315 research outputs found
Combined vertebral fracture assessment and bone mineral density measurement: a new standard in the diagnosis of osteoporosis in academic populations
Vertebral Fracture Analysis enables the detection of vertebral fractures in the same session as bone mineral density testing. Using this method in 2,424 patients, we found unknown vertebral fractures in approximately one out of each six patients with significant impact on management. The presence of osteoporotic vertebral fractures (VF) is an important risk factor for all future fractures independent of BMD. Yet, determination of the VF status has not become standard practice. Vertebral Fracture Assessment (VFA) is a new feature available on modern densitometers. In this study we aimed to determine the prevalence of VF using VFA in all patients referred for BMD testing in a university medical center and to evaluate its added clinical value. Prospective diagnostic evaluation study in 2,500 consecutive patients referred for BMD. Patients underwent VFA in supine position after BMD testing. Questionnaires were used to assess perceived added value of VFA. In 2,424 patients (1,573 women), results were evaluable. In 541 patients (22%), VFA detected a prevalent VF that was unknown in 69%. In women, the prevalence was 20% versus 27% found in men (p <0.0001). The prevalence of VF was 14% in patients with normal BMD (97/678), increased to 21% (229/1,100) in osteopenia and to 26% in those with osteoporosis (215/646) by WHO criteria. After excluding mild fractures VF prevalence was 13% (322/2,424). In 468 of 942 questionnaires (50% response rate), 27% of the referring physicians reported VFA results to impact on patient management. VFA is a patient friendly new tool with a high diagnostic yield, as it detected unknown VF in one out of each six patients, with significant impact on management. We believe these findings justify considering VFA in all new patients referred for osteoporosis assessment in similar populations
Are Bone and Muscle Changes from POWER PE, an 8-month In-school Jumping Intervention, Maintained at Three Years?
Our aim was to determine if the musculoskeletal benefits of a twice-weekly, school-based, jumping regime in healthy adolescent boys and girls were maintained three years later. Subjects of the original POWER PE trial (n = 99) were contacted and asked to undergo retesting three years after cessation of the intervention. All original measures were completed including: sitting height, standing height, weight, calcaneal broadband ultrasound attenuation (BUA), whole body, hip and spine bone mineral content (BMC), lean tissue mass, and fat mass. Physical activity was recorded with the bone-specific physical activity questionnaire (BPAQ) and calcium intake was estimated with a calcium-focussed food questionnaire. Maturity was determined by Tanner staging and estimation of the age of peak height velocity (PHV). Twenty-nine adolescents aged 17.3±0.4 years agreed to participate. Three years after the intervention, there were no differences in subject characteristics between control and intervention groups (p>0.05). Three-year change in weight, lean mass, and fat mass were similar between groups (p>0.05). There were no significant group differences in three-year change in BUA or BMC at any site (p>0.05), although the between-group difference in femoral neck BMC at follow-up exceeded the least significant change. While significant group differences were not observed three years after cessation of the intervention, changes in bone parameters occurred in parallel for intervention and control groups such that the original benefits of the intervention observed within the treatment group were sustained
A Prospective Randomized Controlled Trial of the Effects of Vitamin D Supplementation on Cardiovascular Disease Risk
Vitamin D (VitD) supplementation has been advocated for cardiovascular risk reduction; however, supporting data are sparse. The objective of this study was to determine whether VitD supplementation reduces cardiovascular risk. Subjects in this prospective, randomized, double-blind, placebo-controlled trial of post-menopausal women with serum 25-hydroxyvitamin D concentrations >10 and <60 ng/mL were randomized to Vitamin D3 2500 IU or placebo, daily for 4 months. Primary endpoints were changes in brachial artery flow-mediated vasodilation (FMD), carotid-femoral pulse wave velocity (PWV), and aortic augmentation index (AIx). The 114 subjects were mean (standard deviation) 63.9 (3.0) years old with a 25-hydroxyvitamin D level of 31.3 (10.6) ng/mL. Low VitD (<30 ng/mL) was present in 47% and was associated with higher body-mass index, systolic blood pressure, glucose, CRP, and lower FMD (all p<0.05). After 4 months, 25-hydroxyvitamin D levels increased by 15.7 (9.3) ng/mL on vitamin D3 vs. −0.2 (6.1) ng/mL on placebo (p<0.001). There were no significant differences between groups in changes in FMD (0.3 [3.4] vs. 0.3 [2.6] %, p = 0.77), PWV (0.00 [1.06] vs. 0.05 [0.92] m/s, p = 0.65), AIx (2.7 [6.3] vs. 0.9 [5.6] %, p = 0.10), or CRP (0.3 [1.9] vs. 0.3 [4.2] mg/L, p = 0.97). Multivariable models showed no significant interactions between treatment group and low VitD status (<30 ng/mL) for changes in FMD (p = 0.65), PWV (p = 0.93), AIx (p = 0.97), or CRP (p = 0.26).In conclusion, VitD supplementation did not improve endothelial function, arterial stiffness, or inflammation. These observations do not support use of VitD supplementation to reduce cardiovascular disease risk
Measurement of Lifetime and Decay-Width Difference in B0s -> J/psi phi Decays
We measure the mean lifetime, tau=2/(Gamma_L+Gamma_H), and the width
difference, DeltaGamma=Gamma_L-Gamma_H, of the light and heavy mass eigenstates
of the B0s meson, B0sL and B0sH, in B0s -> J/psi phi decays using 1.7 fb^-1 of
data collected with the CDF II detector at the Fermilab Tevatron ppbar
collider. Assuming CP conservation, a good approximation for the B0s system in
the Standard Model, we obtain DeltaGamma = 0.076^+0.059_-0.063 (stat.) +- 0.006
(syst.) ps^-1 and tau = 1.52 +- 0.04 (stat.) +- 0.02 (syst.) ps, the most
precise measurements to date. Our constraints on the weak phase and DeltaGamma
are consistent with CP conservation.
Dedicated to the memory of our dear friend and colleague, Michael P. Schmid
Validity and reliability of the Foot Function Index (FFI) questionnaire Brazilian-Portuguese version
Plasma vitamin D and risk of colorectal cancer: the Japan Public Health Center-Based Prospective Study
We investigated the association between plasma 25(OH)D and the subsequent colorectal cancer incidence risk by a nested case–control study in The Japan Public Health Center-based Prospective Study, covering 375 newly diagnosed cases of colorectal cancer from 38 373 study subjects during a 11.5-year follow-up after blood collection. Two controls were matched per case on sex, age, study area, date of blood draw, and fasting time. In a conditional logistic regression model with matched pairs adjusted for smoking, alcohol consumption, body mass index, physical exercise, vitamin supplement use, and family history of colorectal cancer, plasma 25(OH)D was not significantly associated with colorectal cancer in men or in women. However, the lowest category of plasma 25(OH)D was associated with an elevated risk of rectal cancer in both men (odds ratio (OR), 4.6; 95% confidence interval (CI), 1.0–20) and women (OR, 2.7, 95% CI, 0.94–7.6), compared with the combined category of the other quartiles. Our results suggest that a low level of plasma 25(OH)D may increase the risk of rectal cancer
Forward-Backward Asymmetry in Top Quark Production in ppbar Collisions at sqrt{s}=1.96 TeV
Reconstructable final state kinematics and charge assignment in the reaction
ppbar->ttbar allows tests of discrete strong interaction symmetries at high
energy. We define frame dependent forward-backward asymmetries for the outgoing
top quark in both the ppbar and ttbar rest frames, correct for experimental
distortions, and derive values at the parton-level. Using 1.9/fb of ppbar
collisions at sqrt{s}=1.96 TeV recorded with the CDF II detector at the
Fermilab Tevatron, we measure forward-backward top quark production asymmetries
in the ppbar and ttbar rest frames of A_{FB,pp} = 0.17 +- 0.08 and A_{FB,tt} =
0.24 +- 0.14.Comment: 7 pages, 2 figures, submitted to Phys.Rev.Lett, corrected references
and change of tex
Search for Pair Production of Scalar Top Quarks Decaying to a tau Lepton and a b Quark in ppbar Collisions at sqrt{s}=1.96 TeV
We search for pair production of supersymmetric top quarks (~t_1), followed
by R-parity violating decay ~t_1 -> tau b with a branching ratio beta, using
322 pb^-1 of ppbar collisions at sqrt{s}=1.96 TeV collected by the CDF II
detector at Fermilab. Two candidate events pass our final selection criteria,
consistent with the standard model expectation. We set upper limits on the
cross section sigma(~t_1 ~tbar_1)*beta^2 as a function of the stop mass
m(~t_1). Assuming beta=1, we set a 95% confidence level limit m(~t_1)>153
GeV/c^2. The limits are also applicable to the case of a third generation
scalar leptoquark (LQ_3) decaying LQ_3 -> tau b.Comment: 7 pages, 2 eps figure
High prevalence of vitamin D insufficiency and its association with obesity and metabolic syndrome among Malay adults in Kuala Lumpur, Malaysia
Background: Vitamin D status, as indicated by 25-hydroxyvitamin D is inversely associated with adiposity, glucose homeostasis, lipid profiles, and blood pressure along with its classic role in calcium homeostasis and bone metabolism. It is also shown to be inversely associated with metabolic syndrome and cardiovascular diseases in western populations. However, evidence from the Asian population is limited. Therefore, we aim to study the prevalence of vitamin D insufficiency (< 50 nmol/L) and the association of 25-hydroxyvitamin D with metabolic risk factors among an existing Malay cohort in Kuala Lumpur. Methods: This is an analytical cross sectional study. A total of 380 subjects were sampled and their vitamins D status (25-hydroxyvitamin D), fasting blood glucose, full lipid profile were assessed using venous blood. Systolic and diastolic blood pressure, weight, height and waist circumference were measured following standard protocols. Socio-demographic data such as sex, age, smoking status etc were also collected. Data was analysed using t-test, chi-square test, General Linear Model and multiple logistic regression. Results: Females made up 58 of the sample. The mean age of respondents was 48.5 (SD 5.2) years. Females had significantly lower mean Vitamin D levels (36.2; 95 CI: 34.5, 38.0 nmol/L) compared to males (56.2; 95 CI: 53.2, 59.2 nmol/L). Approximately 41 and 87 of males and females respectively had insufficient (< 50 nmol/L) levels of 25-hydroxyvitamin D (p < 0.001). The prevalence of Metabolic Syndrome for the whole sample was 38.4 (95 CI: 33.5, 43.3). In the multivariate model (adjusted for age, sex, abdominal obesity, HDL-cholesterol, diastolic blood pressure), insufficient Vitamin D status was significantly associated with 1-year age increments (OR: 0.93; 95 CI: 0.88, 0.98), being female (OR: 8.68; 95 CI: 5.08, 14.83) and abdominal obesity (OR: 2.57; 95 CI: 1.51, 4.39). Respondents with insufficient vitamin D were found to have higher odds of having Metabolic Syndrome (OR: 1.73; 95 CI: 1.02, 2.92) after adjusting for age and sex. Conclusions: Our results highlight the high prevalence of vitamin D insufficiency among Malay adults in Kuala Lumpur. Vitamin D insufficiency is independently associated with younger age, female sex and greater abdominal obesity. Vitamin D insufficiency is also associated with Metabolic Syndrome
Search for Neutral Higgs Bosons in Events with Multiple Bottom Quarks at the Tevatron
The combination of searches performed by the CDF and D0 collaborations at the
Fermilab Tevatron Collider for neutral Higgs bosons produced in association
with b quarks is reported. The data, corresponding to 2.6 fb-1 of integrated
luminosity at CDF and 5.2 fb-1 at D0, have been collected in final states
containing three or more b jets. Upper limits are set on the cross section
multiplied by the branching ratio varying between 44 pb and 0.7 pb in the Higgs
boson mass range 90 to 300 GeV, assuming production of a narrow scalar boson.
Significant enhancements to the production of Higgs bosons can be found in
theories beyond the standard model, for example in supersymmetry. The results
are interpreted as upper limits in the parameter space of the minimal
supersymmetric standard model in a benchmark scenario favoring this decay mode.Comment: 10 pages, 2 figure
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