Dual-energy X-ray Absorptiometry Lean Mass Research Articles

Using magnetic resonance imaging to measure head muscles: An innovative method to opportunistically determine muscle mass and detect sarcopenia.

Sarcopenia is associated with multiple adverse outcomes. Traditional methods to determine low muscle mass for the diagnosis of sarcopenia are mainly based on dual-energy X-ray absorptiometry (DXA), whole-body magnetic resonance imaging (MRI) and bioelectrical impedance analysis. These tests are not always available and are rather time consuming and expensive. However, many brain and head diseases require a head MRI. In this study, we aim to provide a more accessible way to detect sarcopenia by comparing the traditional method of DXA lean mass estimation versus the tongue and masseter muscle mass assessed in a standard brain MRI. The H70 study is a longitudinal study of older people living in Gothenburg, Sweden. In this cross-sectional analysis, from 1203 participants aged 70years at baseline, we included 495 with clinical data and MRI images available. We used the appendicular lean soft tissue index (ALSTI) in DXA images as our reference measure of lean mass. Images from the masseter and tongue were analysed and segmented using 3D Slicer. For the statistical analysis, the Spearman correlation coefficient was used, and concordance was estimated with the Kappa coefficient. The final sample consisted of 495 participants, of which 52.3% were females. We found a significant correlation coefficient between both tongue (0.26) and masseter (0.33) with ALSTI (P<0.001). The sarcopenia prevalence confirmed using the alternative muscle measure in MRI was calculated using the ALSTI (tongue=2.0%, masseter=2.2%, ALSTI=2.4%). Concordance between sarcopenia with masseter and tongue versus sarcopenia with ALSTI as reference has a Kappa of 0.989 (P<0.001) for masseter and a Kappa of 1 for the tongue muscle (P<0.001). Comorbidities evaluated with the Cumulative Illness Rating Scale were significantly associated with all the muscle measurements: ALSTI (odds ratio [OR] 1.16, 95% confidence interval [CI] 1.07-1.26, P<0.001), masseter (OR 1.16, 95% CI 1.07-1.26, P<0.001) and tongue (OR 1.13, 95% CI 1.04-1.22, P=0.002); the higher the comorbidities, the higher the probability of having abnormal muscle mass. ALSTI was significantly correlated with tongue and masseter muscle mass. When performing the sarcopenia diagnostic algorithm, the prevalence of sarcopenia calculated with head muscles did not differ from sarcopenia calculated using DXA, and almost all participants were correctly classified using both methods.

Immune Profile and Body Composition of Independent Oldest Old: The Longevous Project

Introduction: Immunosenescence is associated with changes in lymphocyte function, thymus atrophy, and a chronic inflammatory process referred to as “inflammaging,” which may in part be linked to eating disorders. Objective: The aim of the study was to determine the prevalence rate of immunological alterations, including immune risk profile (IRP), and their association with body composition in the oldest old individuals. Methods: A cross-sectional study of 201 older adults aged 80 years and over, able to walk unaided, with no cognitive or immunological impairment, and with no serious diseases was conducted. Blood samples were collected between 2012 and 2014 during the morning period, and the following tests were conducted: urea, creatinine, hemogram, fasting glucose, glycated hemoglobin, transferrin, albumin, 25-OH vitamin D, and high-sensitivity CRP. Plasma cytokines were measured and mononuclear cell counts were performed by flow cytometry. Anthropometric measurements and densitometry using dual-energy X-ray absorptiometry (DXA) were performed to assess body composition. Results: Mean age was 84.4 ± 3.7 years, and the numbers of T cells were CD4, 784.0 cell/µL; CD8, 371.0 cell/µL; and CD4/CD8, 2.4. The rate of CD4/CD8 <1 (IRP) was 9.4%, CD4/CD8 1–5 was 85.6%, while CD4/CD8 >5 was only 5.5%. CRP, tumor necrosis factor, IL1, IL4, IL6, and IL10 variables showed a high coefficient of variation but low mean values of 1.1 ± 3.1 mg/L for CRP (reference range <3 mg/L) and 3.9 ± 5.0 pg/mL for IL6 (reference range <7.0 pg/mL). The same pattern was found for all other inflammatory variables assessed, characterizing a population whose values indicated low level of inflammation, considering age. Lean mass, as measured by DXA, was higher in men than in women, while the inverse was found for fat % (p < 0.001). A positive association between CRP values and DXA fat % (p value: 0.007, r: 0.49) and a negative association between CRP values and DXA lean mass (p value: 0.046, r:–0.37) was observed. Conclusion: In the independent oldest old, IRP rate proved low and high-sensitivity CRP was shown to be associated with body composition.

Resistance Training Muscle Adaptations Using D3-creatine Dilution In Older Adults: A Pilot Study

High intensity resistance training (RT) is well known to increase muscle mass in older adults. However, the degree to which is dependent on the measurement method. D3-creatine (D3Cr) dilution is a promising new method that provides a direct and accurate measurement of creatine pool size and whole-body skeletal muscle mass. There are a limited number of studies that compare intervention-based adaptations between D3Cr derived skeletal mass versus lean mass by dual energy x-ray absorptiometry (DXA) Purpose: To evaluate and compare D3Cr derived skeletal mass and DXA lean mass changes following whole body progressive RT in moderate to low functioning older adults. Methods: Twenty-four older adults who tested as moderate to low-functioning on a standardized performance battery were randomized to a whole-body RT or health education program. RT was performed 3 days per week for 14 weeks. It included upper and lower body exercises performed at ~70% of maximal strength in progressive manner. Health education workshops were conducted weekly as an attention “control”. D3Cr dilution and whole body DXA scans were performed prior to randomization and shortly after completion of the programs. Results: D3Cr derived whole body skeletal mass increased more in participants randomized to the RT group compared to the health education group (3.5 ± 2.0 vs. 1.2 ± 1.7 kg, p = 0.03). Mean differences between groups was lower with DXA appendicular lean (RT: 0.81 ± 0.67 vs Education: -0.23 ± 0.70 kg, p = 0.008) and DXA total lean body mass (RT: 1.1 ± 1.4 vs Education: -0.19 ± 0.70 kg, p = 0.06). Pearson correlation coefficients showed weak relationships between changes in D3Cr muscle and DEXA appendicular (0.19, p = 0.48) and total lean mass measures (0.41, p = 0.13). Conclusions: This pilot study demonstrates that D3Cr dilution method is sufficiently sensitive to detect whole body changes in skeletal muscle mass of older adults. The unexpected discordance between D3Cr dilution and traditional DXA based measures of lean mass requires further study.

Different Protein Sources Enhance 18FDG-PET/MR Uptake of Brown Adipocytes in Male Subjects.

Background: The unique ability of brown adipocytes to increase metabolic rate suggests that they could be targeted as an obesity treatment. Objective: The objective of the study was to search for new dietary factors that may enhance brown adipose tissue (BAT) activity. Methods: The study group comprised 28 healthy non-smoking males, aged 21–42 years old. All volunteers underwent a physical examination and a 75 g oral glucose tolerance test (75g-OGTT). Serum atrial and brain natriuretic peptide (ANP, BNP), PRD1-BF1-RIZ1 homologous domain containing 16 (PRDM16) and eukaryotic translation initiation factor 4E (eIF4E) measurements were taken, and 3-day food intake diaries were completed. Body composition measurements were assessed using dual-energy X-ray absorptiometry (DXA) scanning and bioimpedance methods. An fluorodeoxyglucose-18 (FDG-18) uptake in BAT was assessed by positron emission tomography/magnetic resonance (PET/MR) in all participants after 2 h cold exposure. The results were adjusted for age, daily energy intake, and DXA lean mass. Results: Subjects with detectable BAT (BAT(+)) were characterized by a higher percentage of energy obtained from dietary protein and fat and higher muscle mass (p = 0.01, p = 0.02 and p = 0.04, respectively). In the BAT(+) group, animal protein intake was positively associated (p= 0.04), whereas the plant protein intake negatively correlated with BAT activity (p = 0.03). Additionally, the presence of BAT was inversely associated with BNP concentration in the 2 h of cold exposure (p = 0.002). Conclusion: The outcomes of our study suggest that different macronutrient consumption may be a new way to modulate BAT activity leading to weight reduction.

CT pectoralis muscle area is associated with DXA lean mass and correlates with emphysema progression in a tobacco-exposed cohort

IntroductionMuscle loss is an important extrapulmonary manifestation of COPD. Dual energy X-ray absorptiometry (DXA) is the method of choice for body composition measurement but is not widely used for muscle...

Putative Cut-Points in Sarcopenia Components and Incident Adverse Health Outcomes: An SDOC Analysis.

Analyses performed by the Sarcopenia Definitions and Outcomes Consortium (SDOC) identified cut-points in several metrics of grip strength for consideration in a definition of sarcopenia. We describe the associations between the SDOC-identified metrics of low grip strength (absolute or standardized to body size/composition); low dual-energy x-ray absorptiometry (DXA) lean mass as previously defined in the literature (appendicular lean mass [ALM]/ht2 ); and slowness (walking speed <.8 m/s) with subsequent adverse outcomes (falls, hip fractures, mobility limitation, and mortality). Individual-level, sex-stratified pooled analysis. We calculated odds ratios (ORs) or hazard ratios (HRs) for incident falls, mobility limitation, hip fractures, and mortality. Follow-up time ranged from 1 year for falls to 8.8 ± 2.3 years for mortality. Eight prospective observational cohort studies. A total of 13,421 community-dwelling men and 4,828 community-dwelling women. MEASUREMENTS Grip strength by hand dynamometry, gait speed, and lean mass by DXA. Low grip strength (absolute or standardized to body size/composition) was associated with incident outcomes, usually independently of slowness, in both men and women. ORs and HRs generally ranged from 1.2 to 3.0 for those below vs above the cut-point. DXA lean mass was not consistently associated with these outcomes. When considered together, those who had both muscle weakness by absolute grip strength (<35.5 kg in men and <20 kg in women) and slowness were consistently more likely to have a fall, hip fracture, mobility limitation, or die than those without either slowness or muscle weakness. Older men and women with both muscle weakness and slowness have a higher likelihood of adverse health outcomes. These results support the inclusion of grip strength and walking speed as components in a summary definition of sarcopenia. J Am Geriatr Soc 68:1429-1437, 2020.

Associations of protein intake in early childhood with body composition, height, and insulin-like growth factor I in mid-childhood and early adolescence

BACKGROUND Early protein intake may program later body composition and height growth, perhaps mediated by insulin-like growth factor I (IGF-I). In infancy, higher protein intake is consistently associated with higher IGF-I concentrations and more rapid growth, but associations of protein intake after infancy with later growth and IGF-I are less clear. OBJECTIVES Our objective was to examine associations of protein intake in early childhood (median 3.2 y) with height, IGF-I, and measures of adiposity and lean mass in mid-childhood (median 7.7 y) and early adolescence (median 13.0 y), and with changes in these outcomes over time. We hypothesized that early childhood protein intake programs later growth. METHODS We studied 1165 children in the Boston-area Project Viva cohort. Mothers reported children's diet using food-frequency questionnaires. We stratified by child sex and examined associations of early childhood protein intake with mid-childhood and early adolescent BMI z score, skinfold thicknesses, dual-energy X-ray absorptiometry (DXA) fat mass, DXA lean mass, height z score, and IGF-I concentration. We adjusted linear regression models for race/ethnicity, family sociodemographics, parental and birth anthropometrics, breastfeeding status, physical activity, and fast food intake. RESULTS Mean protein intake in early childhood was 58.3 g/d. There were no associations of protein intake in early childhood with any of the mid-childhood outcomes. Among boys, however, each 10-g increase in early childhood total protein intake was associated with several markers of early adolescent size, namely BMI z score (0.12 higher; 95% CI: 0.01, 0.23), DXA lean mass index (1.34% higher; 95% CI: -0.07%, 2.78%), and circulating IGF-I (5.67% higher; 95% CI: 0.30%, 11.3%). There were no associations with fat mass and no associations with any adolescent outcomes among girls. CONCLUSIONS Early childhood protein intake may contribute to programming lean mass and IGF-I around the time of puberty in boys, but not to adiposity development. This study was registered at clinicaltrials.gov as NCT02820402.

Associations of protein intake in early childhood with body composition, height, and insulin-like growth factor I in mid-childhood and early adolescence

Early protein intake may program later body composition and height growth, perhaps mediated by insulin-like growth factor I (IGF-I). In infancy, higher protein intake is consistently associated with higher IGF-I concentrations and more rapid growth, but associations of protein intake after infancy with later growth and IGF-I are less clear. Our objective was to examine associations of protein intake in early childhood (median 3.2 y) with height, IGF-I, and measures of adiposity and lean mass in mid-childhood (median 7.7 y) and early adolescence (median 13.0 y), and with changes in these outcomes over time. We hypothesized that early childhood protein intake programs later growth. We studied 1165 children in the Boston-area Project Viva cohort. Mothers reported children's diet using food-frequency questionnaires. We stratified by child sex and examined associations of early childhood protein intake with mid-childhood and early adolescent BMI z score, skinfold thicknesses, dual-energy X-ray absorptiometry (DXA) fat mass, DXA lean mass, height z score, and IGF-I concentration. We adjusted linear regression models for race/ethnicity, family sociodemographics, parental and birth anthropometrics, breastfeeding status, physical activity, and fast food intake. Mean protein intake in early childhood was 58.3 g/d. There were no associations of protein intake in early childhood with any of the mid-childhood outcomes. Among boys, however, each 10-g increase in early childhood total protein intake was associated with several markers of early adolescent size, namely BMI z score (0.12 higher; 95% CI: 0.01, 0.23), DXA lean mass index (1.34% higher; 95% CI: -0.07%, 2.78%), and circulating IGF-I (5.67% higher; 95% CI: 0.30%, 11.3%). There were no associations with fat mass and no associations with any adolescent outcomes among girls. Early childhood protein intake may contribute to programming lean mass and IGF-I around the time of puberty in boys, but not to adiposity development. This study was registered at clinicaltrials.gov as NCT02820402.

Lower Lean Mass Measured by Dual-Energy X-ray Absorptiometry (DXA) is Not Associated with Increased Risk of Hip Fracture in Women: The Framingham Osteoporosis Study.

Although muscle mass influences strength in older adults, it is unclear whether low lean mass measured by dual-energy X-ray absorptiometry (DXA) is an independent risk factor for hip fracture. Our objective was to determine the association between DXA lean mass and incident hip fracture risk among 1978 women aged 50years and older participating in the Framingham Study Original and Offspring cohorts. Leg and total body lean mass (kg) were assessed from whole-body DXA scans collected in 1992-2001. Hip fracture follow-up extended from DXA assessment to the occurrence of fracture, death, drop-out, or end of follow-up in 2007. Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) estimating the relative risk of hip fracture associated with a 1-kg increase in baseline lean mass. Mean age was 66years (range 50-93). Over a median of 8years of follow-up, 99 hip fractures occurred. In models adjusted for age, height, study cohort, and percent total body fat, neither leg (HR 1.11; 95% CI 0.94, 1.31) nor total body (HR 1.06; 95% CI 0.99, 1.13) lean mass were associated with hip fracture. After further adjustment for femoral neck bone mineral density, leg lean mass results were similar (HR 1.10; 95% CI 0.93, 1.30). In contrast, 1kg greater total body lean mass was associated with 9% higher hip fracture risk(HR 1.09; 95% CI 1.02, 1.18). Our findings suggest that in women, lower lean mass measured by DXA is notassociated with increasedrisk of hip fracture.

Body composition of female road and track endurance cyclists: Normative values and typical changes

The aims of this study were to describe normative values and seasonal variation of body composition in female cyclists comparing female road and track endurance cyclists, and to validate the use of anthropometry to monitor lean mass changes. Anthropometric profiles (seven site skinfolds) were measured over 16 years from 126 female cyclists. Lean mass index (LMI) was calculated as body weight × skinfolds−x. The exponent (x) was calculated as the slope of the natural logarithm of body weight and skinfolds. Percentage changes in LMI were compared to lean mass changes measured using dual-energy X-ray absorptiometry (DXA) in a subset of 25 road cyclists. Compared to sub-elite and elite cyclists, world class cyclists were (mean [95% CI]) 1.18 kg [0.46, 1.90] and 0.60 kg [0.05, 1.15] lighter and had skinfolds that were 7.4 mm [3.8, 11.0] and 4.6 mm [1.8, 7.4] lower, respectively. Body weight (0.41 kg [0.04, 0.77]) and skinfolds (4.0 mm [2.1, 6.0]) were higher in the off-season compared to the early-season. World class female road cyclists had lower body weight (6.04 kg [2.73, 9.35]) and skinfolds (11.5 mm [1.1, 21.9]) than track endurance cyclists. LMI (mean exponent 0.15 [0.13, 0.18]) explained 87% of the variance in DXA lean mass. In conclusion, higher performing female cyclists were lighter and leaner than their less successful peers, road cyclists were lighter and leaner than track endurance cyclists, and weight and skinfolds were lowest early in the season. LMI appears to be a reasonably valid tool for monitoring lean mass changes.

Determining the Precision of Dual Energy X-Ray Absorptiometry and Bioelectric Impedance Spectroscopy in the Assessment of Breast Cancer-Related Lymphedema

The composition of breast cancer-related lymphedema (BCRL) has been shown to evolve from the initial accumulation of fluid to the development of fibrotic lesions and abnormal fat deposition. Therefore, precise and reliable assessments of BCRL are required to develop accurate staging and management. Although dual energy x-ray absorptiometry (DXA) and bioelectric impedance spectroscopy (BIS) have been used to assess BCRL, no study has evaluated the precision of these two modalities in the same cohort. We determined the precision of DXA and BIS in lymphedematous (LE) and nonaffected (NA) arms of 24 women with Stage II unilateral BCRL. Precision was calculated from the results of paired bilateral arm measurements obtained from DXA scans measuring fat, lean, and bone mineral masses, BIS measuring extracellular fluid (ECF) and total fluid volume, and circumferential tape measurements (CM) of the arms to calculate the anatomic volume. Precision error was expressed as the root mean square (RMS) of the coefficients of variation (%CV) and standard deviations (SD). The precisions of DXA and BIS varied from 1.16% (DXA measurements of LE arm total volume) to 1.86% (BIS LE arm total fluid volume) and from 0.95% (DXA lean mass of NA arm) to 1.72% (DXA BMC of NA arm). Precision of CM measures of arm volume were 1.71% CV for LE arm and 2.51% CV for NA arm. The fat and lean masses of the LE arm exceeded the NA arm by about 15% (p<0.0001). ECF and total fluid volume of LE arm was 22.6% and 19% greater than the NA arm (p<0.0001), respectively. For BCRL, these findings suggest that DXA and BIS are two measurement instruments that provide acceptable levels of precision for the measurement of arm lean mass, fat mass and ECF volume, respectively.

Early-Phase Adaptations to a Split-Body, Linear Periodization Resistance Training Program in College-Aged and Middle-Aged Men

An 8-week, split-body, linear periodized resistance training program was completed by college-aged (CA: 18-22 years; n = 24) and middle-aged (MA: 35-50 years; n = 25) men to determine early-phase adaptations in body composition and upper- and lower-body strength. Participants completed 2 upper-body and 2 lower-body resistance training workouts each week. During weeks 1-4, subjects completed 3-6 sets at a 10-repetition maximum (RM) intensity and increased to 8RM for weeks 5-8. The 1RM strength levels were determined on the bench press and leg press, and 30-second Wingate tests were assessed at baseline and after 8 weeks of resistance training. Body composition was assessed using dual-energy X-ray absorptiometry (DXA). For selected data, delta values (post - pre values) were calculated and reported as mean +/- SEM. No changes (p > 0.05) were reported for peak and average Wingate power. Bench press (CA, 3.2 +/- 1.9 kg; MA, 6.2 +/- 3.3 kg; p < 0.001) and leg press (CA, 25.0 +/- 4.4 kg; MA, 18.2 +/- 13.3 kg; p < 0.001) 1RM significantly increased in both groups over time. Lean mass significantly increased over time in both groups (CA, 0.9 +/- 2.4 kg; MA, 1.1 +/- 1.9 kg; p < 0.001). Significant group x time effects were seen for fat mass changes (CA, 0.5 +/- 1.3 kg; MA, -0.5 +/- 1.1 kg; p = 0.01) and % body fat changes (CA, 0.4 +/- 1.4%; MA, -0.7 +/- 1.1%; p = 0.01). These results indicate that performing a split-body, linearly periodized resistance training program for 8 weeks significantly increases bench press 1RM, leg press 1RM, and DXA lean mass in CA and MA men. Furthermore, MA men lost significantly more fat mass and significantly decreased % body fat compared with CA men. A split-body, linearly periodized resistance training program may be used as an effective program to increase strength and lean mass in both young and MA populations.

Fat Mass Is Not Beneficial to Bone in Adolescents and Young Adults

Although muscle mass is beneficial to bone, studies on the effect of fat mass on bone have yielded conflicting results. The aim of this study was to assess the relations between lean and fat mass and bone structure. This study was cross-sectional. The study was conducted in a general community. Subjects included 300 healthy sexually mature adolescents and young adults (150 males and 150 females) between the ages of 13 and 21 yr. We investigated the relation between dual-energy x-ray absorptiometry (DXA) measures of total body fat and lean mass and bone values obtained with DXA (legs and lumbar spine bone mineral density and bone mineral content) and computed tomography (CT) (cross-sectional and cortical bone areas of the femurs and cross-sectional area and cancellous bone density of the vertebrae). Simple and multiple linear regression analyses showed significant positive relations between DXA lean mass and all CT and DXA measures of bone in the axial and appendicular skeletons (all P < 0.005). In contrast, whereas Pearson correlations between DXA measures of fat mass and bone parameters were generally positive, multiple regression analyses showed that fat mass, after accounting for lean mass, trunk height/leg length, had a negative, or no, correlation with CT and DXA values for bone. Our findings provide compelling evidence that, despite increased mechanical loading and independent of lean mass, adipose tissue is not beneficial to bone structure.

The Effects of Protein and Amino Acid Supplementation on Performance and Training Adaptations During Ten Weeks of Resistance Training

The purpose of this study was to examine the effects of whey protein supplementation on body composition, muscular strength, muscular endurance, and anaerobic capacity during 10 weeks of resistance training. Thirty-six resistance-trained males (31.0 +/- 8.0 years, 179.1 +/- 8.0 cm, 84.0 +/- 12.9 kg, 17.8 +/- 6.6%) followed a 4 days-per-week split body part resistance training program for 10 weeks. Three groups of supplements were randomly assigned, prior to the beginning of the exercise program, in a double-blind manner to all subjects: 48 g per day (g.d(-1)) carbohydrate placebo (P), 40 g.d(-1) of whey protein + 8 g.d(-1) of casein (WC), or 40 g.d(-1) of whey protein + 3 g.d(-1) branched-chain amino acids + 5 g.d(-1) L-glutamine (WBG). At 0, 5, and 10 weeks, subjects were tested for fasting blood samples, body mass, body composition using dual-energy x-ray absorptiometry (DEXA), 1 repetition maximum (1RM) bench and leg press, 80% 1RM maximal repetitions to fatigue for bench press and leg press, and 30-second Wingate anaerobic capacity tests. No changes (p > 0.05) were noted in all groups for energy intake, training volume, blood parameters, and anaerobic capacity. WC experienced the greatest increases in DEXA lean mass (P = 0.0 +/- 0.9; WC = 1.9 +/- 0.6; WBG = -0.1 +/- 0.3 kg, p < 0.05) and DEXA fat-free mass (P = 0.1 +/- 1.0; WC = 1.8 +/- 0.6; WBG = -0.1 +/- 0.2 kg, p < 0.05). Significant increases in 1RM bench press and leg press were observed in all groups after 10 weeks. In this study, the combination of whey and casein protein promoted the greatest increases in fat-free mass after 10 weeks of heavy resistance training. Athletes, coaches, and nutritionists can use these findings to increase fat-free mass and to improve body composition during resistance training.