VCFs completed the Osteoporosis Quality of Life Questionnaire (OQLQ) a validated, disease specific instrument that measures health related quality of life in women with osteoporosis with back pain caused by VCF. At postoperative week 2, month 2, and month 6, all subjects completed the mini-OQLQ, a validated extraction of OQLQ. Pain was rated with a standard visual analogue scale (VAS). Radiographs were manually digitized and evaluated for the presence of dynamic mobility and VHR. The relationship between VHR achieved at percutaneous vertebroplasty and postoperative pain relief and quality of life outcome was examined by multivariate analysis.

RESULTS

Forty-six subjects (32 women) underwent 49 percutaneous vertebroplasty procedures to treat 66 painful VCFs. Mean patient age was 74.3 years+/-10.9. Mean fracture age was 2.5 months+/-2.1. Pain rating fell from 7.7+/-1.8 to 2.8+/-1.8 within 1 day of percutaneous vertebroplasty and remained improved through month 6 (P<.001). All OQLQ domains improved substantially at week 2 (P<.02) and remained improved through month 6 (P<or=.007). Preoperative dynamic mobility ranged -2.9 to 19.9 mm (average, 5.5 mm). Postoperative VHR in mobile VCFs ranged -2.1 to 9.6 mm (average, 2.9 mm). At all postoperative time points up to 6 months, pain and OQLQ domain scores were similar in patients who achieved partial VHR at percutaneous vertebroplasty compared with those in whom no VHR was achieved.

CONCLUSION

Partial vertebral height restoration achieved at percutaneous vertebroplasty did not result in additional pain relief or improved quality of life beyond cement fixation alone.

Bone density and markers of bone turnover in predicting fracture risk and how changes in these measures predict fracture risk reduction

Surrogate markers in clinical medicine provide a useful means to assess therapeutic response to pharmacologic therapy in a wide range of chronic disease states. In the area of osteoporosis, the surrogate markers of change in bone mineral density (BMD) and bone turnover markers (BTM) provide the clinician with a means of assessing the biologic response to osteoporosis-specific pharmacologic agents. Increases in BMD and/or reductions in BTM can independently be correlated to reductions in vertebral and nonvertebral fracture risk. In managing osteoporosis patients, the BTM change at an earlier point of time after initiation of therapy and a change in BTM can provide earlier feed-back to the patient and clinician regarding issues such as compliance and a bone biologic response. An increase in BMD at 12 or 24 months after initiation of therapy is also evidence of an improvement in bone strength though with antiresorptive agents no change in BMD may also be associated with risk reduction within clinical trial sets. In this regard, changes in BMD and BTM are complimentary in their application to patient management.

The tale of the T-score: review and perspective

The T-score is well known to anyone working in the field of bone densitometry. It is the primary output from a bone densitometry system and is most often used for diagnosis of osteoporosis and for making treatment decisions. Despite widespread acceptance of the T-score, most clinicians are unfamiliar with the historical evolution of the T-score as a clinical measure. Furthermore, evidence is mounting that the T-score is not the optimal diagnostic parameter for clinical decision making. Many additional risk factors have been reported which can be combined with bone density results to assess absolute fracture risk. This editorial provides an historical review of the T-score, followed by summary of the status of the T-score, and concludes with suggestions for the future use of the T-score in bone densitometry.

Forearm single X-ray absorptiometry in the identification of postmenopausal women with osteoporosis at the hip and spine: a correlation study

The International Society for Clinical Densitometry (ISCD) has stated that forearm bone mineral density (BMD) testing combined with a thorough clinical evaluation may be an option for the diagnosis of osteoporosis when central bone density (CBD) testing is not available. This study assessed the performance of two different forearm sites in identifying subjects with spinal and femoral osteoporosis, and defined the 90% sensitivity point for the DTX-100 bone densitometer in the detection of central osteoporosis. Four hundred and two postmenopausal Bulgarian women between the ages of 50 and 81 yr (mean age 60.24 +/- 10.48 yr) participated in this study. Forearm BMD (distal and ultradistal forearm) was measured with a DTX-100 device (Osteometer Meditech, USA) and central BMD (lumbar spine and proximal femur) with a Hologic QDR 4500 A device. Linear T-score correlations among sites, sensitivity and specificity of the forearm site were analyzed. T-score correlations between the forearm and the central sites ranged from 0.32 to 0.69 (p < or = 0.05 for all correlations in age group 50-59). The forearm site sensitivity increased slightly with advancing age, but specificity decreased. When the distal forearm BMD cut point (0.340 g/cm2) was set to achieve 90% sensitivity to identify total hip osteoporosis, specificity was 40%; when the distal forearm BMD cut point (0.410 g/cm2) was set to achieve 90% sensitivity to identify spinal osteoporosis, specificity was 55.4%; when ultradistal forearm BMD cut points (0.280 and 0.320 g/cm2) were set to achieve 90% sensitivity to identify total hip and spinal osteoporosis, specificity was 40.8 and 59.2%, respectively. Forearm bone density measures may be useful to selectively screen for patients with central osteoporosis.

Effect of a single course of isotretinoin therapy on bone mineral density in adolescent patients with severe, recalcitrant, nodular acne

BACKGROUND

Adverse changes in bone have been reported for patients undergoing high-dose, long-term (several years) isotretinoin therapy for disorders of cornification. The effect of short-term (4-5 months) therapy at the lower dose recommended for acne on bone development in younger, growing adolescent (12-17 years) patients has not been well studied.

OBJECTIVE

The purpose of the study was to evaluate the effect of a standard, single course of isotretinoin (Accutane) therapy on bone mineral density (BMD) of the lumbar spine and hip in adolescents ages 12 to 17 years with severe, recalcitrant, nodular acne.

METHODS

In this open-label, multicenter study, 217 adolescents (81 girls) with severe, recalcitrant, nodular acne were enrolled and treated with isotretinoin twice daily with food at the recommended total dose of approximately 1 mg/kg for 16 to 20 weeks. BMD in the lumbar spine and hip was measured at baseline and at the end of therapy by dual energy radiograph absorptiometry.

RESULTS

There was no clinically significant mean change in BMD measured at the lumbar spine (+1.4%, range: -4.9% to +12.3%) or total hip (-0.26%, range: -11.3% to +15.0%). Hyperostosis was not observed in any patient. Typical efficacy expected in the treatment of acne was observed.

CONCLUSIONS

A 16- to 20-week course of isotretinoin treatment at the recommended dose for severe acne has no clinically significant effect on lumbar spine and total hip BMD in the adolescent (12-17 years) population.

Pitfalls in bone mineral density measurements

Bone mineral density (BMD) measurements have been the single greatest advancement for osteoporosis. BMD measurements have helped define a prefracture diagnosis of osteoporosis, predict fracture risk in postmenopausal women and elderly men, and monitor the course of disease processes that negatively affect bone or therapeutic agents that can improve bone strength. Despite the large amount of clinical, epidemiologic, and basic science data that has advanced our understanding of BMD performance and interpretation, many pitfalls in BMD performance and interpretation pervade the practice of bone densitometry. However, all of these pitfalls can be overcome. Proper quality control and clinical interpretation of BMD computer printout reports are paramount for correct diagnosis, risk assessment, and serial BMD measurements. Though BMD application(s) are a clinical tool that can and should be used by many different primary care and specialty physicians, the performances and interpretations are not simple processes. Proper education and training in the use of BMD technologies provides the means of achieving the great intent that BMD measurements are capable of providing.

Use of the lowest vertebral body T-score to diagnose lumbar osteoporosis in men: is "cherry picking" appropriate?

In this study, we hypothesized that use of the lowest T-score among four lumbar vertebral bodies would lessen the impact of degenerative arthritis and other artifacts on diagnostic categorization at this site and increase study sensitivity, classifying more men with prior fracture as osteoporotic than the other two methods of lumbar spine analysis. Bone density studies of 533 male veterans measured between January and October 2002 were reviewed to determine diagnostic classification using the L1-L4 average, International Society for Clinical Densitometry (ISCD)-determined, and lowest lumbar vertebral body T-score. We calculated sensitivity and specificity of the three methods of spine analysis, using spine osteoporosis to indicate a positive test and prior fracture as the true indicator of osteoporosis. The lowest lumbar T-score performed with similar sensitivity and specificity to that of the lowest hip or wrist T-score in the ability to classify men with prior fracture as osteoporotic, whereas the average L1-L4 and ISCD-determined T-scores performed with lower sensitivity, but better specificity. In conclusion, this retrospective study suggests that use of the lowest vertebral body T-score among men increases diagnostic sensitivity of lumbar spine bone mass measurement. Prospective studies are needed to determine which of these three methods of lumbar spine analysis best predicts future fragility fracture in men and women.