1,988 research outputs found

    Differences in Bone Mineral Density between the Right and Left Hips in Postmenopausal Women

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    Bone mineral density (BMD) using dual energy radiography absorptiometry are commonly used for the diagnosis of osteoporosis. It is usually measured at the spine and also at one hip joint. Controversy still exists regarding the use of bilateral hip scanning. We analyzed the difference of BMD at bilateral hips in 384 postmenopausal women, retrospectively. The concordance and discordance rates of the lowest T-score and BMD between both hips were evaluated. The BMDs of the femoral neck and trochanter were significantly different between both hips (P < 0.05). There were also discrepancies between the lowest T-scores of both hips (P < 0.05). The discordance rates were about 30%. Due to significant differences in BMD between both hips at the femoral neck and trochanter and high discordance rate, bilateral hip measurements using DEXA are recommended to avoid underestimating osteoporosis

    lcc: an R package to estimate the concordance correlation, Pearson correlation and accuracy over time

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    Background and Objective: Observational studies and experiments in medicine, pharmacology and agronomy are often concerned with assessing whether different methods/raters produce similar values over the time when measuring a quantitative variable. This article aims to describe the statistical package lcc, for are, that can be used to estimate the extent of agreement between two (or more) methods over the time, and illustrate the developed methodology using three real examples. Methods: The longitudinal concordance correlation, longitudinal Pearson correlation, and longitudinal accuracy functions can be estimated based on fixed effects and variance components of the mixed-effects regression model. Inference is made through bootstrap confidence intervals and diagnostic can be done via plots, and statistical tests. Results: The main features of the package are estimation and inference about the extent of agreement using numerical and graphical summaries. Moreover, our approach accommodates both balanced and unbalanced experimental designs or observational studies, and allows for different within-group error structures, while allowing for the inclusion of covariates in the linear predictor to control systematic variations in the response. All examples show that our methodology is flexible and can be applied to many different data types. Conclusions: The lcc package, available on the CRAN repository, proved to be a useful tool to describe the agreement between two or more methods over time, allowing the detection of changes in the extent of agreement. The inclusion of different structures for the variance-covariance matrices of random effects and residuals makes the package flexible for working with different types of databases

    Corporal body adiposity (BAI) and abdominal volume (AVI) indices: Relationship with obesity scales in the working population

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    Objective: Obesity is a growing pandemic and body mass index (BMI) is insufficient to assess the risk of complications. Other estimates of adiposity are used.Materials and methods: Cross-sectional study in 193,462 workers. BMI, CUN-BAE (ClĂ­nica Universitaria de Navarra Body adiposity Estimator), Cordoba Equation (ECORE-BF), Relative Fat Mass (RFM), Metabolic Score for Visceral Fat (METS-VF) and Palafolls formula. Their correlation with body adiposity index (BAI) and abdominal volume (AVI) was estimated. SPSS 27.0 was used, considering statistical significance p&lt;0.05.Results: With all scales AVI and BAI are higher in obesity. AVI is higher in men, except with METS-VF. BAI in women has higher values in all scales. The highest values of AVI and BAI are with METS-VF, the lowest with PALAFOLLS. There is a good correlation of BMI with AVI and BAI and with the RFM and METS-VF scales and a very good correlation with Palafolls, ECORE-BF and CUN BAE. AVI and BAI show good correlation with Palafolls, ECORE-BF and CUN BAE and very good correlation with RFM and METS-VF.Conclusions: AVI and BAI show differences in their values according to sex. With METS-VF, both indexes are higher in men and women. AVI and BAI show good correlation with BMI and RFM. With METS-VF very good correlation with AVI. With the rest of the scales BAI and AVI show moderate or good correlation. The simplicity of these formulas and of both indexes makes them recommendable in clinical practice

    Anabolic resistance does not explain sarcopenia in patients with type 2 diabetes mellitus, compared with healthy controls, despite reduced mTOR pathway activity

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    BackgroundAgeing and type 2 diabetes mellitus (T2DM) are risk factors for skeletal muscle loss. We investigated whether anabolic resistance to feeding might underlie accelerated muscle loss in older people with T2DM and whether dysregulated mTOR signalling was implicated.Subjects8 obese men with T2DM, and 12 age-matched controls were studied (age 68±3 vs. 68±6y; BMI: 30±2 vs. 27±5 kg·m-2).MethodsBody composition was measured by dual-X-ray absorptiometry. Insulin and glucose were clamped at post-absorptive concentrations (13±2 vs. 9±3 mU·l-1; 7.4±1.9 vs. 4.6±0.4 mmol·l-1; T2DM vs. controls). Fractional synthetic rates (FSR) of myofibrillar and sarcoplasmic proteins were measured as the rate of incorporation of [13C] leucine during a primed, constant infusion of [1-13C] α-ketoisocaproic acid, 3 h after 10 or 20g of essential amino acids (EAA) were orally administered. Protein expression of total and phosphorylated mTOR signalling proteins was determined by Western blot analysis.ResultsDespite a significantly lower appendicular lean mass index and a greater fat mass index in T2DM vs. controls, basal myofibrillar and sarcoplasmic and post-prandial myofibrillar FSR were similar. After 20g EAA, stimulation of sarcoplasmic FSR was slightly blunted in T2DM patients. Furthermore, feeding 20g EAA increased phosphorylation of mTOR, p70S6k and 4E-BP1 by 60-100% in controls with no response observed in T2DM.ConclusionsThere was clear dissociation between changes in mTOR signalling versus changes in protein synthesis rates. However, the intact anabolic response of myofibrillar FSR to feeding in both groups suggests anabolic resistance may not explain accelerated muscle loss in T2DM

    Integrative genomic analysis implicates limited peripheral adipose storage capacity in the pathogenesis of human insulin resistance.

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    Insulin resistance is a key mediator of obesity-related cardiometabolic disease, yet the mechanisms underlying this link remain obscure. Using an integrative genomic approach, we identify 53 genomic regions associated with insulin resistance phenotypes (higher fasting insulin levels adjusted for BMI, lower HDL cholesterol levels and higher triglyceride levels) and provide evidence that their link with higher cardiometabolic risk is underpinned by an association with lower adipose mass in peripheral compartments. Using these 53 loci, we show a polygenic contribution to familial partial lipodystrophy type 1, a severe form of insulin resistance, and highlight shared molecular mechanisms in common/mild and rare/severe insulin resistance. Population-level genetic analyses combined with experiments in cellular models implicate CCDC92, DNAH10 and L3MBTL3 as previously unrecognized molecules influencing adipocyte differentiation. Our findings support the notion that limited storage capacity of peripheral adipose tissue is an important etiological component in insulin-resistant cardiometabolic disease and highlight genes and mechanisms underpinning this link.This study was funded by the UK Medical Research Council through grants MC_UU_12015/1, MC_PC_13046, MC_PC_13048 and MR/L00002/1. This work was supported by the MRC Metabolic Diseases Unit (MC_UU_12012/5) and the Cambridge NIHR Biomedical Research Centre and EU/EFPIA Innovative Medicines Initiative Joint Undertaking (EMIF grant 115372). Funding for the InterAct project was provided by the EU FP6 program (grant LSHM_CT_2006_037197). This work was funded, in part, through an EFSD Rising Star award to R.A.S. supported by Novo Nordisk. D.B.S. is supported by Wellcome Trust grant 107064. M.I.M. is a Wellcome Trust Senior Investigator and is supported by the following grants from the Wellcome Trust: 090532 and 098381. M.v.d.B. is supported by a Novo Nordisk postdoctoral fellowship run in partnership with the University of Oxford. I.B. is supported by Wellcome Trust grant WT098051. S.O'R. acknowledges funding from the Wellcome Trust (Wellcome Trust Senior Investigator Award 095515/Z/11/Z and Wellcome Trust Strategic Award 100574/Z/12/Z)

    Bone preserving level of osteotomy in short-stem total hip arthroplasty does not influence stress shielding dimensions – a comparing finite elements analysis

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    Background The main objective of every new development in total hip arthroplasty (THA) is the longest possible survival of the implant. Periprosthetic stress shielding is a scientifically proven phenomenon which leads to inadvertent bone loss. So far, many studies have analysed whether implanting different hip stem prostheses result in significant preservation of bone stock. The aim of this preclinical study was to investigate design- depended differences of the stress shielding effect after implantation of a selection of short-stem THA-prostheses that are currently available. Methods Based on computerised tomography (CT), a finite elements (FE) model was generated and a virtual THA was performed with different stem designs of the implant. Stems were chosen by osteotomy level at the femoral neck (collum, partial collum, trochanter sparing, trochanter harming). Analyses were performed with previously validated FE models to identify changes in the strain energy density (SED). Results In the trochanteric region, only the collum-type stem demonstrated a biomechanical behaviour similar to the native femur. In contrast, no difference in biomechanical behaviour was found between partial collum, trochanter harming and trochanter sparing models. All of the short stem-prostheses showed lower stress-shielding than a standard stem. Conclusion Based on the results of this study, we cannot confirm that the design of current short stem THA-implants leads to a different stress shielding effect with regard to the level of osteotomy. Somehow unexpected, we found a bone stock protection in metadiaphyseal bone by simulating a more distal approach for osteotomy. Further clinical and biomechanical research including long-term results is needed to understand the influence of short- stem THA on bone remodelling and to find the optimal stem-design for a reduction of the stress shielding effect

    Comparing Anthropometric Methods To Quantify Relations Between Adiposity And Headache

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    Obesity is associated with increased risk for chronic migraine and migraine progression, but associations with episodic migraine (em) and episodic tension-type headache (tth) are unclear. Most studies have relied on bmi as an indicator of adiposity. More accurate anthropometric measures that distinguish adipose tissue from other body tissue are critical to examine adiposity-headache associations, including validated measures of abdominal adiposity and established measurement formulas such as body adiposity index (bai) and body composition equations developed by Peterson et al. (2003) and Garcia et al. (2005). The present study explored adiposity-headache associations by employing established anthropometric measures of adiposity and comparing individuals with migraine, with tth, and without headache. Participants were 109 young adults meeting ichd-3 criteria for tth or migraine, or without headache. Ninety-three percent of migraineurs had em, and 92.5% of tth sufferers had etth. Researchers measured each participant and calculated adiposity as a function of: bmi, waist circumference, bai, waist-to-hip ratio, and the aforementioned body composition equations. Headache severity and frequency were obtained via diagnostic interview (sdih-3), and headache-related disability was assessed by the headache impact test (hit-6). Manova and a subsequent mancova did not reveal significant differences in adiposity between migraine, tth, and non-headache groups. Regression analyses indicated that among migraineurs, adiposity accounted for 11%, 13%, and 10% of the variance in headache severity, frequency, and disability, respectively, though these proportions were not statistically significant. Among participants with tth, adiposity accounted for 8% (p = .82), 21% (p =.23), and 39% (p = .009) of the variance in headache severity, frequency, and disability. The association with disability among those with tth fell short of significance after Bonferroni correction for multiple comparisons. Adiposity did not differ between headache groups, and no significant associations were found between adiposity and headache frequency, severity, and disability. Findings extend upon existing literature that has established a positive association between obesity and chronic headache, suggesting that adiposity may not be a distinguishing characteristic among individuals with em and etth. Longitudinal studies that employ gold standard methods of adiposity measurement among diverse samples are needed to further clarify the role of adiposity in headache

    Malnutrition risk questionnaire combined with body composition measurement in malnutrition screening in inflammatory bowel disease.

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    The purpose of malnutrition screening is to predict the probability of a worse outcome due to nutritional factors. The Malnutrition Universal Screening Tool (MUST) can be used for screening in inflammatory bowel disease (IBD); however, it does not provide details about body composition. Our aim was to assess the body composition and combine this with the MUST method to screen risk of malnutrition and sarcopenia. A total of 173 IBD outpatients were enrolled in this cross-sectional study. The MUST scale indicated 21.4% of IBD patients to be at risk of malnutrition. A risk of sarcopenia was detected in 27.7%. However, one third of these patients were not considered to be at risk by their MUST score. Furthermore, Crohn's disease (CD) patients had a strongly unfavorable fat-free mass index (FFMI) value compared to ulcerative colitis (UC) patients, and these differences were significant among men (FFMI: 18.62 +/- 2.16 vs 19.85 +/- 2.22, p = 0.02, in CD and UC males, respectively). As sarcopenia is a relevant prognostic factor, the MUST method should be expanded to include body composition analysis to detect more IBD patients at risk of malnutrition and sarcopenia in order to start their nutritional therapy immediately
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