Hologic QDR Research Articles

Radial quantitative ultrasound and dual energy x-ray absorptiometry: intermethod agreement for bone status assessment in children.

Aim. To validate a radial quantitative ultrasound (QUS) system with dual energy X-ray absorptiometry (DXA), a criterion technique in bone status assessment among children. Methods. Bone health was evaluated using a radial QUS system (Sunlight Omnisense 8000P) to measure the speed of sound (SOS) at one-third distal radius of the nondominant hand and DXA (Hologic QDR) was used to assess whole body bone mineral density (BMD). Results. Some 29.9% of the children were grossly misclassified according to quartiles of BMD and radial SOS. Poor agreement was observed between Z-scores of radial SOS and whole-body BMD (mean difference = 0.6 ± 0.9; 95% limits of agreement = −1.4 to 2.6). With a cut-off value of −1.0, radial SOS yielded satisfactory sensitivity (80%) and specificity (93%) for the detection of children with low BMD. Conclusion. The observed poor agreement in the present study suggests that radial QUS and DXA are not comparable and hence are not interchangeable in evaluating bone status of the children.

Long-term fat redistribution in ARV-naïve HIV+ patients initiating a non-thymidine containing regimen in clinical practice.

IntroductionLipodystrophy is still a matter of concern in HIV+ patients receiving ART. However, long-term fat change in patients taking non-thymidine regimens is not well known.Materials and MethodsA prospective ongoing fat change assessment including clinical evaluation and dexa scans (Hologic QDR 4500) is being conducted in all consecutive patients initiating ART from January 2008. Arm, leg, trunk and total fat as well as fat mass ratio (FMR=% trunk fat/% leg fat) were determined. Patients with data at baseline (BL), 12 and 36 m are included in this analysis. ITT and OT were performed. Multivariate general linear models were used to assess changes in fat measures.ResultsOne hundred patients were included. 81% men, 42.9 years, 18% AIDS, CD4 218.5 (6-756), viral load 5 log (2.9-6.8), leg fat 4644g, trunk fat 6693g, FMR 0.94. Around 40 patients (40%) initiated a PIr (17 LPVr, 11 ATVr, 9 DRVr, 3 FPVr), 34 (34%) NVP and 21 (21%) EFV. About 83% received TDF/FTC and 10% ABC/3TC. Groups were comparable at BL except for a lower viral load in NVP patients (p=0.047) and lower c-LDL in PI patients (p=0.043). After 36 m, no patient presented a clinically evident lipodystrophy. At 12 m, an overall significant increase was found from baseline in trunk, leg and FMR (median 759 g, 479.4 g and 0.03, respectively, p<0.05) and at 36 m in trunk and leg fat (median 989.9 g, 566 g, respectively, p<0.05). According to ART, at 12 m a significant increase in trunk and leg fat was observed in EFV and PIr. At 36 m, in NVP patients trunk and leg fat as well as FMR increased, whereas in PIr patients only leg fat increased (see figure). In ITT analysis, adjusted by age, sex, risk practice and BL CD4, EFV was associated with a greater increase in FMR (p=0.036) at 36 m vs PIr. In OT analysis, at 12 m, NVP was associated with a smaller percentage increase in trunk fat (vs PIr and EFV, p=0.006) and in leg fat (vs PIr, p=0.046). These differences did not persist at 36 m.ConclusionsIn this cohort of patients taking non-thymidine-based regimens, after 36 m without a clinically evident lipodystrophy, no significant changes in FMR were observed. However, some differences in fat redistribution according to ART were present: PIr was associated with an initial and continuous increase in trunk and leg fat, NVP with a slower and progressive increase in both fat compartments, while in EFV patients, the initial fat increase was followed by a decrease in peripheral fat at 36 m. Longer follow up will help to confirm these trends.

Prediction equation for lower limbs lean soft tissue in circumpubertal boys using anthropometry and biological maturation.

Lean soft tissue (LST), a surrogate of skeletal muscle mass, is largely limited to appendicular body regions. Simple and accurate methods to estimate lower limbs LST are often used in attempts to partition out the influence of body size on performance outputs. The aim of the current study was to develop and cross-validate a new model to predict lower limbs LST in boys aged 10–13 years, using dual-energy X-ray absorptiometry (DXA) as the reference method. Total body and segmental (lower limbs) composition were assessed with a Hologic Explorer-W QDR DXA scanner in a cross-sectional sample of 75 Portuguese boys (144.8±6.4 cm; 40.2±9.0 kg). Skinfolds were measured at the anterior and posterior mid-thigh, and medial calf. Circumferences were measured at the proximal, mid and distal thigh. Leg length was estimated as stature minus sitting height. Current stature expressed as a percentage of attained predicted mature stature (PMS) was used as an estimate of biological maturity status. Backward proportional allometric models were used to identify the model with the best statistical fit: ln (lower limbs LST) = 0.838× ln (body mass) +0.476× ln (leg length) – 0.135× ln (mid-thigh circumference) – 0.053× ln (anterior mid-thigh skinfold) – 0.098× ln (medial calf skinfold) – 2.680+0.010× (percentage of attained PMS) (R = 0.95). The obtained equation was cross-validated using the predicted residuals sum of squares statistics (PRESS) method (R 2 PRESS = 0.90). Deming repression analysis between predicted and current lower limbs LST showed a standard error of estimation of 0.52 kg (95% limits of agreement: 0.77 to −1.27 kg). The new model accurately predicts lower limbs LST in circumpubertal boys.

AB0248 Analysis of Bone Mineral Density at the Hand by Radiogrammetry and Dual X-RAY Absorptiometry as A Predictor of Severity in Early Rheumatoid Arthritis Patients. Comparative Study

BackgroundThe evaluation of cortical bone mineral density (BMD) on metacarpal bones by digital radiogrammetry (DXR) has been proven to be a simple, reliable and predictive method to evaluate the severity...

Alendronate Effect on the Prevention of Bone loss in Early Stages of Ankylosing Spondylitis: A Randomized, Double-Blind, Placebo-Controlled Pilot Study.

Background:Ankylosing spondylitis (AS) is an inflammatory rheumatic disease that leads to a progressive ankylosis of vertebras and ossification of paravertebral ligaments. Bone loss and osteoporosis are amongst the important complications of AS, treatment of which is a challenging issue.Objectives:This study aimed to clarify the effect of alendronate on the prevention of bone loss in patients with early AS.Patients and Methods:In a randomized, double-blind, placebo-controlled study, 24 patients with early stages of AS were recruited in Emam Reza Hospital, Tabriz University of Medical Sciences. The diagnostic criteria of early AS were Schober’s index ≥ 5, normal hip joint in pelvic radiography, and absence or rarity of syndesmophytes in spine radiography (Taylor index ≤ 1). The participants were randomly allocated to the treatment and control groups and received 70 mg/week of alendronate and the same dose of placebo, respectively, for 12 months. Before and 12 months after the intervention, bone densitometry was performed from lumbar and pelvic region using the dual-energy X-ray absorptiometry (DEXA) method with Hologic QDR model instrument. Patients, physicians who prescribed the medications and those who interpreted the outcomes, and densitometry technicians were unaware of the assigned medication to each patient. Both groups received supplemental calcium (1000 mg/day) and vitamin D (400 mg/day).Results:After 12 months of treatment, hip and lumbar bone mineral density differences were not statistically significant between study groups (P = 0.061 and P = 0.112, respectively). No case of clinically apparent vertebral and nonvertebral fracture were observed in the treatment and control groups.Conclusions:Our results suggested that applying alendronate was ineffective in preventing bone loss in patients with early stages of AS.

Relationship of nutrition and bone mineral density among Hispanic subjects in “En Balance” diabetes education program (1035.10)

Objective: The purpose of this study was to determine the association of selected nutrients (protein, calcium, phosphorus and vitamin D) and BMD in Hispanic subjects.Methods: This was a prospective three‐month uncontrolled intervention pilot study. A culturally sensitive diabetes education program was conducted to determine the clinical impact on glycemic control in Hispanics subjects with type 2 diabetes. Besides glycemic control, BMD measured by fan beam DXA with Hologic QDR 4500‐A software version 8.1A and dietary intake measured by a validated food frequency questionnaires. Paired t‐tests and Wilcoxon sign rank test used to compare the change after intervention, while multiple linear regression used to determine the association between BMD and selected nutrients.Results: The study had 39 subjects, 59 % females, mean age 54 years old and 28.2 % had low BMD (T‐score ‐1 and less). Results showed there was no significant difference of T‐score (p=0.314), energy, protein, calcium, phosphorous, vitamin D, sodium, alcohol and caffeine intake before and after intervention. Adjusted for gender result showed there is no significant association between L total BMD (g/cmsq) and protein (p=0.694), calcium (p=0.419), phosphorus (p=0.551) and vitamin D (p=0.772) after intervention.Conclusions: There was no significant association between BMD and selected nutrients intake adjusted for gender in Hispanic subjects.

Bone Mineral Density and Biochemical Markers of Bone Turnover During the First Year of Injury in Patients with Spinal Cord Injury

BackgroundSpinal cord injury (SCI) is associated with bone mass loss that can be complicated by fractures, which result in further disabilities for patients. After a SCI, the body starts losing large amounts of calcium and other minerals in the urine (demineralisation). This study aimed to assess the changes in bone mineral density (BMD) during the 1st year of acute SCI in patients with neurological deficit. MethodsA total of 95 patients with acute SCI and neurological deficit were evaluated in this prospective study. Haematological investigations such as evaluation of serum calcium, serum phosphate, serum creatinine, and serum alkaline phosphatase (ALP) were carried out. Urinary investigations such as 24-hour urinary creatinine level and excretion of calcium and phosphate in the urine were measured. BMD was measured using dual-energy X-ray absorptiometry scan with Hologic QDR 2000 scanner (Explorer). All of the aforementioned parameters were measured again at 3, 6, and 12 months. ResultsSerum ALP at 1-year follow up was significantly raised (p<0.05). The BMD at 1-year follow up had statistically significant lower values than the initial BMD at the hip (p<0.05), proximal tibia (p < 0.00l), and distal tibial epiphysis (p < 0.001). The BMD in motor-complete SCI patients [American Spinal Injury Association (ASIA) grades A and B] had significant lower values than motor-incomplete SCI patients (ASIA C and D) at the hip (p < 0.05) and proximal tibial epiphysis (p < 0.05). ConclusionThere was a marked decrease in BMD in metaphyseal sites than below the neurological deficit level with maximum decrease at the proximal tibia during the 1st year of SCI. Although the markers of osteoblastic activity did not show much change, the decrease in BMD was influenced by the neurological recovery after SCI.

Body fat, lean mass and bone density of the spine and forearm in women

Abstract The aim of this study was to determine the relative contributions of fat mass and lean mass to the variability of bone mineral density (BMD) of the lumbar spine and proximal 1/3 forearm in Bulgarian women. 180 women aged 21 through 76 years participated (mean age 50.8 ± 9.7 years). 130 of them were postmenopausal. Lumbar spine and forearm BMD were measured by dual-energy X-ray absorptiometry, followed by a whole-body scan for body composition examination (Hologic QDR 4500 A device, software version 1.26). The strongest linear correlation was found with body weight (r2=0.231, p&lt;0.001). Using this model, 18.1 % of the variability of lumbar spine BMD was attributable to fat mass and 16.0 % to lean mass. The relative influence of fat mass on L1-L4 BMD was greater than that of lean mass (standardized regression coefficient 0.291 versus 0.199). There were weak correlations of body weight, fat and lean mass with the forearm BMD. Lean mass correlated slightly better (r=0.187, p=0.050) to forearm BMD than fat mass (r=0.162, p=0.055). In conclusion, the differentiation between fat and lean mass does not strengthen the BMD correlations beyond that with total body weight.

AB0395 Systemic osteoporosis and its relationship with disease activity in patients with early arthritis

BackgroundThe etiopathogenesis of bone loss seen in patients with rheumatoid arthritis (RA) is multifactorial. Factors that are intrinsic to the individual (age, gender), as well as disease- and treatment-related factors...

THU0375 Can Radial Speed of Sound Measurements Identify Osteoporosis at the Radius as Measured by DXA?

BackgroundOne-third radius (33% radius) bone mineral density (BMD) measurements of the non-dominant forearm using dual-energy X-ray absorptiometry (DXA) may be used for the diagnosis of osteoporosis in certain circumstances.ObjectivesThe aim...

SAT0365 Evaluation of bone status in algerian epileptic patients

BackgroundOsteoporosis and epilepsy are two common affections, mostly diagnosed in the elderly. The prevalence of epilepsy is 1% in people over 60 years and increases with age. An increased risk...

AB0366 Bone mineral density and frequency of osteoporosis in non menopausal women with rheumatoid arthritis

BackgroundRheumatoid arthritis (RA) is a systemic and chronic inflammatory disease that has been associated with disability and several extra-articular complications such us generalised osteoporosis.ObjectivesTo quantify the bone mineral density (BMD)...

AB0433 Prevalence of osteopenia and osteoporosis in women with systemic lupus erythematosus

BackgroundSystemic Lupus Erythematosus (SLE) is a chronic, autoimmune disease characterized by acute and chronic inflammation of various tissues of the body. Studies have found an increase in bone loss and...

SAT0476 The Role of Vitamin D Receptor Gene Polymorphism (VDR) in Pathogenesis of Juvenile Idiopathic Arthritis and Bone Metabolism Disturbances.

BackgroundJuvenile idiopathic arthritis (JIA) – chronic articular disease related to immune system dysfunctions. JIA course and complications have genetic background.ObjectivesWe evaluated features of JIA and related bone mineralization and metabolism...

SAT0376 Hepatic osteodystrophy in patients with chronic autoimmune cholangiopathies: Primary biliary cirrhosis, primary sclerosing cholangitis and autoimmune cholangitis

BackgroundHepatic osteodystrophy is a frequent complication of chronic hepatopathies, although its knowledge in immune mediated chronic liver disease as primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and autoimmune cholangitis...

Assessment of bone mineral density by dual energy x-ray absorptiometry in patients with mucopolysaccharidoses

BackgroundPatients with mucopolysaccharidoses (MPS) are associated with poor bone growth and mineralization, however, information regarding the assessment of bone mineral density (BMD) in relation to age and treatment in this disorder is limited.MethodsDual energy x-ray absorptiometry (DXA) was performed in 30 patients with MPS (21 males and 9 females; 2 with MPS I, 12 with MPS II, 2 with MPS IIIB, 9 with MPS IVA, and 5 with MPS VI; median age, 10.8 years; age range, 5.0 years to 23.7 years; 26 patients were under 19 and 4 were above 19 years of age) to assess BMD of the lumbar spine (L1-L4), using the Hologic QDR 4500 system (Bedford, MA, USA).ResultsFor 26 patients under 19 years of age, standard deviation scores (z scores) for height, weight, body mass index (BMI), and BMD were −4.53 ± 2.66, -1.15 ± 1.55, 0.74 ± 1.23, and −3.03 ± 1.62, respectively, and they were all negatively correlated with age (p < 0.05). However, after correction for height-for-age z score (HAZ), HAZ adjusted BMD z score was −0.7 ± 1.24. Eight patients (31%) had osteopenia (HAZ adjusted BMD z score < −1 and ≥ −2), and 4 patients (15%) had osteoporosis (HAZ adjusted BMD z score < −2). Of 8 patients with MPS I, II or VI who underwent follow-up DXA after receiving enzyme replacement therapy for 1.0 to 7.4 years, all showed increase in absolute BMD values.ConclusionsThese findings and the follow-up data can be used to develop quality of care strategies for patients with MPS.

Clinical risk factors, bone density and fall history in the prediction of incident fracture among men and women

The FRAXtr algorithm uses clinical risk factors (CRF) and bone mineral density (BMD) to predict fracture risk but does not include falls history in the calculation. Using results from the Hertfordshire Cohort Study, we examined the relative contributions of CRFs, BMD and falls history to fracture prediction. We studied 2299 participants at a baseline clinic that included completion of a health questionnaire and anthropometric data. A mean of 5.5years later (range 2.9–8.8years) subjects completed a postal questionnaire detailing fall and fracture history. In a subset of 368 men and 407 women, bone densitometry was performed using a Hologic QDR 4500 instrument. There was a significantly increased risk of fracture in men and women with a previous fracture. A one standard deviation drop in femoral neck BMD was associated with a hazards ratio (HR) of incident fracture (adjusted for CRFs) of 1.92 (1.04–3.54) and 1.77 (1.16–2.71) in men and women respectively. A history of any fall since the age of 45years resulted in an unadjusted HR of fracture of 7.31 (3.78–14.14) and 8.56 (4.85–15.13) in men and women respectively. In a ROC curve analysis, the predictive capacity progressively increased as BMD and previous falls were added into an initial model using CRFs alone. Falls history is a further independent risk factor for fracture. Falls risk should be taken into consideration when assessing whether or not to commence medication for osteoporosis and should also alert the physician to the opportunity to target falls risk directly.

A prospective study of thyroid function, bone loss, and fractures in older men: The MrOS study

Excess thyroid hormone is associated with increased bone loss and fracture risk in older women, but few data exist for men. We sought to determine if thyroid function is independently associated with bone loss and fracture risk in older men. Data were analyzed from the Osteoporotic Fractures in Men (MrOS) study, a cohort of community-dwelling U.S. men aged 65 years and older. Using a case-cohort design, fasting baseline serum archived at -80°C was assayed for thyroid-stimulating hormone (thyrotropin) (TSH) and free thyroxine (FT4) in 397 men with confirmed nonspine fracture, including 157 hip fractures, and 1420 randomly selected men without fracture. TSH and FT4 were analyzed as continuous variables and as thyroid function categories (subclinical hyperthyroid, euthyroid, and subclinical hypothyroid). Hip dual-energy X-ray absorptiometry (DXA) (Hologic QDR4500) was measured at baseline and after a mean follow-up of 4.6 years. Incident nonspine fractures were centrally adjudicated. Bone loss was evaluated with multivariate regression methods and fractures risk was evaluated using hazard models that accounted for the case-cohort sampling, adjusted for age, clinic-site, body mass index (BMI), race, physical activity, corticosteroid use, smoking, alcohol intake, and thyroid medication use. In fully adjusted analyses, TSH was not associated with risk of nonspine fracture (relative hazard [RH] 0.92 per SD decrease in TSH; 95% confidence interval [CI], 0.74-1.14), but was significantly associated with risk of hip fracture (RH 1.31; 95% CI, 1.01-1.71), which persisted among normal range TSH values (RH 1.21; 95% CI, 1.00-1.47). There was no association between TSH or FT4 and bone loss, and fracture risk did not differ significantly by thyroid function category. We conclude that although neither TSH nor FT4 are associated with bone loss, lower serum TSH may be associated with an increased risk of hip fractures in older men.

Weight in Infancy and Adult Calcium Absorption as Determinants of Bone Mineral Density in Adult Men: The Hertfordshire Cohort Study

Adult bone mass is modified by early life environmental influences, but the mechanism of this association is uncertain. Data support an inverse relationship between intestinal calcium absorption (αCa) and birth weight in women. However, little is known regarding determinants in men. This study examines the association between weight in infancy and adult αCa in healthy men and whether this could be a mechanism by which the early life environment may influence bone mass. Men were recruited from the MRC Hertfordshire Cohort Study, for whom detailed early life records were available. Areal bone mineral density (aBMD) was measured using a Hologic QDR 4500 at the femoral neck (FN) and lumbar spine. We randomly selected 123 men stratified by birth weight and assessed αCa using the stable strontium absorption test. The mean age was 63.6 (SD 2.5) years. αCa was not associated with birth weight or weight at 1 year. FN aBMD was associated with both weight at 1 year (r = 0.20, p = 0.03) and αCa (r = 0.20, p = 0.03). Both of these associations remained statistically significant in a mutually adjusted, multivariable model but would account for only ~4 % variance in BMD. We demonstrated a positive association between weight at 1 year and aBMD and between αCa and FN BMD, but no association was found between birth weight and αCa. This suggests that in men, although αCa is a contributing factor in FN bone density, it is not the main mechanism whereby the early environment modifies adult BMD.

Differential changes in vascular mRNA levels between rat iliac and renal arteries produced by cessation of voluntary running

Early vascular changes at the molecular level caused by adoption of a sedentary lifestyle are incompletely characterized. Herein, we employed the rodent wheel-lock model to identify mRNAs in the arterial wall that are responsive to the acute transition from higher to lower levels of daily physical activity. Specifically, we evaluated whether short-term cessation of voluntary wheel running alters vascular mRNA levels in rat conduit arteries previously reported to have marked increases (i.e. iliac artery) versus marked decreases (i.e. renal artery) in blood flow during running. We used young female Wistar rats with free access to voluntary running wheels. Following 23 days of voluntary running (average distance of ∼15 km per night; ∼4.4 h per night), rats in one group were rapidly transitioned to a sedentary state by locking the wheels for 7 days (n = 9; wheel-lock 7 day rats) or remained active in a second group for an additional 7 days (n = 9; wheel-lock 0 day rats). Real-time PCR was conducted on total RNA isolated from iliac and renal arteries to evaluate expression of 25 pro-atherogenic and anti-atherogenic genes. Compared with the iliac arteries of wheel-lock 0 day rats, iliac arteries of wheel-lock 7 day rats exhibited increased expression of TNFR1 (+19%), ET1 (+59%) and LOX-1 (+31%; all P < 0.05). Moreover, compared with renal arteries of wheel-lock 0 day rats, renal arteries of wheel-lock 7 day rats exhibited decreased expression of ETb (-23%), p47phox (-32%) and p67phox (-19%; all P < 0.05). These data demonstrate that cessation of voluntary wheel running for 7 days produces modest, but differential changes in mRNA levels between the iliac and renal arteries of healthy rats. This heterogeneous influence of short-term physical inactivity could be attributed to the distinct alteration in haemodynamic forces between arteries.