Body composition determination by bioimpedance: an update

Bioimpedence to Assess Breast Density as a Risk Factor for Breast Cancer in Adult Women and Adolescent Girls

Although high mammographic density is one of the strongest predictors of breast cancer risk, X-ray based mammography cannot be performed before the recommended screening age, especially not in adolescents and young women. Therefore, new techniques for breast density measurement are of interest. In this pilot study in Guam and Hawaii, we evaluated a radiation-free, bioimpedance device called Electrical Breast DensitometerTM (EBD; senoSENSE Medical Systems, Inc., Ontario, Canada) for measuring breast density in 95 women aged 31-82 years and 41 girls aged 8-18 years. Percent density (PD) was estimated in the women's most recent mammogram using a computer-assisted method. Correlation coefficients and linear regression were applied for statistical analysis. In adult women, mean EBD and PD values of the left and right breasts were 230±52 and 226±50 Ω and 23.7±15.1 and 24.2±15.2%, respectively. The EBD measurements were inversely correlated with PD (rSpearman=-0.52, p<0.0001); the correlation was stronger in Caucasians (rSpearman=-0.70, p<0.0001) than Asians (rSpearman=-0.54, p<0.01) and Native Hawaiian/Chamorro/Pacific Islanders (rSpearman=-0.34, p=0.06). Using 4 categories of PD (<10, 10-25, 26-50, 51-75%), the respective mean EBD values were 256±32, 249±41, 202±46, and 178±43 Ω (p<0.0001). In girls, the mean EBD values in the left and right breast were 148±40 and 155±54 Ω; EBD values decreased from Tanner stages 1 to 4 (204±14, 154±79, 136±43, and 119±16 Ω for stages 1-4, respectively) but were higher at Tanner stage 5 (165±30 Ω). With further development, this bioimpedance method may allow for investigations of breast development among adolescent, as well as assessment of breast cancer risk early in life and in populations without access to mammography.

Validation of self-reported figural drawing scales against anthropometric measurements in adults

OBJECTIVE

The aim of the present study was to validate figural drawing scales depicting extremely lean to extremely obese subjects to obtain proxies for BMI and waist circumference in postal surveys.

DESIGN

Reported figural scales and anthropometric data from a large population-based postal survey were validated with measured anthropometric data from the same individuals by means of receiver-operating characteristic curves and a BMI prediction model.

SETTING

Adult participants in a Scandinavian cohort study first recruited in 1990 and followed up twice since.

SUBJECTS

Individuals aged 38-66 years with complete data for BMI (n 1580) and waist circumference (n 1017).

RESULTS

Median BMI and waist circumference increased exponentially with increasing figural scales. Receiver-operating characteristic curve analyses showed a high predictive ability to identify individuals with BMI > 25·0 kg/m2 in both sexes. The optimal figural scales for identifying overweight or obese individuals with a correct detection rate were 4 and 5 in women, and 5 and 6 in men, respectively. The prediction model explained 74 % of the variance among women and 62 % among men. Predicted BMI differed only marginally from objectively measured BMI.

CONCLUSIONS

Figural drawing scales explained a large part of the anthropometric variance in this population and showed a high predictive ability for identifying overweight/obese subjects. These figural scales can be used with confidence as proxies of BMI and waist circumference in settings where objective measures are not feasible.

Percent Body Fat Is More Predictive of Function After Total Joint Arthroplasty Than Body Mass Index

BACKGROUND

Obesity has an important impact on the future of total joint arthroplasty; however, the definition and influence of obesity on surgical risks and outcomes remain controversial. Our hypothesis was that percent body fat was better than body mass index (BMI) at identifying clinical risks and patient-reported functional outcomes following arthroplasty.

METHODS

Clinical and functional outcomes were collected prospectively in 215 patients undergoing primary total knee arthroplasty (115 patients) or total hip arthroplasty (100 patients) at a mean time of twenty-four months (range, twelve to forty months). Clinical data included patient demographic characteristics, preoperative evaluation including measurements of BMI and percent body fat, intraoperative records, hospital course or events, and postoperative outpatient follow-up. Patient-reported outcomes were obtained through a series of questionnaires: a surgical satisfaction survey; the University of California, Los Angeles (UCLA) activity scale; the Knee Injury and Osteoarthritis Outcome Score (KOOS) for total knee arthroplasty; and the Hip Disability and Osteoarthritis Outcome Score (HOOS) for total hip arthroplasty. Multivariable regression models were used to identify significant body mass predictors of outcomes (p < 0.05).

RESULTS

Higher percent body fat predicted occurrence of any medical or surgical complication (odds ratio per one standard deviation increase, 1.58 [95% confidence interval, 1.04 to 2.40]; p = 0.033). Percent body fat was also a predictor of the UCLA activity score (risk ratio, 0.92 [95% confidence interval, 0.85 to 0.98]; p = 0.013) and pain scores (risk ratio, 1.18 [95% confidence interval, 1.03 to 1.36]; p = 0.017), and it trended toward significance for the surgical satisfaction score (odds ratio, 1.96 [95% confidence interval, 0.93 to 4.15]; p = 0.078), whereas BMI was not predictive of these functional outcomes. Additionally, with regard to surgical procedure-specific outcome scores, percent body fat was predictive of outcomes after total knee arthroplasty (KOOS pain, p = 0.015, and KOOS activities of daily living, p = 0.002), but not for those after total hip arthroplasty.

CONCLUSIONS

Percent body fat should be considered when predicting clinical and functional outcomes at two years following total joint arthroplasty. Percent body fat may help surgeons to improve risk stratifications, to project patient-reported functional outcomes, and to better educate obese patients with regard to postoperative expectations prior to undergoing elective total joint arthroplasty.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Body composition and functional assessment of nutritional status in adults: a narrative review of imaging, impedance, strength and functional techniques

The accurate and valid assessment of body composition is essential for the diagnostic evaluation of nutritional status, identifying relevant outcome measures, and determining the effectiveness of current and future nutritional interventions. Developments in technology and our understanding of the influences of body composition on risk and outcome will provide practitioners with new opportunities to enhance current practice and to lead future improvements in practice. This is the second of a two-part narrative review that aims to critically evaluate body composition methodology in diverse adult populations, with a primary focus on its use in the assessment and monitoring of under-nutrition. Part one focused on anthropometric variables [Madden and Smith (2016) J Hum Nutr Diet 29: 7-25] and part two focuses on the use of imaging techniques, bioelectrical impedance analysis, markers of muscle strength and functional status, with particular reference to developments relevant to practice.

Relationship Between Low Relative Muscle Mass and Coronary Artery Calcification in Healthy Adults

OBJECTIVE

Sarcopenia or low muscle mass is related to cardiovascular risk factors; however, the association between low muscle mass and subclinical atherosclerosis has been largely unexplored. We investigated whether muscle mass is related to coronary artery calcification (CAC) in a large sample of middle-aged asymptomatic adults.

APPROACH AND RESULTS

We performed a cross-sectional study of 31 108 asymptomatic adults without cancer, diabetes mellitus, or known cardiovascular disease who underwent a health checkup examination including cardiac tomography estimation of CAC scores between 2012 and 2013. Skeletal muscle mass index (SMI) [SMI (%)=total skeletal muscle mass (kg)/body weight (kg)×100] was estimated using a bioelectrical impedance analyzer. We assessed the relationship between SMI and CAC scores using both multivariate-adjusted Tobit models and multinomial logistic regression models. Of the 31 108 subjects, 3374 subjects (10.9%) had a CAC score 1 to 100, and 628 subjects (2.0%) had a CAC score >100. SMI was inversely associated with CAC score ratios. Specifically, in a multivariable-adjusted model adjusting for potential confounders, CAC score ratios (95% confidence intervals) of SMI for quartiles 1, 2, and 3 compared with quartile 4 were 2.27 (1.70-3.05), 1.46 (1.15-1.85), and 1.24 (0.98-1.55), respectively (P for trend <0.001). Adjusting for insulin resistance reduced the magnitude of the associations, but they remained statistically significant.

CONCLUSIONS

Relative muscle mass was negatively associated with the prevalence of coronary calcification, supporting low muscle mass as an independent risk factor of coronary heart disease.

Lower Muscle Strength and Increased Visceral Fat Associated With No-reflow and High Gensini Score in STEMI

Background:

The impact of fat distribution, muscle mass, and muscle strength on no-reflow and severity of coronary artery disease in patients with ST-segment elevation myocardial infarction (STEMI) remains unclear.

Objective:

To investigate association between muscle strength and fat and muscle mass and severity of coronary atherosclerosis.

Methods:

We included 218 patients with STEMI who had undergone primary percutaneous coronary intervention. We evaluated the no-reflow phenomenon in infarct-related artery and calculated Gensini scores from initial angiograms as indicative of coronary atherosclerosis severity. The patients were divided into 2 groups as patients with no-reflow and with thrombolysis in myocardial infarction grade 3 flow and patients with low (<55) Gensini and with high (≥55) Gensini. Patients’ total fat, muscle mass, visceral fat mass, and muscle strength were measured via body composition analyzer and handgrip dynamometer.

Results:

High Gensini patients had a greater body mass index (BMI) and lower handgrip strength and more visceral fat ( P = .05, P = .017, and P < .001, respectively). The patients with no-reflow had significantly lower handgrip strength and more visceral fat (both, P < .001). In multivariate regression analysis, visceral fat and handgrip strength were associated with high no-reflow rate and high Gensini scores in patients with STEMI ( P = .001, P = .014, P = .022, and P = .010; respectively).

Conclusion:

Increased visceral fat and lower handgrip strength may be related to increased no-reflow rate and coronary plaque burden in STEMI. Visceral fat and muscle strength may be better prognostic markers than weight, BMI, total fat, and muscle mass in coronary artery disease.

Evaluation of total body water in canine breeds by single-frequency bioelectrical impedance analysis method: specific equations are needed for accuracy

Background

Equations based on single-frequency bioelectrical impedance analysis at 50 kHz for determination of total body water content (TBW) have been previously validated in healthy non-sedated beagle dogs. We investigated whether these equations are predictive of TBW in various canine breeds by comparing the results of these equations with TBW values evaluated directly by deuterium oxide (D₂O) dilution.

Methods

Total body water content of 13 healthy adult pet dogs of various breeds was determined directly using D₂O dilution and indirectly using previous equations based on values obtained with a portable bioelectric impedance device. Paired Student’s t-tests were used to compare TBW obtained by single-frequency bioelectrical impedance analysis and D₂O dilution. A p-value of <0.05 was considered statistically significant for all analyses.

Results

Significant differences were observed between TBW determined by the reference method and the values obtained with both predictive equations.

Conclusions

The proposed equations including single-frequency bioelectrical impedance analysis parameters validated at 50 kHz in healthy adult beagles need to be modified including morphological parameters such as body size and shape in a first approach. As in humans, morphological-specific equations have to be developed and validated.

Bioimpedance analysis of body composition in an international twin cohort

OBJECTIVE

Multiple twin studies have demonstrated the heritability of anthropometric and metabolic traits. However, assessment of body composition parameters by bioimpedance analysis (BIA) has not been routinely performed in this setting.

DESIGN

A cross-sectional study.

SETTING

Study subjects were recruited and assessed at twin festivals or at major university hospitals in Italy, Hungary, and the United States to estimate the influence of genetic and environmental components on body composition parameters in a large, wide age range, international twin cohort by using bioelectrical impedance analysis.

SUBJECTS

380 adult twin pairs (230 monozygotic and 150 dizygotic pairs; male:female ratio, 68:32; age years 49.1 ± 15.4; mean ± standard deviation; age range 18-82) were included in the analysis.

RESULTS

Heritability was calculated for weight (82%; 95% confidence interval [CI]: 78-85), waist and hip circumferences (74%; 95%CI: 68-79), body fat percentage (74%; 95%CI: 69-79), fat-free mass (74%; 95%CI: 69-79) and body mass index (79%; 95%CI: 74-83). The completely environmental model showed no impact of shared environmental effects on the variance, while unshared environmental effects were estimated as between 18% and 26%.

CONCLUSIONS

BIA findings provide additional evidence to the heritability of anthropometric attributes related to obesity and indicate the practical value of this simple method in supporting efforts to prevent obesity-related adverse health events.

Comparison of percentage body fat and body mass index for the prediction of inflammatory and atherogenic lipid risk profiles in elderly women

OBJECTIVE

To compare the clinical classification of the body mass index (BMI) and percentage body fat (PBF) for the prediction of inflammatory and atherogenic lipid profile risk in older women.

METHOD

Cross-sectional analytical study with 277 elderly women from a local community in the Federal District, Brazil. PBF and fat-free mass (FFM) were determined by dual energy X-ray absorptiometry. The investigated inflammatory parameters were interleukin 6 and C-reactive protein.

RESULTS

Twenty-five percent of the elderly women were classified as normal weight, 50% overweight, and 25% obese by the BMI. The obese group had higher levels of triglycerides and very low-density lipoproteins than did the normal weight group (P≤0.05) and lower levels of high-density lipoproteins (HDL) than did the overweight group (P≤0.05). According to the PBF, 49% of the elderly women were classified as eutrophic, 28% overweight, and 23% obese. In the binomial logistic regression analyses including age, FFM, and lipid profile, only FFM (odds ratio [OR]=0.809, 95% confidence interval [CI]: 0.739-0.886; P<0.0005) proved to be a predictor of reaching the eutrophic state by the BMI. When the cutoff points of PBF were used for the classification, FFM (OR=0.903, CI=0.884-0.965; P=0.003) and the total cholesterol/HDL ratio (OR=0.113, CI=0.023-0.546; P=0.007) proved to be predictors of reaching the eutrophic state.

CONCLUSION

Accurate identification of obesity, systemic inflammation, and atherogenic lipid profile is key to assessing the risk of cardiometabolic diseases. Classification based on dual energy X-ray absorptiometry measures, along with biochemical and inflammatory parameters, seems to have a great clinical importance, since it allows the lipid profile eutrophic distinction in elderly overweight women.

The Impact of Feet Callosities, Arm Posture, and Usage of Electrolyte Wipes on Body Composition by Bioelectrical Impedance Analysis in Morbidly Obese Adults

OBJECTIVE

This study evaluated the impact of feet callosities, arm posture, and use of electrolyte wipes on body composition measurements by bioelectrical impedance analysis (BIA) in morbidly obese adults.

METHODS

36 morbidly obese patients (13 males, aged 28-70 years, BMI 41.6 ± 4.3 kg/m2) with moderate/severe feet callosities participated in this study. Body composition (percent body fat (%BF)) was measured while fasting using multi-frequency BIA (InBody 720®), before and after removal of callosities, with and without InBody® electrolyte wipes and custom-built auxiliary pads (to assess arm posture impact). Results from BIA were compared to air displacement plethysmography (ADP, BodPod®).

RESULTS

Median %BF was significantly higher with auxiliary pads than without (50.1 (interquartile range 8.2) vs. 49.3 (interquartile range 9.1); p < 0.001), while no differences were found with callosity removal (49.3 (interquartile range 9.1) vs. 50.0 (interquartile range 7.9); NS) or use of wipes (49.6 (interquartile range 8.5) vs. 49.3 (interquartile range 9.1); NS). No differences in %BF were found between BIA and ADP (49.1 (IQR: 8.9) vs. 49.3 (IQR: 9.1); NS).

CONCLUSION

Arm posture has a significant impact on %BF assessed by BIA, contrary to the presence of feet callosities and use of electrolyte wipes. Arm posture standardization during BIA for body composition assessment is, therefore, recommended.

Hypovolaemia was associated with clustering of major cardiovascular risk factors in general population

Background

Previous studies indicated that the clustering of major cardiovascular disease (CVD) risk factors is common, and multiple unhealthy lifestyles are responsible for the clustering of CVD risk factors. However, little is known about the direct association between the volume load and the clustering of CVD risk factors in general population.

Methods

We investigated the association of the clustering of CVD risk factors (defined as two or more of the following factors: hypertension, diabetes, dyslipidemia and overweight) with volume load, which was evaluated by bioelectrical impedance analysis. Hypovolaemia was defined as extracellular water/total body water (ECW/TBW) at and under the 10th percentile for the normal population.

Results

Among the 7900 adults, only 29.3% were free of any pre-defined CVD risk factors and 40.8% had clustering of CVD risk factors. Hypovolaemia in clustering group was statistically higher than that either in the single or in the none risk factor group, which was 23.7% vs. 17.0% and 10.0%, respectively (P <0.001). As a categorical outcome, the percentage of the lowest quartiles of ECW/TBW and TBW/TBWwatson in clustering group were statistically higher than either those in the single or in the none risk factor group, which were 44.9% vs. 36.9% and 25.1% (P <0.001), 36.2% vs. 32.2% and 25.0%, respectively (P <0.001). After adjusting of potential confounders, hypovolaemia was significantly associated with clustering of CVD risk factors, with an OR of 1.66 (95% CI, 1.45-1.90).

Conclusions

Hypovolaemia was associated with clustering of major CVD risk factors, which further confirms the importance of lifestyle for the development of CVD.

Effects of bed-rest on urea and creatinine: correlation with changes in fat-free mass

Background

Bed-rest experiments are designed for investigation on catabolic effects of hypokinetic conditions and/or for microgravity simulation in on-ground aerospace research. Bed-rest effects include a reduction in fat-free mass and muscle mass. Urea and creatinine are catabolites of endogenous protein and of muscular energetic metabolism which are excreted mainly by the kidney. The study investigated on urea, creatinine, and kidney function during bed-rest.

Methods

Twenty healthy young men underwent a 7-day adaptation period (day-6 to day-0) and a 35-day bed-rest experiment (day1 to day35) during normocaloric diet. Urine were collected from day-3 to day0 (baseline) and from day1 to day35. Blood samples and anthropometrical data were collected at day0 (baseline) and bed-rest days 7, 14, 21, 28, and 35.

Results

Bed-rest reduced plasma volume, weight, fat-free mass, and muscle mass (P<0.001). During bed-rest there was a transient increase in plasma and urinary urea, a decrease in plasma creatinine, and no change in urinary creatinine. The overall integral of changes from day0 to day35 was on average +101.7 mg/dL for plasma urea (95%CI = +43.4/+159.9), +82.2 g/24 h for urinary urea (95%CI = +55.8/+108.7), −2.5 mg/dL for plasma creatinine (95%CI = −3.1/−1.9). Bed-rest reduced plasma cistatyn C also, which was used as mass-independent marker of glomerular filtration rate (−13.1%, P<0.05). Correlations with final reduction in fat-free mass and muscle mass were significant for the overall integral of changes in urinary urea from day0 to day35 (R = 0.706, P<0.001) and for early changes in urinary urea and plasma urea from day0 to day7 (R = 0.566, P = 0.009 and R = 0.715, P<0.001, respectively).

Conclusions

Study results shows that urea is a marker of catabolic conditions secondary to hypokinetic conditions.

From wasting to obesity, changes in nutritional concerns in HIV/AIDS

Optimal nutrition is an important part of human immunodeficiency virus (HIV) care; to support the immune system, limit HIV-associated complications as well as maintain better quality of life and survival. The presentation and nature of malnutrition in patients with HIV has changed dramatically over the past 30 years from predominantly a wasting syndrome to lipodystrophy and, now, frailty. Nevertheless, we continue to see all 3 presentations in patient care today. The pathogenesis of poor nutrition in HIV-infected patients depends on caloric intake, intestinal nutrient absorption/translocation, and resting energy expenditure, which are features seen in all chronic diseases.

Body composition in patients with rheumatoid arthritis is not different than healthy subjects

OBJECTIVE

Rheumatoid arthritis (RA) is associated with an increased risk of cardiovascular disease (CVD). Increased body fat, particularly its central distribution, is a well-known risk factor for CVD. A change in body composition in RA has been described previously. However, in most of these studies, age- and sex- but not body mass index (BMI)-matched controls were used. The aim of this study was to evaluate body composition in RA patients and compare it with age-, sex-, and BMI-matched controls.

MATERIAL AND METHODS

Sixty-five RA patients (55 females and 10 males; mean age 54.9 ± 10.8) and 31 healthy controls (25 females, 6 males; 53.8±8.6) were included in this study. Mean disease duration was 9.2±9.6 years. Body composition was assessed by anthropometric methods (skinfold thicknesses, body circumferences), bioimpedance analysis, and dual-energy X-ray absorptiometry (DXA). Visceral adipose tissue (VAT) was assessed with computed tomography.

RESULTS

There were no significant differences for total body fatness, regional fat distribution, and total body water and fat-free mass between RA patients and control subjects. Bone mineral content (BMC), assessed by DXA, was significantly lower in RA patients (p=0.004). Clinical disease activity indices and steroid treatment do not affect soft tissue body composition or BMC.

CONCLUSION

At least some RA patients do not have soft tissue composition alterations and may have similar health risks in comparison with subjects with similar age, sex, and total adiposity.

Comparison of anthropometric and body composition measures as predictors of components of the metabolic syndrome in a clinical setting

PROBLEM

The use of body mass index (BMI) to assess obesity and health risks has been criticized in scientific and lay publications because of its failure to account for body shape and inability to distinguish fat mass from lean mass. We sought to determine whether other anthropometric measures (waist circumference (WC), waist-to-height ratio (WtH), percent body fat (%BF), fat mass index (FMI), or fat-free mass index (FFMI)) were consistently better predictors of components of the metabolic syndrome than BMI is.

METHODS

Cross-sectional measurements of height, weight, waist circumference and percent body fat were obtained from 12,294 adults who took part in annual physical exams provided by EHE International, Inc. Blood pressure was measured during the exam and HDL, LDL, and fasting glucose were measured from blood samples. Pearson correlations, linear regression, and adjusted Receiver Operator Characteristic (ROC) curves were used to relate each anthropometric measure to each metabolic risk factor.

RESULTS

None of the measures was consistently the strongest predictor. BMI was the strongest predictor of blood pressure, measures related to central adiposity (WC and WtH) performed better at predicting fasting glucose, and all measures were roughly comparable at predicting cholesterol levels. In all, differences in areas under ROC curves were 0.03 or less for all measure/outcome pairs that performed better than BMI.

CONCLUSION

Body mass index is an adequate measure of adiposity for clinical purposes. In the context of lay press critiques of BMI and recommendations for alternative body-size measures, these data support clinicians making recommendations to patients based on BMI measurements.

The theory and fundamentals of bioimpedance analysis in clinical status monitoring and diagnosis of diseases

Bioimpedance analysis is a noninvasive, low cost and a commonly used approach for body composition measurements and assessment of clinical condition. There are a variety of methods applied for interpretation of measured bioimpedance data and a wide range of utilizations of bioimpedance in body composition estimation and evaluation of clinical status. This paper reviews the main concepts of bioimpedance measurement techniques including the frequency based, the allocation based, bioimpedance vector analysis and the real time bioimpedance analysis systems. Commonly used prediction equations for body composition assessment and influence of anthropometric measurements, gender, ethnic groups, postures, measurements protocols and electrode artifacts in estimated values are also discussed. In addition, this paper also contributes to the deliberations of bioimpedance analysis assessment of abnormal loss in lean body mass and unbalanced shift in body fluids and to the summary of diagnostic usage in different kinds of conditions such as cardiac, pulmonary, renal, and neural and infection diseases.

Dipeptidyl peptidase IV inhibitor lowers PPARγ agonist-induced body weight gain by affecting food intake, fat mass, and beige/brown fat but not fluid retention

Peroxisome proliferator-activated receptor-γ (PPARγ) agonists like pioglitazone (PGZ) are effective antidiabetic drugs, but they induce fluid retention and body weight (BW) gain. Dipeptidyl peptidase IV (DPP IV) inhibitors are antidiabetic drugs that enhance renal Na(+) and fluid excretion. Therefore, we examined whether the DPP IV inhibitor alogliptin (ALG) ameliorates PGZ-induced BW gain. Male Sv129 mice were treated with vehicle (repelleted diet), PGZ (220 mg/kg diet), ALG (300 mg/kg diet), or a combination of PGZ and ALG (PGZ + ALG) for 14 days. PGZ + ALG prevented the increase in BW observed with PGZ but did not attenuate the increase in body fluid content determined by bioimpedance spectroscopy (BIS). BIS revealed that ALG alone had no effect on fat mass (FM) but enhanced the FM-lowering effect of PGZ; MRI analysis confirmed the latter and showed reductions in visceral and inguinal subcutaneous (sc) white adipose tissue (WAT). ALG but not PGZ decreased food intake and plasma free fatty acid concentrations. Conversely, PGZ but not ALG increased mRNA expression of thermogenesis mediator uncoupling protein 1 in epididymal WAT. Adding ALG to PGZ treatment increased the abundance of multilocular cell islets in sc WAT, and PGZ + ALG increased the expression of brown-fat-like "beige" cell marker TMEM26 in sc WAT and interscapular brown adipose tissue and increased rectal temperature vs. vehicle. In summary, DPP IV inhibition did not attenuate PPARγ agonist-induced fluid retention but prevented BW gain by reducing FM. This involved ALG inhibition of food intake and was associated with food intake-independent synergistic effects of PPARγ agonism and DPP-IV inhibition on beige/brown fat cells and thermogenesis.

Changes in anthropometric measurements, body composition, blood pressure, lipid profile, and testosterone in patients participating in a low-energy dietary intervention

OBJECTIVE

The purpose of this study was to describe changes in anthropometric measurements, body composition, blood pressure, lipid profile, and testosterone following a low-energy-density dietary intervention plus regimented supplementation program.

METHODS

The study design was a pre-post intervention design without a control group. Normal participants were recruited from the faculty, staff, students, and community members from a chiropractic college to participate in a 21-day weight loss program. All participants (n = 49; 36 women, 13 men; 31 ± 10.3 years of age) received freshly prepared mostly vegan meals (breakfast, lunch, and dinner) that included 1200 to 1400 daily calories (5020.8 to 5857.6 J) for the women and 1600 to 1800 (6694.4 to 7531.2 J) daily calories for the men. Nutritional supplements containing enzymes that were intended to facilitate digestion, reduce cholesterol levels, increase metabolic rate, and mediate inflammatory processes were consumed 30 minutes before each meal. The regimented supplementation program included once-daily supplementation with a green drink that contained alfalfa, wheatgrass, apple cider vinegar, and fulvic acid throughout the study period. A cleanse supplementation containing magnesium, chia, flaxseed, lemon, camu camu, cat's claw, bentonite clay, tumeric, pau d'arco, chanca piedra, stevia, zeolite clay, slippery elm, garlic, ginger, peppermint, aloe, citrus bioflavonoids, and fulvic acid was added before each meal during week 2. During week 3, the cleanse supplementation was replaced with probiotic and prebiotic supplementation.

RESULTS

Multiple paired t tests detected clinically meaningful reductions in weight (- 8.7 ± 5.54 lb) (- 3.9 ± 2.5 kg), total cholesterol (- 30.0 ± 29.77 mg/dL), and low-density lipoprotein cholesterol (- 21.0 ± 25.20 mg/dL) (P < .05). There was a pre-post intervention increase in testosterone for men (111.0 ± 121.13 ng/dL, P < .05).

CONCLUSIONS

Weight loss and improvements in total cholesterol and low-density lipoprotein cholesterol levels occurred after a low-energy-density dietary intervention plus regimented supplementation program.

Effect of high-intensity interval training on progression of cardiac allograft vasculopathy

BACKGROUND

Cardiac allograft vasculopathy (CAV) is a progressive form of atherosclerosis occurring in heart transplant (HTx) recipients, leading to increased morbidity and mortality. Given the atheroprotective effect of exercise on traditional atherosclerosis, we hypothesized that high-intensity interval training (HIIT) would reduce the progression of CAV among HTx recipients.

METHODS

Forty-three cardiac allograft recipients (mean ± SD age 51 ± 16 years; 67% men; time post-HTx 4.0 ± 2.2 years), all clinically stable and >18 years old, were randomized to either a HIIT group or control group (standard care) for 1 year. The effect of training on CAV progression was assessed by intravascular ultrasound (IVUS).

RESULTS

IVUS analysis revealed a significantly smaller mean increase [95% CI] in atheroma volume (PAV) of 0.9% [95% CI -;0.3% to 1.9%] in the HIIT group as compared with the control group, 2.5% [1.6% to 3.5%] (p = 0.021). Similarly, the mean increase in total atheroma volume (TAV) was 0.3 [0.0 to 0.6] mm(3)/mm in the HIT group vs 1.1 [0.6 to 1.7] mm(3)/mm in the control group (p = 0.020), and mean increase in maximal intimal thickness (MIT) was 0.02-0.01 to 0.04] mm in the HIIT group vs 0.05 [0.03 to 0.08] mm in the control group (p = 0.054). Qualitative plaque progression (virtual histology parameters) and inflammatory activity (biomarkers) were similar between the 2 groups during the study period.

CONCLUSIONS

HIIT among maintenance HTx recipients resulted in a significantly impaired rate of CAV progression. Future larger studies should address whether exercise rehabilitation strategies should be included in CAV management protocols.

Blood pressure relation to body composition and age: analysis of a nurse-led investigation and consultation program

BACKGROUND

Blood pressure (BP) increases with age and obesity. We have assessed the relative contribution of age and fatness to BP regulation in a healthy population investigated by nurse practitioners.

MATERIAL AND METHODS

Preventive investigation and counseling was offered at the entrance hall of the regional authority´s office in the town of Nitra by 2 nursing specialists who investigated 120 men and 276 women. In men the mean body mass index (BMI) was 26.8 kg/m2, mean weight was 84.4 kg, mean fat percentage was 23.3, mean age was 46.1 years, mean systolic BP was 133.1 mmHg, and mean diastolic BP was 82.5 mmHg. In women the mean BMI was 24.8 kg/m2, mean weight was 67.3 kg, mean fat percentage was 29.4, mean age was 45.4 years, mean systolic BP was 127.7 mmHg, and mean diastolic BP was 78.5 mmHg. Correlation analysis was performed and in multiple regression analysis we used BP values as the dependent variable and fat percentage and age as independent variables. Normality of variables distribution was checked and found satisfactorily.

RESULTS

Most of the subjects had an untreated component of metabolic syndrome. There was a correlation between BP values, age, and percent body fat. BP was regulated only to a certain degree by fatness and age, with the influence being relatively small. Our results showed that BP was more influenced by fatness than age, and body fatness was more related to higher systolic than to diastolic BP.

CONCLUSIONS

Age and fatness could explain BP values by only 3-30%, although BP was more influenced by fatness than by age. Nurse practitioners can effectively detect and motivate people with metabolic syndrome.

Measures of body fat in South Asian adults

BACKGROUND

South Asian people who originate from the Indian subcontinent have greater percent body fat (%BF) for the same body mass index (BMI) compared with white Caucasians. This has been implicated in their increased risk of type 2 diabetes and cardiovascular disease. There is limited information comparing different measures of body fat in this ethnic group.

OBJECTIVES

The objectives of this study were: (1) to investigate the correlation of %BF measured by a foot-to-foot bioelectrical impedance analysis (FF-BIA) against the BOD POD, a method of air-displacement plethysmography, and (2) to determine the correlations of simple anthropometric measures, (that is, BMI, body adiposity index (BAI), waist circumference (WC), hip circumference (HC) and waist-to-hip ratio (WHR)) against the BOD POD measure of body fat.

METHODS

Eighty apparently healthy South Asian men and women were recruited from the community, and measurements of height, weight, WC, HC and body composition using Tanita FF-BIA and BOD POD were taken.

RESULTS

The mean±s.d. age of participants was 27.78±10.49 years, 42.5% were women, and the mean BMI was 22.68±3.51 kg m(-2). The mean body fat (%BF) calculated by FF-BIA and BOD POD was 21.94±7.88% and 26.20±8.47%, respectively. The %BF calculated by FF-BIA was highly correlated with the BOD POD (Pearson's r=0.83, P<0.001), however, FF-BIA underestimated %BF by 4.3%. When anthropometric measures were compared with % BF by BOD POD, the BAI showed the strongest correlation (r=0.74) and the WHR showed the weakest (r=0.33). BAI generally underestimated %BF by 2.6% in comparison with %BF by BOD POD. The correlations of BOD POD with other measures of %BF were much stronger in subjects with a BMI >21 kg m(-2) than those with a BMI 21 kg m(-2).

CONCLUSION

The FF-BIA and BAI estimates of %BF are highly correlated with that of BOD POD among people of South Asian origin, although both methods somewhat underestimate % BF. Furthermore, their correlations with % BF from BOD POD are significantly weakened among men and women with a BMI 21 kg m(-2).

Comparison of body adiposity index (BAI) and BMI with estimations of % body fat in clinically severe obese women

OBJECTIVE

Body adiposity index (BAI), a new surrogate measure of body fat (hip circumference/(height(1.5) - 18)), has been proposed as an alternative to body mass index (BMI). We compared BAI with BMI, and each of them with laboratory measures of body fat-derived from bioimpedance analysis (BIA), air displacement plethysmography (ADP), and dual-energy X-ray absorptiometry (DXA) in clinically severe obese (CSO) participants.

DESIGN AND METHODS

Nineteen prebariatric surgery CSO, nondiabetic women were recruited (age = 32.6 ± 7.7 SD; BMI = 46.5 ± 9.0 kg/m(2) ). Anthropometrics and body fat percentage (% fat) were determined from BIA, ADP, and DXA. Scatter plots with lines of equality and Bland-Altman plots were used to compare BAI and BMI with % fat derived from BIA, ADP, and DXA. BAI and BMI correlated highly with each other (r = 0.90, P < 0.001).

RESULTS

Both BAI and BMI correlated significantly with % fat from BIA and ADP. BAI, however, did not correlate significantly with % fat from DXA (r = 0.42, P = 0.08) whereas BMI did (r = 0.65, P = 0.003). BMI was also the single best predictor of % fat from both BIA (r(2) = 0.80, P < 0.001) and ADP (r(2) = 0.65, P < 0.001). The regression analysis showed that the standard error of the estimate (SEE), or residual error around the regression lines, was greater for BAI comparisons than for BMI comparisons with BIA, ADP, and DXA. Consistent with this, the Bland and Altman plots indicated wider 95% confidence intervals for BAI difference comparisons than for BMI difference comparisons for their respective means for BIA, ADP, and DXA.

CONCLUSIONS

Thus, BAI does not appear to be an appropriate proxy for BMI in CSO women.

Validation of a portable bioelectrical impedance analyzer for the assessment of body composition

One of the major challenges in field research has been the difficulty to adequately measure body composition, such as % body fat and fat-free mass (FFM). Therefore, the purpose of the present study was to investigate the convergent validity of the portable bioelectrical impedance body composition analyzer, the Inbody 230, with dual X-ray absorptiometry (DXA) (General Electric Lunar Prodigy). The study population consisted of 145 men and women (age, 44.6 ± 20 years; BMI, 24.5 ± 3.8 kg·m(-2)). We measured body composition (fat mass, % body fat, total FFM, trunk FFM, and appendicular FFM) using DXA and the Inbody 230. Results show strong significant correlations between both methods for fat mass, % body fat, total FFM, and trunk FFM (r = 0.94-0.99). Furthermore, we showed a modest significant correlation between both methods for appendicular FFM (r = 0.63). Finally, as shown by Bland-Altman analysis, no significant biases were observed between Inbody 230 and DXA for fat mass, % body fat, and total FFM. However, trunk and appendicular FFM were shown to have significant biases between the Inbody 230 and DXA. In conclusion, the present study indicated that the portable Inbody 230 may be an acceptable device to measure fat mass, % body fat, and total FFM (except for women) in healthy adults. In addition, there appears to be a systematic bias for the estimation of trunk and appendicular FFM with the Inbody 230 in men and women.

Caucasian children's fat mass: routine anthropometry v. air-displacement plethysmography

The present paper will use fat mass percentage (FM%) obtained via BOD POD® air-displacement plethysmography (FMADP%) to examine the relative validity of (1) anthropometric measurements/indices and (2) of FM% assessed with equations (FMeq%) based on skinfold thickness and bioelectrical impedance (BIA). In 480 Belgian children (aged 5–11 years) weight, height, skinfold thickness (triceps and subscapular), body circumferences (mid-upper arm, waist and hip), foot-to-foot BIA (Tanita®) and FMADP% were measured. Anthropometric measurements and calculated indices were compared with FMADP%. Next, published equations were used to calculate FMeq% using impedance (equations of Tanita®, Tyrrell, Shaefer and Deurenberg) or skinfold thickness (equations of Slaughter, Goran, Dezenberg and Deurenberg). Both indices and equations performed better in girls than in boys. For both sexes, the sum of skinfold thicknesses resulted in the highest correlation with FMADP%, followed by triceps skinfold, arm fat area and subscapular skinfold. In general, comparing FMeq% with FMADP% indicated mostly an age and sex effect, and an increasing underestimation but less dispersion with increasing FM%. The Tanita® impedance equation and the Deurenberg skinfold equation performed the best, although none of the used equations were interchangeable with FMADP%. In conclusion, the sum of triceps and subscapular skinfold thickness is recommended as marker of FM% in the absence of specialised technologies. Nevertheless, the higher workload, cost and survey management of an immobile device like the BOD POD® remains justified.

Different anthropometric adiposity measures and their association with cardiovascular disease risk factors: a meta-analysis

Objectives

To investigate which anthropometric adiposity measure has the strongest association with cardiovascular disease (CVD) risk factors in Caucasian men and women without a history of CVD.

Design

Systematic review and meta-analysis.

Methods

We searched databases for studies reporting correlations between anthropometric adiposity measures and CVD risk factors in Caucasian subjects without a history of CVD. Body mass index (BMI), waist circumference, waist-to-hip ratio, waist-to-height ratio and body fat percentage were considered the anthropometric adiposity measures. Primary CVD risk factors were: systolic blood pressure, diastolic blood pressure, high density lipoprotein (HDL) cholesterol, triglycerides and fasting glucose. Two independent reviewers performed abstract, full text and data selection.

Results

Twenty articles were included describing 21,618 males and 24,139 females. Waist circumference had the strongest correlation with all CVD risk factors for both men and women, except for HDL and LDL in men. When comparing BMI with waist circumference, the latter showed significantly better correlations to CVD risk factors, except for diastolic blood pressure in women and HDL and total cholesterol in men.

Conclusions

We recommend the use of waist circumference in clinical and research studies above other anthropometric adiposity measures, especially compared with BMI, when evaluating CVD risk factors.

Segmental bioelectrical impedance analysis: an update

PURPOSE OF REVIEW

Bioelectrical impedance analysis is a popular, noninvasive and practical method for assessment of body composition. The last decade has seen the development of impedance analyzers designed to assess the composition of body segments as well as the whole body. This review outlines the theoretical basis for segmental impedance analysis, validity and use in practice.

RECENT FINDINGS

Segmental impedance analysis tends to underestimate fat-free mass and overestimate fat mass when compared to reference techniques, although the magnitude of these differences can be small. Performance is improved with population-specific prediction equations; algorithms in-built into instrument firmware should not be relied upon. Prediction of whole-body composition from the sum of the individual segments, although theoretically preferable, shows little advantage over whole body wrist to ankle impedance approaches. Prediction of appendicular skeletal muscle mass, although promising, requires further research. The use of measured impedance data directly as indices of composition, rather than for prediction, has not found extensive application in nutritional research despite its success in other fields.

SUMMARY

Segmental bioimpedance techniques have advanced substantially in recent years due to availability of simple-to-use analyzers and simplified measurement protocols. The method has been well validated and increasingly adopted in nutritional and clinical practice. Segmental impedance, like conventional whole body impedance approaches, provides indirect prediction of body composition whose accuracy is yet to achieve that of reference techniques such as magnetic reference imaging. This lack of accuracy, however, is outweighed by the method's practicality of use in many settings.

Electrical impedance myography as a biomarker to assess ALS progression

Electrical impedance myography (EIM), a non-invasive, electrophysiological technique, has preliminarily shown value as an ALS biomarker. Here we perform a multicenter study to further assess EIM's potential for tracking ALS. ALS patients were enrolled across eight sites. Each subject underwent EIM, handheld dynamometry (HHD), and the ALS Functional Rating Scale-revised (ALSFRS-R) regularly. Techniques were compared by assessing the coefficient of variation (CoV) in the rate of decline and each technique's correlation to survival. Results showed that in the 60 patients followed for one year, EIM phase measured from the most rapidly progressing muscle in each patient had a CoV in the rate of decline of 0.62, compared to HHD (0.82) and the ALSFRS-R (0.74). Restricting the measurements to the first six months gave a CoV of 0.55 for EIM, 0.93 for HHD, and 0.84 for ALSFRS-R. For both time-periods, all three measures correlated with survival. Based on these data, a six-month clinical trial designed to detect a 20% treatment effect with 80% power using EIM would require only 95 patients/arm compared to the ALSFRS-R, which would require 220 subjects/arm. In conclusion, EIM can serve as a useful ALS biomarker that offers the prospect of greatly accelerating phase 2 clinical trials.

Muscular exercise capacity and body fat predict VO(2peak) in heart transplant recipients

BACKGROUND

Heart transplant (HTx) recipients usually have reduced exercise capacity, with reported VO2peak levels of 50-70% of predicted values. This study aimed to evaluate central and peripheral factors predictive of VO2peak.

METHODS AND RESULTS

Fifty-one clinically stable HTx recipients >18 years old and 1-8 years after HTx, underwent maximal exercise testing on a treadmill. Clinical laboratory, haemodynamic and echocardiographic data, lung function, and isokinetic muscle strength and muscular exercise capacity were recorded. The mean ± SD age was 52 ± 16 years, 71% were male, and time from HTx was 4.1 ± 2.2 years. The patients were assigned to one of two groups: VO2peak ≤or >27.3 ml/kg/min, which was the median value, corresponding to 80% of predicted value. The group with the higher VO2peak had significantly lower body mass index, body fat, and triglycerides, and significantly higher body water, muscular exercise capacity, high-density lipoprotein (HDL) cholesterol, lung function, mitral annular velocity, peak ventilation, O2 pulse, and VE/VCO2 slope. Donor age, recipient age, sex, medication, ischaemic time, cardiac dimensions, systolic function, and chronotropic responses during exercise were similar. Multiple regression analysis showed that muscular exercise capacity and body fat were the strongest VO2peak predictors.

CONCLUSIONS

Chronotropic incompetence is not a limiting factor for exercise capacity in a population of relatively fit HTx patients. The most significant predictors, representing only peripheral factors, are similar to those often determining VO2peak in healthy, non-athletic individuals. Our findings emphasize the importance of a low percentage of body fat and high muscular exercise capacity in order to attain a sufficient VO2peak level after HTx.

Gastrointestinal manifestations of scleroderma: recent progress in evaluation, pathogenesis, and management

Gastrointestinal (GI) involvement is frequent in scleroderma (systemic sclerosis [SSc]) and is the most frequent internal complication of the disease. Patients with GI involvement have impaired quality of life, and their prognosis may be one of severe impairment. Unfortunately, GI involvement is often noticed when severe complications have already occurred, is irreversible, and is difficult to manage. The past 2 to 3 years have been rich in exciting studies that we hope will help identify, prevent, treat, and monitor disease progression. Recent studies on the pathophysiology of GI tract disease could lead to advances in the treatment of GI tract involvement. The importance of treating gastroesophageal reflux (GER) has been reinforced by studies showing GER damage in almost all SSc patients, and the fact that GER damage is reversible if early treatment with proton pump inhibitors is introduced. Moreover, recent data showing a link between GER and interstitial lung disease in SSc underscore the importance of aggressive GER treatment in SSc patients. A novel lung pattern possibly related to GER also has been described. New, exciting data on gastric vascular antral ectasia have been published. Finally, malnutrition in SSc patients has been highlighted, and anorectal involvement has been emphasized.

Gastrointestinal manifestations of scleroderma: recent progress in evaluation, pathogenesis, and management

Gastrointestinal (GI) involvement is frequent in scleroderma (systemic sclerosis [SSc]) and is the most frequent internal complication of the disease. Patients with GI involvement have impaired quality of life, and their prognosis may be one of severe impairment. Unfortunately, GI involvement is often noticed when severe complications have already occurred, is irreversible, and is difficult to manage. The past 2 to 3 years have been rich in exciting studies that we hope will help identify, prevent, treat, and monitor disease progression. Recent studies on the pathophysiology of GI tract disease could lead to advances in the treatment of GI tract involvement. The importance of treating gastroesophageal reflux (GER) has been reinforced by studies showing GER damage in almost all SSc patients, and the fact that GER damage is reversible if early treatment with proton pump inhibitors is introduced. Moreover, recent data showing a link between GER and interstitial lung disease in SSc underscore the importance of aggressive GER treatment in SSc patients. A novel lung pattern possibly related to GER also has been described. New, exciting data on gastric vascular antral ectasia have been published. Finally, malnutrition in SSc patients has been highlighted, and anorectal involvement has been emphasized.

Mannose-binding lectin in obesity with different degrees of metabolic syndrome abnormalities: association with atherogenic and metabolic traits

AIM

In subjects with metabolic syndrome (MetS) endothelial dysfunction is a very consistent finding. Processes leading to endothelial dysfunction and atherosclerosis involve the altered control of subclinical inflammation by innate immune defenses that possibly include mannose-binding lectin (MBL). We investigated the associations of MBL with traits of MetS and early atherosclerosis in obese subjects before and after marked weight reduction.

METHODS

In a prospective longitudinal study, MBL concentrations of 96 severely obese subjects with and without MetS (Ø BMI with MetS 41.0±7.9 kg/m(2), Ø BMI without MetS 39.4±7.7 kg/m(2) were examined in association with markers of insulin resistance, dyslipidemia, adipokines, and subclinical atherosclerosis before and after marked weight loss (Ø weight loss 20±8 kg after 3 months of participation in a standardized weight reduction program), in addition to the study of 25 seemingly healthy lean subjects (BMI 20-25 kg/m(2).

RESULTS

MBL concentrations did not differ between healthy lean and severely obese subjects independently of the presence of metabolic abnormalities. In severely obese subjects there was no significant difference concerning the cardiovascular risk profile, apolipoproteins, inflammatory and metabolic parameters, and markers of endothelial dysfunction and atherosclerosis between subjects with functional MBL deficienct (MBL<778 ng/mL) and MBL sufficient (MBL≥778 ng/mL) obesity. Marked weight loss did not influence MBL levels.

CONCLUSIONS

Our findings suggest that plasma levels of MBL did not differ between healthy lean and severely obese subjects. MBL did not affect cardiovascular risk factors, or markers of endothelial dysfunction and early atherosclerosis in severely obese patients before and after marked weight loss.

Effect of bioimpedance body composition analysis on function of implanted cardiac devices

BACKGROUND

It is routinely recommended that patients with pacemakers, implantable cardioverter defibrillators (ICD), and cardiac resynchronization therapy-defibrillators (CRT-D) avoid bioelectrical impedance analysis (BIA)--a commonly used method to estimate body composition--because of the concern for the potential for BIA interference with pacemaker or ICD function. However, the prevalence of such interference is not known.

OBJECTIVE

Assess for incidence of interference between BIA and ICD or CRT-D devices.

METHODS AND RESULTS

Twenty patients with heart failure and cardiac implanted electronic devices (50% ICD, 50% CRT-D) underwent BIA during real-time device interrogation to detect interference. Study patients were 90% male, with mean age 54 ± 14 years, and mean LVEF 23 ± 11%. Devices from all four leading cardiac device manufacturers were included. Device therapies were temporarily disabled to prevent inappropriate shocks. During body composition testing using BIA, no evidence of interference with ICD function was seen in any patient, including no telemetry disruption, no oversensing on any lead, and no patient symptoms.

CONCLUSIONS

Despite the manufacturers' recommendation to avoid BIA in patients with ICDs, this study showed no evidence of any interference in 20 patients. Bioimpedance analysis might be safe in such patients, but further confirmatory studies are required.

Assessment of body composition using dry mass index and ratio of total body water to estimated volume based on bioelectrical impedance analysis in chronic kidney disease patients

OBJECTIVE

Body mass index (BMI) is commonly used for assessment of nutritional status. However, changes in BMI in chronic kidney disease (CKD) patients are affected not only by muscle and fat but also by fluid volume. The ratio of extracellular water (ECW(BIA)) to total body water (TBW(BIA)) in multifrequency bioelectrical impedance analysis is commonly used for assessing abnormal fluid status. This study reexamines ECW(BIA)/TBW(BIA) and evaluates the reliability of TBW(BIA)/TBW(watson) and dry mass index (DMI) in the assessment of fluid and nutritional status.

DESIGN, SETTING, AND SUBJECTS

TBW(BIA), intracellular water (ICW(BIA)), and ECW(BIA) were measured in 45 randomly selected CKD patients. Participants were surveyed for age, gender, BMI, blood pressure, serum albumin, estimated glomerular filtration rate, and proteinuria. DMI was calculated by the formula ([weight--TBW(BIA)]/height(2)) and TBW(BIA)/TBW(watson) using an anthropometric formula (Watson). Fluid and nutritional status were assessed using ECW(BIA)/TBW(BIA), TBW(BIA)/TBW(watson), and DMI.

RESULTS

TBW(BIA)/TBW(watson) positively correlated with weight, BMI, and diastolic blood pressure and negatively correlated with age and serum albumin level. In contrast, ECW(BIA)/TBW(BIA) correlated with ICW deficit, aging, and body weight loss. On the basis of DMI and TBW(BIA)/TBW(watson), participants were categorized as follows: 1 obese patient with hypovolemia and 2 with euvolemia; 17 overweight patients with hypovolemia (n = 6), euvolemia (n = 8), or hypervolemia (n = 3); 24 patients of optimal weight with hypovolemia (n = 10), euvolemia (n = 9), or hypervolemia (n = 5); and 1 underweight patient with euvolemia.

CONCLUSIONS

A combination of DMI, BMI, and TBW(BIA)/TBW(watson) makes it possible to include assessment of fluid volume to the physique index. In addition, ECW(BIA)/TBW(BIA) is not a reliable marker of edematous state in CKD patients.

Body composition: why, when and for who?

Body composition reflects nutritional intakes, losses and needs over time. Undernutrition, i.e. fat-free mass (FFM) loss, is associated with decreased survival, worse clinical outcome and quality of life, as well as increased therapy toxicity in cancer patients. In numerous clinical situations, such as sarcopenic obesity and chronic diseases, the measurement of body composition with available methods, such as dual-X ray absorptiometry, computerized tomography and bioelectrical impedance analysis, quantifies the loss of FFM, whereas body weight loss and body mass index only inconstantly reflect FFM loss. The measurement of body composition allows documenting the efficiency of nutrition support, tailoring the choice of disease-specific and nutritional therapies and evaluating their efficacy and putative toxicity. Easy-to-use body composition methods integrated to the routine of care allow sequential measurements for an initial nutritional assessment and objective patients follow-up. By allowing an earlier and objective management of undernutrition, body composition assessment could contribute to reduce undernutrition-induced morbidity, worsening of quality of life, and global health care costs by a timely nutrition intervention.

Bioelectrical impedance and dual-energy x-ray absorptiometry assessments of changes in body composition following exercise in patients with type 2 diabetes mellitus

We aimed to compare the level of agreement between leg-to-leg bioelectrical impedance analysis (LBIA) and dual-energy X-ray absorptiometry (DXA) for assessing changes in body composition following exercise intervention among individuals with Type 2 diabetes mellitus (T2DM). Forty-four adults with T2DM, age 53.2 ± 9.1 years; BMI 30.8 ± 5.9 kg/m(2) participated in a 6-month exercise program with pre and post intervention assessments of body composition. Fat free mass (FFM), % body fat (%FM) and fat mass (FM) were measured by LBIA (TBF-300A) and DXA. LBIA assessments of changes in %FM and FM post intervention showed good relative agreements with DXA variables (P < 0.001). However, Bland-Altman plot(s) indicated that there were systematic errors in the assessment of the changes in body composition using LBIA compared to DXA such that, the greater the changes in participant body composition, the greater the disparity in body composition data obtained via LBIA versus DXA data (FFM, P = 0.013; %FM, P < 0.001; FM, P < 0.001). In conclusion, assessment of pre and post intervention body composition implies that LBIA is a good tool for assessment qualitative change in body composition (gain or loss) among people with T2DM but is not sufficiently sensitive to track quantitative changes in an individual's body composition.

Relationship between the body adiposity index and cardiometabolic risk factors in obese postmenopausal women

OBJECTIVE

The purpose of the present secondary analysis study was to investigate the ability of the body adiposity index (BAI) to detect changes in % body fat levels before and after a weight loss intervention when compared to % body fat levels measured using dual-energy X-ray absorptiometry (DXA) and to examine the relationship between the BAI with cardiometabolic risk factors.

METHODS

The study population for this secondary analysis included 132 non-diabetic obese sedentary postmenopausal women (age: 57.2 ± 4.7 years, BMI: 35.0 ± 3.7 kg/m(2)) participating in a weight loss intervention that consisted of a calorie-restricted diet with or without resistance training. We measured: (1) visceral fat using CT-scan, (2) body composition using DXA, (3) hip circumference and height from which the BAI was calculated, and (4) cardiometabolic risk factors such as insulin sensitivity (using the hyperinsulinemic-euglycemic clamp), blood pressure as well as fasting plasma lipids, hsC-reactive protein (CRP), leptin, and glucose.

RESULTS

Percent body fat levels for both methods significantly decreased after the weight loss intervention. In addition, the percent change in % body fat levels after the weight loss intervention was significantly different between % body fat measured using the DXA and the BAI (-4.5 ± 6.6 vs. -5.8 ± 5.9%; p = 0.03, respectively). However, we observed a good overall agreement between the two methods, as shown by the Bland-Altman analysis, for percent change in % body fat. Furthermore, similar correlations were observed between both measures of % body fat with cardiometabolic risk factors. However, results from the multiple linear regression analysis showed that % body fat using the BAI appeared to predict cardiometabolic risk factors differently than % body fat using the DXA in our cohort.

CONCLUSIONS

Estimating % body fat using the BAI seems to accurately trace variations of % body fat after weight loss. However, this index showed differences in predicting cardiometabolic risk factors when compared to % body fat measured using DXA.

The evaluation of body composition: a useful tool for clinical practice

Undernutrition is insufficiently detected in in- and outpatients, and this is likely to worsen during the next decades. The increased prevalence of obesity together with chronic illnesses associated with fat-free mass (FFM) loss will result in an increased prevalence of sarcopenic obesity. In patients with sarcopenic obesity, weight loss and the body mass index lack accuracy to detect FFM loss. FFM loss is related to increasing mortality, worse clinical outcomes, and impaired quality of life. In sarcopenic obesity and chronic diseases, body composition measurement with dual-energy X-ray absorptiometry, bioelectrical impedance analysis, or computerized tomography quantifies the loss of FFM. It allows tailored nutritional support and disease-specific therapy and reduces the risk of drug toxicity. Body composition evaluation should be integrated into routine clinical practice for the initial assessment and sequential follow-up of nutritional status. It could allow objective, systematic, and early screening of undernutrition and promote the rational and early initiation of optimal nutritional support, thereby contributing to reducing malnutrition-induced morbidity, mortality, worsening of the quality of life, and global health care costs.

Ethnic variation in body composition assessment in a sample of adolescent girls

OBJECTIVE

To compare body composition assessment by bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) in a multiethnic sample of adolescent girls.

METHOD

Data were from a physical activity intervention study among 254 14-20-year-old sedentary American girls, including 69 whites, 74 blacks, 42 Hispanics, and 69 Asians. Height and weight were objectively measured. Body composition was assessed using a foot-to-foot BIA and a fan-beam DXA. We calculated ethnic-specific estimates of percentage body fat (BF%), fat mass (FM), fat mass index (FMI), fat-free mass (FFM), and fat-free mass index (FFMI) from BIA and DXA. We used Bland-Altman plots to examine ethnic-specific agreement between BIA and DXA, and used linear regression to test whether the BIA-DXA difference varied across the mean.

RESULTS

Compared to DXA, BIA estimates of fat measures (BF%, FM, and FMI) were lower and lean tissue measures (FFM and FFMI) higher. For example, the BIA-estimated BF% was lower than the DXA estimate by between 4.9% (95% CI: -5.9, -3.9) in blacks and 8.7% (-7.0, -5.0) in Asians, with large limits of agreement (-15.4 to -5.4 in blacks and -16.8 to -0.4 in Asians). Regression analysis showed that BIA-DXA differences were not constant across means for any body composition measure among Asians or for any measure except BF% among whites.

CONCLUSION

Compared to DXA, BIA yielded lower estimates of adiposity in a multiethnic adolescent sample. BIA-DXA differences varied by ethnicity, and across mean body composition values for some ethnicities.

Evaluation of bioimpedance as novel predictor of extracorporeal shockwave lithotripsy success

BACKGROUND AND PURPOSE

Obesity has been identified as a limitation of extracorporeal shockwave lithotripsy (SWL). The obesity metrics of body mass index (BMI) and skin-to-stone distance (SSD) have been evaluated as predictors of SWL success. While SSD has demonstrated a strong correlation with success, BMI has not. Bioimpedance analysis (BIA) is an accurate way of determining body adiposity. We evaluated fat mass percentage (FMP) as measured by BIA as a predictor of SWL success.

PATIENTS AND METHODS

We prospectively collected body composition data using the Imp-DF50 Body Impedance Analyzer on consecutive patients undergoing SWL. All generated variables, including FMP, along with demographics, BMI, stone size, and stone composition, were analyzed. Patients were evaluated for success, defined as no evidence of stones on radiography of the kidneys, ureters, and bladder at follow-up.

RESULTS

Fifty-two consecutive patients were enrolled in the study, of which 37 had the necessary metrics to be included in the analysis. Twenty-three (62.2%) patients were stone free while 14 (37.8%) were found to have residual stone at follow-up. There was no difference in sex, stone laterality, mean age, and stone size between the groups. For the success and failure groups, the mean BMI was 25.8 kg/m(2) and 29.8 kg/m(2) (P=0.0091), and mean FMP 24.6% and 32.2% (P=0.0034). On mirrored multivariable analysis, both BMI (OR=0.735, P=0.026) and FMP (OR=0.806, P=0.010) were associated with success. Patients with a FMP ≥35% had a reduced success rate compared with those with a FMP <35% (14% vs 73%, respectively, P=0.0028).

CONCLUSIONS

Both BMI and FMP both appear to be independent predictors of success. Based on these findings, a large study examining the relationship between BMI, FMP, SSD, and SWL success is warranted. A preoperative FMP ≥35% is associated with a 14% success rate, and alternative treatment strategies for urolithiasis should be considered.

Adaptive changes of pancreatic protease secretion to a short-term vegan diet: influence of reduced intake and modification of protein

In our previous study, we demonstrated that abstaining from meat, for 1 month, by healthy omnivores (lacto-ovovegetarian model) resulted in a statistical decrease in pancreatic secretion as measured by faecal elastase-1 output. However, no correlation between relative and non-relative changes of energy and nutrient consumption and pancreatic secretion was documented. Therefore, in the present study, we aimed to assess the changes of exocrine pancreatic secretion with a more restrictive dietetic modification, by applying a vegan diet. A total of twenty-one healthy omnivores (sixteen females and five males) participated in the prospective study lasting for 6 weeks. The nutrient intake and faecal output of pancreatic enzymes (elastase-1, chymotrypsin and lipase) were assessed twice during the study. Each assessment period lasted for 7 d: the first before the transition to the vegan diet (omnivore diet) and the second during the last week of the study (vegan diet). The dietary modification resulted in a significant decrease in faecal elastase-1 (P < 0·05) and chymotrypsin output (P < 0·04). The lipase excretion remained unchanged. The decrease in proteolytic enzymes was documented to be positively correlated with a decreased protein intake (P < 0·05). In addition, elastase-1 and chymotrypsin outputs were also related to the changes of protein type, plantv.animal (P < 0·04 andP < 0·03, respectively). It was concluded that significant reduction and modification of protein intake due to a short-term vegan diet resulted in an adaptation of pancreatic protease secretion in healthy volunteers.

Influence of obesity on the risk of esophageal disorders

Obesity is associated with an increased risk of esophageal disorders, including esophageal adenocarcinoma, Barrett esophagus and GERD. For reasons yet unknown, the association between obesity and esophageal adenocarcinoma seems to be stronger than that for other types of obesity-related cancers. Predominantly abdominal or intra-abdominal adiposity (representing visceral fat and other fat within the abdominal cavity), which is more frequently observed in men than in women, is more strongly linked with these esophageal disorders than BMI alone, a finding that might contribute to the striking male predominance of esophageal adenocarcinoma. Research has identified potential mechanisms underlying the strong link between obesity and esophageal conditions. These findings are summarized in this Review, but more research remains to be carried out before these mechanisms are established.

Regional and total body bioelectrical impedance analysis compared with DXA in Icelandic elderly

BACKGROUND/OBJECTIVES

The aims were (1) to compare fat free mass (FFM) estimates from regional hand-held bioelectrical impedance analysis (HHBIA) with conventional BIA (CBIA) and dual energy X-ray absorptiometry (DXA) and (2) to develop a population specific equation for FFM prediction in Icelandic elderly.

SUBJECTS/METHODS

DXA, CBIA and HHBIA data were available for 98 free-living Icelandic elderly (age=73.0 ± 5.6 years, body mass index=28.8 ± 5.2 kg/m(2)). Participants were randomized into a development block (n=50) and validation block (n=48). A population specific equation for FFM prediction was calculated using CBIA-derived resistance and anthropometric data from the development block and then compared with other BIA equations (Deurenberg, Segal, company-specific equations) and DXA estimates using the validation block.

RESULTS

The correlations between BIA methods and DXA were very high, that is, >0.9; however, mean differences compared with DXA were quite variable, ranging from -5.0 (Deurenberg) to +2.5 (Segal, HHBIA) and +3.3 kg (CBIA). Mean difference of the population-specific equation was below 0.1 kg. The standard deviations of the differences ranged from 2.6 to 3.3 kg. The limits of agreement of the BIA methods were similar and between 9.9 and 12.9 kg.

CONCLUSIONS

In Icelandic elderly, HHBIA and CBIA produce similar FFM estimates when using company-specific prediction equations. CBIA provides the additional possibility to use a population-specific prediction equation, which yields best results. However, limits of agreement were wide and similar of all employed BIA methods, which indicates principal limitations of BIA analysis in the determination of FFM.