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Bone Nov 2017Body composition measurements from DXA have been available since DXA technology was developed 30years ago, but are historically underutilized. Recently, there have been...
Body composition measurements from DXA have been available since DXA technology was developed 30years ago, but are historically underutilized. Recently, there have been rapid developments in body composition assessment including the analysis and publication of representative data for the US, official usage guidance from the International Society for Clinical Densitometry, and development of regional body composition measures with clinical utility. DXA body composition is much more than whole body percent fat. In this paper celebrating 30years of DXA for body composition, we will review the principles of DXA soft tissue analysis, practical clinical and research applications, and what to look for in the future.
Topics: Absorptiometry, Photon; Bariatrics; Body Composition; Body Size; Humans; Osteoporosis
PubMed: 28625918
DOI: 10.1016/j.bone.2017.06.010 -
Archives of Endocrinology and Metabolism Nov 2022Osteoporosis, a disease classically attributed to postmenopausal women, is underappreciated, underdiagnosed, and undertreated in men. However, it is not uncommon for... (Review)
Review
Osteoporosis, a disease classically attributed to postmenopausal women, is underappreciated, underdiagnosed, and undertreated in men. However, it is not uncommon for osteoporotic fractures to occur in men. About 40% of fractures occur in men with an incidence that has increased over the years. After a first fracture, the risk of a subsequent episode, as well as the risk of death, is higher in the male than in the female population. Despite these facts, only 10% of men with osteoporosis receive adequate treatment. Up to half of the cases of male osteoporosis have a secondary cause, the most common being hypogonadism, excessive alcohol consumption, and chronic use of glucocorticoids. The International Society for Clinical Densitometry (ISCD) recommends using the female database for the diagnosis of osteoporosis by DXA (T-score ≤ -2.5 in men over 50 years old). In addition, osteoporosis can also be diagnosed independently of the BMD if a fragility fracture is present, or if there is a high risk of fractures by FRAX. Treatment is similar to postmenopausal osteoporosis, because the data regarding changes in bone density track closely to those in women. Data concerning fracture risk reduction are not as certain because the clinical trials have included fewer subjects for shorter period of time. In men with symptomatic hypogonadism, testosterone replacement, if indicated, can improve BMD.
Topics: Female; Male; Humans; Middle Aged; Osteoporosis; Osteoporotic Fractures; Bone Density; Osteoporosis, Postmenopausal; Hypogonadism; Risk Factors; Risk Assessment; Absorptiometry, Photon
PubMed: 36382763
DOI: 10.20945/2359-3997000000563 -
Nutrients Mar 2021Whilst the assessment of body composition is routine practice in sport, there remains considerable debate on the best tools available, with the chosen technique often... (Review)
Review
Whilst the assessment of body composition is routine practice in sport, there remains considerable debate on the best tools available, with the chosen technique often based upon convenience rather than understanding the method and its limitations. The aim of this manuscript was threefold: (1) provide an overview of the common methodologies used within sport to measure body composition, specifically hydro-densitometry, air displacement plethysmography, bioelectrical impedance analysis and spectroscopy, ultra-sound, three-dimensional scanning, dual-energy X-ray absorptiometry (DXA) and skinfold thickness; (2) compare the efficacy of what are widely believed to be the most accurate (DXA) and practical (skinfold thickness) assessment tools and (3) provide a framework to help select the most appropriate assessment in applied sports practice including insights from the authors' experiences working in elite sport. Traditionally, skinfold thickness has been the most popular method of body composition but the use of DXA has increased in recent years, with a wide held belief that it is the criterion standard. When bone mineral content needs to be assessed, and/or when it is necessary to take limb-specific estimations of fat and fat-free mass, then DXA appears to be the preferred method, although it is crucial to be aware of the logistical constraints required to produce reliable data, including controlling food intake, prior exercise and hydration status. However, given the need for simplicity and after considering the evidence across all assessment methods, skinfolds appear to be the least affected by day-to-day variability, leading to the conclusion 'come back skinfolds, all is forgiven'.
Topics: Absorptiometry, Photon; Athletes; Body Composition; Densitometry; Electric Impedance; Humans; Plethysmography; Reproducibility of Results; Skinfold Thickness; Spectrum Analysis; Sports; Ultrasonography
PubMed: 33806245
DOI: 10.3390/nu13041075 -
International Journal of Environmental... Jun 2021Anthropometrics are a set of direct quantitative measurements of the human body's external dimensions, which can be used as indirect measures of body composition. Due to... (Review)
Review
Anthropometrics are a set of direct quantitative measurements of the human body's external dimensions, which can be used as indirect measures of body composition. Due to a number of limitations of conventional manual techniques for the collection of body measurements, advanced systems using three-dimensional (3D) scanners are currently being employed, despite being a relatively new technique. A systematic review was carried out using Pubmed, Medline and the Cochrane Library to assess whether 3D scanners offer reproducible, reliable and accurate data with respect to anthropometrics. Although significant differences were found, 3D measurements correlated strongly with measurements made by conventional anthropometry, dual-energy X-ray absorptiometry (DXA) and air displacement plethysmography (ADP), among others. In most studies (61.1%), 3D scanners were more accurate than these other techniques; in fact, these scanners presented excellent accuracy or reliability. 3D scanners allow automated, quick and easy measurements of different body tissues. Moreover, they seem to provide reproducible, reliable and accurate data that correlate well with the other techniques used.
Topics: Absorptiometry, Photon; Anthropometry; Body Composition; Humans; Plethysmography; Reproducibility of Results; Somatotypes
PubMed: 34201258
DOI: 10.3390/ijerph18126213 -
BioMed Research International 2019Densitometry data generated for Western blots are commonly used to compare protein abundance between samples. In the last decade, it has become apparent that assumptions...
Densitometry data generated for Western blots are commonly used to compare protein abundance between samples. In the last decade, it has become apparent that assumptions underpinning these comparisons are often violated in studies reporting Western blot data in the literature. These violations can lead to erroneous interpretations of data and may contribute to poor reproducibility of research. We assessed the reliability of Western blot data obtained to study human myometrial tissue proteins. We ran dilution series of protein lysates to explore the linearity of densitometry data. Proteins analysed included SMA, HSP27, ERK1/2, and GAPDH. While ideal densitometry data are directly proportional to protein abundance, our data confirm that densitometry data often deviate from this ideal, in which case they can fit nonproportional linear or hyperbolic mathematical models and can reach saturation. Nonlinear densitometry data were observed when Western blots were detected using infrared fluorescence or chemiluminescence, and under different SDS-PAGE conditions. We confirm that ghosting artefacts associated with overabundance of proteins of interest in Western blots can skew findings. We also confirm that when data to be normalised are not directly proportional to protein abundance, it is a mistake to use the normalisation technique of dividing densitometry data from the protein-of-interest with densitometry data from loading control protein(s), as this can cause the normalised data to be unusable for making comparisons. Using spiked proteins in a way that allowed us to control the total protein amount per lane, while only changing the amount of spiked proteins, we confirm that nonlinearity and saturation of densitometry data, and errors introduced from normalisation processes, can occur in routine assays that compare equal amounts of lysate. These findings apply to all Western blot studies, and we highlight quality control checks that should be performed to make Western blot data more quantitative.
Topics: Blotting, Western; Densitometry; Electrophoresis, Polyacrylamide Gel; Humans; Proteins; Reproducibility of Results
PubMed: 30800670
DOI: 10.1155/2019/5214821 -
Nutrients Apr 2022The historical 1975 Reference Man is a ‘model’ that had been used as a basis for the calculation of radiation doses, metabolism, pharmacokinetics, sizes for organ... (Review)
Review
The historical 1975 Reference Man is a ‘model’ that had been used as a basis for the calculation of radiation doses, metabolism, pharmacokinetics, sizes for organ transplantation and ergonomic optimizations in the industry, e.g., to plan dimensions of seats and other formats. The 1975 Reference Man was not an average individual of a population; it was based on the multiple characteristics of body compositions that at that time were available, i.e., mainly from autopsy data. Faced with recent technological advances, new mathematical models and socio-demographic changes within populations characterized by an increase in elderly and overweight subjects a timely ‘state-of-the-art’ 2021 Reference Body are needed. To perform this, in vivo human body composition data bases in Kiel, Baton Rouge, San Francisco and Honolulu were analyzed and detailed 2021 Reference Bodies, and they were built for both sexes and two age groups (≤40 yrs and >40 yrs) at BMIs of 20, 25, 30 and 40 kg/m2. We have taken an integrative approach to address ‘structure−structure’ and ‘structure−function’ relationships at the whole-body level using in depth body composition analyses as assessed by gold standard methods, i.e., whole body Magnetic Resonance Imaging (MRI) and the 4-compartment (4C-) model (based on deuterium dilution, dual-energy X-ray absorptiometry and body densitometry). In addition, data obtained by a three-dimensional optical scanner were used to assess body shape. The future applications of the 2021 Reference Body relate to mathematical modeling to address complex metabolic processes and pharmacokinetics using a multi-level/multi-scale approach defining health within the contexts of neurohumoral and metabolic control.
Topics: Absorptiometry, Photon; Adipose Tissue; Adult; Aged; Body Composition; Body Water; Female; Humans; Magnetic Resonance Imaging; Male; Whole Body Imaging
PubMed: 35406138
DOI: 10.3390/nu14071526 -
Deutsches Arzteblatt International May 2020
Topics: Absorptiometry, Photon; Digestive System Surgical Procedures
PubMed: 32657752
DOI: 10.3238/arztebl.2020.0362b -
Canadian Association of Radiologists... Aug 2017
Review
Topics: Absorptiometry, Photon; Bone Density; Female; Gender Identity; Humans; Male; Osteoporosis; Transgender Persons
PubMed: 28396004
DOI: 10.1016/j.carj.2016.10.006 -
Best Practice & Research. Clinical... Sep 2022In subjects older than 50 years, the presence of clinical risk factors (CRFs) for fractures or a recent fracture is the cornerstone for case finding. In patients who are... (Review)
Review
In subjects older than 50 years, the presence of clinical risk factors (CRFs) for fractures or a recent fracture is the cornerstone for case finding. In patients who are clinically at high short- and long-term risk of fractures (those with a recent clinical fracture or with multiple CRFs), further assessment with bone mineral density (BMD) measurement using dual-energy absorptiometry (DXA), imaging of the spine, fall risk evaluation and laboratory examination contributes to treatment decisions according to the height and modifiability of fracture risk. Treatment is available with anti-resorptive and anabolic drugs, and from the start of treatment a lifelong strategy is needed to decide about continuous, intermittent, and sequential therapy. Implementation of guidelines requires further initiatives for improving case finding, public awareness about osteoporosis and national policies on reimbursement of assessment and therapy.
Topics: Humans; Osteoporotic Fractures; Absorptiometry, Photon; Spinal Fractures; Bone Density; Osteoporosis
PubMed: 35729036
DOI: 10.1016/j.berh.2022.101759 -
Revue Medicale de Liege Oct 2023We here describe the case of a post-menopausal woman presenting with a recent vertebral fracture and cortical osteopenia on bone dual energy X-ray absorptiometry. Based...
We here describe the case of a post-menopausal woman presenting with a recent vertebral fracture and cortical osteopenia on bone dual energy X-ray absorptiometry. Based on this case, we will discuss the definition and diagnosis of osteoporosis as well as the indications to treat, which go beyond the densitometric-based definition of osteoporosis. We will also address the osteoporosis screening recommendations, and the blood workup required before treatment initiation. The choice of the treatment, its duration and the non-pharmacological measures will be discussed in another article.
Topics: Female; Humans; Bone Density; Osteoporosis; Absorptiometry, Photon; Bone Diseases, Metabolic
PubMed: 37830325
DOI: No ID Found