Bone mineral density scans.
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SUBMITTER: Berger A
PROVIDER: S-EPMC1124002 | biostudies-literature | 2002 Aug
REPOSITORIES: biostudies-literature
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Project description:Intervals between dual-energy X-ray absorptiometry (DXA) scans were evaluated in a large cohort of typical clinical practice. Intensive DXA scanning (intervals < 23 months) decreased substantially, from 16.7% in 2006 to 6.7% in 2015. INTRODUCTION:Serial dual-energy X-ray absorptiometry (DXA) measurements are suggested for patients at high risk of fractures. However, little is known about how often DXA testing occurs in clinical practice. METHODS:We examined time intervals between DXA testing for monitoring purpose at two academic medical centers in the US between 2004 and 2017. The primary outcome was the presence of testing intervals < 23 months (termed "intensive DXA testing"). A generalized linear mixed model was used to evaluate the association between selected patient-level clinical factors and intensive DXA testing. RESULTS:Forty-nine thousand four hundred ninety-four DXA tests from 20,200 patients were analyzed. The mean time interval between scans was 36 ± 21 months. Only 11.1% of the repeated DXA testing met the criterion for intensive testing. The percentage of intensive DXA testing dropped from 16.7% in 2006 to 6.7% in 2015 (p for trend < 0.001). After adjusting for age, gender, number of outpatient visits, and calendar year, correlates of intensive DXA testing included a baseline T-score < -2.5 at any anatomic site (OR, 4.8; 95%CI, 4.0-5.7), active use of drugs for osteoporosis (OR, 1.6; 95%CI, 1.3-1.9), and active use of glucocorticoids (OR, 1.3; 95%CI, 1.2-1.4). CONCLUSIONS:The predictors of intensive DXA testing suggest that this practice is used preferentially in patients with multiple risk factors and to monitor the response to pharmacotherapy. However, intensive DXA testing has become less common in real-world clinical practice over the last decade. Further studies are required to better define the optimal use of bone mineral density testing in this vulnerable population.
| S-EPMC6499657 | biostudies-literature
Project description:UNLABELLED:New models describing anthropometrically adjusted normal values of bone mineral density and content in children have been created for the various measurement sites. The inclusion of multiple explanatory variables in the models provides the opportunity to calculate Z-scores that are adjusted with respect to the relevant anthropometric parameters. INTRODUCTION:Previous descriptions of children's bone mineral measurements by age have focused on segmenting diverse populations by race and sex without adjusting for anthropometric variables or have included the effects of a single anthropometric variable. METHODS:We applied multivariate semi-metric smoothing to the various pediatric bone-measurement sites using data from the Bone Mineral Density in Childhood Study to evaluate which of sex, race, age, height, weight, percent body fat, and sexual maturity explain variations in the population's bone mineral values. By balancing high adjusted R(2) values with clinical needs, two models are examined. RESULTS:At the spine, whole body, whole body sub head, total hip, hip neck, and forearm sites, models were created using sex, race, age, height, and weight as well as an additional set of models containing these anthropometric variables and percent body fat. For bone mineral density, weight is more important than percent body fat, which is more important than height. For bone mineral content, the order varied by site with body fat being the weakest component. Including more anthropometrics in the model reduces the overlap of the critical groups, identified as those individuals with a Z-score below -2, from the standard sex, race, and age model. CONCLUSIONS:If body fat is not available, the simpler model including height and weight should be used. The inclusion of multiple explanatory variables in the models provides the opportunity to calculate Z-scores that are adjusted with respect to the relevant anthropometric parameters.
| S-EPMC4768717 | biostudies-literature
Project description:CONTEXT:Dual-energy X-ray absorptiometry (DXA) is a cornerstone of pediatric bone health assessment, yet differences in height-for-age confound the interpretation of areal bone mineral density (aBMD) measures. To reduce the confounding of short stature on spine bone density, use of bone mineral apparent density (BMAD) and height-for-age Z-score (HAZ)?adjusted aBMD (aBMDHAZ) are recommended. However, spine BMAD reference data are sparse, and the degree to which BMAD and aBMDHAZ account for height-related artifacts in bone density remains unclear. OBJECTIVE:We developed age-, sex-, and population ancestry?specific spine BMAD reference ranges; compared height-adjustment methods in accounting for shorter stature; and assessed the stability of these measures over time. DESIGN:Secondary analysis of data from a previous longitudinal study. PARTICIPANTS:Children and adolescents aged 5 to 19 years at baseline (n = 2014; 922 males; 22% black) from the Bone Mineral Density in Childhood Study. MAIN OUTCOME MEASURES:Lumbar spine BMAD and aBMDHAZ from DXA. RESULTS:Spine BMAD increased nonlinearly with age and was greater in blacks and females (all P < 0.001). Age-specific spine BMAD z-score reference curves were constructed for black and non?black males and females. Overall, both BMAD and aBMDHAZz scores reduced the confounding influence of shorter stature, but neither was consistently unbiased across all age ranges. Both BMAD and aBMDHAZz scores tracked strongly over 6 years (r = 0.70 to 0.80; all P < 0.001). CONCLUSION:This study provided robust spine BMAD reference ranges and demonstrated that BMAD and aBMDHAZ partially reduced the confounding influence of shorter stature on bone density.
| S-EPMC6397436 | biostudies-literature
Project description:ObjectiveTo review the current knowledge on bone health in patients with hemophilia A and the underlying pathogenetic mechanisms.Data sourcesOriginal research articles, meta-analyses, and scientific reviews.Data synthesisAlready in childhood, patients with hemophilia A are prone to low bone mineral density, leading to osteopenia and/or osteoporosis. Initially associated with the life style of hemophilia, today we are faced with accumulating evidence that coagulation factor VIII is involved directly or indirectly in bone physiology.ConclusionUnderstanding the role of factor VIII and the mechanisms of decreased bone mineral density in hemophilia A is critically important, especially as non-factor replacement therapies are available, and treatment decisions potentially impact bone health.
| S-EPMC8849249 | biostudies-literature
Project description:To date, the only published reports of bone mineral density (BMD) in MPS IV involve patients with MPS IVA; no reports exist describing BMD for MPS IVB. In this prospective study of BMD in three patients with MPS IVB, BMD was acquired by dual-energy X-ray absorptiometry (DXA) at whole body (WB), lumbar spine (LS), and lateral distal femur (LDF). Functional abilities, ambulatory status, medical history, and height z-score were evaluated. Three patients with MPS IVB (two females), aged 17.7, 31.4 and 31.7 years, were evaluated. Every patient was ambulatory and one sustained two fractures caused by trauma. Whole body and hip DXA scans were technically invalid in every patient due to the presence of prosthetic hip hardware. Lumbar spine was valid in only 1 patient due skeletal abnormalities, and was normal (Z-score of - 0.8). The LDF was valid in every patient and was low at all three regions of interest: average LDF z-scores were - 3.1 (range, - 2.9 to - 3.6), - 2.3 (range, - 2.0 to - 2.5), and - 2.1 (range, - 2.0 to - 2.3) for region 1-region 3, respectively. Patients with MPS IVB have low BMD of the lower extremities even with full-time ambulation. Routine body sites to measure by DXA were problematic; hip and WB were invalid due to artifact, and LS had limited utility. The LDF was the only body site consistently available on all patients. Patients did not experience low-energy fractures despite low BMD.
| S-EPMC5036531 | biostudies-literature
Project description:ObjectivesTo assess the effects of antiretroviral therapy (ART) on bone mineral density (BMD) DESIGN: Randomized comparison of continuous ART (viral suppression group; VS) with intermittent ART (drug conservation group; DC) SETTING: Outpatient clinics in the United States, Australia, and Spain.ParticipantsParticipants in the Strategies for Management of Antiretroviral Therapy (SMART) Body Composition substudy.Main outcome measuresAnnual hip and spine BMD by dual-energy radiographic absorptiometry (DXA) and spine BMD by quantitative computed tomography (qCT).MethodsComparisons were by intention-to-treat analysis, using longitudinal models for change in BMD. Risk factors for BMD loss were evaluated.ResultsThe 214 participants (median 44 years, 19% female participants, 73% on ART; median T-scores -0.5 total hip, -0.7 spine DXA, -0.9 spine qCT; 98 randomized to VS and 116 to DC) were followed for a mean 2.4 years. With continuous ART, BMD declined per year by 0.8% (hip), 0.4% (spine DXA), and 2.4% (spine qCT). BMD declined significantly less with intermittent ART. Estimated DC minus VS group differences in mean BMD change through follow-up were 1.4% [hip; 95% confidence interval (CI) 0.6-2.3; P = 0.002], 1.3% (spine DXA; 95% CI 0.1-2.4, P = 0.03), and 3.0% (spine qCT; 95% CI 0.8-5.2, P = 0.007). No consistent drug-specific association with BMD decline was found. In the parent study, 10 of 2753 participants in the VS group and two of 2720 in the DC group reported serious fractures (hazard ratio 4.9; 95% CI 1.1-22.5; P = 0.04).ConclusionContinuous ART is associated with decline in BMD and possibly more fractures relative to intermittent, CD4 cell count-guided ART.
| S-EPMC2748675 | biostudies-literature
Project description:Ovariectomy in young, growing rodents results in decreased trabecular bone mineral density (BMD) and increased radial growth of the cortical bone. Both of these effects are reversed by treatment with estrogen. The aim of the present study was to determine the physiological role of estrogen receptor-beta (ERbeta) on bone structure and bone mineral content (BMC). The BMC was increased in adult (11 weeks old), but not prepubertal (4 weeks old), female ERbeta(-/-) mice compared with wild-type (WT) mice. This increase in BMC in females was not due to increased trabecular BMD, but to an increased cross-sectional cortical bone area associated with a radial bone growth. Male ERbeta(-/-) mice displayed no bone abnormalities compared with WT mice. Ovariectomy decreased the trabecular BMD to the same extent in adult female ERbeta(-/-) mice as in WT mice. The expression levels of osteoblast-associated genes - alpha1(I) collagen, alkaline phosphatase, and osteocalcin mRNAs - were elevated in bone from adult ERbeta(-/-) females compared with WT mice. These observations provide a possible explanation for the increased radial bone growth seen in female mutants, suggesting a repressive function for ERbeta in the regulation of bone growth during female adolescence. In summary, ERbeta is essential for the pubertal feminization of the cortical bone in female mice but is not required for the protective effect of estrogens on trabecular BMD.
| S-EPMC408552 | biostudies-literature
Project description:BACKGROUND:Body mass compartments may have different directions of influence on bone accrual. Studies of children are limited by relatively small sample sizes and typically make strong assumptions of linear regression. OBJECTIVE:To evaluate associations of overall body mass, components of overall body mass (fat-free and total fat), and components of total fat mass (truncal and non-truncal fat), measured via dual-energy X-ray absorptiometry (DXA) and anthropometry, with total body less head areal bone mineral density (aBMD) Z-score in mid-childhood. METHODS:We performed a cross-sectional study among 876 Boston-area children who had DXA measures. We evaluated linearity of associations using generalized additive models. RESULTS:Children were median 7.7 (range 6-10) years of age, and 61% were white. After adjustment for sociodemographics and other compartments of body mass, overall body mass, particularly the fat-free mass component, appeared to have a positive relationship with aBMD Z-score [e.g., 0.25 (95% CI: 0.23, 0.28) per 1-kg fat-free mass]. The relationship between truncal fat and aBMD Z-score appeared non-linear, with a negative association only in children with levels of fat mass in the upper 15th percentile [-0.17 (95% CI: -0.26, -0.07) aBMD Z-score per 1-kg truncal fat mass], while non-truncal fat mass was not associated with aBMD Z-score. CONCLUSIONS:Our analyses suggest that central adiposity is associated with lower aBMD Z-score only in children with the highest levels of abdominal fat. This finding raises the possibility of a threshold above which central adipose tissue becomes more metabolically active and thereby adversely impacts bone.
| S-EPMC6391186 | biostudies-literature
Project description:Bone mineral density (BMD) measurement by dual-energy x-ray absorptiometry (DXA) is an internationally accepted standard-of-care screening tool used to assess fragility-fracture risk. Society guidelines have recommended which populations may benefit from DXA screening and the use of the fracture risk assessment tool (FRAX) to guide decisions regarding pharmacologic treatment for osteoporosis. According to the U.S. National Osteoporosis Foundation guidelines, postmenopausal women and men at least 50 y old with osteopenic BMD warrant pharmacologic treatment if they have a FRAX-calculated 10-y probability of at least 3% for hip fracture or at least 20% for major osteoporotic fracture. Patients with osteoporosis defined by a clinical event, namely a fragility fracture, or with an osteoporotic BMD should also be treated. Patients who are treated for osteoporosis should be monitored regularly to track expected gains in BMD by serial DXA scans. With some drug therapies, BMD targets can be reached whereby further improvements in BMD are not associated with further reductions in fracture risk. Although reaching this target might suggest a stopping point for therapy, the reversibility of most treatments for osteoporosis, except for the bisphosphonates, has dampened enthusiasm for this approach. In the case of denosumab, it is now apparent that stopping therapy at any point can lead to an increase in multiple-fracture risk. For patients who do not respond to antiosteoporosis pharmacologic therapy with an improvement in BMD, or who have an incident fragility fracture on therapy, secondary causes of osteoporosis or non-compliance with medical therapy should be considered.
| S-EPMC8049374 | biostudies-literature
Project description:BackgroundPatients with inherited bone marrow failure syndromes (IBMFS) may have several risk factors for low bone mineral density (BMD). We aimed to evaluate the prevalence of low BMD in IBMFS and determine the associated risk factors.MethodsPatients with IBMFS with at least one dual-energy X-ray absorptiometry (DXA) scan were evaluated. Diagnosis of each IBMFS, Fanconi anemia (FA), dyskeratosis congenita, Diamond-Blackfan anemia, and Shwachman-Diamond syndrome was confirmed by syndrome-specific tests. Data were gathered on age, height, and clinical history. DXA scans were completed at the lumbar spine, femoral neck, and forearm. BMD was adjusted for height (HAZ) in children (age ≤20 years). Low BMD was defined as a BMD Z-score and HAZ ≤-2 in adults and children, respectively, in addition to patients currently on bisphosphonate therapy.ResultsNine of thirty-five adults (26%) and eleven of forty children (27%) had low BMD. Adults with FA had significantly lower BMD Z-scores than those with other diagnoses; however, HAZ did not vary significantly in children by diagnosis. Risk factors included hypogonadism, iron overload, and glucocorticoid use.ConclusionsAdults and children with IBMFS have high prevalence of low BMD. Prompt recognition of risk factors and management are essential to optimize bone health.
| S-EPMC5570650 | biostudies-literature