Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
6,140
result(s) for
"Bauer, D C"
Sort by:
Inflammatory markers are associated with ventilatory limitation and muscle dysfunction in obstructive lung disease in well functioning elderly subjects
by
Satterfield, S
,
Harris, T
,
Taaffe, D R
in
Aged
,
Biological and medical sciences
,
Body composition
2006
Background: Inflammatory markers are increased in chronic obstructive pulmonary disease (COPD) and are hypothesised to play an important part in muscle dysfunction and exercise intolerance. Methods: The Health Aging and Body Composition (Health ABC) study is a prospective observational cohort of well functioning individuals aged 70–79 years. A cross sectional analysis of the baseline data was conducted to examine the association between inflammatory markers and ventilatory limitation, muscle strength, and exercise capacity. These associations were compared in participants with and without obstructive lung disease (OLD). Results: Of the 3075 participants enrolled in the Health ABC cohort, OLD was identified by spirometric testing in 268 participants and 2005 participants had normal spirometric results. Of the participants with OLD, 35%, 38%, and 27% participants had mild, moderate, and severe OLD, respectively. Participants with OLD had lower quadriceps strength (102.5 Nm v 108.9 Nm, p = 0.02), lower maximum inspiratory pressure (64.7 cm H2O v 74.2 cm H2O, p<0.0001), higher systemic interleukin (IL)-6 levels (2.6 pg/ml v 2.2 pg/ml, p<0.0001), and higher C-reactive protein (CRP) levels (3.5 mg/l v 2.5 mg/l, p<0.0001) than those with normal spirometry. In participants with OLD and those with normal spirometry, forced expiratory volume in 1 second (FEV1) was associated with IL-6 (adjusted regression coefficients (β) = −5.3 (95% CI −9.1 to−1.5) and −3.1 (95% CI −4.3 to −1.9), respectively). IL-6 and TNF were also associated with quadriceps strength among participants with OLD and those with normal spirometry (β = −6.4 (95% CI −12.8 to −0.03) and −3.4 (95% CI −5.4 to −1.3), respectively, for IL-6 and β = −10.1 (95% CI −18.7 to −1.5) and −3.8 (95% CI −7 to −0.6), respectively, for TNF). IL-6, quadriceps strength, and maximum inspiratory pressures were independent predictors of reduced exercise capacity in both groups. Conclusions: In well functioning elderly subjects with or without OLD, IL-6 is associated with reduced FEV1, quadriceps strength, and exercise capacity.
Journal Article
Zoledronic acid reduces the rate of clinical fractures after surgical repair of a hip fracture regardless of the Pretreatment bone mineral density
2021
SummaryIn patients with surgical repair of a low-trauma hip fracture, zoledronic acid (ZA) reduced the risk of subsequent fractures regardless of pretreatment femoral neck and total hip bone mineral density (BMD).IntroductionZoledronic acid reduces the risk of subsequent fractures after repair of a hip fracture. It is still unclear whether the benefits in fracture reduction with ZA depend upon hip bone mineral density at the time of fracture.MethodsWe preformed additional post hoc analyses of data from the HORIZON Recurrent Fracture Trial to determine if ZA treatment reduced the risk of new clinical fractures regardless of pretreatment BMD. We modeled femoral neck and total hip BMD as both continuous and dichotomous variables (BMD T-score above and below −2.5).ResultsThere are no evidence that baseline femoral neck and total hip BMD modified the anti-fracture efficacy of ZA when pretreatment BMD was analyzed as a continuous or a dichotomous variable (interaction p-values > 0.20). The clinical fracture efficacy of ZA was similar among patients with pretreatment femoral neck BMD values above and below −2.5 (relative hazards = 0.60 and 0.67, respectively, interaction p-value = 0.95). A similar result was obtained using pretreatment total hip BMD values (relative hazards = 0.72 and 0.57, respectively, interaction p-value = 0.41).ConclusionThere data should provide more comfort in prescribing ZA after surgical repair of a hip fracture, regardless of pretreatment BMD.
Journal Article
HMG CoA reductase inhibitors and the skeleton: a comprehensive review
2003
Recent studies suggest that the mevalonate pathway plays an important role in skeletal metabolism. HMG CoA reductase inhibitors (\"statins\"), which inhibit a key enzyme in the mevalonate pathway, are widely used for the treatment of hyperlipidemia. In vitro and animal studies demonstrate that statins stimulate the production of BMP-2, a potent regulator of osteoblast differentiation and activity, suggesting that statins may have an anabolic effect on bone. Statin use in most, but not all observational studies is associated with a reduced risk of fracture, particularly hip fracture, even after adjustment for the confounding effects of age, weight and other medication use. This beneficial effect has not been observed in clinical trials designed to assess cardiovascular endpoints. The effects of statins on bone mass and bone turnover are controversial, but increased bone mass and reduced bone turnover have been observed in controlled studies. Further studies of the skeletal effects of statins are needed, particularly their effects on surrogate markers such as bone mass, bone turnover, and microarchitecture, to determine the optimal formulation, dosing and route of administration. Clinical trials with fracture endpoints are needed before statins can be recommended as therapeutic agents for osteoporosis.
Journal Article
Rate and circumstances of clinical vertebral fractures in older men
2008
Summary
We examined the rate of clinical vertebral fractures, and the circumstances associated with the fractures, in a cohort of 5,995 US older men. Fractures were more common in the most elderly men, and were usually associated with falls and other low-energy trauma.
Introduction
Little is known about clinical vertebral fractures in older men. We postulated that clinical vertebral fractures occur with falls, affect men with osteoporosis, and are more common as age increases.
Methods
Five thousand nine hundred and ninety-five men aged ≥65 years were followed prospectively for an average of 4.7 years. Men with incident clinical vertebral fractures were compared to controls.
Results
One percent (n = 61) sustained incident clinical vertebral fractures (2.2/1,000 person-years). The rate of fracture rose with age (0.7% in men 65–69 years and 5% ≥85 years). Fractured men were more likely frail (8.2% vs. 2.2%), more often fell (36.1% vs. 21%) and had lower total hip and lumbar spine BMD (all
p
values ≤0.002). In 73.8% of cases fractures were precipitated by no known trauma or by low-energy trauma, including falls in 57.3% Fractures were thoracic in 33% and lumbar in 56%. Men with an incident vertebral fracture were more likely to be osteoporotic (13% vs. 2%,
p
< 0.0001), but most men with incident fractures did not have osteoporosis.
Conclusions
Incident clinical vertebral fractures were relatively common in older men and the rate increased after age 80 years. Fractures were usually associated with minimal trauma, most commonly a fall.
Journal Article
Insights into the bisphosphonate holiday: a preliminary FTIRI study
2018
SummaryBone composition evaluated by FTIRI analysis of iliac crest biopsies from post-menopausal women treated with alendronate for 10 years, continuously or alendronate for 5 years, followed by a 5-year alendronate-holiday, only differed with the discontinued biopsies having increased cortical crystallinity and heterogeneity of acid phosphate substitution and decreased trabecular crystallinity heterogeneity.IntroductionBisphosphonates (BP) are the most commonly used and effective drugs to prevent fragility fractures; however, concerns exist that prolonged use may lead to adverse events. Recent recommendations suggest consideration of a BP “holiday” in individuals taking long-term BP therapy not at high risk of fracture. Data supporting or refuting this recommendation based on bone quality are limited. We hypothesized that a “holiday” of 5 years would cause no major bone compositional changes.MethodsWe analyzed the 31 available biopsies from the FLEX-Long-term Extension of FIT (Fracture Intervention Trial) using Fourier transform infrared imaging (FTIRI). Biopsies from two groups of post-menopausal women, a “Continuously treated group” (N = 16) receiving alendronate for ~ 10 years and a “Discontinued group” (N = 15), alendronate treated for 5 years taking no antiresorptive medication during the following 5 years. Iliac crest bone biopsies were provided at 10 years.ResultsKey FTIRI parameters, mineral-to-matrix ratio, carbonate-to-phosphate ratio, acid phosphate substitution, and collagen cross-link ratio as well as heterogeneity of these parameters were similar for Continuously treated and Discontinued groups in age-adjusted models. The Discontinued group had 2% greater cortical crystallinity (p = 0.01), 31% greater cortical acid phosphate heterogeneity (p = 0.02), and 24% lower trabecular crystallinity heterogeneity (p = 0.02).ConclusionsDiscontinuation of alendronate for 5 years did not affect key FTIRI parameters, supporting the hypothesis that discontinuation would have little impact on bone composition. Modest differences were observed in three parameters that are not likely to affect bone mechanical properties. These preliminary data suggest that a 5-year BP holiday is not harmful to bone composition.
Journal Article
Quantitative ultrasound predicts hip and non-spine fracture in men: the MrOS study
by
Bauer, D. C.
,
Ewing, S. K.
,
Cauley, J. A.
in
Aged
,
Aged, 80 and over
,
Biological and medical sciences
2007
Quantitative ultrasound (QUS) is associated with fracture risk in women, but there are few data in men. We studied 5,607 older men and found that QUS predicts hip and any non-spine fracture risk nearly as well as BMD. Combined measurements of QUS and BMD are not superior to either measurement alone.
Quantitative ultrasound (QUS) predicts fracture risk among older women, but there are few prospective studies among older men. We studied the ability of QUS and BMD measurements to predict hip and other non-spine fractures in a population-based study of older men.
Calcaneal QUS and hip BMD were measured in 5,607 men aged > or =65 years recruited from six US centers. At baseline duplicate QUS measurements with repositioning were obtained, and subsequent hip and other non-spine fractures were documented by review of x-rays or x-ray reports. The relationships between QUS and fractures were examined with proportional hazard models adjusted for age and clinic. We used receiver operating characteristic curves and predicted fracture risk models to determine the utility of QUS alone, BMD alone or the combination of QUS+BMD.
During a mean follow-up of 4.2 years with 99% complete follow-up, 239 men suffered a non-spine fracture, including 49 hip fractures. Each standard deviation reduction in broadband ultrasonic attenuation (BUA) was associated with an increased risk of hip (relative hazard=2.0, CI: 1.5, 2.8) and any non-spine fracture (relative hazard=1.6, CI: 1.4, 1.8). The area under the receiver operating characteristic curve and the predicted probability of fracture were similar for BUA alone, BMD alone and the combination of BUA+BMD, indicating that once BUA or BMD is known, the other measurement does not add useful information. Other QUS parameters gave similar results.
QUS measurements predict the risk of hip and any non-spine fracture in older men, and do so nearly as well as hip BMD measurements. Combined measurements of QUS and BMD are not superior to either measurement alone.
Journal Article
Radiological criteria for atypical features of femur fractures: what we can learn when applied in a clinical study setting
2019
SummaryThe paper focuses on the identification of atypical fractures (AFFs). This paper examines the concordance between objective classification and expert subjective review. We believe the paper adds critical information about how to apply the American Society of Bone and Mineral Research (ASBMR) criteria to diagnose AFFs and is of high interest to the field.IntroductionAssess American Society of Bone and Mineral Research (ASBMR) criteria for identifying atypical femoral fractures (AFFs).MethodsTwo orthopedic surgeons independently evaluated radiographs of 372 fractures, applying ASBMR criteria. We assessed ease of applying ASBMR criteria and whether criteria-based assessment matched qualitative expert assessment.ResultsThere was up to 27% uncertainty about how to classify specific features. 84% of films were classified similarly for the presence of AFF according to ASBMR criteria; agreement increased to 94% after consensus meeting. Of 37 fractures categorized as AFFs based on ASBMR criteria, 23 (62.2%) were considered AFFs according to expert assessment (not relying on criteria). Only one (0.5%) femoral shaft fracture that did not meet ASBMR criteria was considered an AFF per expert assessment. The number of major ASBMR features present (four vs five) and whether there was periosteal or endosteal thickening (“beaking” or “flaring”) played major roles in the discrepancies between ASBMR criteria-based and expert-based determinations.ConclusionsASBMR AFF criteria were useful for reviewers but several features were difficult to interpret. Expert assessments did not agree with the ASBMR classification in almost one-third of cases, but rarely identified an AFF when a femoral shaft fracture did not meet ASBMR AFF criteria. Experts identified lateral cortical transverse fracture line and associated new-bone formation along with no or minimal comminution as crucial features necessary for the definition of atypical femoral fractures.
Journal Article
Incidence and risk factors for a second hip fracture in elderly women. The Study of Osteoporotic Fractures
by
Chapurlat, R. D.
,
Stone, K.
,
Bauer, D. C.
in
Aged
,
Biological and medical sciences
,
Black people
2003
Women with hip fracture have an increased risk of second hip fracture but other risk factors for a second hip fracture have not been established. We sought to determine the incidence and risk factors for second hip fracture, in a prospective cohort study of community-dwelling postmenopausal women over 65 years: the Study of Osteoporotic Fractures. From a cohort of 9,704 women, 632 women with a documented first hip fracture during the study were followed up until a second hip fracture or the end of follow-up. Clinical risk factors and bone mineral density were assessed at the beginning of the study. Fifty-three second hip fractures were validated by radiographs. Women with hip fracture had a 2.3% per year risk of second hip fracture. Women who walked for exercise at baseline were less likely to sustain a second hip fracture with a relative risk (RR) of 0.5 [0.3-0.9], as were those who had normal depth perception (RR=0.5 [0.3-0.9]). Women who lost weight since age 25 years had an increased risk of second incident hip fracture (RR = 2.7 [1.6-4.6]), as did those who had a low calcaneal bone mineral density (RR=1.5 [1.1-2.0] per standard deviation decrease in bone mineral density). Current use of estrogen replacement therapy at baseline was protective (RR=0.5 [0.3-0.9]) up to 2 years of follow-up. We conclude that community-dwelling women with a first hip fracture have a high risk of second hip fracture, and risk factors for this second fracture are similar to those of first hip fracture.
Journal Article
Laboratory reproducibility of biochemical markers of bone turnover in clinical practice
by
Mahmoudi, N
,
Bauer, D. C
,
Ramachandran, R
in
Aged
,
Alkaline Phosphatase - blood
,
Biological and medical sciences
2010
Summary To determine the laboratory reproducibility of urine N-telopeptide and serum bone-specific alkaline phosphatase measurements, we sent identical specimens to six US commercial labs over an 8-month period. Longitudinal and within-run laboratory reproducibility varied substantially. Efforts to improve the reproducibility of these tests are needed. Introduction We assessed the laboratory reproducibility of urine N-telopeptide (NTX) and serum bone-specific alkaline phosphatase (BAP). Methods Serum and urine were collected from five postmenopausal women, pooled, divided into identical aliquots, and frozen. To evaluate longitudinal reproducibility, identical specimens were sent to six US commercial labs on five dates over an 8-month period. To evaluate within-run reproducibility, on the fifth date, each lab was sent five identical specimens. Labs were unaware of the investigation. Results Longitudinal coefficients of variation (CVs) ranged from 5.4% to 37.6% for NTX and from 3.1% to 23.6% for BAP. Within-run CVs ranged from 1.5% to 17.2% for NTX. Compared to the Osteomark NTX assay, the Vitros ECi NTX assay had significantly higher longitudinal reproducibility (mean CV 7.2% vs. 30.3%, p < 0.0005) and within-run reproducibility (mean CV 3.5% vs. 12.7%, p < 0.0005). Conclusions Reproducibility of urine NTX and serum BAP varies substantially across US labs.
Journal Article
Clinical Use of Biochemical Markers of Bone Remodeling: Current Status and Future Directions
by
Bauer, D. C.
,
Gundberg, C. M.
,
Bell, N. H.
in
Biological and medical sciences
,
Biomarkers - blood
,
Biomarkers - urine
2000
Biochemical markers of bone turnover provide a means of evaluating skeletal dynamics that complements static measurements of bone mineral density (BMD). This review evaluates the use of commercially available bone turnover markers as aids in diagnosis and monitoring response to treatment in patients with osteoporosis. High within-person variability complicates but does not preclude their use. Elevated bone resorption markers appear to be associated with increased fracture risk in elderly women, but there is less evidence of a relationship between bone formation markers and fracture risk. The critical question of predicting fracture efficacy with treatment has not been answered. Changes in bone markers as currently determined do not predict BMD response to either bisphosphonates or hormone replacement therapy. Single measurements of markers do not predict BMD cross-sectionally (except possibly in the very elderly), or change in BMD in individual patients, either treated or untreated. On the other hand, research applications of bone turnover markers are of value in investigating the pathogenesis and treatment of bone diseases. Markers have potential in the clinical management of osteoporosis, but their use in this regard is not established. Additional studies with fracture endpoints and information on negative and positive predictive value are needed to evaluate fully the utility of bone turnover markers in individual patients.
Journal Article