Dual Bioelectrical Impedance Analysis Research Articles

Body composition and phase angle in rugby union athletes: A comparison between forward and back positions

IntroductionRugby union has been increasingly attracting a multitude of enthusiasts over the past years. Nevertheless, there is a need for a more profound understanding of body composition, particularly regarding body fluids, and phase angle by playing position in rugby union athletes. MethodsThis study aimed to compare body composition components and phase angle among rugby union athletes based on their playing positions (forwards vs. backs). The sample consisted of 26 male athletes from rugby union clubs in Florianópolis, Brazil. Body composition [fat mass, lean soft tissue mass (LSTM)], body fluids (total body water, intra and extracellular water, and their proportions) and phase angle were evaluated using dual emission X-ray absorptiometry and bioelectrical impedance analysis, respectively. Statistical analysis was carried out using the analysis of covariance to compare body composition, and phase angle between playing positions (forwards vs. backs). ResultsThe primary findings indicated that rugby union athletes playing as forwards demonstrated higher values for fat mass, FFBM, and body fluids (total body water, intracellular, and extracellular water) compared to those playing as backs (p < 0.01). No difference was observed between playing positions for the other variables. ConclusionsBody composition may vary depending on the playing position in rugby union athletes.

Correlation and Validation of Body Composition Analyzers (i Series) with Dual Energy X- ray Absorptiometry (DEXA)

This paper presents the development and evaluation of the i Series BIA (bioelectrical impedance analysis) device (models i20, i25, i30, i35, i50, i55), by MEDIANA Co., Ltd. The device utilizes a tetra-polar electrode method incorporating 8-point electrodes to improve the accuracy and reliability of body composition analysis. This paper employs a multi-frequency segmental measurement method with a wide range of measurement frequencies from 1 kHz to 1000 kHz. In comparing the correlation between Dual Energy X-ray Absorptiometry (DEXA) and BIA devices for fat-free mass (FFM) and muscle mass measurements, the results demonstrated a high correlation, with a coefficient of determination (R) of 0.984 for fat-free mass and 0.983 for muscle mass, respectively.

Prediction Model including Gastrocnemius Thickness for the Skeletal Muscle Mass Index in Japanese Older Adults.

Non-invasive and easy alternative methods to indicate skeletal muscle mass index (SMI) have not been established when dual energy X-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) cannot be performed. This study aims to construct a prediction model including gastrocnemius thickness using ultrasonography for skeletal muscle mass index (SMI). Total of 193 Japanese aged ≥65 years participated. SMI was measured by BIA, and subcutaneous fat thickness and gastrocnemius thickness in the medial gastrocnemius were measured by using ultrasonography, and age, gender and body mass index (BMI), grip strength, and gait speed were collected. The stepwise multiple regression analysis was conducted, which incorporated SMI as a dependent variable and age, gender, BMI, gastrocnemius thickness, and other factors as independent variables. Gender, BMI, and gastrocnemius thickness were included as significant factors, and the formula: SMI = 1.27 × gender (men: 1, women: 0) + 0.18 × BMI + 0.09 × gastrocnemius thickness (mm) + 1.3 was shown as the prediction model for SMI (R = 0.89, R2 = 0.8, adjusted R2 = 0.8, p < 0.001). The prediction model for SMI had high accuracy and could be a non-invasive and easy alternative method to predict SMI in Japanese older adults.

Estimation Of Skeletal Muscle Tissue In Athletes Using Dual X Ray Absorptiometry, Anthropometry, And Bioelectrical Impedance

Anthropometry and Bioelectrical Impedance Analysis (BIA) are the most used procedures to assess musculoskeletal tissue (MST) and body composition in athletes; however, the evidence exhibits significant diferences when compared against reference methods or even in intra-analytical analyses. PURPOSE: To analyze the correlations and differences found in the MST determined by Dual X-Ray Absorptiometry (DXA), Anthropometry, and BIA in a sample of Mexican triathletes. METHODS: Amateur triathletes (n = 30; 20 males, 10 females), aged 18-40, were included. Estimations were performed by using DXA Hologic QDR, BIA BodyStat 1500, and the anthropometric evaluation as defined by the International Society for the Advancement of Kinanthropometry (ISAK) by an ISAK level 3 anthropometrist. The equation used as a reference to derive MST from appendicular lean soft tissue (ALST) measured with DXA, was compared with the results obtained from the Janssen formula for BIA, and the Heymsfield and Kerr formulas accepted for anthropometric data. RESULTS: The bivariate correlation showed significant associations between the variables expressed in kg and percentage (DXA vs Janssen: r = .967, r = .838; DXA vs Heymsfield: r = .973, r = .867; DXA vs Kerr: r = .967, r = .824, respectively). Significant differences (p < 0.001) were found when compared the mean between DXA vs Kerr in terms of kg and percentage (25.41 kg ± 5.89 vs 33.00 kg ± 6.82; and 36.66% ± 4.04 vs 47.75% ± 3.57, respectively). In a post-hoc analysis, heterogeneous results of means were identified with all the formulas used. CONCLUSIONS: The Heymsfield and Janssen equations can be used in people with similar features to the study population, showing reliable results when compared with the reference method. Kerr's formula overestimated the MST values. Whether an estimation using any of the proposed equations, it is always recommended to use the same in subsequent evaluations. Studies with larger samples are necessary to prove if the results can be replicated.

Serum high-molecular-weight adiponectin and response to dapagliflozin in patients with type 2 diabetes and non-alcoholic fatty liver disease

A better baseline renal function is associated with a better response to sodium-glucose co-transporter-2 inhibitors in patients with type 2 diabetes. Low serum adiponectin is associated with visceral fat accumulation...

Fat-Free Mass Index Controlled for Age and Sex and Malnutrition Are Predictors of Survival in Interstitial Lung Disease

Background: Literature focusing on nutritional variables and survival in interstitial lung disease (ILD) is limited by its focus on weight and BMI and has not considered body composition. Objectives: The primary objective of this study was to examine whether body composition measures, specifically fat-free mass index z-score (z-FFMI) and body fat mass index z-score (z-BFMI), were predictors of survival in fibrotic ILD patients. The second objective was to examine if nutrition status was a predictor of survival. Method: Seventy-eight outpatients diagnosed with fibrotic ILD were recruited in this cross-sectional study. Body composition data using dual frequency bioelectrical impedance analysis (BodyStat 1500MD; UK) and nutrition status using the subjective global assessment (SGA) were determined. To control for age and sex, z-FFMI and z-BFMI were calculated using population means. Participant charts were reviewed for diagnosis, age, disease severity, and exercise capacity. Results: Age (HR 1.08, 95% CI [1.03–1.13], p < 0.01), BMI (HR 0.90, 95% CI [0.84–0.97], p < 0.01]), z-FFMI (HR 0.70, 95% CI [0.56–0.87], p = 0.02), z-BFMI (HR 0.74, 95% CI [0.57–0.96], p < 0.01), 6-min walk distance (6MWD) (HR 0.99, 95% CI [0.99–1.00], p < 0.01), percent predicted diffusing capacity for carbon monoxide (%DLco) (HR 0.93, 95% CI [0.89–0.97], p < 0.01), and severe malnutrition (SGA-C) (HR 6.98, 95% CI [2.00–24.27], p < 0.01) were significant predictors of survival. When controlled for exercise capacity and disease severity, z-FFMI and severe malnutrition were significant predictors of survival independent of %DLco. Conclusion: z-FFMI and severe malnutrition were significant predictors of survival in fibrotic ILD patients independent of disease severity.

P0944UREMIC SARCOPENIA IN THE ELDER: PRELIMINARY RESULTS OF A PRECISION MEDICINE APPROACH IN A COHORT OF UREMIC PATIENTS

Abstract Background and Aims Sarcopenia is defined as a chronic condition of “muscle failure”, characterized by reduced muscular strength, mass and performance. End-stage renal disease (ESRD) and sarcopenia have several complications in common including inflammation, low sexual hormones, reduced levels of Vitamin D, and low satellite cells proliferation rate. Sarcopenic and uremic patients have higher risk for fracture, cardiovascular events, cognitive impairment, low quality of life, hospitalization and death. The European Working Group on Sarcopenia in Older People (EWGSOP2) 2019 guidelines standardize the diagnostic criteria and recommend a systematic approach for sarcopenia assessment. The aim of our study is to evaluate the prevalence of sarcopenia in ESRD patients not yet on dialysis and to characterize their clinical, laboratory and behavioral features. Method This is a pilot cross-sectional study. ESRD patients expected to initiate replacement therapy (hemodialysis or peritoneal dialysis), age ≥60 years, free mobility and hemoglobin levels ≥9.5 g/dL were enrolled. Exclusion criteria were: use of steroids &amp;gt;3 months during the previous year, previous renal replacement treatments. Enrolled patients were screened for sarcopenia following the three diagnostic criteria: muscle strength (through “handgrip strength” and “chair stand-up test”), muscle mass (with dual X-ray absorptiometry and bio-electrical impedance analysis), and muscle performance (with “4m gait speed test”). Clinical data were collected as well as anthropometric measures. Patients also underwent an abdominal ultrasound and a hematology, chemistry, urinary and inflammation laboratory panel. Finally, they filled questionnaires for sarcopenia identification (SARC-F), quality of life (SF-36), daily activity (ADL and iADL) and nutritional status. GFR was estimated according to CKD-EPI formula. Results We evaluated 9 patients (2 females and 7 males), mean age 72 ± 7 years, mean GFR 10.2±1.5 mL/min/1.73 m2 (range 7.3, 11.8). 7/9 reported hypertension history, 4/9 were diabetic. The prevalence of sarcopenia was 44% (4 patients) according EWGSOP2 criteria. Table 1 reports diagnostic exam results from our cohort. Taking individually EGWSOP2 criteria 4 patients showed low muscle strength, 5 reached the threshold for a low DXA muscle mass while 3 patients had a low gait speed performance, marker for sarcopenia severity. Compared with controls, sarcopenic patients (Table 2) showed a significantly lower handgrip strength (15.0±4.3 vs 23.0±6.7 Kg respectively, p-value 0.03), a lower but not significant appendicular lean mass (ALM) index normalized for squared height (European criteria) or for BMI (American criteria). Moreover, sarcopenic patients were more anemic (p 0.05), with a lower hematocrit (p 0.04). Finally, SF36 questionnaire describes sarcopenic patients as more jaded about physical activity, with impaired social activity and higher bodily pain. Conclusion Sarcopenia has a complex and diversified background, and ESRD represents an important risk factor. Sarcopenic patients with ESRD might need more carefulness on daily activity, anemia management, physical functioning and muscle recovery.

Visceral adiposity is associated with the discrepancy between glycated albumin and HbA1c in type 2 diabetes.

We investigated the association of visceral adiposity with glycated albumin (GA) as well as GA/hemoglobin A1c (HbA1c) in type 2 diabetes. One hundred twenty-three patients (68 males, 55 females) with type 2 diabetes were enrolled in this cross-sectional study. Visceral fat area (VFA) was determined using an abdominal dual bioelectrical impedance analysis (dual BIA) instrument. The relationship of VFA with GA and GA/HbA1c was analyzed. Simple regression analysis showed that BMI was inversely correlated with GA as well as GA/HbA1c, but not with HbA1c, while VFA had a significant correlation with GA and GA/HbA1c. Furthermore, multiple regression analysis revealed VFA as an independent contributor to GA/HbA1c. These results suggest that visceral adiposity is a primary factor associated with GA and HbA1c level discrepancy in patients with type 2 diabetes. GA is a useful indicator for glycemic control, while visceral obesity should also be taken into consideration in type 2 diabetes cases.

Reference Values for Skeletal Muscle Mass - Current Concepts and Methodological Considerations.

Assessment of a low skeletal muscle mass (SM) is important for diagnosis of ageing and disease-associated sarcopenia and is hindered by heterogeneous methods and terminologies that lead to differences in diagnostic criteria among studies and even among consensus definitions. The aim of this review was to analyze and summarize previously published cut-offs for SM applied in clinical and research settings and to facilitate comparison of results between studies. Multiple published reference values for discrepant parameters of SM were identified from 64 studies and the underlying methodological assumptions and limitations are compared including different concepts for normalization of SM for body size and fat mass (FM). Single computed tomography or magnetic resonance imaging images and appendicular lean soft tissue by dual X-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) are taken as a valid substitute of total SM because they show a high correlation with results from whole body imaging in cross-sectional and longitudinal analyses. However, the random error of these methods limits the applicability of these substitutes in the assessment of individual cases and together with the systematic error limits the accurate detection of changes in SM. Adverse effects of obesity on muscle quality and function may lead to an underestimation of sarcopenia in obesity and may justify normalization of SM for FM. In conclusion, results for SM can only be compared with reference values using the same method, BIA- or DXA-device and an appropriate reference population. Limitations of proxies for total SM as well as normalization of SM for FM are important content-related issues that need to be considered in longitudinal studies, populations with obesity or older subjects.

Change in body composition in patients with achalasia before and after peroral endoscopic myotomy.

Patients with achalasia experience weight loss because of dysphagia caused by impaired relaxation of the lower esophageal sphincter. This study aimed to use dual bioelectrical impedance analysis (BIA) to determine the change in bodyweight and body composition in patients with achalasia before and after peroral endoscopic myotomy (POEM). Patients with achalasia who underwent POEM from 2013 to 2018 (n=72) were retrospectively analyzed for change in bodyweight before and after 3months. Additionally, change in body composition was prospectively investigated in the final 10 of 72 patients using non-radiation dual BIA. Twenty patients (27.8%) were underweight (body mass index<18.5) before undergoing POEM. No clinical parameters were identified to be associated with the underweight condition before POEM and be predictive of an increase in bodyweight after POEM. Low visceral fat volume observed on dual BIA correlated closely with the result obtained using computed tomography (Pearson correlation coefficient: r=0.850, P<0.01). Patients with achalasia had a statistically significant increase in visceral (P<0.01) and subcutaneous fat volumes (P<0.01) after POEM. Skeletal muscle mass index slightly increased (P=0.02), although the value after POEM was still low. No blood biomarkers were indicators for low bodyweight or low visceral fat volume. Dual BIA is an effective non-invasive tool to evaluate the change in body composition of underweight patients with achalasia. Skeletal muscle volume was not enough after POEM, although a rapid increase in the intra-abdominal fat volume was observed. Additional studies are warranted to understand the pathological implications.

Efficacy of visceral fat estimation by dual bioelectrical impedance analysis in detecting cardiovascular risk factors in patients with type 2 diabetes

BackgroundVisceral fat area (VFA) is a good surrogate marker of obesity-related disorders, such as hypertension, dyslipidemia and glucose intolerance. Although estimating the VFA by X-ray computed tomography (CT) is the primary index for visceral obesity, it is expensive and requires invasive radiation exposure. Dual bioelectrical impedance analysis (BIA) is a simple and reliable method to estimate VFA; however, the clinical usefulness of dual BIA remains unclear in patients with type 2 diabetes (T2D).MethodsWe estimated the VFAs by dual BIA and CT in 98 patients with T2D and assessed anthropometric parameters, blood test results, and the presence of comorbid hypertension and dyslipidemia. We compared the correlation between the VFAs examined by dual BIA and CT. Furthermore, we performed the receiver operating characteristic (ROC) analyses for the VFAs to detect the presence of comorbid hypertension and/or dyslipidemia with T2D, which are major comorbidities of visceral obesity, and estimated the area under the curve (AUC).ResultsThe measurement error between the VFAs by dual BIA and CT was significantly higher among patients with brain natriuretic peptide (BNP) ≥ 100 pg/mL than those with BNP < 100 pg/mL (39.2% ± 31.1% vs. 24.1% ± 18.6%, P < 0.05). After excluding patients with BNP ≥ 100 pg/mL, the VFA by dual BIA significantly correlated with the VFA by CT (r = 0.917; P < 0.0001). The AUC in the ROC analysis for the VFA by dual BIA to detect the presence of comorbid hypertension and/or dyslipidemia with T2D was almost equivalent to that for the VFA by CT.ConclusionsIn patients with T2D without elevated BNP > 100 pg/mL as indicator for fluid accumulation interfering with BIA, estimation of the VFA by dual BIA significantly correlated with that by CT and also detected comorbid hypertension and/or dyslipidemia with T2D equivalent to those detected by CT. Hence, dual BIA could be an alternative to CT as a standard method for estimating the VFA in patients with diabetes.

1229-P: Dapagliflozin Improves Liver Dysfunction in Parallel with a Decrease in Serum Soluble DPP-4/CD26 Level in Type 2 Diabetic Patients with Nonalcoholic Fatty Liver Disease

Objective: Serum levels of soluble DPP-4/CD26 are elevated in patients with type 2 diabetes and nonalcoholic fatty disease (NAFLD). Hepatocyte-secreted sDPP-4 induce directly adipose inflammation and insulin resistance in the liver. SGLT2 inhibitors reduce hepatic steatosis by inhibiting hepatic de novo lipogenesis. We investigated effects of dapagliflozin, an SGLT2 inhibitor, on liver dysfunction, hepatic steatosis, and serum levels of sDPP-4 in patients with type 2 diabetes and NAFLD. Methods: Fifty-seven patients with type 2 diabetes and NAFLD were randomized into a dapagliflozin (5 mg/day) treatment group (n=33) or an active placebo group (n=24) for 24 weeks. Visceral adipose tissue (VAT) volumes were measured using a dual bioelectrical impedance analysis. Hepatic steatosis was evaluated by controlled attenuated parameter (CAP) using a transient elastography. Results: At baseline, serum sDPP-4 showed positive correlations with AST, ALT, GGT, and HOMA-IR in a total of 57 patients. VAT significantly decreased in the dapagliflozin group, but not in the placebo group. AST, ALT, and GGT showed a significant decrease at 24 weeks in the dapagliflozin group, while they were unchanged in the control group. CAP also significantly decreased in the dapagliflozin group. Although both groups showed a significant reduction in serum sDPP-4 at 24 weeks after treatment, the magnitude of sDPP-4 reduction was greater in the dapagliflozin group. Changes in liver enzymes after dapagliflozin treatment correlated positively with those in serum sDPP-4 levels, but not those in VAT or HbA1c. Conclusions: An improvement of liver dysfunction was associated with a decrease in serum sDPP-4, but not that in VAT or HbA1c, after treatment with dapagliflozin in these patients, suggesting that reducing serum sDPP-4 by SGLT2 inhibitors may be a therapeutic strategy for treatment of NAFLD/NASH in people with type 2 diabetes. Disclosure K. Kato: None. Y. Aso: Research Support; Self; Ono Pharmaceutical Co., Ltd. T. Jojima: None. T. Iijima: None. I. Usui: None.

Impact of dapagliflozin, an SGLT2 inhibitor, on serum levels of soluble dipeptidyl peptidase-4 in patients with type 2 diabetes and non-alcoholic fatty liver disease.

Soluble dipeptidyl peptidase-4 (sDPP-4) is secreted by hepatocytes and induces adipose tissue inflammation and insulin resistance. Sodium-glucose co-transporter-2 (SGLT2) inhibitors can improve hepatic steatosis by inhibiting hepatic de novo lipogenesis. We investigated the effects of dapagliflozin (an SGLT2 inhibitor) on serum levels of sDPP-4 in patients with type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). Fifty-seven patients with type 2 diabetes and NAFLD were randomized to a dapagliflozin group (5mg/d for 24weeks) (n=33) or the control group (n=24). Serum levels of sDPP-4 were measured with a commercial ELISA kit. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas were measured by dual bioelectrical impedance analysis. In a total of 57 patients, baseline serum sDPP-4 was positively correlated with aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ-glutamyl transferase (GGT) and HOMA-IR Both VAT and SAT areas decreased significantly in the dapagliflozin group alone. Liver enzymes were decreased at 24weeks in the dapagliflozin group, but were unchanged in the control group. Although both groups showed significant reduction of serum sDPP-4 after 24weeks of treatment, the magnitude of decrease was significantly larger in the dapagliflozin group. Changes in liver enzymes during treatment with dapagliflozin were positively correlated with the change in serum sDPP-4, but not with changes in VAT volume or HbA1c. Improvement of liver dysfunction after treatment with dapagliflozin was associated with a decrease in serum sDPP-4, suggesting that reduction of serum sDPP-4 by SGLT2 inhibitors may be a therapeutic strategy for NAFLD/NASH in patients with type 2 diabetes that is independent of glucose lowering or weight loss.

Cross-sectional study of the association between day-to-day home blood pressure variability and visceral fat area measured using the dual impedance method.

BackgroundThe blood pressure (BP) variability (BPV) is a predictor of cardiovascular disease, independently of the BP itself. In addition, visceral fat accumulation can trigger atherosclerotic disease through various mechanisms.Methods and resultsWe examined the association between fat accumulation and day-to-day BPV in 61 adult hypertensive patients. Visceral fat area (VFA) was measured using the dual bioelectrical impedance analysis method. Participants were divided into three groups based on VFA. The standard deviation (SD) in home systolic BP (SBP) for 7 consecutive days was significantly lower in the high VFA tertile (low VFA, 8.40±4.15 mmHg; intermediate VFA, 8.47±2.80 mmHg; and high VFA, 5.84±2.37 mmHg, p of One-way ANOVA = 0.017, p for trend = 0.0126). A similar association was observed between the coefficient of variance (CV) of home SBP and the VFA tertile. Multiple-regression analysis adjusted for age, sex, antihypertensive drug, diabetes, habitual drinking, and SBP level also showed a significant association between the VFA tertile and the SD or CV of home SBP. The adjusted coefficient of regression for the SD of home SBP was -3.28 (95%CI: -5.60 to -0.97, p = 0.008) and the CV of home SBP was -2.51 (95%CI: -4.31 to -0.71, p = 0.008) for the highest VFA tertile as compared to the lowest VFA tertile.ConclusionsThese results show for the first time negative correlation between VFA and day-to-day BPV. The degree of obesity should be taken into account when evaluating the value of BPV.

Dual frequency bioelectrical impedance analysis to estimate hematocrit for prognosis of dengue fever in Indian children.

A noninvasive investigation to ascertain the hematocrit (HCT) or packed cell volume (PCV) was conducted on 44 hospitalized dengue hemorrhagic fever (DHF) subjects, male and female aged between 3 and 14 years using bioelectrical impedance analysis (BIA). Among the 44 subjects, 30 subjects were confirmed to be non-structural protein-1 (NS1) positive at the time of admission, whose blood investigations such as HCT level, platelet (PLT) count, aspartate aminotransferase (AST) level and alanine aminotransferase (ALT) level were taken for the classification of risk as low risk (LR) and high risk (HR) DHF. Electrical conductivity of blood reflects a linear correlation with HCT. To provide a better and more accurate estimate of HCT, a dual frequency method is proposed to calculate the conductivities of plasma and blood cells. The resistance at 100 kHz is used to estimate the conductivity of blood cells and the impedance at 5 kHz to estimate the conductivity of plasma. Statistical analysis reveals that the HCT estimated using the proposed dual frequency method shows a significant difference with a single frequency (50 kHz) estimate of HCT and also shows a good correlation with the blood investigation results. In addition, statistical analysis of the proposed method on different fever subjects indicates a significant difference with DHF.

Effects of monthly feedback of VFA measured by dual BIA method in Japanese patients with obesity: a randomized controlled study.

SummaryObjectiveTo investigate the effects of monthly feedback of changes in visceral fat area (VFA) as measured by dual bioelectrical impedance analysis method and the importance of VFA in individuals with obesity.MethodsThirty‐eight Japanese patients with obesity underwent VFA measurements. The feedback group was given feedback on VFA measurements each month for 4 months. The control group underwent VFA measurements at the beginning and end of the study but was not informed of the results. All the study participants completed eating behaviour and weight efficacy lifestyle questionnaires.ResultsMean age was 53.9 (14.3) years; mean body mass index was 30.6 (4.3) kg m−2. At the 4‐month follow‐up, there was no significant difference in VFA reduction between the control and feedback groups (−4.4% vs. −3.0%; 95% CI, −3.8 to 5.5). In post‐hoc analysis using the overall group irrespective of allocation, changes of eating style were significantly associated with a reduction in VFA at 4 months (p = 0.034).ConclusionsMonthly feedback on changes in VFA does not reduce VFA. More frequent feedback may be required. In post‐hoc analysis, changes of eating style were associated with a reduction in VFA.

Large meta-analysis of genome-wide association studies identifies five loci for lean body mass

Lean body mass, consisting mostly of skeletal muscle, is important for healthy aging. We performed a genome-wide association study for whole body (20 cohorts of European ancestry with n = 38,292) and appendicular (arms and legs) lean body mass (n = 28,330) measured using dual energy X-ray absorptiometry or bioelectrical impedance analysis, adjusted for sex, age, height, and fat mass. Twenty-one single-nucleotide polymorphisms were significantly associated with lean body mass either genome wide (p < 5 × 10−8) or suggestively genome wide (p < 2.3 × 10−6). Replication in 63,475 (47,227 of European ancestry) individuals from 33 cohorts for whole body lean body mass and in 45,090 (42,360 of European ancestry) subjects from 25 cohorts for appendicular lean body mass was successful for five single-nucleotide polymorphisms in/near HSD17B11, VCAN, ADAMTSL3, IRS1, and FTO for total lean body mass and for three single-nucleotide polymorphisms in/near VCAN, ADAMTSL3, and IRS1 for appendicular lean body mass. Our findings provide new insight into the genetics of lean body mass.

Comparison of bioelectrical impedance and DXA for measuring body composition among adults with Down syndrome

BackgroundIndividuals with Down syndrome (DS) have been shown to display high levels of adiposity and a unique body shape. Laboratory methods used to evaluate body composition might be too cumbersome for this special population. Therefore, field methods are desired due to their non-invasive nature.Objective: to determine the agreement between dual energy x-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA) for measuring body fat percentage BF% and fat-free mass (FFM) among adults with DS. MethodsTwenty-one adults (male: n = 10; female: n = 11) with DS participated in this study. BF% and FFM were determined by DXA and BIA. ResultsThere was a significant mean difference between DXA and BIA for BF% (41.33 ± 8.98% and 34.23 ± 9.22%, respectively) and FFM (41.80 ± 8.74 kg and 46.95 ± 9.92 kg, respectively). The correlation between the two devices for BF% and FFM were significant (r = 0.89 and r = 0.94, respectively, p < 0.001 for both). The standard error of estimate and total error values were 4.38% and 8.27%, respectively, for BF% and 3.04 kg and 6.13 kg, respectively, for FFM. The 95% limits of agreement ranged from −15.64% below to 1.46% above the constant error (CE) of −7.09% for BF% and from −1.52 kg below to 11.83 kg above the CE of 5.15 kg for FFM. ConclusionsThe significant mean differences and large amount of individual error suggest that BIA may not be an appropriate surrogate body composition measure compared to DXA in adults with DS.

Visceral Fat Area and Serum Adiponectin Level Predict the Development of Metabolic Syndrome in a Community-Based Asymptomatic Population.

BackgroundAlthough it has been demonstrated that visceral adipose tissue content and serum levels of adiponectin are associated with metabolic syndrome, their predictive potential for the development of metabolic syndrome remains to be elucidated.MethodsWe studied 1,130 participants of the Seoul Metabolic Syndrome cohort. A total of 337 subjects without metabolic syndrome underwent the follow-up evaluation and finally analyzed. Visceral fat area (VFA) was measured using dual bioelectrical impedance analysis. We compared the 1-year incidence rate of metabolic syndrome among four different groups: Group 1 (high adiponectin level and low VFA), Group 2 (low adiponectin level and low VFA), Group 3 (high adiponectin level and high VFA) and Group 4 (low adiponectin level and high VFA).ResultsMedian follow-up duration was 17 months. Cut-off points of adiponectin level and VFA for metabolic syndrome were 7.34 ng/ml and 84 cm2 for men, and 12.55 and 58 cm2 ng/ml for women, respectively. The incidence of metabolic syndrome was the highest in Group 4 (Group 1; 16.47%, Group 2; 22.08%, Group 3; 25%, and Group 4; 46.15%, p<0.001). Adjusted logistic regression analyses for metabolic syndrome prediction demonstrated that Group 4 exhibited the highest odds ratio compared with Group 1 (4.918 [2.05–11.795]), which was predominantly affected by waist circumference and serum triglyceride levels. Notably, triglyceride/high-density lipoprotein cholesterol (TG/HDL) ratio was significantly higher in Group 4 (p = 0.017).ConclusionIncidence rate of metabolic syndrome was the highest in subjects with low serum adiponectin levels and high visceral fat area. Higher TG/HDL ratio in these subjects suggested insulin resistance may contribute to the development of metabolic syndrome.

Validation of Fat-Free Mass Estimation Using Prediction Equations in Male Patients with Chronic Obstructive Pulmonary Disease

Context: The use of predictive equations in hospital settings lacking access to dual energy X-ray absorptiometry or bioelectrical impedance analysis (BIA) can be beneficial because cachexia, muscle wasting and related increase in morbidity and mortality are known occurrences in patients with chronic obstructive pulmonary disease (COPD). Aim: To analyse the predictive performance of reported equations for fat-free mass (FFM) prediction against BIA-derived FFM in patients with stable COPD. Design/Materials and Methods: Seventy-two male patients aged between 40 and 75 years with stable COPD were evaluated for FFM by BIA. FFM was also predicted for the same patients using equations reported by Kulkarni et al., Solomon Yu et al., Janmahasatian et al., as well as Deurenberg equation. Statistical Analysis Used: The predictive performance was assessed by Bland–Altman plots, with subsequent calculations of bias, precision and accuracy. The performance was also analysed across the age and body mass index sub-groups. Results: The mean differences (95% confidence intervals) in the prediction of FFM using equations by Kulkarni et al. and Deurenberg equation were −0.33 kg (−4.910, 4.258) and 0.31 kg (−3.330, 3.946), respectively. The equation by Solomon Yu et al. and Janmahasatian et al. overestimated FFM with a mean difference of 3.99 kg (−2.449, 10.428) and 3.76 kg (−0.443, 7.956), respectively. Conclusion: The equation by Kulkarni et al. provides an acceptable prediction of FFM in patients who were underweight or had normal weight with COPD and were aged between 50 and 69 years. The Deurenberg equation was used to predict FFM in patients aged between 40–49 and 60–75 years. Further validation of the predictive performance in overweight and obese COPD patients is required.