Differences in bioimpedance-derived fluid status between two versions of the Body Composition Monitor

OBJECTIVES

The Body Composition Monitor (BCM) (Fresenius Medical Care) measures body impedances in alternating currents to subsequently calculate fat and lean tissue mass, fluid compartments, and overhydration (OH). The aim of this study was to investigate differences between two versions of the BCM (an older version, 3.2.5, and a newer version, 3.3.3).

METHODS

Between September 2021 and December 2021, 28 hemodialysis patients were included to undergo BCM measurements before each of 14 consecutive dialysis sessions with versions 3.2.5 and 3.3.3 devices. Measurements were performed according to instructions provided by the manufacturer. Differences between BCM devices were tested for statistical significance using paired Wilcoxon tests, neglecting clustering.

RESULTS

A total of 288 measurement pairs of 27 patients were left after exclusion of 43 flawed data points. The mean difference in OH between both BCM devices was 0.548 L (higher for version 3.2.5). Analysis of impedance data revealed differences in the high-frequency spectrum, quantifiable by the intracellular resistance, Ri (median Ri version 3.2.5 = 1750.3 Ω; Ri version 3.3.3 = 1612.45 Ω; P < 0.001), and the time delay, Td (median Td version 3.2.5 = 1.85 ns; Td version 3.3.3 = 8.88 nanoseconds; P < 0.001).

CONCLUSIONS

This study finds that results between the two versions of the BCM differed in a clinically meaningful fashion and that the newer version 3.3.3 device had a bias toward less OH. Circulating BCM devices should be checked for versions and only devices of the same version should be used for each patient to ensure better within-patient consistency.

A Randomized Controlled Trial of Changes in Fluid Distribution across Menstrual Phases with Creatine Supplementation

This study examined the effects of creatine (Cr) loading on body mass (BM) and fluid markers of total body water (TBW), extra-cellular fluid (ECF), and intra-cellular fluid (ICF) across the menstrual cycle (MC). Thirty moderately active females, either naturally-menstruating (NM) or using hormonal contraceptives (HC), were randomized to Cr (Cr; 4 × 5 g/day of creatine monohydrate for 5 days; n = 15) or a non-caloric placebo (PL; n = 15) using a double-blind, placebo-controlled design, with a menstrual phase crossover. BM, TBW, ECF, and ICF were measured at pre- and post-supplementation in randomized order of follicular phase (FP; NM: MC days 0−8, HC: inactive pill days) or luteal phase (LP; NM: ≤15 days from next projected cycle start date, HC: active pill days) using bioelectrical impedance spectroscopy. Acute hydration status and salivary estrogen were used as covariates. Change in BM was not different between groups across MC ([PL-Cr] Δ 0.40 ± 0.50 kg; p = 0.427) or between MC phase across groups ([FP-LP] Δ 0.31 ± 0.48 kg; p = 0.528). TBW (p = 0.802), ECF (p = 0.373), and ICF (p = 0.795) were not different between supplement groups at pre-supplementation/FP time points. There were no significant differences between the NM and HC subjects at any time point, for any outcome (p > 0.05). Following LP supplementation, significant changes were observed in TBW (Cr: Δ 0.83 ± 0.38 L, PL: Δ −0.62 ± 0.38 L; p = 0.021), ECF (Cr: Δ 0.46 ± 0.15 L, PL: Δ −0.19 ± 0.15 L; p = 0.013), and ICF (Cr: Δ 0.74 ± 0.23 L, PL: Δ −0.02 ± 0.23 L; p = 0.041). These data demonstrate an increase in all fluid compartments in the LP following Cr loading, without observed alterations in body weight for females.

Effects of exercise, furosemide, blood depletion, and reinfusion on body fluid compartment volumes in horses

High pulmonary blood pressure contributes to exercise-induced pulmonary hemorrhage. The objective of this study was to use bioimpedance spectroscopy to assess body fluid compartment volumes under 3 conditions in 6 racehorses: i) Pre- and post-supramaximal treadmill exercise (control); ii) Exercise 4 hours after furosemide (0.5 mg/kg body weight, IV); iii) Exercise, removal of ~14 L of blood and subsequent reinfusion of the blood. Statistical analysis used linear mixed effects models. Body compartment volumes did not change during the control runs. Total body water (TBW) (P = 0.007, P = 0.007), extracellular fluid (ECF) (P = 0.003, P = 0.003), and intracellular fluid (ICF) volumes (P = 0.04, P = 0.04) decreased pre- and post-exercise following furosemide administration. The ICF trended to decrease (P = 0.07) after slow removal of blood. Blood reinfusion increased TBW (P = 0.02, P = 0.02) and ICF (P = 0.005, P = 0.005) pre- and post-exercise.

A Five-Ingredient Nutritional Supplement and Home-Based Resistance Exercise Improve Lean Mass and Strength in Free-Living Elderly

Old age is associated with lower physical activity levels, suboptimal protein intake, and desensitization to anabolic stimuli, predisposing for age-related muscle loss (sarcopenia). Although resistance exercise (RE) and protein supplementation partially protect against sarcopenia under controlled conditions, the efficacy of home-based, unsupervised RE (HBRE) and multi-ingredient supplementation (MIS) is largely unknown. In this randomized, placebo-controlled and double-blind trial, we examined the effects of HBRE/MIS on muscle mass, strength, and function in free-living, older men. Thirty-two sedentary men underwent twelve weeks of home-based resistance band training (3 d/week), in combination with daily intake of a novel five-nutrient supplement (‘Muscle5’; M5, n = 16, 77.4 ± 2.8 y) containing whey, micellar casein, creatine, vitamin D, and omega-3 fatty acids, or an isocaloric/isonitrogenous placebo (PLA; n = 16, 74.4 ± 1.3 y), containing collagen and sunflower oil. Appendicular and total lean mass (ASM; +3%, TLM; +2%), lean mass to fat ratios (ASM/% body fat; +6%, TLM/% body fat; +5%), maximal strength (grip; +8%, leg press; +17%), and function (5-Times Sit-to-Stand time; −9%) were significantly improved in the M5 group following HBRE/MIS therapy (pre vs. post tests; p < 0.05). Fast-twitch muscle fiber cross-sectional areas of the quadriceps muscle were also significantly increased in the M5 group post intervention (Type IIa; +30.9%, Type IIx, +28.5%, p < 0.05). Sub-group analysis indicated even greater gains in total lean mass in sarcopenic individuals following HBRE/MIS therapy (TLM; +1.65 kg/+3.4%, p < 0.05). We conclude that the Muscle5 supplement is a safe, well-tolerated, and effective complement to low-intensity, home-based resistance exercise and improves lean mass, strength, and overall muscle quality in old age.

Establishment and assessment of the hepatic venous pressure gradient using biofluid mechanics (HVPGBFM): protocol for a prospective, randomised, non-controlled, multicentre study

INTRODUCTION

Portal hypertension (PH) is a severe disease with a poor outcome. Hepatic venous pressure gradient (HVPG), the current gold standard to detect PH, is available only in few hospitals due to its invasiveness and technical difficulty. This study aimed to establish and assess a novel model to calculate HVPG based on biofluid mechanics.

METHODS AND ANALYSIS

This is a prospective, randomised, non-controlled, multicentre trial. A total of 248 patients will be recruited in this study, and each patient will undergo CT, blood tests, Doppler ultrasound and HVPG measurement. The study consists of two independent and consecutive cohorts: original cohort (124 patients) and validation cohort (124 patients). The researchers will establish and improve the HVPG using biofluid mechanics (HVPG_BFM)model in the original cohort and assess the model in the validation cohort.

ETHICS AND DISSEMINATION

The study was approved by the Scientific Research Projects Approval Determination of Independent Ethics Committee of Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (approval number 2017-430 T326). Study findings will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03470389.

Maintenance fluid therapy in a tertiary hospital: A prevalence study

OBJECTIVE

To assess the types of maintenance fluids used in our hospital, comparing their volume and composition to the standards recommended by the guidelines.

MATERIAL AND METHODS

Observational, cross-sectional study. Volume and type of fluid therapy administered during 24h to patients admitted to various hospital departments were recorded. Patients receiving fluid therapy because of water-electrolyte imbalance were excluded.

RESULTS

Out of 198 patients registered, 74 (37.4%) were excluded because they did not meet the criteria for inclusion. Mean administered volume was 2,500cc/day. Mean daily glucose dose was 36g per 24h (SD: 31.4). The most frequent combination included normal saline solution (NSS) and glucose 5% (64.4%). Mean daily dose of sodium and chlorine was, respectively, 173mEq (SD: 74.8) and 168mEq (SD: 75), representing a surplus daily dose of +87.4mEq and +85mEq. Potassium, magnesium and calcium daily deficit was, respectively, -50mEq, -22mEq and -21mEq per day. Buffer administration was exceptional, bicarbonate (2.29%), acetate (1.29%), lactate (1.15%) and gluconate (1.10%) being the buffering agents most frequently used.

CONCLUSION

NNS is the most frequently used solution. In contrast to excess doses of sodium and chlorine, there is a great deficit of other ions, buffering agents and caloric intake in the fluid therapy regimens that are usually prescribed.

Association of Body Composition with Curve Severity in Children and Adolescents with Idiopathic Scoliosis (IS)

The link between scoliotic deformity and body composition assessed with bioimpedance (BIA) has not been well researched. The objective of this study was to correlate the extent of scoliotic-curve severity with the anthropometrical status of patients with idiopathic scoliosis (IS) based on standard anthropometric measurements and BIA. The study encompassed 279 IS patients (224 girls/55 boys), aged 14.21 ± 2.75 years. Scoliotic curve severity assessed by Cobb's angle was categorized as moderate (10°-39°) or severe (≥40°). Corrected height, weight, waist and hip circumferences were measured and body mass index (BMI), corrected height z-score, BMI Z-score, waist/height ratio (WHtR) and waist/hip ratio (WHR) were calculated for the entire group. Body composition parameters: fat mass (FAT), fat-free mass (FFM) and predicted muscle mass (PMM) were determined using a bioelectrical impedance analyzer. The mean Cobb angle was 19.96° ± 7.92° in the moderate group and 52.36° ± 12.54° in the severe group. The corrected body heights, body weights and BMIs were significantly higher in the severe IS group than in the moderate group (p < 0.05). Significantly higher FAT and lower FFM and PMM were observed in the severe IS group (p < 0.05). The corrected heights and weights were significantly higher in patients with severe IS and normal weight (p < 0.01). Normal and overweight patients with a severe IS had significantly higher adiposity levels assessed by FAT, FFM and PMM for normal and BMI, BMI z-score, WHtR, FAT and PMM for overweight, respectively. Overweight IS patients were significantly younger and taller than underweight and normal weight patients. The scoliotic curve severity is significantly related to the degree of adiposity in IS patients. BMI z-score, WHtR and BIA seem to be useful tools for determining baseline anthropometric characteristics of IS children.

The Relationship between Diet Quality and Falls Risk, Physical Function and Body Composition in Older Adults

OBJECTIVES

We aimed to examine associations between diet quality, falls risk, physical function, physical activity and body composition.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

Data collected from 171 men and women, aged 60-88 years old, as part of the Falls Risk and Osteoporosis Longitudinal Study.

MEASUREMENTS

Dietary Intake (Dietary Questionnaire for Epidemiological Studies Version 2 (DQES v2)), Falls Risk (FES-I, ABC, Berg Balance and Physiological Profile Assessment), Physical Function (SPPB), Physical Activity (PASE) and Body Composition (fat mass, lean mass, BMD, BMI, android/gynoid ratio) were ascertained. Diet quality was determined using two measures (Healthy Eating Index - HEI and Healthy Diet Indicator - HDI). One-way Analysis of Variance was used to compare mean scores between females and males and Pearson product-moment correlation coefficients were calculated to examine bivariate relationships.

RESULTS

Although females and males were analysed separately, the HDI-total score showed more associations that the HEI in both genders. The HDI showed, in females weak negative associations with BMI (r =-.21, p=.04), gynoid fat (r = -.20, p=.01), total fat mass (r = -.20, p=.02), with a weak positive association between HDI and percentage lean mass (r =.20, p=.03). Males showed positive associations between HDI and age (r =.30 p=.02) physical function (SPPB)(r =.26, p=.04), and subjective falls-risk (ABC) (r =.26, p=.03). In addition, in males, a negative association was found between HDI and FES-I (r = -.25, p=.04). The only measure that was significantly associated with the HEI-total score was the android/gynoid ratio in males (r = -.29, p=.04). When controlling for age, females demonstrated weak positive associations between gynoid (r = .19 p = .02), android (r = .19, p = .02) and total fat mass (r = .20 p = .02) as well as weak negative correlation with lean mass (r = 1.19, p = .03). Age also impacts on the FES-I (r = .29 p <.01) and ABC (r = -.23 p <.01).

CONCLUSIONS

The relationships between dietary quality and body composition, falls risk and physical function in older community dwelling, higher functioning adults appear to be gender specific. Better diet quality in females, is associated with lower BMI and fat mass, and higher lean mass, compared to males that are older and appear to have better physical function, are less likely to self-report falls risk, and have a better fat distribution i.e. a lower android/gynoid ratio have better diet quality. Furthermore, age is an important confounder and should be taken into consideration when assessing diet quality in older adults. In addition these gender and age differences may be clinically relevant and could aid in the delivery of targeted interventions.

Trend of Body Compositions with Aging among Chinese Adolescents, Adults and Elders

INTRODUCTION

Rare reports can be found about sex- and age-specific body composition survey among Chinese population. The aim of this study is to explore the change of sex-specific body compositions with aging among Chinese adolescents, adults and elders.

METHODS

In a large-scale population survey about physiological constants and health conditions, 75,714 subjects who aged from 8 to 80 completed body composition array. Body mass index (BMI), percentage body fat (PBF), water percentage of body weight (WPBW), water percentage of lean body mass (WPLBM), fat-free mass index (FFMI) and basic metabolic rate were examined with Biodynamics BI-310 body composition analyzer. General obesity is defined as BMI equal to or greater than 28 kg/m2.

RESULTS

The prevalence rates of general obesity were 9.4% for males and 7.7% for females respectively. With aging, PBF and FMI showed a U-shape curvilinear trend and WPBW showed a parabolic trend for males. At same age group: 18-19 age groups, PBF and FMI declined to the valley and WPBW rose to the peak. For females, PBF, WPBW and FMI changed in a linear trend. The values of WPLBM and FFMI showed same curvilinear trend for two genders. WPLBM changed in a U-shape trend and touched the valley in twenties for males and in 18-19 age groups for females. The value of FFMI was larger for older age groups in the younger generation but smaller in the older generation. A parabolic trend peaking was seen in the thirties for males and in the forties for females. Regression models with age as independent variable showed that the larger rate of increase of PBF and smaller rates of increase for WPBM and WPLBM with aging for males.

CONCLUSION

This study presents detailed data about sex-specific body composition conditions. Different change trend with aging was found about body composition conditions.

Body composition phenotypes and obesity paradox

PURPOSE OF REVIEW

The obesity paradox is a highly controversial concept that may be attributed to methodological limitations related to its identification. One of the primary concerns is the use of BMI to define obesity. This index does not differentiate lean versus adipose tissue compartments (i.e. body composition) confounding health consequences for morbidity and mortality, especially in clinical populations. This review will describe the past year's evidence on the obesity paradox phenomenon, primarily focusing on the role of abnormal body composition phenotypes in explaining the controversies observed in the literature.

RECENT FINDINGS

In spite of the substantial number of articles investigating the obesity paradox phenomenon, less than 10% used a direct measure of body composition and when included, it was not fully explored (only adipose tissue compartment evaluated). When lean tissue or muscle mass is taken into account, the general finding is that a high BMI has no protective effect in the presence of low muscle mass and that it is the latter that associates with poor prognosis.

SUMMARY

In view of the body composition variability of patients with identical BMI, it is unreasonable to rely solely on this index to identify obesity. The consequences of a potential insubstantial obesity paradox are mixed messages related to patient-related prognostication.

Methods and problems in the measurement of body water and electrolyte pools with radionuclide tracers

With the possible exception of ECF, body electrolyte spaces and pools can be measured with fair accuracy and are useful in their proper experimental context. The use of improved tracer techniques and mathematical analysis to study transfer rates between pools and the physiological factors which influence these rates offer a promising means of further progress in this field.

Effect of intravitreal bevacizumab on serum, aqueous, and vitreous humor levels of erythropoietin in patients with proliferative diabetic retinopathy

AIM

The aim of this study was to evaluate concentrations of erythropoietin (EPO) and vascular endothelial growth factor (VEGF) in serum, aqueous and vitreous humour of diabetic patients with proliferative retinopathy (PDR) and to verify their possible modifications induced by intravitreal injection of bevacizumab (IVB).

METHODS

This prospective observational study was performed on patients who underwent vitrectomy for proliferative diabetic retinopathy and macular hole or pucker. The study sample consisted of 33 patients with proliferative diabetic retinopathy and 20 non-diabetic patients with macular hole or pucker. EPO and VEGF levels in serum, aqueous and vitreous humour were measured in both groups. In diabetic patients measures were performed before and after IVB.

RESULTS

EPO and VEGF levels in aqueous and vitreous humour were markedly increased in diabetic patients with PDR as compared with those recorded in the control group (P<0.001); contrarily, EPO serum levels were similar in both groups (p=not significant). IVB did not affect EPO levels (aqueous 39.1 ± 29.2 vs. 38.6 ± 26.1; vitreous 179.3 ± 88.3 vs. 131.6 ± 67.8; serum 9.2 ± 5.8 vs. 6.9 ± 3.7 mUI/mL); conversely, VEGF concentration significantly decreased 15 days after IVB in serum and ocular fluids (aqueous 141.6 ± 12.3 vs. 81.4 ± 5.4; vitreous 180.4 ± 45.8 vs. 95.8 ± 23.6; serum 113.9 ± 52.8 vs. 73.2 ± 65.6 mUI/mL).

CONCLUSION

These findings demonstrate that the production of VEGF and EPO is regulated by different mechanisms. Intraocular levels of EPO in diabetic patients were significantly higher than those recorded in serum, suggesting a local production. In addition, bevacizumab does not influence intraocular levels of EPO.

Exploitation of diagnostic computed tomography scans to assess the impact of nutrition support on body composition changes in respiratory failure patients

BACKGROUND

Assessment of nutritional status in intensive care unit (ICU) patients is limited. Computed tomography (CT) scans that include the first to fifth lumbar region completed for diagnostic purposes measures fat and lean body mass (LBM) depots and are frequently done in ICU populations and can be used to quantify fat and LBM depots. The purpose of this study was to assess if these scans could measure change in skeletal muscle (SKT), visceral adipose (VAT), and intermuscular adipose (IMAT) tissue and to examine the association between the amount of energy and protein received and changes in these depots.

METHODS

Cross-sectional area of SKT, VAT, and IMAT from CT scans at the third lumbar region was quantified at 2 time points (CT1 and CT2). Change scores between CT1 and CT2 for each of these depots and the percentage of estimated energy/protein needs received were determined in 33 adults that with acute respiratory failure. Descriptive statistics and multiple regression was used to evaluate the influence of baseline characteristics and the percentage energy/protein needs received between CT1 and CT2 on percentage change/day between CT1 and CT2 on SKM, IMAT, and VAT.

RESULTS

Participants were on average (SD) 59.7 (16) years old, received 41% of energy and 57% of protein needs. The average time between CT1 and CT2 was 10 (5) days. SKM declined 0.49%/day (men P = .07, women P = .09) and percentage of energy needs received reduced loss (β = 0.024, P = .03). No change in VAT or IMAT occurred.

CONCLUSIONS

CT scans can be exploited to assess change in body composition in ICU patients and may assist in detecting the causal link between nutritional support and outcomes in future clinical trials.

Body composition changes in pregnancy: measurement, predictors and outcomes

Prevalence of overweight and obesity has risen in the United States over the past few decades. Concurrent with this rise in obesity has been an increase in pregravid body mass index and gestational weight gain affecting maternal body composition changes in pregnancy. During pregnancy, many of the assumptions inherent in body composition estimation are violated, particularly the hydration of fat-free mass, and available methods are unable to disentangle maternal composition from fetus and supporting tissues; therefore, estimates of maternal body composition during pregnancy are prone to error. Here we review commonly used and available methods for assessing body composition changes in pregnancy, including: (1) anthropometry, (2) total body water, (3) densitometry, (4) imaging, (5) dual-energy X-ray absorptiometry, (6) bioelectrical impedance and (7) ultrasound. Several of these methods can measure regional changes in adipose tissue; however, most of these methods provide only whole-body estimates of fat and fat-free mass. Consideration is given to factors that may influence changes in maternal body composition, as well as long-term maternal and offspring outcomes. Finally, we provide recommendations for future research in this area.

A NovelIn VitroPharmacokinetic/Pharmacodynamic Model Based on Two-Compartment Open Model Used to Simulate Serum Drug Concentration-Time Profiles

An in vitro pharmacokinetic/pharmacodynamic perfusion model that simulates a two-compartment open model of serum drug concentration-time profiles following intravenous bolus injection and infusion was developed and mathematically described. In the present apparatus model, flow was kept in a one-way mode to avoid liquid traffic, and the washout effect seen in dilution models was overcome by embedding the tested bacteria in low melting point agarose gel. The validity of the equations and the reproducibility of the apparatus model were ascertained by simulating the concentration-time profiles of cefazolin and fosfomycin by substitution of their pharmacokinetic parameters obtained from humans for the equations. An empirical regimen 1X(q24h) of 1 g with cefazolin administered by intravenous infusion effectively killed a Staphylococcus aureus strain. The same regimen with fosfomycin produced a marked kill-curve with a fosfomycin-susceptible enterohaemorrhagic Escherichia coli O157:H7, whereas considerable regrowth was observed with a resistant strain. These results indicated that the present model was able to provide a convenient and reliable method for evaluating the efficacy of antimicrobial agents administered by intravenous infusion.

The effects of season-long vitamin D supplementation on collegiate swimmers and divers

The purpose of this 6-month randomized, placebo-controlled trial was to determine the effect of season-long (September-March) vitamin D supplementation on changes in vitamin D status, which is measured as 25(OH) D, body composition, inflammation, and frequency of illness and injury. Forty-five male and female athletes were randomized to 4,000 IU vitamin D (n = 23) or placebo (n = 22). Bone turnover markers (NTx and BSAP), 25(OH)D, and inflammatory cytokines (TNF-alpha, IL-6, and IL1-β) were measured at baseline, midpoint, and endpoint. Body composition was assessed by DXA and injury and illness data were collected. All athletes had sufficient 25(OH)D (> 32 ng/ml) at baseline (mean: 57 ng/ml). At midpoint and endpoint, 13% and 16% of the total sample had 25(OH)D < 32 ng/ml, respectively. 25(OH)D was not positively correlated with bone mineral density (BMD) in the total body, proximal dual femur, or lumbar spine. In men, total body (p = .04) and trunk (p = .04) mineral-free lean mass (MFL) were positively correlated with 25(OH)D. In women, right femoral neck BMD (p = .02) was positively correlated with 25(OH)D. 25(OH)D did not correlate with changes in bone turnover markers or inflammatory cytokines. Illness (n = 1) and injury (n = 13) were not related to 25(OH)D; however, 77% of injuries coincided with decreases in 25(OH)D. Our data suggests that 4,000 IU vitamin D supplementation is an inexpensive intervention that effectively increased 25(OH)D, which was positively correlated to bone measures in the proximal dual femur and MFL. Future studies with larger sample sizes and improved supplement compliance are needed to expand our understanding of the effects of vitamin D supplementation in athletes.

Nutritional status in Parkinson's disease patients undergoing deep brain stimulation surgery: a pilot study

OBJECTIVES

People with Parkinson's disease (PD) are at higher risk of malnutrition due to PD symptoms and pharmacotherapy side effects. When pharmacotherapy is no longer effective for symptom control, deep-brain stimulation (DBS) surgery may be considered. The aim of this study was to assess the nutritional status of people with PD who may be at higher risk of malnutrition related to unsatisfactory symptom management with optimised medical therapy.

DESIGN

This was an observational study using a convenience sample.

SETTING

Participants were seen during their hospital admission for their deep brain stimulation surgery.

PARTICIPANTS

People with PD scheduled for DBS surgery were recruited from a Brisbane neurological clinic (n=15).

MEASUREMENTS

The Patient-Generated Subjective Global Assessment (PG-SGA), weight, height and body composition were assessed to determine nutritional status.

RESULTS

Six participants (40%) were classified as moderately malnourished (SGA-B). Eight participants (53%) reported previous unintentional weight loss (average loss of 13%). On average, participants classified as well-nourished (SGA-A) were younger, had shorter disease durations, lower PG-SGA scores, higher body mass (BMI) and fat free mass indices (FFMI) when compared to malnourished participants (SGA-B). Five participants had previously received dietetic advice but only one in relation to unintentional weight loss.

CONCLUSION

Malnutrition remains unrecognised and untreated in this group despite unintentional weight loss and presence of nutrition impact symptoms. Improving nutritional status prior to surgery may improve surgical outcomes.

Gestational and early life influences on infant body composition at 1 year

Excess weight gain during both pre- and postnatal life increases risk for obesity in later life. Although a number of gestational and early life contributors to this effect have been identified, there is a dearth of research to examine whether gestational factors and weight gain velocity in infancy exert independent effects on subsequent body composition and fat distribution.

OBJECTIVE

To test the hypothesis that birth weight, as a proxy of prenatal weight gain, and rate of weight gain before 6 months would be associated with total and truncal adiposity at 12 months of age.

DESIGN AND METHODS

Healthy, term infants (N = 47) were enrolled in the study and rate of weight gain (g/day) was assessed at 0-3 months, 3-6 months, and 6-12 months.

RESULTS

Total and regional body composition were measured by dual-energy X-ray absorptiometry (DXA) at 12 months. Stepwise linear regression modeling indicated that lean mass at 12 months, after adjusting for child length, was predicted by rate of weight gain during each discrete period of infancy (P < 0.05), and by maternal pre-pregnancy BMI (P < 0.05). Total fat mass at 12 months was predicted by rate of weight gain during each discrete period (P < 0.01), and by older maternal age at delivery (P < 0.05). Trunk fat mass at 12 months, after adjusting for leg fat mass, was predicted by rate of weight gain from 0-3 months and 3-6 months (P < 0.05).

CONCLUSION

Results suggest that growth during early infancy may be a critical predictor of subsequent body composition and truncal fat distribution.

Ghrelin and leptin secretion in patients with moderate Alzheimer's disease

BACKGROUND

Weight loss is a characteristic finding of patients with Alzheimer's disease (AD). It seems that precedes cognitive impairment by some years, but the underlying causes are not fully understood. Ghrelin and leptin are involved in energy homeostasis, and may be implicated in weight losing observed in these patients.

OBJECTIVE

To examine the potential relationship between ghrelin and leptin levels and weight loss in patients with AD.

DESIGN

The study included 27 patients (10 men and 17 women) with AD of moderate severity, and 23 controls (10 males and 13 females), matched for age and BMI. Body fat and lean mass content were assessed using a portable apparatus. Cognitive function was assessed with the Mini-Mental State Examination. Basal serum samples for the measurement of leptin, ghrelin, insulin and glucose were obtained, and serum ghrelin, insulin and glucose were measured after a 75-gr glucose load in both groups.

RESULTS

Patients with Alzheimer Disease (AD) have lower lean mass content compared to controls. Basal ghrelin and leptin is similar in patients with AD and controls. The area-under-the-curve for ghrelin (AUC) is lower in male patients with AD compared to control males, while no difference was observed between females AD and controls.

CONCLUSION

Male patients with AD, in contrast with female patients, fail to maintain a normal energy homeostasis even in the early stages of the disease, as shown by the decreased lean mass content in males AD compared to controls. Disruption of the normal compensatory modulation of ghrelin secretion might contribute to the metabolic changes observed in male patients with AD.

Dynamic energy-balance model predicting gestational weight gain

BACKGROUND

Gestational weight gains (GWGs) that exceed the 2009 Institute of Medicine recommended ranges increase risk of long-term postpartum weight retention; conversely, GWGs within the recommended ranges are more likely to result in positive maternal and fetal outcomes. Despite this evidence, recent epidemiologic studies have shown that the majority of pregnant women gain outside the target GWG ranges. A mathematical model that predicts GWG and energy intake could provide a clinical tool for setting precise goals during early pregnancy and continuous objective feedback throughout pregnancy.

OBJECTIVE

The purpose of this study was to develop and validate a differential equation model for energy balance during pregnancy that predicts GWG that results from changes in energy intakes.

DESIGN

A set of prepregnancy BMI-dependent mathematical models that predict GWG were developed by using data from a longitudinal study that measured gestational-changes in fat-free mass, fat mass, total body water, and total energy expenditure in 63 subjects.

RESULTS

Mathematical models developed for women with low, normal, and high prepregnancy BMI were shown to fit the original data. In 2 independent studies used for validation, model predictions of fat-free mass, fat mass, and total body water matched actual measurements within 1 kg.

CONCLUSIONS

Our energy-balance model provides plausible predictions of GWG that results from changes in energy intakes. Because the model was implemented as a Web-based applet, it can be widely used by pregnant women and their health care providers.

Physical function predicts improvement in quality of life in elderly Icelanders after 12 weeks of resistance exercise

BACKGROUND

Little is known about the effects of resistance training on health related quality of life (HRQL) in the elderly.

AIM

The main purpose of the study was to investigate the effects of resistance training on strength, body composition, functional capacity and HRQL in independent living elderly people. We hypothesised that resistance training would improve lean mass, muscle strength, physical function and HRQL.

METHODS

Subjects (N = 237, 73.7±5.7 yrs, 58.2% female) participated in a 12-week resistance exercise program (3 times/week; 3 sets, 6-8 repetitions at 75-80% of the 1-repetition maximum) designed to increase strength and muscle mass of major muscle groups. Body composition, quadriceps- and grip strength, timed up and go test (TUG), six minute walk for distance (6MW) and HRQL were measured at baseline and endpoint.

RESULTS

Two hundred-and-four participants completed the study. Although the increase in lean mass was small (+0.8 kg, P<0.01), quadriceps strength (+53.5 N), grip strength (+3.0 lb), TUG (-0.6 sec), 6MW (+33.6 m) and HRQL (+1.2 t-score) improved significantly (all P<0.01). Changes in 6MW predicted improvement in HRQL after 12 weeks.

CONCLUSIONS

Our study shows that a 12-week resistance exercise program significantly improves lean mass, muscle strength, physical function and HRQL in elderly individuals, and that improvements in physical function predict improvements in HRQL. Our study indicates that resistance training should be promoted for the elderly as it has the potential to improve physical performance, thereby prolonging healthy, independent aging.

Physical fitness is independently related to blood leptin concentration and insulin sensitivity index in male subjects with central adiposity

AIM

To compare the maximal power output (MPO) of subjects presenting a central adiposity to those of controls and to study the links between plasma leptin or indices of insulin sensitivity (QUICKI) and physical fitness (PF).

METHODS

MPO was determined for 169 middle-aged men divided into two groups according to waist circumference (WC- < 94 cm, WC+ ≥ 94 cm) each subdivided in two subgroups with low and high PF (WC-L, WC-H, WC+L, WC+H) determined from the median MPO relative to fat free mass (3.06 W/kg(FFM)).

RESULTS

MPO (W/kg(FFM)) was lower in WC+ than in WC-. Expressed relative to fat mass, leptin was lower and QUICKI higher in WC- than in WC+. In WC+H, leptin and QUICKI were significantly less disturbed than in WC+L and were independently correlated to MPO (r = -0.36 and r = 0.32 respectively; p < 0.001). In WC+, when visceral perimeter was added to the analysis, the relationships MPO/leptin remained significant but not MPO/QUICKI.

CONCLUSION

The low PF in subjects with abdominal obesity is independently linked to plasma leptin and insulin sensitivity even if leptin and insulin may share common pathways in their peripheral effects. Visceral adiposity participates to the link between MPO and QUICKI, but not between MPO and leptin.

Body circumferences are predictors of weight adjusted resting energy expenditure in older people

OBJECTIVE

To evaluate predictors of resting energy expenditure (REE) in older people which are more comfortable for them than indirect calorimetry and which are suitable for field studies.

DESIGN

Cross-sectional study.

SETTING

Department of Human Biology, Kiel University.

PARTICIPANTS

100 (51 males, 49 females) healthy independently-living normal-weight (BMI, males 26.0±2.67 kg/m², females 25.0±3.29 kg/m²) Germans, aged 60-83 years.

MEASUREMENTS

REE, body composition, anthropometry, peak expiratory flow rate (PEF), and physical activity level were determined using indirect calorimetry, bioimpedance analysis, anthropometrics, peak-flow-meter, and standardized questionnaire, respectively. Stepwise linear multiple regression analysis was performed with REE or weight adjusted REE as dependent variables. Independent variables were body height, weight, body mass index (BMI), waist circumference, abdomen circumference, hip circumference, waist-to-hip ratio (WHR), lean body mass (LBM), PEF, and physical activity level.

RESULTS

The only significant predictor of REE was LBM in males and BMI in females. Trunk circumferences emerged as strong predictors of weight adjusted REE. Abdomen circumference and hip circumference explained in males and females 69% and 70% of variation in adjusted REE, respectively. Weaker predictors were LBM in males (R² increased from 0.69 to 0.80) as well as body height and BMI in females (R² increased from 0.70 to 0.91). Waist circumference, WHR, physical activity level, and PEF were no significant determinants of adjusted REE.

CONCLUSION

These findings demonstrate that trunk circumferences, but not WHR, are very strong predictors of weight adjusted REE in non-geriatric older people. This implies that the sex-specific use of abdomen or hip circumference in combination with LBM or body height and BMI seems to be well sufficient to predict weight adjusted REE in the aged. These measures might also be of clinical relevance, because they are more comfortable for older sick people than indirect calorimetry. Further studies are needed to test the applicability of the prediction equations to frail older populations.

Longitudinal associations of adiposity with adult lung function in the Childhood Determinants of Adult Health (CDAH) study

Childhood BMI has been reported to be positively associated with adult lung function. The aim of this study was to investigate the effect of childhood BMI on young adult lung function independently of the effects of lean body mass (LBM). Clinical and questionnaire data were collected from 654 young Australian adults (aged 27-36 years), first studied when age 9, 12, or 15 years. Adult lung function was measured by forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)), FEV(1)/FVC ratio, and the forced expiratory flow in the middle 50% of FVC (FEF(25-75)). BMI and LBM were derived from anthropometric measures at baseline (1985) and at follow-up (2004-2006). Multivariable models were used to investigate the effect of age and sex standardized BMI in childhood on adult lung function, before and after adjustment for LBM. Adult adiposity had a strong deleterious effect on lung function, irrespective of childhood BMI, and adjustment for childhood LBM eliminated any apparent beneficial effect of childhood BMI on adult FEV(1) or FVC. This suggests that the beneficial effect of increased BMI in childhood on adult FEV(1) and FVC observed in previous longitudinal studies is likely to be attributable to greater childhood LBM not adiposity. Obese children who become obese adults can expect to have poorer lung function than those who maintain healthy weight but large deficits in lung function are also likely for healthy weight children who become obese adults. This highlights the importance of lifetime healthy weight maintenance.

Body mass index in a large cohort of patients assigned to age decades between <20 and ≥80 years: relationship with cardiovascular morbidity and medication

OBJECTIVE

There is an ongoing debate about the relationship between obesity and morbidity in the elderly, the clinical relevance of overweight and obesity in older patients and the need or harms of treatment. The main purpose of our study was to investigate whether a higher BMI is associated with a worse cardiovascular risk in all age groups, especially in the older ones.

SUBJECTS AND DESIGN

We performed a retrospective evaluation of clinical data from 3926 patients who visited a medical outdoor center for diagnostic and/or therapeutic interventions in the period from January 1995 to July 2010. Patients were assigned to eight age groups of one decade from <20 years to ≥80 years.

RESULTS

The Body Mass Index (BMI) of our patients showed a continuous increase with increasing age with peak values in the age decade 61-70 years (26.29 ±4.42 kg/m2). This was paralleled by an increase in cardiovascular events and need for continuous medication, demonstrating peak values in the age decade 61-70 years (22.3% in the female and 24.7% in the male group). In all age decades up to 80 years the BMI values were higher in patients with events compared to those without it. multivariable linear regression analysis - including confounding variables (blood pressure, fasting glucose, HDL-cholesterol, triglycerides, physical activity, smoking) - revealed for all age groups a strong positive relation of BMI and a negative relation of fat free mass (FFM) to the probability for a cardiovascular event and need for medication.

CONCLUSION

In all age groups, the percentage of cardiovascular events was directly correlated with the BMI. Having in mind the transition to an aging society, therapeutic and preventive strategies should, therefore, include weight management strategies also for the elderly.

Cognitive function is associated with body composition and nutritional risk of geriatric patients

BACKGROUND

Most patients with dementia lose body weight over the course of the disease. Yet it is not known whether this weight loss is predominantly in the form of fat-free mass (FFM) or fat mass (FM), the latter of which one would expect if the weight loss were caused simply by a chronic decrease of energy intake.

OBJECTIVES

To determine body composition and nutritional risk in geriatric patients and their association with cognitive function.

DESIGN

A retrospective, cross-sectional single-center database analysis.

METHODS

We analyzed 4,095 consecutive geriatric hospital patients for body composition, nutritional risk, need of care and cognitive function using bioelectric impedance analysis, NRS 2002, Barthel Index and Mini Mental State Examination.

RESULTS

Subjects with cognitive dysfunction showed significant lower body weight, body mass index (BMI), FM, fat mass index, FFM and fat-free mass index and a higher NRS score compared to cognitively intact subjects. Mean body weight decreased 10.2%, mean FM decreased 21.1%, mean FFM decreased 5.9% and mean NRS 2002 score increased from 2.1 to 3.0 points with increasing cognitive deterioration. A multivariate analysis revealed that cognitive dysfunction, age and female gender were all significant risk factors for a low body mass index and a low fat mass index. Age, male gender and need of care, but not cognitive dysfunction, were risk factors for a low fat-free mass index.

CONCLUSION

Dementia patients seem to lose predominantly fat mass with weight loss. Female dementia patients are at a higher nutritional risk than male patients, presumably as a result of their different social situation in old age. That is why the nutritional state of female patients with dementia requires special attention.

Thigh muscle volume predicted by anthropometric measurements and correlated with physical function in the older adults

OBJECTIVES

(1) to correlate thigh muscle volume measured by magnetic resonance image (MRI) with anthropometric measurements and physical function in elderly subjects; (2) to predict MRI-measured thigh muscle volume using anthropometric measurements and physical functional status in elderly subjects.

DESIGN

Cross-sectional, nonrandomized study.

SETTING

Outpatient clinic in Taiwan.

PARTICIPANTS

Sixty-nine elderly subjects (33 men and 36 women) aged 65 and older.

MEASURMENTS

The anthropometric data (including body height, body weight, waist size, and thigh circumference), physical activity and function (including grip strength, bilateral quadriceps muscle power, the up and go test, chair rise, and five meters walk time) and bioelectrical impedance analysis data (including total body fat mass, fat-free mass, and predictive muscle size) were measured. MRI-measured muscle volume of both thighs was used as the reference standard.

RESULTS

The MRI-measured thigh volume was positively correlated with all anthropometric data, quadriceps muscle power and the up and go test as well as fat-free mass and predictive muscle mass, whereas it was negatively associated with age and walk time. In predicting thigh muscle volume, the variables of age, gender, body weight, and thigh circumference were significant predictors in the linear regression model: Muscle volume (cm3) =4226.3－42.5 × Age (year)－955.7 × gender (male=1, female=2) + 45.9 × body weight(kg) + 60.0 × thigh circumference (cm) (r2 = 0.745, P < 0.001; standard error of the estimate = 581.6 cm3).

CONCLUSION

The current work provides evidence of a strong relationship between thigh muscle volume and physical function in the elderly. We also developed a prediction equation model using anthropometric measurements. This model is a simple and noninvasive method for everyday clinical practice and follow-up.

Two faces of drug therapy in cancer: drug-related lean tissue loss and its adverse consequences to survival and toxicity

PURPOSE OF REVIEW

A common feature of cancer patients is loss of lean tissue, specifically skeletal muscle, which may be the result of the tumor or a side-effect of chemotherapy or other drugs. Lean tissue loss in turn has important adverse implications for toxicity of antineoplastic therapy and, hence, cancer prognosis.

RECENT FINDINGS

Contemporary cancer populations have heterogeneous proportions of lean tissue, regardless of body weight. Wasting of lean tissue during the cancer trajectory has been associated with tumor progression. Lean tissue depletion is an independent predictor of severe toxicity in patients treated with chemotherapeutic agents of diverse classes. Patients with lean tissue depletion behave as if overdosed and have toxicity of sufficient magnitude to require dose reductions, treatment delays or definitive termination of treatment. Muscle loss may occur due to a specific effect of a chemotherapy agent (i.e. sorafenib), androgen suppression therapy or other drugs (i.e. statins such as atorvastatin).

SUMMARY

Lean tissue wasting occurs due to cancer progression and may be exacerbated by several drug classes. This loss of lean tissue is not proportional to changes in body weight and is prognostic of enhanced treatment toxicity and reduced survival.

Bioimpedance analysis parameters and epicardial adipose tissue assessed by cardiac magnetic resonance imaging in patients with heart failure

There is increasing evidence that body composition should be considered as a systemic marker of disease severity in congestive heart failure (CHF). Prior studies established bioelectrical impedance analysis (BIA) as an objective indicator of body composition. Epicardial adipose tissue (EAT) quantified by cardiac magnetic resonance (CMR) is the visceral fat around the heart secreting various bioactive molecules. Our purpose was to investigate the association between BIA parameters and EAT assessed by CMR in patients with CHF. BIA and CMR analysis were performed in 41 patients with CHF and in 16 healthy controls. Patients with CHF showed a decreased indexed EAT (22 ± 5 vs. 34 ± 4 g/m(2), P < 0.001) and phase angle (PA) (5.5° vs. 6.4°, P < 0.02) compared to healthy controls. Linear regression analysis showed a significant correlation of CMR indexed EAT with left ventricular ejection fraction (LV-EF) (r = 0.56, P < 0.001), PA (r = 0.31, P = 0.01), total body muscle mass (TBMM) (r = 0.41, P = 0.001), fat-free mass (FFM) (r = 0.30, P = 0.02), and intracellular water (ICW) (0.47, P = 0.0003). Multivariable analysis demonstrated that LV-EF was the only independent determinant of indexed EAT (P < 0.0001). Receiver operating characteristic curve analysis indicated good predictive performance of PA and EAT (area under the curve (AUC) = 0.86 and 0.82, respectively) with respect to cardiac death. After a follow-up period of 5 years, 8/41 (19.5%) patients suffered from cardiac death. Only indexed EAT <22 g/m(2) revealed a statistically significant higher risk of cardiac death (P = 0.02). EAT assessed by CMR correlated with the BIA-derived PA in patients with CHF. EAT and BIA-derived PA might serve as additional prognostic indicators for survival in these patients. However, further clinical studies are needed to elucidate the prognostic relevance of these new findings.

Ethnic-specific differences in abdominal subcutaneous adipose tissue compartments

South Asians have a higher prevalence of cardiovascular disease (CVD) than Europeans. Studies have identified distinct subcompartments of subcutaneous adipose tissue (SAT) that provide insight into the relationship between abdominal obesity and metabolic risk factors in different ethnic groups. Our objective was to determine the relationship between SAT compartments and fat-free mass (FFM) between South Asian and European cohorts, and between men and women. Healthy Europeans and South Asians (n = 408) were assessed for FFM via dual energy X-ray absorptiometry, and SAT areas by computed tomography (CT). SAT was subdivided into superficial subcutaneous abdominal adipose tissue (SSAT) and deep subcutaneous abdominal adipose tissue (DSAT). Linear regression analyses were performed using DSAT and SSAT as separate dependent variables and FFM and ethnicity as primary independent variables adjusting for age, gender, income, education, and smoking status. Results showed that South Asian men had significantly higher amounts of DSAT (median 187.65 cm(2) vs. 145.15 cm(2), P < 0.001), SSAT (median 92.0 cm(2) vs. 76.1 cm(2), P = 0.046), and body fat mass (BFM) (25.1 kg vs. 22.6 kg, P = 0.049) than European men. In a fully adjusted model, South Asians showed significantly greater DSAT at any FFM than Europeans. Women had more SSAT at any given FFM than men and less DSAT at any given FFM than men, irrespective of ethnic background. In conclusion, South Asians had more DSAT than Europeans and men had relatively more DSAT than women. These data suggest that specific fat depots are influenced by ethnicity and gender; therefore, could provide insight into the relationship between ethnicity, gender and subsequent risk for CVD.

Physical activity energy expenditure of adolescents in India

Physical activity (PA) has rarely been quantified in adolescent populations undergoing economic transition; therefore relationships with disease still remain uncertain. This study assessed whether absolute PA energy expenditure (PAEE), PAEE/kg, and PAEE/kg(FFM) could be accurately estimated using accelerometry and a questionnaire in Indian adolescents and how these values compared to those of other populations. PAEE was assessed using doubly labeled water (DLW) in 30 adolescents from Chennai, India, over seven consecutive days, simultaneous with the measurement of PA using accelerometry and a previous-week recall questionnaire. Accelerometry counts (regression analysis) and questionnaire data were used to estimate PAEE; estimates were cross-validated using the Bland-Altman method. Accelerometry data and DLW-derived PAEE were visually compared to values from four North American and European populations. For boys, 49% of the variance in DLW-derived PAEE was explained with an equation including accelerometry counts and fat-free mass (FFM). Questionnaire-derived estimates did not contribute to the explained variance in DLW derived PAEE. The group-level PA of these Indian adolescents was successfully assessed using accelerometry, but not questionnaire. DLW-derived PAEE/kg(FFM) (mean (s.d.): 53.0 (27.5) kJ/kg(FFM)/day) was lower in this group than other adolescent populations in Europe and similar to those in North America. Additionally, four boys and none of the girls accumulated ≥60 min/day of accelerometry-derived moderate intensity activity, indicating low levels of PAEE and PA in these adolescents. Further research is necessary to investigate the association between PA and health outcomes in Indian adolescents.

Diet-induced obesity in two C57BL/6 substrains with intact or mutant nicotinamide nucleotide transhydrogenase (Nnt) gene

The C57BL/6J (B6/J) male mouse represents a standard for diet-induced obesity (DIO) and is unique in expressing a loss-of-function nicotinamide nucleotide transhydrogenase (Nnt) gene. This mutation was associated with a marked reduction in glucose-stimulated insulin secretion from B6/J islets in vitro and moderately impaired glucose clearance in vivo. To assess the contribution of this Nnt mutation, we compared DIO responsiveness of Nnt-mutant B6/J males to Nnt wild-type C57BL/6NJ (B6/NJ) males over a 14-week period of feeding a high-fat (60% of calories) diet. Initial mean body weights at 6 weeks did not distinguish the substrains and both substrains were DIO-sensitive. However, B6/J males outgained the B6/NJ males, with a significant 3 g higher mean body weight at 20 weeks accompanied by significant increases in both lean and fat mass. Mean nonfasting serum glucose over time was also significantly higher in B6/J males, as was impairment of glucose tolerance assessed at 8 and 20 weeks of age. Serum leptin, but not insulin, was significantly higher in B6/J males over time. Potential contributions of the wild-type Nnt gene were demonstrable on a lower fat diet (10% of calories) where a significantly greater weight gain over time by B6/NJ males was correlated with a significantly higher serum insulin. In conclusion, DIO developed in response to 60% fat feeding regardless of Nnt allele status. Contribution of the B6/J-unique Nnt mutation was most evident in response to 10% fat feeding that resulted in reduced serum insulin and weight gain compared to B6/NJ males.

Evaluation of a quantitative magnetic resonance imaging system for whole body composition analysis in rodents

We evaluated the EchoMRI-900 combination rat and mouse quantitative magnetic resonance (QMR) body composition method in comparison to traditional whole-body chemical carcass composition analysis (CCA) for measurements of fat and fat-free mass in rodents. Live and postmortem (PM) QMR fat and lean mass measurements were obtained for lean, obese and outbred strains of rats and mice, and compared with measurements obtained using CCA. A second group of rats was measured before and after 18 h food or water deprivation. Significant positive correlations between QMR and CCA fat and lean mass measurements were shown for rats and mice. Although all live QMR fat and lean measurements were more precise than CCA for rats, values obtained for mice significantly differed from CCA for lean mass only. QMR performed PM slightly overestimated fat and lean values relative to live QMR but did not show lower precision than live QMR. Food deprivation reduced values for both fat and lean mass; water deprivation reduced estimates of lean mass only. In summary, all measurements using this QMR system were comparable to those obtained by CCA, but with higher overall precision, similar to previous reports for the murine QMR system. However, PM QMR measurements slightly overestimated live QMR values, and lean and fat mass measurements in this QMR system are influenced by hydration status and animal size, respectively. Despite these caveats, we conclude that the EchoMRI QMR system offers a fast in vivo method of body composition analysis, well correlated to but with greater overall precision than CCA.

Validation of BIA in obese children and adolescents and re-evaluation in a longitudinal study

Decrease in fat mass (FM) is a one of the aims of pediatric obesity treatment; however, measurement techniques suitable for routine clinical assessment are lacking. The objective of this study was to validate whole-body bioelectrical impedance analysis (BIA; TANITA BC-418MA) against the three-component (3C) model of body composition in obese children and adolescents, and to test the accuracy of our new equations in an independent sample studied longitudinally. A total of 77 white obese subjects (30 males) aged 5-22 years, BMI-standard deviation score (SDS) 1.6-3.9, had measurements of weight, height (HT), body volume, total body water (TBW), and impedance (Z). FM and fat-free mass (FFM) were calculated using the 3C model or predicted from TANITA. FFM was predicted from HT(2)/Z. This equation was then evaluated in 17 other obese children (5 males) aged 9-13 years. Compared to the 3C model, TANITA manufacturer's equations overestimated FFM by 2.7 kg (P < 0.001). We derived a new equation: FFM = -2.211 + 1.115 (HT(2)/Z), with r(2) of 0.96, standard error of the estimate 2.3 kg. Use of this equation in the independent sample showed no significant bias in FM or FFM (mean bias 0.5 +/- 2.4 kg; P = 0.4), and no significant bias in change in FM or FFM (mean bias 0.2 +/- 1.8 kg; P = 0.7), accounting for 58% (P < 0.001) and 55% (P = 0.001) of the change in FM and FFM, respectively. Our derived BIA equation, shown to be reliable for longitudinal assessment in white obese children, will aid routine clinical monitoring of body composition in this population.

Haemodialysis followed by continuous veno-venous haemodiafiltration in lithium intoxication; a model and a case

For severe lithium intoxication haemodialysis is recommended to lower serum lithium levels rapidly. Frequently, serum lithium levels rebound after dialysis and repeated dialysis is needed. This is the first report of an adult patient with severe lithium intoxication who underwent haemodialysis (HD) followed by continuous veno-venous haemodiafiltration (CVVHDF). Mean lithium clearances with HD and CVVHDF were 173 and 61 ml/min, respectively. Serum lithium levels were rapidly lowered and did not rebound. Two compartment simulations illustrate that HD followed by CVVHDF is the most effective strategy for removing lithium from the intracellular compartment.

Effect of a moderately energy- and salt-reduced diet on body compartments and blood pressure control in obese men with mild hypertension

Ten middle-aged moderately obese men with untreated mild hypertension were studied during a 6-week weight maintenance period and a 9-week period on a diet containing 5 MJ when body mass decreased by 8.4 kg (SE 1.4). According to urinary sodium excretion there was a mean reduction of 89 mmol/day (SE 16) in sodium intake. Mean arterial pressure fell by 2.5 to 14.1 mmHg (95% confidence interval) which was correlated to the reduction of body mass. The sympathetic nervous activity diminished with decreasing noradrenaline excretion and heart rate. There were no changes in the renin-aldosterone system. Estimation of the body composition with a four-compartment model utilizing determinations of body mass, total body potassium and total body water (TBW) showed reductions of body fat (8.4 kg (SE 1.4] and body cell mass (BCM) (2.4 kg (SE 0.6], but not of TBW. Extracellular water (ECW) increased significantly as judged from ECW/BCM calculations. Plasma volume was determined by Evan's blue and did not change significantly. We suggest that the observed changes in body composition represent one aspect of the adjustment to a weight reducing diet, while blood pressure is lowered by another mechanism in the adaptive response to dieting, i.e. reduction in sympathetic nervous activity.

Changes in water content of intervertebral discs and paravertebral muscles before and after bed rest

BACKGROUND

Although low back pain can be principally produced or increased during action, it may also be induced or enhanced in the morning after bed rest. During bed rest, tissue edema (increased water content) may occur. In this study, we measured the changes in water content in the intervertebral disc and the paravertebral muscle before and after bed rest using a magnetization transfer magnetic resonance imaging (MT-MRI) technique that permits measuring water content in tissues.

METHODS

A total of 20 student volunteers were enrolled in this study. MT-MRI evaluation was performed before and after bed rest. To measure water content in the intervertebral disc and paravertebral muscle, two MRI sequences were performed using MT pulse-off and MT pulse-on. Based on the two images obtained, the equivalent cross-relaxation rate (ECR) was calculated.

RESULTS

The ECR for intervertebral discs was significantly lower after bed rest than before bed rest (P < 0.01). The ECR for paravertebral equivalent cross-relaxation rate muscles was significantly higher after bed rest than before bed rest (P < 0.05).

CONCLUSION

We obtained results indicating that after bed rest the water content in the intervertebral disc and the paravertebral muscle was increased and decreased, respectively.

[Influence of recombinant human growth hormone on body fluid compartments and water-sodium retention in severe burn patients]

OBJECTIVE

To investigate the influence of recombinant human growth hormone (rhGH) on body fluid compartments and water-sodium retention in severe burn patients.

METHODS

Thirty adult patients with severe burn were divided into treatment (T) and control (C) groups by block randomized design. Patients in both groups were subcutaneously injected with same amount of rhGH (12 IU/d) or isotonic saline during 7 - 21 post burn day (PBD). The total body water (TBW), intracellular water (ICW), extracellular water (ECW) were measured by bioelectrical impedance analysis (BIA) on 7, 14, 21 PBD. The 24 h urinary output of Na+ was determined by ion selective electrode method (ISE).

RESULTS

There were no significant difference in levels of TBW, ICW, ECW and 24 h urinary output of Na+ between two groups on 7, 14, 21 PBD (P > 0.05). No difference in results was found between groups at different time points (P > 0.05). After the data were analyzed, the level of TBW (36 +/- 6 L), ICW (21 +/- 4 L) on 21 PBD were evidently lower than those on 7 PBD (38 +/- 6 L, 23 +/- 7 L, P < 0.01).

CONCLUSION

The level of ICW and TBW in severe burn patients decreased along with the time. Proper dosage of rhGH has no significant effect on body fluid compartments and water-sodium retention.

[Information value of electrolytes, glucose, and urea in pericardial liquid in different terminal conditions]

The informative worth of sodium, potassium, calcium, magnesium, glucose, and urea levels in the pericardial liquid is analysed. The values of these parameters in a terminal disease of cerebral origin may testify to the absence of disturbances of energy and protein metabolism or electrolyte disbalance in the myocardium. Disturbances of myocardial electrolyte balance, energy and protein metabolism develop in cardiac, pulmonary, and mixed type terminal conditions. Cardiac arrest is associated with impaired myocardial conduction.

[The informative value of pericardial fluid electrolytes and glucose in acute forms of coronary heart disease]

The informative value of the levels of calcium, potassium, sodium, magnesium, and glucose was estimated in individuals who had suddenly died from acute coronary insufficiency or acute myocardial infarction in the prenecrotic phase. The informational variations in the concentrations of electrolytes and glucose were found to reflect the differences available in the pathogenesis of an ischemic process in acute coronary insufficiency and acute myocardial infarction in the prenecrotic phase.

Measurements of total body water with a foot-to-foot impedancemeter

The objective was to set-up a method for measuring total body water volumes (TBW) using a Tefal foot-to-foot impedancemeter (FFI) by comparison with a multifrequency medical impedancemeter and to validate this method against deuterium dilution data. The investigation was carried out in 57 Caucasian adult subjects. Impedancemeters were a Tefal Bodymaster Vision (foot-to-foot) featuring a square wave signal and a Xitron Hydra 4200 (5-1000 kHz) using BIS method. TBW was measured by the Xitron using a new method that we have developed which applies the BIS method directly to extra and intracellular fluids combined. Although the high frequency impedance of the FFI (R(hf)) was higher than the Xitron infinite frequency resistance and corresponded to a frequency around 100 kHz, TBW differences between the FFI and Xitron were not significant, 0.17+/-2.17 L for men (P=0.694) and 0.04+/-1.88 L for women (P=0.902). Then, our method was tested on another Caucasian population in which R(hf) had been measured with the same FFI, together with TBW measurements by deuterium dilution. TBW differences between the FFI and dilution were -0.38+/-2.27 L for men (P=0.237) and -0.72+/-2.37 L for women (P=0.06). Our method permits, at least in a Caucasian healthy population, to measure TBW using this FFI with the same accuracy as a whole body multifrequency medical impedancemeter, and the measurement, made in upright position, is much quicker.

Development of a physiologically based toxicokinetic model for butadiene and four major metabolites in humans: Global sensitivity analysis for experimental design issues

1,3-Butadiene (BD) is metabolized in humans and rodents to mutagenic and carcinogenic species. Our previous work has focused on developing a physiologically based toxicokinetic (PBTK) model for BD to estimate its metabolic rate to 1,2-epoxy-3-butene (EB), using exhaled breath BD concentrations in human volunteers exposed by inhalation. In this paper, we extend our BD model to describe the kinetics of its four major metabolites EB, 1,2:3,4-diepoxybutane (DEB), 3-butene-1,2-diol (BDD), and 3,4-epoxy-1,2-butanediol (EBD), and to test whether the extended model and experimental data (to be collected for BD and metabolites in humans) are together adequate to estimate the metabolic rate constants of each of the above chemicals. Global sensitivity analyses (GSA) were conducted to evaluate the relative importance of the model parameters on model outputs during the 20min of exposure and the 40min after exposure ended. All model parameters were studied together with various potentially measurable model outputs: concentrations of BD and EB in exhaled air, concentrations of BD and all metabolites in venous blood, and cumulated amounts of urinary metabolites excreted within 24h. Our results show that pulmonary absorption of BD and subsequent distribution and metabolism in the well-perfused tissues compartment are the critical processes in the toxicokinetics of BD and metabolites. In particular, three parameters influence numerous outputs: the blood:air partition coefficient for BD, the metabolic rate of BD to EB, and the volume of the well-perfused tissues. Other influential parameters include other metabolic rates, some partition coefficients, and parameters driving the gas exchanges (in particular, for BD outputs). GSA shows that the impact of the metabolic rate of BD to EB on the BD concentrations in exhaled air is greatly increased if a few of the model's important parameters (such as the blood:air partition coefficient for BD) are measured experimentally. GSA also shows that all the transformation pathways described in the PBTK model may not be estimable if only data on the studied outputs are collected, and that data on a specific output for a chemical may not inform all the transformations involving that chemical.

Hypoalbuminemia is Also a Marker of Fluid Excess Determined by Bioelectrical Impedance Parameters in Dialysis Patients

Hypoalbuminemia may be secondary to volume expansion conditions and an independent risk factor for cardiovascular disease. Bioelectrical impedance analysis (BIA) is an accurate, non-invasive method to measure body composition, especially the water compartments in humans. The aim of this cross-sectional study is to evaluate the relationship between serum albumin concentration (SA) and hydration state measured by whole BIA. The study investigated 108 non-selected patients (73 on hemodialysis, 35 on peritoneal dialysis) with a mean age of 61.4 +/- 15.6 years, 42.7% of whom were female. The patients were allotted to groups according to their SA: Group 1, < or = 3.5 g/dL; Group 2, 3.6-4.0 g/dL; and Group 3, >4.0 g/dL. The BIA parameters used included: total body water, intracellular water (ICW), extracellular water (ECW), phase angle (PA), body cell mass (BCM), ICW/ECW ratio and ICW/ECW ratio patients/controls (fluid index). Seventy-five healthy volunteers formed the control group. A strong positive correlation was found between the PA and fluid index (r (2) = 0.993, P < 0.001), as well as between the PA and SA (r = 0.386, P < 0.001), and the ICW/ECW ratio and SA (r = 0.227, P < 0.001). The ECW was negatively correlated with SA (r = -0.330, P < 0.001). Every 0.1 g/dL decrease in SA was associated with a 0.33 L increase in ECW. Group 1 patients had lower reactance (P = 0.006), PA (P < 0.001), BCM (P = 0.012), fluid index (P < 0.001) and ICW/ECW ratio (P = 0.015), and an increased ECW (NS) than groups 2 and 3. We conclude that hypoalbuminemia is also a marker of fluid excess. The SA is associated to the fluid index and the PA allows assessment of the dry weight and its variations in an individualized manner in dialysis patients.

An integrative description of dialysis adequacy indices for different treatment modalities and schedules of dialysis

Dialysis adequacy indices that are applied for the evaluation of the efficiency of urea removal include fractional water volume cleared from urea during dialysis (KT T/V), fractional solute removal (FSR), and equivalent urea clearance (EKR). Using a constant-volume, one-compartment urea kinetic model for an anuric patient, the FSR and EKR are shown to depend on only three nondimensional parameters: (i) KT/V, where K is the dialyzer clearance for hemodialysis (HD) or peritoneal mass transport coefficient for peritoneal dialysis (PD), T is the time period of dialysis, and V is urea distribution volume; (ii) T/Tc, where Tc is the length of treatment cycle; and (iii) VD/V, where VD is the volume of dialysis fluid applied. In particular, analytical formulas for FSR and EKR, valid for HD as well as for PD, were derived as functions of these three parameters. Numerical simulations, performed using a two-compartment urea kinetic model, showed that the analytical formulas are valid also for the two-compartment model, except for short, highly effective HD, where the overestimation of FSR and EKR using the analytical formulas is however, not higher than 20 and 16%, respectively. KT T/V is equal to KT/V for HD and FSR for PD. Thus, our formulas provide an integrative description of the relationships between dialysis efficiency indices and operational dialysis parameters that is valid for all modalities and schedules of dialysis. They may be applied not only for standard HD and continuous ambulatory PD, but also for HD with circulating dialysis fluid or intermittent forms of PD.

Comparison of body compositional indices assessed by underwater weighing, bioelectrical impedance and anthropometry in Indonesian adolescent girls

OBJECTIVE

To investigate the accuracy of bioelectric impedance analysis and anthropometry to assess percentage body fat (BF %) against underwater weighing (UW).

DESIGN AND METHODS

A cross sectional study, 102 girls, aged 11-15, were recruited from two Junior High Schools in Jakarta.

MEASUREMENTS

Measurements of percent-age body fat (BF%) using underwater weighing (UW), bioelectrical impedance analysis (BIA), Tanita BIA, body mass index (BMI) and skinfold equations.

RESULTS

Correlation between different methods was significant (p < 0.001). The mean difference of BF % from BIA, Tanita, BMI and skinfold compared to UW were 1.87 +/- 3.14, -3.46 +/- 3.28, 1.57 +/- 2.90 and -0.360 +/- 3.09, respectively. Assessments between UW and other methods were significantly different (p < 0.0001) except for skinfolds (p = 0.3031).

CONCLUSION

The results between UW and other methods was significantly different, except for skinfolds. There was overestimation and underestimation of BF%. The agreement between skinfold measurement and underwater weighing was also influenced by menarche status.

A whole-body model to distinguish excess fluid from the hydration of major body tissues

BACKGROUND

Excess fluid (ExF) accumulates in the body in many conditions. Currently, there is no consensus regarding methods that adequately distinguish ExF from fat-free mass.

OBJECTIVE

The aim was to develop a model to determine fixed hydration constants of primary body tissues enabling ExF to be calculated from whole-body measurements of weight, intracellular water (ICWWB), and extracellular water (ECWWB).

DESIGN

Total body water (TBW) and ECWWB were determined in 104 healthy subjects by using deuterium and NaBr dilution techniques, respectively. Body fat was estimated by using a reference 4-component model, dual-energy X-ray absorptiometry, and air-displacement plethysmography. The model considered 3 compartments: normally hydrated lean tissue (NH_LT), normally hydrated adipose tissue (NH_AT), and ExF. Hydration fractions (HF) of NH_LT and NH_AT were obtained assuming zero ExF within the diverse healthy population studied.

RESULTS

The HF of NH_LT mass was 0.703 +/- 0.009 with an ECW component of 0.266 +/- 0.007. The HF of NH_AT mass was 0.197 +/- 0.042 with an ECW component of 0.127 +/- 0.015. The ratio of ECW to ICW in NH_LT was 0.63 compared with 1.88 in NH_AT. ExF can be estimated with a precision of 0.5 kg.

CONCLUSIONS

To calculate ExF over a wide range of body compositions, it is important that the model takes into account the different ratios of ECW to ICW in NH_LT and NH_AT. This eliminates the need for adult age and sex inputs into the model presented. Quantification of ExF will be beneficial in the guidance of treatment strategies to control ExF in the clinical setting.