Lunar Densitometer Research Articles

Osteocalcin, a promising marker of osteoporosis: evaluation in post-menopausal females with osteoporosis

Background: Osteocalcin, has high affinity for calcium. In osteoporotic women, deficiency of calcium may lead to lowering of the formation of hydroxyapatite crystals. Thus, in the state of hypo mineralization, free osteocalcin available in the circulation. Therefore, present study was designed to evaluate significance of serum osteocalcin in diagnosis of osteoporosis, and relationship between Serum Osteocalcin and BMD (Bone mineral Density) in post-menopausal females with osteoporosis and without osteoporosis.Methods: One hundred and forty seven post-menopausal women between age 45 to 80 years attending the hospital OPD were studied. To be eligible for the study they had to have been postmenopausal for at least one year. The diagnosis of osteoporosis was made based on T-Scores (BMD) at the lumber spine (L1 to L4 and femaral neck) by DEXA (GE lunar Densitometer). Serum osteocalcin level was estimated by LIAISON osteocalcin assay. Patients with chronic conditions affecting skeletal health and patients on drugs affecting the skeleton were excluded from the study.Results: Serum osteocalcin level in post-menopausal female without osteoporosis was 9.87±1.04ng/ml, while post-menopausal female with osteoporosis had 22.62±2.25ng/ml suggesting significant increase in bone marker level in osteoporotic females (p<0.05.) Correlation study between BMD and osteocalcin showed strong Negative Correlation (r=-0.77, p<0.05).Conclusions: Serum osteocalcin can be considered as a specific marker of osteoblast function as its levels have been shown to correlate with bone formation rates. Thus, serum osteocalcin can be used for diagnosis and monitoring of response to therapy and this may be the better predictor than BMD.

SUN-542 Comparison of Different Muscle Mass Indices for Evaluation of Low Muscle Mass Regarding Muscle Function, Bone Mineral Density and Metabolic Profile in Obese Patients Prior to Bariatric Surgery

Sarcopenic obesity increases the risk of metabolic complications (MC), falls, fractures and even increased mortality. The identification of a low muscle mass (LMM) occurs through the muscle mass index (MMI). The height-adjusted MMI in the elderly is the most used for the diagnosis of sarcopenia (SARC). However, in the young obese subject there is data in the literature favoring the weight-adjusted MMI, due to a better identification of SARC and correlation with MC. Objective: To identify obese patients with low muscle mass (O-LMM) prior to bariatric surgery through three different MMIs regarding muscle function (hand grip (HG) and gait velocity (GV)), bone mineral density (BMD) and metabolic profile. Methods: The cross-sectional study, involving 59 obese women of a public hospital in Brazil, was conducted. The sample was divided into two groups according to the presence of O-LMM and obese patients with normal muscle mass (O-NMM) for each IMM. We considered O-LMM patients who were in the lowest quintile for each IMM and the patients who were in the other quintiles were considered as O-NMM. The body composition was evaluated by bio-impedance (inbody-370), multifrequency (5, 50, 250 HZ), with fasting of 12 hours and BMD by lunar densitometer prodigy advance. To estimate muscle mass, the following MMIs were used: height-adjusted MMI (MMI-height): appendicular muscle mass (AMM) / height2; MMI adjusted for weight (MMI-weight): AMM / weight x 100 and MMI adjusted for body mass index (MMI-BMI): MMA / BMI. The HG was evaluated by jamar dynamometer (3 measurements with interval of 30 seconds between them) and the physical performance by the GV for 6 minutes. Fasting glycemia, HbA1c, HOMA-IR, insulin, total cholesterol, HDL, LDL, triglycerides and high sensitivity quantitative C-reactive protein were assessed. Results: The participants had a mean age of 39.53 ± 8,99 years, weight: 108.60 ± 13.86 kg and BMI: 42.6 ± 4.64 kg / m2. O-LMM were identified at 30.5% (n = 18) by MMI-weight, and also at 20.33% by MMI-BMI and MMI-height. Patients in the lowest quintile for the MMI-weight had a lower HG (24.16 x 30.69 kg, p = 0.000), lower BMD in L1-L4 (1.17 x 1.27 g / cm2, p = 0.001), in the femoral neck (FN) ( 1.04 x 1.14 g / cm2, p = 0.012) and in the total femur (TF) (1.10 x 1.19 g / cm2, p = 0.039), respectively, but without significant difference for GV. For MMI-BMI, O-LMM presented lower GV (0.93 x 1.06 m / s, p = 0.017) and HG (23.19 x 30.22 kg, p = 0.000), however without significant difference for BMD. The O-LMM identified by the MMI-height had lower BMD in FN (1.01 x 1.13 g / cm2, p = 0.009) and TF (1.06 x 1.19 g / cm2, p = 0.012), with no significant difference for muscle function. Metabolic profile was not worse in the O-LMM by the three MMIs. Conclusion: The MMI-weight identifies more O-LMM patients than the other MMI. The O-LMM diagnosed by MMI-weight had lower BMD in all sites and lower HG than O-NMM, possibly being a better IMM to diagnose SARC in obese patients.

SAT-LB018 Different Definitions of Sarcopenia and Its Correlations with Anthropometric Measurements, Body Composition, Handgrip Strength, Metabolic Profile and Bone Mineral Density in Obese Women

BACKGROUND: The concept of sarcopenic obesity hasn’t been fully elucidated, due to the different muscle mass indexes (MMIs) as a dilemma in its definition. There are few trials about MMIs related to the clinical outcomes in young adults with severe obesity. OBJECTIVE: To correlate 3 MMIs, used in the diagnosis of sarcopenia, with age, anthropometric measures, body composition, handgrip strength (HS), metabolic profile and bone mineral density (BMD) in obese women preceding bariatric surgery (BS). METHODS: A cross-sectional study involving 62 obese women of a public hospital in Brazil. Body composition was given by bio-impedance (inbody-370), multifrequency (5, 50, 250Hz) with 12 hours fasting, and BMD by Lunar Densitometer Prodigy Advance. The following MMIs were studied: height2-adjusted appendicular skeletal muscle mass (ASMM): ASMM/ht2 (Kg/m2); weight-adjusted ASMM: ASMM/weight x100 (%) and BMI-adjusted ASMM: ASMM/BMI (m2). The HS (dominant) was evaluated by Jamar Dynamometer (3 measurements; 30 sec interval). Metabolic profile included: Fasting glucose, HbA1c, HOMA-IR, insulin, lipid profile and hs-CRP. RESULTS: Patients were 39±8,99 years old; weight 108.6±13.8 Kg; BMI 42.6±4.6 kg/m2; ASMM/wt 19.76±1.87%; ASMM/BMI 0.505±0.080 m2; ASMM/ht2 8.46±1.00 Kg/m2 and body fat percentage (BFP) 51.8±3.32%. None of the MMIs were associated with age. Concerning anthropometric measures, only the ASMM/ht2 was correlated with wt (r=0.701 p<0.001), otherwise all MMIs were associated with ht (had p<0.05). ASMM/wt x100 and ASMM/BMI had negative and significant association with BMI, while ASMM-ht was positively associated with BMI (r=0.597 p<0.001). Regarding body composition, ASMM/wt and ASMM/BMI had negative correlation with BFP (r=-0.769 p<0.001; r=-0.669 p<0.001), respectively. All MMIs correlated positively and significantly with skeletal muscle mass. ASMM/ht2 was correlated with appendicular fat mass (p<0.001) and ASMM/wt x100 obtained negative and significant association with fat mass of upper limbs. All MMIs were positively and significantly associated with HS. Concerning metabolic profile, ASMM/ht2 was the only MMI to correlate with HOMA-IR (r=0.381 p=0.003). Regarding BMD, only the ASMM/wt x100 correlated positively and significantly with all sites (L1-L4, CF and FT) of BMD evaluated. There was only correlation between ASMM/wt x100 and ASMM/BMI (r=0.933 p=0.001). CONCLUSION: The ASMM/wt x100 and the ASMM/BMI seem to be more accurate to evaluate the sarcopenia in obese women than ASMM/ht2, because they have correlated negatively with adiposity (BMI and BFP). Besides that, both ASMM/wt x100 and ASMM/BMI have correlated with HS, which is an important parameter of disability and mortality. However, only ASMM/wt x100 had correlated positively with all BMD sites evaluated proving to be useful in the evaluation of sarcopenia in obese women preceding BS. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Impact of Very Dense Artifacts on Hologic and GE Lunar Densitometers

Impact of Very Dense Artifacts on Hologic and GE Lunar Densitometers

Densitometer-Specific Differences in the Correlation Between Body Mass Index and Lumbar Spine Trabecular Bone Score

Trabecular bone score (TBS) is a gray-level texture measure derived from lumbar spine dual-energy X-ray absorptiometry (DXA) images that predicts fractures independent of bone mineral density (BMD). Increased abdominal soft tissue in individuals with elevated body mass index (BMI) absorbs more X-rays during image acquisition for BMD measurement and must be accommodated by the TBS algorithm. We aimed to determine if the relationship between BMI and TBS varied between 2 major manufacturers' densitometers, because different densitometers accommodate soft tissues differently. We identified 1919 women and 811 men, participants of the Canadian Multicentre Osteoporosis Study, aged ≥40 yr with lumbar spine DXA scans acquired on GE Lunar (4 centers) or Hologic (3 centers) densitometers at year 10 of follow-up. TBS was calculated for L1–L4 (TBS iNsight® software, version 2.1). A significant negative correlation between TBS and BMI was observed when TBS measurements were performed on Hologic densitometers in men (Pearson r = −0.36, p < 0.0001) and in women (Pearson r = −0.33, p < 0.0001); significant correlations were not seen when TBS was measured on GE Lunar densitometers (Pearson r = 0.00 in men, Pearson r = −0.02 in women). Age-adjusted linear regression models confirmed significant interactions between BMI and densitometer manufacturer for both men and women (p < 0.0001). In contrast, comparable positive correlations were observed between BMD and BMI on both Hologic and GE Lunar densitometers in men and women. In conclusion, BMI significantly affects TBS values in men and women when measured on Hologic but not GE Lunar densitometers. This finding has implications for clinical and research applications of TBS, especially when TBS is measured sequentially on DXA densitometers from different manufacturers or when results from different machines are pooled for analysis.

DIETARY PATTERNS, BODY COMPOSITION, AND COGNITIVE PERFORMANCE IN COMMUNITY-DWELLING HEALTHY ELDERS (NUTRDEM PROJECT)

Healthy dietary patterns, such as the Mediterranean diet, are recommended as part of non-pharmacological strategy to prevent or delay the onset of cognitive decline or dementia. Western diet and abnormal body composition (especially increased amount of visceral fat) are postulated as risk factor of cognitive decline in elderly subjects. The aim of this study is to evaluate dietary patterns, nutritional status, anthropometric parameters, body composition, and cognitive performance in community dwelling elderly subjects. 192 European Caucasian subjects were included into the prospective, observational study. The following data were acquired: detailed medical history, current treatment and clinical status. Data on the presence of vascular risk factors (hypertension, dyslipidemia, diabetes, history of cerebro-vascular incidents) and comorbidity were also collected. The Food Intake Variety Questionnaire (FIVeQ) and a daily diary for 7 days were used for the collecting data on dietary patterns. Body mass index, abdominal, waist and hip circumferences were measured. Body composition (total fat mass, lean body mass, body water, visceral and subcutaneous fat) was assessed using Maltron 920- 2-S bioimpedance analyzer (BIA measurements) and iDXA GE Lunar densitometer (DXA measurements) serving as reference method. Cognitive performance was assessed using set of neuropsychological methods: Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Color Trails Test (CTT-2), Verbal Fluency, CANTABeclipse Test Battery. 192 European Caucasian healthy subjects (156 women; mean age, 71,2 years) were included into the first large prospective observational study performed in Poland. Here we present preliminary results of analysis of relationships between dietary patterns, nutritional status, body composition, and cognitive performance in population of community dwelling healthy elders. Abnormal body composition (numerous parameters, including amount of fat depot, and especially significantly increased amount of visceral fat) has been found in the study group. No correlation between cognitive performance (MoCA, MMSE) and BMI, body weight, DXA Fat (kg, %), VAT (g, cm3) has been found in the NutrDem group participants at the baseline visit. No correlation between cognitive performance and nutritional status has been found at the baseline visit. However, a longitudinal assessment of over 200 healthy elderly with pre-planned 5 years follow-up is ongoing.

An Investigation into the Differences in Body Composition Measurements between Two GE Lunar Densitometers and in Comparison to a Four Compartment Model

An Investigation into the Differences in Body Composition Measurements between Two GE Lunar Densitometers and in Comparison to a Four Compartment Model

Gender Disparity in BMD Conversion: A Comparison Between Lunar and Hologic Densitometers

Female-derived inter-conversion and standardised BMD equations at the lumbar spine and hip have not been validated in men. This study of 110 male subjects scanned on Hologic and Lunar densitometers demonstrates that published equations may not applicable to men at the lumbar spine. Male inter-conversion equations have also been derived. Currently, available equations for inter-manufacturer conversion of bone mineral density (BMD) and calculation of standardised BMD (sBMD) are used in both males and females, despite being derived and validated only in women. Our aim was to test the validity of the published equations in men. One hundred ten men underwent lumbar spine (L2-4), femoral neck (FN) and total hip (TH) dual X-ray absorptiometry (DXA) using Hologic and Lunar scanners. Hologic BMD was converted to Lunar using published equations derived from women for L2-4 and FN. Actual Lunar BMD (A-Lunar) was compared to converted (Lunar equivalent) Hologic BMD values (H-Lunar). sBMD was calculated separately using Hologic (sBMD-H) and Lunar BMD (sBMD-L) at L2-4, FN and TH. Conversion equations in men for Hologic to Lunar BMD were derived using Deming regression analysis. There was a strong linear correlation between Lunar and Hologic BMD at all skeletal sites. A-Lunar BMD was however significantly higher than derived H-Lunar BMD (p < 0.001) at L2-L4 (mean difference, 0.07 g/cm2). There was no significant difference at the FN (mean difference, 0.01 g/cm2). sBMD-L at the spine was significantly higher than sBMD-H (mean difference, 0.06 g/cm2, p < 0.001), whilst there was little difference at the FN and TH (mean difference, 0.01 g/cm2). Published conversion equations for Lunar BMD to Hologic BMD, and formulae for lumbar spine sBMD, derived in women may not be applicable to men.

Assessing body composition in taller or broader individuals using dual-energy X-ray absorptiometry: a systematic review

Dual-energy X-ray absorptiometry (DXA) is an accurate and reliable method for determining body composition, but a limiting feature is the restricted scanning areas (∼190 × 60 cm(2)). This shortcoming is relevant not only to athletes involved in sports where height is a major performance determinant but also to obese individuals with a large trunk mass and breadth in whom body dimensions frequently exceed the scan area. This study reviews solutions for DXA length and/or width limitations and its accuracy for body composition assessment using the PRISMA statement guidelines. Reviewed studies included English language articles from MEDLINE and Thomson Reuters Web of Knowledge platform (1990-2013), and were selected if procedures to overcome the scan area limitations and its validity in assessing the body composition of healthy participants were addressed. Search terms included: DXA, scan, height, width, length, wide, large, tall and obese. A total of seven studies met the criteria and were selected. The sum of two DXA scans and adopting a knee-bent position are alternative procedures proposed for evaluating individuals using pencil and fan-beam Hologic instruments, who are taller than the scan area, whereas a half-body scan is recommended for overcoming the limitations of whole-body measurements in subjects who are wider than the scan area width of Lunar densitometers. Overall, the proposed procedures are useful and valid, in particular the half-body scan alternative, which avoids unnecessary radiation exposure and scanning time. However, these alternatives were developed for specific densitometers, models and scan mode, and applicability to other instruments requires further research.

Bone mineral density in children with long-term antiepileptic therapy

Vitamin D active metabolites deficit that is al: tered by negative calcium and phosphorus balance is a potential complication during long-term antiepileptic drug therapy. The aim of this study was to examine lumbar bone mineral density (BMD) in epileptic children receiving antiepileptic drug therapy longer than one year. The examined sample consisted of 34 epileptic children, 18 male and 16 female, aged 6-12 (9.77+/-2.01) years, treated with carbamazepine, valproate, phenobarbital, lamotrigine or their combination without vitamin D supplementation. The lumbar spine BMD (L1-L4) was estimated by a Lunar densitometer and obtained results were compared with results of 35 matched population of healthy children from the control group. Lumbar BMD Z-score was significantly lower in female patients treated with antiepileptic therapy compared with those in the control group (-1.048+/-1.35 vs. -0.399+/-0.518; p=0.03). Bone mineral density Z-score decrease of both gender groups receiving antiepileptic polytherapy was significantly lower compared to the control group (-1.153+/-0.938 vs. -0.043+/-0.815; p=0.007). Therapy duration had no influence on the lumbar BMD level decrease either in boys (rxy=0.33; p=0.174) or in girls (rxy=0.02; p=0.935) treated with antlepileptic therapy. Our results have indicated that antiepileptic drug therapy usage longer than one year can have adverse affects on the lumbar spine BMD (L1-L4) in epileptic children, and that prophylactic vitamin D supplementation is also necessary in these patients.

Effects of Long Term Imatinib on Bone Mineral Density In Patients with Chronic Myelogenous Leukemia (CML) or Gastrointestinal Stromal Tumor (GIST)

AbstractAbstract 2276Imatinib (IM) inhibits several disease-associated tyrosine kinases, including BCR-ABL in CML, C-KIT in GIST, and PDGFR α and β in patients (pts) with certain myeloproliferative disorders and dermatofibrosarcoma protuberans, respectively. We have previously shown that most pts taking IM have low levels of osteocalcin, a marker of bone formation, and serum N-telopeptide of collagen cross links (sNTX), a marker of bone resorption (Berman, 2006). We postulated that the decrease in bone turnover was, in part, related to the fact that IM inhibits PDGFR α and β which are important for osteoblast and osteoclast function, as well as M-CSF activation of C-FMS which is needed for osteoclast maturation from monocytic precursors (Dewar, 2005). In order to determine whether these findings had a clinical impact on pts taking IM for either CML or GIST, we undertook a prospective analysis of BMD in pts already on the drug. Patients with known metabolic bone disease or pts taking supplemental calcium or biphosphonates were excluded. At time of study entry, we examined fasting serum calcium, phosphate, parathyroid hormone (PTH), vitamin D (25 and diOH 1,25), osteocalcin, bone alkaline phosphatase (BAP), urinary phosphate excretion, and serum and urinary NTX. Tests were repeated every 3 months for 2 years. Bone densitometry was performed at time of study entry and then at 12 and 24 months using a GE Lunar densitometer. A significant change in BMD was defined as a decrease of > 3.6% at the lumbar spine, > 3.8% at the femoral neck, and > 2.4% at the hip. Nineteen adults (9 M/10F; 14 with CML)), median age 52 (range 24–73), completed the study. Nine of the 19 pts (47%) had a significant decrease in BMD in at least one site; this included 2 patients with a significant decrease at the femoral neck, 4 patients with a decrease at the hip, and 3 pts with a decrease at both femoral neck and hip. Four pts (21%) had a significant increase in BMD: 2 at the lumbar spine, and 2 at the femoral neck and hip. Six pts (31%) had no change in BMD. The median time on IM before study entry was 31 months (range 1–71) for all 19 pts. For the groups with a decrease, increase, or no change in BMD, the median times on treatment were 27, 3, and 54 months. Serum osteocalcin levels were consistently low in all 3 groups with a median of 2.7 ng/ml (range 2.7–3.4) after 24 months on study; 7 pts (37%) had no measurable amount of osteocalcin on at least one occasion. In all 3 groups, BAP was in the low- normal range, serum and urine NTX were normal, and PTH levels were consistent with vitamin D levels. Although numbers are small, bone loss occurred at sites consisting of cortical bone (hip and femoral neck), and not at the site of predominantly trabecular bone (lumbar spine). In summary, BMD may decrease in ∼50 % of patients taking IM. Osteocalcin levels remained low in nearly all pts while serum NTX levels were normal, suggesting that IM inhibits osteoblast function to a greater degree than osteoclast function. It remains to be determined which pts need serial BMD testing, and whether bisphosphonates or other agents might improve BMD in this setting. Disclosures:Berman: Novartis Inc: Research Funding. Maki: Novartis Inc: Advisory Committee, Honoraria.

Bone mineral density reference ranges for Australian men: Geelong Osteoporosis Study

A large population-based random sample of Australian white men was used to provide normative bone mineral density (BMD) data at multiple anatomical sites. The femoral neck BMD data are very similar to those obtained in USA non-Hispanic white males participating in the National Health and Nutrition Examination Survey III (NHANES III). The reference ranges will be suitable for similar populations. To provide normative BMD data for Australian men derived from a large population-based random sample. An age-stratified random sample of men was recruited from the Australian electoral rolls (n = 1,467 aged 20-97 years). BMD was quantified at multiple sites using Lunar densitometers. Age-related differences in BMD were best predicted by linear relationships at the spine and hip and by quadratic functions at the whole body and forearm. At the spine, a small age-related increase in mean BMD was observed. Although in the subset with no spinal abnormalities, there was a decrease of 0.003 g/cm(2) per year from age 20. At the hip sites, mean BMD decreased at 0.001-0.006 g/cm(2) per year from age 20. At the forearm and whole body, BMD peaked at 41-47 years. Apart from a small difference in men greater than or equal to 80 years, the Australian femoral neck BMD data are not different to those obtained in USA non-Hispanic white males participating in NHANES III and were generally similar to those of large studies from Canada (CaMos) and Spain. These data supply BMD reference ranges at multiple anatomical sites that will be applicable to white Australian men and similar populations such as USA non-Hispanic white men.

Bone mineral density of the spine and femur in a group of healthy Moroccan men

BackgroundBone mineral density (BMD) measurements using dual-energy X-rays absorptiometry (DXA) are widely used to diagnose osteoporosis and to assess its severity. Previous studies show the necessity to establish reference data for bone mass measurements for each particular population. Such data are lacking for the male Moroccan population. AimTo establish reference values for the healthy Moroccan male population and to compare them with those for Caucasian and Arab males, and to study the impact of different curves implemented in the DXA system on the diagnosis of osteoporosis. MethodsA cross-sectional study of 592 Moroccan men, recruited from the area of Rabat, the capital of Morocco, aged between 20 and 79 years was carried to establish reference values of bone mineral density. Measurements were taken at the lumbar spine and proximal femurs using DXA (Lunar Prodigy Vision, GE). The data were compared with published normative taken by US, European, Iranian, Lebanese, and Saudi men over six decades of age. Impact on osteoporosis diagnosis according to the WHO criteria using the personalized curve and US (NHANES), European and Middle-East reference curves (as implemented in the Lunar densitometers) was studied. ResultsOur results showed that the Moroccan men showed the expected decline in BMD at both sites with age after peaking at 20–29 years age group. Every anatomical region has a different rate of bone loss: lumbar spine (0.3% per year) femoral neck (0.6%), trochanter (0.3%), and total hip (0.4%). The lumbar spine and femoral subregions BMD exhibited increases from 0.3 to 0.5% per kilogram of body weight. In the spine, the US/European Lunar reference values classified a larger proportion of men as osteoporotic (18.1% vs. 7.4%) while using the Arabic Lunar reference values, only 7.8% were classified as osteoporotic. However, using Arabic curve for the femurs resulted in underdiagnosis of osteoporosis (1.8% vs. 6.0%), whereas the US/European Lunar reference values classified men as osteoporotic in 3.9% and 5.3% respectively. DiscussionIn comparison with the other Countries, the spine BMD of Moroccan men were slightly lower than Iranian's, Europeans and Brazilians but higher than the Saudi and Lebanese males. We found BMD values taken at the lumbar spine to be around 4% lower than European values between ages 50 and 59 years, and 10% lower for older subjects. These values were 4–6% higher than Saudis/Lebanese values between ages 20–39. For older subjects, Moroccan values were more than 10% higher than Saudis and almost similar to Lebanese. Femoral neck BMD values were 8% higher in young adults (age 20–39 years) to US/Saudis/Lebanese values, but about 10% lower in ages over 60 to US values whereas it was similar to Saudis and Lebanese values. ConclusionOur study emphasises the importance of using population-specific reference values for BMD measurements to avoid over or underdiagnosis of osteoporosis.

Evaluation of T-score agreement between Norland and GE healthcare Lunar densitometers

Evaluation of T-score agreement between Norland and GE healthcare Lunar densitometers

2006 Abstracts: Twenty-Eighth Annual Meeting of the American Society for Bone and Mineral Research: Pennsylvania Convention Convention Center Philadelphia, Pennsylvania, USA, September 15–19, 2006

Vertebral fractures serve as sentinel markers for the epidemiological study of osteoporosis. Using vertebral morphometry from lateral scans of the spine, vertebral fractures were identified in an age-stratified, random sample of 1148 men enrolled in the Geelong Osteoporosis Study (median age 58.5yr, range 20-93). Scans were performed using a Lunar densitometer (Prodigy Pro) for TI 0- 12 and LJ-4. Moderate and severe wedge, biconcave or compression deformities (>25% reduction in any height and accompanying area) were classified as vertebral fractures. Prevalence data were standardised to national age profiles. Osteoporosis and osteopenia were defined using -2.5 SD and -1.0 SD below young normal mean bone mineral density (BMD) values, respectively. Vertebral fractures were identified in 64 men (29 Land 41 T), 47% of whom had selfreported height loss. No fractures were detected for men in their twenties. Agestandardised figures show that men in their thirties have 1.5% prevalence, in their forties 1.4%, fifties 3.2%, sixties 4.7%, seventies 10.0%, and eighties and older 14.6% prevalence. Among men with vertebral fracture, 8% had osteoporosis and 24% osteopenia at the spine, whereas 18% had osteoporosis and 5 I% had osteopenia at the femoral neck. Most (94%) were unaware of their vertebral fracture. Vertebral fracture affects approximately 3% of Australian adult men. Similar to postmenopausal women, a substantial proportion of men with vertebral fracture had mild deficits in BMD and 31% were associated with apparently normal areal BMD at the femoral neck. However, consistent with osteoporosis-related fractures, the prevalence increases with age. Despite nearly half the fracture cases reporting height loss. vertebral fractures are mostly undiagnosed.

Lateral vertebral assessment: a valuable technique to detect clinically significant vertebral fractures

Although many vertebral fractures are clinically silent, they are associated with increased risk for subsequent osteoporotic fractures. A substantial number of these fractures are demonstrable using instant vertebral assessment with Hologic densitometers. Whether similar recognition is possible using dual-energy lateral vertebral assessment (LVA) with GE Lunar densitometers remains uncertain. Thus, we evaluated the ability of clinicians using LVA to detect prevalent vertebral fractures. Dual-energy LVA and conventional thoracic and lumbar spine radiographs were concurrently obtained in 80 postmenopausal women. Using an established visual semiquantitative system, vertebral fractures were identified individually by two non-radiologist clinicians on LVA images, and the results were compared with spinal radiograph evaluation by an expert radiologist. Using LVA, 95% of vertebral bodies from T7 through L4 were evaluable, but a majority (66%) of vertebrae from T4 to T6 were not adequately visualized. In the LVA-evaluable vertebrae, prevalent fractures were identified in 40 vertebral bodies by radiography. In this regard, the clinicians using LVA detected 17 of 18 radiographically evident vertebral fractures of grade 2 or 3, a false negative rate of 6%. They identified 50% (11/22) of grade 1 fractures. Additionally, the vast majority of evaluable non-fractured vertebrae, (764/794, 96.2%) were correctly classified as normal by LVA. Thus, clinicians utilizing LVA correctly identified the vast majority of grade 2 or 3 vertebral compression fractures and normal vertebral bodies, although detection of grade 1 fractures was less effective. In conclusion, the low-radiation, dual-energy LVA technique provides a rapid and convenient way for clinicians to identify patients with, and without, grade 2 or 3 vertebral fractures, thereby enhancing care of osteoporotic patients.

Recalculation of the NHANES Database SD Improves T-Score Agreement and Reduces Osteoporosis Prevalence

In attempt to improve diagnostic agreement between manufacturers, a recent software update incorporated NHANES III data in GE Lunar densitometers. As a result, the femur neck and trochanter T-scores were lowered, and osteoporosis prevalence was increased. Use of a recalculated young-normal SD for the GE Lunar-adjusted NHANES III database improved diagnostic agreement and is recommended. Use of manufacturer-specific normative databases for T-score derivation leads to discordance in T-score values and differences in diagnostic classification. To address this issue, the International Committee for Standards in Bone Measurement (ICSBM) recommended the NHANES III database for femur T-score derivation. Acquired on Hologic (Hol) instruments, this database requires conversion equations for application to other DXA systems. NHANES III total femur (TF) conversions for GE Lunar (GE) have previously been available, and femoral neck (FN) and trochanter (TR) equations were reported recently. Per the ICSBM recommendation, GE Lunar incorporated these values into their female database. This should produce T-score and diagnostic agreement between Hol and GE instruments; however, this has not been evaluated. We compared GE femur scans in 115 postmenopausal women using software before and after the NHANES III software update. Subsequently, T-scores derived from femur scans obtained on GE and Hol densitometers were compared in a different group of 89 postmenopausal women. The NHANES III software update had no effect on measured BMD (g/cm2) at any femur region. However, because of changes in values used for T-score calculation (increase in the mean young-normal BMD at the FN and TR and a reduction in SD at the TR), the T-scores were lower (mean, 0.48 and 0.68, respectively) at the FN and TR using post-NHANES III software. Consequently, this update increased femur osteoporosis prevalence in these 115 women from 7.8% to 18.3%. Comparison of GE with Hol total proximal femur T-scores revealed a minimal difference (<0.1) and equal diagnoses of osteoporosis. FN and TR differences were larger, with mean GE T-scores lower than Hol (p < 0.001) by 0.17 and 0.50, respectively, thereby introducing osteoporosis diagnostic disagreement (13 [GE] versus 9 [Hol]). Our evaluation suggested that this disparity resulted from direct application of published NHANES III SDs at the FN and TR. As such, we applied the conversion formulae to the NHANES III published Hologic data and found the FN and TR SDs were greater than assumed by GE. Using our recalculated SD to derive T-scores reduced the mean GE/Hol T-score difference to 0.03 at the FN and 0.32 at the TR and resolved osteoporosis diagnostic disagreement. The GE NHANES III software update leads to lower FN and TR T-scores than obtained with Hol or prior GE software. Recalculation of the young-normal SD reduces this difference and is recommended. Clinicians are advised to avoid using the TR for diagnosis or, at a minimum, use caution when making treatment decisions based solely on T-score at this site.

Body Weight Change Since Menopause and Percentage Body Fat Mass are Predictors of Subsequent Bone Mineral Density Change of the Proximal Femur in Women Aged 75 Years and Older: Results of a 5 Year Prospective Study

Few studies have evaluated risk factors for bone loss in elderly women. We examined risk factors associated with a 5-year longitudinal change in bone mineral density (BMD) at the hip in healthy women aged 75 years and older. The BMD of 276 women from the French EPIDOS (Epidémiologie des Osteoporoses) study was assessed in Montpellier from 1992 to 1993 and again from 1997 to 1998. BMD was measured at the femoral neck, trochanter, and Ward's area using the same Lunar densitometer. We examined the relationship between clinical and behavioral factors at baseline and their variations during follow-up, with percentage BMD change adjusted for baseline BMD. Depending on the femur subregion studied, a significant decrease in BMD (exceeding the least significant difference, i.e., > 2.8 CV) was observed in 36.2% to 51.1% of women. Multivariate analysis showed that both postmenopausal weight change before baseline and baseline percentage of fat mass were positively correlated with BMD change at the Ward's triangle and the trochanter. Yearly absolute and relative weight changes over the follow-up period were significantly associated with change of trochanter and femoral neck BMD. Our results show that maintenance of body weight throughout the postmenopause period and body fat mass play protective roles against bone loss at the proximal femur in women aged 75 years and older and suggest the value in including assessment of weight change throughout postmenopause and percentage body fat mass in screening programs for elderly women who are at higher risk of accelerated bone loss.

Risk factors for longitudinal bone loss in elderly men and women: the Framingham Osteoporosis Study.

Few studies have evaluated risk factors for bone loss in elderly women and men. Thus, we examined risk factors for 4-year longitudinal change in bone mineral density (BMD) at the hip, radius, and spine in elders. Eight hundred elderly women and men from the population-based Framingham Osteoporosis Study had BMD assessed in 1988-1989 and again in 1992-1993. BMD was measured at femoral neck, trochanter, Ward's area, radial shaft, ultradistal radius, and lumbar spine using Lunar densitometers. We examined the relation of the following factors at baseline to percent BMD loss: age, weight, change in weight, height, smoking, caffeine, alcohol use, physical activity, serum 25-OH vitamin D, calcium intake, and current estrogen replacement in women. Multivariate regression analyses were conducted with simultaneous adjustment for all variables. Mean age at baseline was 74 years +/-4.5 years (range, 67-90 years). Average 4-year BMD loss for women (range, 3.4-4.8%) was greater than the loss for men (range, 0.2-3.6%) at all sites; however, BMD fell with age in both elderly women and elderly men. For women, lower baseline weight, weight loss in interim, and greater alcohol use were associated with BMD loss. Women who gained weight during the interim gained BMD or had little change in BMD. For women, current estrogen users had less bone loss than nonusers; at the femoral neck, nonusers lost up to 2.7% more BMD. For men, lower baseline weight and weight loss also were associated with BMD loss. Men who smoked cigarettes at baseline lost more BMD at the trochanter site. Surprisingly, bone loss was not affected by caffeine, physical activity, serum 25-OH vitamin D, or calcium intake. Risk factors consistently associated with bone loss in elders include female sex, thinness, and weight loss, while weight gain appears to protect against bone loss for both men and women. This population-based study suggests that current estrogen use may help to maintain bone in women, whereas current smoking was associated with bone loss in men. Even in the elderly years, potentially modifiable risk factors, such as weight, estrogen use, and cigarette smoking are important components of bone health.

COMPARISON OF MULTI-COMPARTMENTAL MODELS OF BODY COMPOSITION IN AGING MEN AND WOMEN (NHRT, HRT).

923 This study compares the two compartment model to the three and four (4C) compartment models in the body composition of aging men (MEN), women either on hormone replacement therapy (HRT) or not on HRT (NHRT). The Bod Pod (BP) was validated against the criterion method, hydrostatic weighing (HW). Body Density (Db) from the BP and HW, bone density via a Lunar densitometer and total body water via deuterium tracer were measured to assess compartmental models. (Table)TableComparing the 2C to the 4C model, no differences were found between the NHRT (p<.6) or any other group. Men had higher Db than women (p<.000), but a 3X2 ANOVA showed no difference between Db BP or HW. BP was not different from the HW in the 4C model. These results show the DbBP is valid for multi-compartment models in these groups. Supported by NIH-NCRR-ORMH-P20 RR11805.