Identification of Sarcopenia Components That Discriminate Slow Walking Speed: A Pooled Data Analysis.

Background: The Sarcopenia Definitions and Outcomes Consortium (SDOC) sought to identify cut points for muscle strength and body composition measures derived from dual-energy x-ray absorptiometry (DXA) that discriminate older adults with slow walking speed. This article presents the core analyses used to guide the SDOC position statements.

Design: Cross-sectional data analyses of pooled data.

Association Between Abdominal Aortic Calcification, Bone Mineral Density, and Fracture in Older Women.

Although a relationship between vascular disease and osteoporosis has been recognized, its clinical importance for fracture risk evaluation remains uncertain. Abdominal aortic calcification (AAC), a recognized measure of vascular disease detected on single-energy images performed for vertebral fracture assessment, may also identify increased osteoporosis risk. In a prospective 10-year study of 1024 older predominantly white women (mean age 75.

Adding Lateral Spine Imaging for Vertebral Fractures to Densitometric Screening: Improving Ascertainment of Patients at High Risk of Incident Osteoporotic Fractures.

The current diagnosis of osteoporosis is limited to a T-score ≤-2.5. However, asymptomatic vertebral fractures (VF) are known to predict a high risk of subsequent fractures and pharmaceutical intervention is known to reduce future fracture risk in these individuals.

Validation of rapid 4-component body composition assessment with the use of dual-energy X-ray absorptiometry and bioelectrical impedance analysis.

Background: The 4-component (4C) model is a criterion method for human body composition that separates the body into fat, water, mineral, and protein, but requires 4 measurements with significant cost and time requirements that preclude wide clinical use. A simplified model integrating only 2 measurements-dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA)-and 10 min of patient time has been proposed.

Objective: We aimed to validate a rapid, simplified 4C DXA + BIA body composition model in a clinical population.

Long-Term Atherosclerotic Vascular Disease Risk and Prognosis in Elderly Women With Abdominal Aortic Calcification on Lateral Spine Images Captured During Bone Density Testing: A Prospective Study.

Lateral spine images are captured using bone densitometers for vertebral fracture assessment (VFA) in older women. Abdominal aortic calcification (AAC) is commonly seen on these images; however, the long-term prognosis in women with AAC remains uncertain. In a prospective study of 1052 community-dwelling ambulant white women over 70 years old abdominal aortic calcification 24 scale (AAC24) scores were calculated from digital lateral spine images captured during bone density testing in 1998 or 1999.

Abdominal Aortic Calcification Identified on Lateral Spine Images From Bone Densitometers Are a Marker of Generalized Atherosclerosis in Elderly Women.

Objective: Dual-energy x-ray absorptiometry is a low-cost, minimal radiation technique used to improve fracture prediction. Dual-energy x-ray absorptiometry machines can also capture single-energy lateral spine images, and abdominal aortic calcification (AAC) is commonly seen on these images.

Approach And Results: We investigated whether dual-energy x-ray absorptiometry-derived measures of AAC were related to an established test of generalized atherosclerosis in 892 elderly white women aged >70 years with images captured during bone density testing in 1998/1999 and B-mode carotid ultrasound in 2001.

Assessment of abdominal fat compartments using DXA in premenopausal women from anorexia nervosa to morbid obesity.

Objective: To test a newly developed dual energy X-ray absorptiometry (DXA) method for abdominal fat depot quantification in subjects with anorexia nervosa (AN), normal weight, and obesity using CT as a gold standard.

Design And Methods: 135 premenopausal women (overweight/obese: n = 89, normal-weight: n = 27, AN: n = 19); abdominal visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and total adipose tissue (TAT) areas determined on CT and DXA.

Results: There were strong correlations between DXA and CT measurements of abdominal fat compartments in all groups with the strongest correlation coefficients in the normal-weight and overweight/obese groups.

Dual-energy X-ray performs as well as clinical computed tomography for the measurement of visceral fat.

Visceral adipose tissue (VAT) is associated with adverse health effects including cardiovascular disease and type 2 diabetes. We developed a dual-energy X-ray absorptiometry (DXA) measurement of visceral adipose tissue (DXA-VAT) as a low cost and low radiation alternative to computed tomography (CT). DXA-VAT was compared to VAT assessed using CT by an expert reader (E-VAT).

Volumetric DXA (VXA): A new method to extract 3D information from multiple in vivo DXA images.

Three-dimensional geometric and structural measurements of the proximal femur are of considerable interest in understanding the strength of the femur and its susceptibility to fracture. Quantitative computed tomography (QCT) with a small voxel size (≤1 mm per side) is the current "gold standard" to examine the macrostructure of the femur, but it has a high effective radiation dose (approximately 2 to 5 mSv) and cost. Volumetric dual-energy X-ray absorptiometry (VXA) uses a commercially available DXA system (Hologic Discovery A) to reconstruct the proximal femur from four DXA scans delivering an effective radiation dose of 0.

Dual energy X-Ray absorptiometry body composition reference values from NHANES.

In 2008 the National Center for Health Statistics released a dual energy x-ray absorptiometry (DXA) whole body dataset from the NHANES population-based sample acquired with modern fan beam scanners in 15 counties across the United States from 1999 through 2004. The NHANES dataset was partitioned by gender and ethnicity and DXA whole body measures of %fat, fat mass/height(2), lean mass/height(2), appendicular lean mass/height(2), %fat trunk/%fat legs ratio, trunk/limb fat mass ratio of fat, bone mineral content (BMC) and bone mineral density (BMD) were analyzed to provide reference values for subjects 8 to 85 years old. DXA reference values for adults were normalized to age; reference values for children included total and sub-total whole body results and were normalized to age, height, or lean mass.

Abdominal aortic calcification detected on lateral spine images from a bone densitometer predicts incident myocardial infarction or stroke in older women.

Unlabelled: Among a cohort of elderly women, abdominal aortic calcification scored on baseline lateral spine densitometric images intended for vertebral fracture assessment was associated with subsequent myocardial infarction or stroke over a median 4-yr period, independent of clinical cardiovascular disease risk factors.

Introduction: Cardiovascular disease (CVD) risk among older women is not adequately captured by traditional CVD risk factors. Lateral spine images obtained on bone densitometers for vertebral fracture assessment (VFA) can detect abdominal aortic calcification (AAC), an important marker of subclinical CVD.

Detection of aortic calcification during vertebral fracture assessment (VFA) compared to digital radiography.

Background: Cardiovascular disease is the most common cause of mortality among post-menopausal women. Our objective was to determine whether or not lateral spine images obtained on a bone densitometer to detect prevalent vertebral fracture can also accurately detect radiographic abdominal aortic calcification (AAC), an important risk factor for cardiovascular disease independent of clinical risk factors.

Methodology/principal Findings: One hundred seventy four postmenopausal women had bone densitometry, lateral spine densitometry imaging (called vertebral fracture assessment, or VFA), and lateral spine digital radiographs.

Detection of abdominal aortic calcification with lateral spine imaging using DXA.

Radiographic abdominal aortic calcification (AAC) is associated with incident cardiovascular disease and mortality independent of other risk factors. Lateral spine imaging using dual-energy X-ray absorptiometry (DXA) is now available to detect prevalent vertebral fracture (called vertebral fracture assessment), but its potential utility to detect radiographic AAC has not been investigated. Fifty-seven of 205 women age 65 or older who had participated in a prior study of the detection of prevalent vertebral fracture with lateral DXA had technically adequate radiographs and lateral DXA images to assess AAC.

Emerging trends in dual energy X-ray absorptiometry.

The risk of osteoporosis and cardiovascular disease increase significantly with age. Because of the long silent latency of these diseases, there is the opportunity for primary prevention before clinical symptoms occur. The newer fan beam dual energy x-ray absorptiometry (DXA) systems can detect vertebral fractures with fast, low dose lateral scans of the vertabrae from T4 to L4 in as little as 10 s.