Bioelectrical impedance analysis and age-related differences of body composition in the elderly

Differences in heart rate variability and body composition in breast cancer survivors and women without cancer

The aim of this study was to explore cardiac autonomic changes assessed by linear and nonlinear indexes of heart rate variability (HRV) and body composition modifications in breast cancer survivors and cancer-free control women. Women who were breast cancer survivors (BCS, n = 27) and without cancer with similar characteristics (Control, n = 31) were recruited for this study. We calculated some relevant linear and nonlinear parameters of 5 min of RR interval time series such as mean RR interval (RRave), the corrected Poincaré index (cSD1/SD2), the sample entropy (SampEn), the long-term fractal scaling exponent (α2) and 2UV from symbolic dynamics. Additionally, we indirectly assessed body composition measures such as body weight, fat mass, visceral fat rating (VFR), normalized VRF (nVFR), muscle mass, metabolic age, and total body water. We found that diverse HRV indexes and only one body composition measure showed statistical differences (p < 0.05) between the BCS and Control groups. RRave: 729 (648-802) vs. 795 (713-852) ms; cSD2/SD1: 3.4 (2.7-5.0) vs. 2.9 (2.3-3.5); SampEn: 1.5 (1.3-1.8) vs. 1.7 (1.5-1.8); α2: 0.6 (0.3-0.6) vs. 0.5 (0.4-0.5); 2UV: 7.1 (4.3-11.5) vs. 10.8 (6.4-15.7) and nVFR 0.12 (0.11-0.13) vs. 0.10 (0.08-0.12) points/kg, respectively. The nVFR was strongly significantly correlated with several indexes of HRV only in the BCS group.Our findings suggest that BCS exhibit lower parasympathetic cardiac activity and changes in HRV patterns compared to Controls. A concomitant increase of visceral fat, among other factors, may contribute to cardiac autonomic disturbances and changes in HRV patterns in BCS.

Lutein supplementation combined with a low-calorie diet in middle-aged obese individuals: effects on anthropometric indices, body composition and metabolic parameters

Lutein is considered as a major biologically active carotenoid, with potential benefits for obesity and cardiometabolic health. This double-blind, randomised controlled trial aimed to assess whether the consumption of lutein along with a low-calorie diet (LCD) can influence anthropometric indices, body composition and metabolic parameters in obese middle-aged individuals. After a 2-week run-in period with an LCD, forty-eight participants aged 45–65 years were randomly assigned to consume 20 mg/d lutein or placebo along with the LCD for 10 weeks. Dietary intake, anthropometric indices, body composition, lipid profile, glucose homoeostasis parameters, NEFA and appetite sensations were assessed at the beginning and end of the study. After 10 weeks, body weight and waist circumference significantly decreased in both groups, although between-group differences were not significant. There was more of a decrease in the percentage of body fat in the lutein group v. the placebo group. Moreover, the placebo group experienced a significant reduction in fat-free mass (FFM), whereas the lutein group preserved FFM during calorie restriction, although the between-group difference did not reach statistical significance. Visceral fat and serum levels of total cholesterol (TC) and LDL-cholesterol were significantly decreased only in the lutein group, with a statistically significant difference between the two arms only for TC. No significant changes were observed in the TAG, HDL-cholesterol, glucose homoeostasis parameters, NEFA and appetite sensations. Lutein supplementation in combination with an LCD could improve body composition and lipid profile in obese middle-aged individuals.

Estimation of glomerular filtration rate from skeletal muscle mass. A new equation independent from age, weight, gender, and ethnicity

BACKGROUND AND AIMS

The most used indicator for the renal function is the glomerular filtration rate (GFR). Current used predictive GFR equations were calibrated on patients with chronic kidney disease. Thus, they are not very precise in healthy individuals. The estimation of skeletal muscle mass (SMM) allows the prediction of the daily urinary creatinine excretion (24hUCrE). This study proposes an equation for the estimation of GFR based on SMM (eGFRMuscle) and serum creatinine (SCr).

METHODS AND RESULTS

Four hundred sixty-six free-living men underwent a bioelectrical impedance analysis for the evaluation of SMM (kg), a blood withdrawal for the measurement of SCr (mg/dL), and a 24-h urinary collection for the assessment of 24hUCrE (g/24 h). The linear regression analysis between SMM and 24hUCrE and the measurement of SCr allowed developing a predictive equation of eGFRMuscle. The equation predicting eGFRMuscle (ml/min/1.73 m²) was SMM (kg) × 3.06/SCr (mg/dL). eGFRMuscle was statistically different from eGFR predicted by Cockroft-Gault, MDRD Study, and CKD-EPI equations (p = 0.017, p < 0.001, and p < 0.001, respectively). Pairwise comparison of standard error of the area under the ROC curve (AUC) of eGFRMuscle with all the other AUCs of ROC curves highlighted significant differences.

CONCLUSIONS

The equation presented in this study results in age, weight, gender, and ethnicity independent because it arises directly from SMM estimation. Therefore, the proposed equation could allow evaluating the GFR also in healthy people with low, average, or high weight, and in older people, regardless of GFR and SCr levels.

Testing Bioimpedance to Estimate Body Fat Percentage across Different Hip and Waist Circumferences

Many studies have validated the use of bioimpedance analysis (BIA) to quantify body fat percentage (BF%). However, it is unknown if some model types (i.e., hand to hand, foot to foot, and hand to foot) are differing in their validity depending on hip and waist circumferences. The purpose of this study was to compare the difference in BF% between three BIA models (i.e., hand to hand, foot to foot, and hand to foot) against the Bod Pod across different hip and waist circumferences. A total of 92 people aged 19-72 years were recruited in this study. After following the pretesting procedures recommended for BIA measures, BF% was estimated using three BIA models and the Bod Pod. Hip and waist circumferences were obtained using standard procedures and tertiles were computed. The Bland-Altman was plotted and 1-sample T-test as well as correlation between the average measure and the difference between the two measures was tested. Within the entire sample, across all BIA models, the Bland-Altman analysis showed significant difference compared to 0 and a significant difference for the proportional. However, when stratified by tertiles, the two measurements were only significant for the highest tertiles of hip and waist for all BIA apparatus (all p <0.01) and the proportional bias was nonsignificant for all tertiles and across all BIA apparatus. For the highest tertile of waist and hip, the average difference was between 1.67% and 3.29% compared with the Bod Pod estimation. In conclusion, the three BIA models offer a BF% measurement agreeing with the estimation obtained with the Bod Pod with the exception of people having a greater waist or greater hip.

Bioelectrical Impedance Analysis-Derived Phase Angle Predicts Protein-Energy Wasting in Maintenance Hemodialysis Patients

OBJECTIVE(S)

To explore the validity of using bioelectrical impedance analysis (BIA)-derived 50 kHz phase angle (PhA) in predicting protein-energy wasting (PEW) in Chinese maintenance hemodialysis (MHD) patients.

DESIGN AND METHODS

The design was a cross-sectional study. A total of 173 of MHD patients and 173 healthy adults were enrolled in the study. The prevalence of PEW in patients was performed by the International Society of Renal Nutrition and Metabolism criteria. The PhA, body cell mass, fat mass, body fat percentage, fat-free mass, and extracellular water/total body water were measured by InBody S10 body composition analyzer. The biochemical indices and anthropometric measurements were assessed using the way published elsewhere. The PhA, other values of BIA and its relationship with age, visceral protein, anthropometric measurements of the MHD patients were compared with the healthy group. The independent variables for predicting PEW and its cutoff values were explored using logistic regression model and receiver operating characteristic curve analysis, respectively.

RESULTS

The MHD patients' PhA value was significantly lower than the healthy group (4.89°± 1.19 vs. 6.32°± 2.23, P < .01). A total of 34.1% MHD patients with PEW had significantly lower PhA values compared with well-nourished patients (P < .05). The PhA decreased more significantly with age in MHD (r = -0.35, P < .001), compared with controls (r = -0.26, P < .001). The PhA values were positively associated with nutritional indices related to serum albumin, prealbumin, fat-free mass, and mid-arm muscle circumference. PhA values were not associated significantly with fat mass and body fat percentage (P > .05). Multivariate logistic regression analysis showed that PhA and body mass index were independent predictors of PEW, but the PhA was the stronger predictor (odds ratio = 4.48, P < .05). Receiver operating characteristic curve analysis suggested that the optimal PhA cutoff value to predict PEW was 4.6°.

CONCLUSIONS

BIA-derived PhA appears to be a useful bioelectrical marker for predicting PEW in Chinese hemodialysis patients with a cutoff value of 4.6°.

Validation of daily urinary creatinine excretion measurement by muscle-creatinine equivalence

BACKGROUND

Twenty-four-hour urinary creatinine excretion (24hUCrE) is strongly correlated with skeletal muscle mass (SMM). This study suggests how to exploit the power of the SMM-24hUCrE correlation to assess the accuracy of 24hUCrE measurement.

METHODS

Four hundred and sixty-six men, a subgroup of participants in the 2002-2004 follow-up examination of the Olivetti Heart Study, performed a 24-h urine collection to measure 24hUCrE and underwent bioelectrical impedance analysis to evaluate SMM. Linear regression analysis between 24hUCrE and SMM was used to calculate the muscle-creatinine equivalence and to develop an equation to predict the 24hUCrE depending on SMM. The accuracy of the 24hUCrE measurement was assessed using the change in the SMM-24hUCrE correlation coefficient upon variation in the percentage deviation (%D) between the measured and predicted 24hUCrE.

RESULTS

The calculated muscle-creatinine equivalence was 1 g of 24hUCrE = 22.73 kg of SMM. The %Ds and the corresponding SMM-24hUCrE correlation coefficients were as follows: %D = 3.0, r = .997; %D = 4.7, r = .989; %D = 8.1, r = .963; %D = 10.5, r = .940; %D = 12.6, r = .909; %D = 18.9, r = .825; %D = 25.8, r = .707; %D = 33.5, r = .595; %D = 41.4, r = .453.

CONCLUSION

The increase in %D corresponds to a reduced correlation between muscle mass and creatinine excretion, which indicated a poor performance in the measurement of the 24hUCrE. For studies on single individuals, where small variations in 24hUCrE could be significant, a %D up to 12.6% is suggested; on the other hand, a wider %D interval could be acceptable for population studies.

Phase angle assessment by bioelectrical impedance analysis and its predictive value for malnutrition risk in hospitalized geriatric patients

BACKGROUND

Phase angle (PhA) value determined by bioelectrical impedance analysis (BIA) is an indicator of cell membrane damage and body cell mass. Recent studies have shown that low PhA value is associated with increased nutritional risk in various group of patients. However, there have been only a few studies performed globally assessing the relationship between nutritional risk and PhA in hospitalized geriatric patients. The aim of the study is to evaluate the predictive value of the PhA for malnutrition risk in hospitalized geriatric patients.

METHODS

One hundred and twenty-two hospitalized geriatric patients were included in this cross-sectional study. Comprehensive geriatric assessment tests and BIA measurements were performed within the first 48 h after admission. Nutritional risk state of the patients was determined with NRS-2002. Phase angle values of the patients with malnutrition risk were compared with the patients that did not have the same risk. The independent variables for predicting malnutrition risk were determined. SPSS version 15 was utilized for the statistical analyzes.

RESULTS

The patients with malnutrition risk had significantly lower phase angle values than the patients without malnutrition risk (p = 0.003). ROC curve analysis suggested that the optimum PhA cut-off point for malnutrition risk was 4.7° with 79.6 % sensitivity, 64.6 % specificity, 73.9 % positive predictive value, and 73.9 % negative predictive value. BMI, prealbumin, PhA, and Mini Mental State Examination Test scores were the independent variables for predicting malnutrition risk.

CONCLUSIONS

PhA can be a useful, independent indicator for predicting malnutrition risk in hospitalized geriatric patients.

Short-Term Changes in Body Composition and Response to Micronutrient Supplementation After Laparoscopic Sleeve Gastrectomy

BACKGROUND

We evaluated dietary intakes, body composition, micronutrient deficiency, and response to micronutrient supplementation in 47 patients before and for 6 months after laparoscopic sleeve gastrectomy (LSG).

METHODS

Before, 3, and 6 months after LSG, we measured dietary intakes with food-frequency questionnaires, body composition with bioimpedance analysis (BIA) and bioelectrical vector analysis (BIVA), and plasma concentrations of iron, Zn, water-, and lipo-soluble vitamins.

RESULTS

After LSG, energy intake significantly decreased and patients lost weight, fat mass, and free-fat mass. BIVA showed a substantial loss of soft tissue body cell mass (BCM) with no change in hydration. Before surgery, 15 % of patients were iron deficient, 30 % had low levels of zinc and/or water-soluble vitamins, and 32 % of vitamin 25(OH)-D3. We treated iron deficiency with ferrous sulfate, isolated folate deficiency with N5-methyiltetrahydrofolate-Ca-pentahydrate, and deficiencies in vitamin B1, B12, or Zn, with or without concomitant folate deficiency, with multivitamin. No supplementation was given to vitamin 25(OH)-D3 deficient patients. At first follow-up, 7 % of patients developed new deficiencies in iron, 7 % in folic acid (n = 3), and 36 % in water-soluble vitamins and/or zinc whereas no new deficit in vitamin 25(OH)-D3 occurred. At final follow-up, deficiencies were corrected in all patients treated with either iron or folate but only in 32 % of those receiving multivitamin. Vitamin 25(OH)-D3 deficiency was corrected in 73 % of patients even though these patients were not supplemented.

CONCLUSION

LSG-induced weight loss is accompanied by a decrease in BCM with no body fluid alterations. Deficiencies in water-soluble vitamins and Zn respond poorly to multivitamin supplementation.

The body composition of patients with knee osteoarthritis: relationship with clinical parameters and radiographic severity

BACKGROUND AND AIMS

We investigated body composition in knee osteoarthritis (OA) patients and evaluated its relationship with clinical parameters and radiographic severity.

METHODS

Sixty-four patients with knee OA (52 females and 12 males with a mean age of 57.7 ± 8.6 years) and thirty healthy volunteers (20 females and 10 males with a mean age of 56.3 ± 9.5 years) were evaluated. Controls were selected among similar to demographic and hematologic characteristics of patients. Body compositions were assessed via bioelectrical impedance analysis (BIA). Each patient was clinically evaluated by the Western Ontario and McMaster University Osteoarthritis Index (WOMAC). In addition, radiographic severity was classified according to Kellgren-Lawrence's criteria.

RESULTS

Phase angle, body capacitance, resistance, reactance, lean body mass, and intracellular water values of the patients with knee OA were found to be significantly lower than those of the controls (p < 0.05). Furthermore, fat mass and extracellular water levels were significantly higher in the patients compared to the controls (p < 0.05). Lean body mass was inversely correlated with WOMAC score (r = -0.716, p < 0.001), whereas fat mass was moderately correlated with WOMAC score (r = 0.281, p < 0.05) in bivariate analysis. However, with respect to the body composition, there was no significant difference between early grades and late grades in the knee OA with patients (p > 0.05).

CONCLUSION

Body composition assessed using BIA might be associated with knee OA, and be a noninvasive tool for diagnosis of knee OA. However, body composition may not be predictive of the progression of knee OA.

Assessment of body composition in subjects with metabolic syndrome comparing single-frequency bioelectrical impedance analysis and bioelectrical spectroscopy

BACKGROUND

The aim of this study was to investigate the agreement between body composition measurements made with two methods-single-frequency bioelectrical impedance analysis (SF-BIA) and bioelectrical impedance spectroscopy (BIS).

METHODS

The body composition measurements using SF-BIA and BIS were performed seven times during 6 months on 41 patients (13 men and 28 women) with metabolic syndrome who were taking part in a dietary intervention study.

RESULTS

The mean [standard deviation (SD)] fat mass (FM) and median [interquartile range (IQR)] FM% measured with SF-BIA were 32.7 (6.7) kg and 36.3 (30.3-39.3)%, respectively, compared with 38.2 (8.7) kg and 40.9 (35.5-45.6)%, respectively, using BIS. The median (IQR) fat-free mass (FFM) was 60.0 (53.3-73.5) kg according to SF-BIA and 55.4 (48.8-66.5) kg according to BIS. These results obtained with the two methods were significantly different (P<0.001). Still highly significant correlations were found between the results obtained with SF-BIA and BIS for FM and FFM (all r≥0.89, P<0.001). Using Bland-Altman analysis, the bias was found to be -5.4 (4.1) kg for FM, -5.5 (3.7)% for FM%, and 5.4 (4.1) kg for FFM. Rather wide limits of agreement were found for FM, FM%, and FFM.

CONCLUSION

Body composition data obtained using SF-BIA and BIS in subjects with metabolic syndrome were highly correlated but not interchangeable. FM was systematically lower when using SF-BIA than when using BIS.

Bioelectrical impedance vector analysis (BIVA) for the assessment of two-compartment body composition

This review is directed to define the efficacy of bioelectrical impedance vector analysis (BIVA) for assessing two-compartment body composition. A systematic literature review using MEDLINE database up to 12 February 2014 was performed. The list of papers citing the first description of BIVA, obtained from SCOPUS, and the reference lists of included studies were also searched. Selection criteria included studies comparing the results of BIVA with those of other techniques, and studies analyzing bioelectrical vectors of obese, athletic, cachectic and lean individuals. Thirty articles met the inclusion criteria. The ability of classic BIVA for assessing two-compartment body composition has been mainly evaluated by means of indirect techniques, such as anthropometry and bioelectrical impedance analysis (BIA). Classic BIVA showed a high agreement with body mass index, that can be interpreted in relation to the greater body mass of obese and athletic individuals, whereas the comparison with BIA showed less consistent results, especially in diseased individuals. When a reference method was used, classic BIVA failed to accurately recognize FM% variations, whereas specific BIVA furnished good results. Specific BIVA is a promising alternative to classic BIVA for assessing two-compartment body composition, with potential application in nutritional, sport and geriatric medicine.

Accuracy of specific BIVA for the assessment of body composition in the United States population

Background

Bioelectrical impedance vector analysis (BIVA) is a technique for the assessment of hydration and nutritional status, used in the clinical practice. Specific BIVA is an analytical variant, recently proposed for the Italian elderly population, that adjusts bioelectrical values for body geometry.

Objective

Evaluating the accuracy of specific BIVA in the adult U.S. population, compared to the ‘classic’ BIVA procedure, using DXA as the reference technique, in order to obtain an interpretative model of body composition.

Design

A cross-sectional sample of 1590 adult individuals (836 men and 754 women, 21–49 years old) derived from the NHANES 2003–2004 was considered. Classic and specific BIVA were applied. The sensitivity and specificity in recognizing individuals below the 5^th and above the 95^th percentiles of percent fat (FM_DXA%) and extracellular/intracellular water (ECW/ICW) ratio were evaluated by receiver operating characteristic (ROC) curves. Classic and specific BIVA results were compared by a probit multiple-regression.

Results

Specific BIVA was significantly more accurate than classic BIVA in evaluating FM_DXA% (ROC areas: 0.84–0.92 and 0.49–0.61 respectively; p = 0.002). The evaluation of ECW/ICW was accurate (ROC areas between 0.83 and 0.96) and similarly performed by the two procedures (p = 0.829). The accuracy of specific BIVA was similar in the two sexes (p = 0.144) and in FM_DXA% and ECW/ICW (p = 0.869).

Conclusions

Specific BIVA showed to be an accurate technique. The tolerance ellipses of specific BIVA can be used for evaluating FM% and ECW/ICW in the U.S. adult population.

Elderly subjects with type 2 diabetes show altered tissue electrical properties

OBJECTIVE

The aim of the present research was to show the characteristics of body composition in a sample of elderly subjects with type 2 diabetes compared with healthy controls matched by age and body mass index (BMI) by bioelectrical impedance vector analysis.

METHODS

The sample consisted of 144 free-living patients (84 women and 60 men) with type 2 diabetes 60 to 84 y old and 209 age-matched controls (116 women and 93 men). Anthropometric measurements (weight; height; upper arm, hip, waist, and calf circumferences; biceps; triceps; and subscapular and suprailiac skinfolds) were taken. Blood samples for the assessment of plasma glucose and glycated hemoglobin were collected. The BMI, upper arm muscular area, and waist-to-hip ratio were calculated. Bioelectrical impedance vector analysis was applied. The analysis was performed in the entire diabetic sample and the healthy BMI-matched groups.

RESULTS

Compared with healthy subjects, patients had greater weight (P < 0.01 in women), higher BMI (P < 0.01 in women), smaller muscular area (P < 0.01 in men), and thicker skinfolds (P < 0.01 in women and men). Female and male patients showed larger phase angles (P < 0.01). Moreover, female patients showed a shorter vector length and lower resistance (P < 0.01) and male patients showed a higher reactance (P < 0.01). The BMI-matched analysis confirmed that patients were characterized by larger phase angles.

CONCLUSIONS

Older patients with type 2 diabetes were characterized by peculiar anthropometric and bioelectrical patterns, which can be related to their smaller appendicular muscular area and lower extracellular/intracellular water ratio.

Comparing measures of fat-free mass in overweight older adults using three different bioelectrical impedance devices and three prediction equations

OBJECTIVES

To compare measures of fat-free mass (FFM) by three different bioelectrical impedance analysis (BIA) devices and to assess the agreement between three different equations validated in older adult and/or overweight populations.

DESIGN

Cross-sectional study.

SETTING

Orthopaedics ward of Brisbane public hospital, Australia.

PARTICIPANTS

Twenty-two overweight, older Australians (72 yr ± 6.4, BMI 34 kg/m² ± 5.5) with knee osteoarthritis.

MEASUREMENTS

Body composition was measured using three BIA devices: Tanita 300-GS (foot-to-foot), Impedimed DF50 (hand-to-foot) and Impedimed SFB7 (bioelectrical impedance spectroscopy (BIS)). Three equations for predicting FFM were selected based on their ability to be applied to an older adult and/ or overweight population. Impedance values were extracted from the hand-to-foot BIA device and included in the equations to estimate FFM.

RESULTS

The mean FFM measured by BIS (57.6 kg ± 9.1) differed significantly from those measured by foot-to-foot (54.6 kg ± 8.7) and hand-to-foot BIA (53.2 kg ± 10.5) (P < 0.001). The mean ± SD FFM predicted by three equations using raw data from hand-to-foot BIA were 54.7 kg ± 8.9, 54.7 kg ± 7.9 and 52.9 kg ± 11.05 respectively. These results did not differ from the FFM predicted by the hand-to-foot device (F = 2.66, P = 0.118).

CONCLUSIONS

Our results suggest that foot-to-foot and hand-to-foot BIA may be used interchangeably in overweight older adults at the group level but due to the large limits of agreement may lead to unacceptable error in individuals. There was no difference between the three prediction equations however these results should be confirmed within a larger sample and against a reference standard.

Angiotensin-converting enzyme/vitamin D receptor gene polymorphisms and bioelectrical impedance analysis in predicting athletic performances of Italian young soccer players

We evaluated the association between 2 genetic polymorphisms known to be involved in fitness and performance, and anthropometric features, body composition, and athletic performances in young male soccer players with the goal of identifying genetic profiles that can be used to achieve maximal results from training. One hundred twenty-five medium-high-level male soccer players were genotyped for angiotensin-converting enzyme (ACE) I/D, and vitamin D receptor (VDR) FokI gene polymorphisms and scored for anthropometric measurements, body composition, and athletic performance. Body mass index, fat mass, fat-free mass, resistance, reactance, impedance, phase angle (PA), and body cell mass were measured. Athletic performance was evaluated by squat jump, countermovement jump (CMJ), 2-kg medicine ball throw, 10- and 20-m sprint time. We observed that the homozygous ff genotype of the VDR gene was significantly more represented in young soccer players than in a matched sedentary population. Values of reactance and PA were differently distributed in ACE and VDR genotypes with high mean values in subjects with DD (ACE) and FF (VDR) genotypes. No correlation was observed between ACE or VDR genotypes and 2-kg medicine ball throw, 10- and 20-m sprint times. The ID genotype of ACE was associated with the best performances in squat jump and CMJ. Our results suggest that determination of ACE and VDR genotypes might help select those young athletes harboring the most favorable genetic potential to succeed in soccer.

Bioelectrical impedance analysis in clinical practice: implications for hepatitis C therapy BIA and hepatitis C

Background

Body composition analysis using phase angle (PA), determined by bioelectrical impedance analysis (BIA), reflects tissue electrical properties and has prognostic value in liver cirrhosis. Objective of this prospective study was to investigate clinical use and prognostic value of BIA-derived phase angle and alterations in body composition for hepatitis C infection (HCV) following antiviral therapy.

Methods

37 consecutive patients with HCV infection were enrolled, BIA was performed, and PA was calculated from each pair of measurements. 22 HCV genotype 3 patients treated for 24 weeks and 15 genotype 1 patients treated for 48 weeks, were examined before and after antiviral treatment and compared to 10 untreated HCV patients at 0, 24, and 48 weeks. Basic laboratory data were correlated to body composition alterations.

Results

Significant reduction in body fat (BF: 24.2 ± 6.7 kg vs. 19.9 ± 6.6 kg, genotype1; 15.4 ± 10.9 kg vs. 13.2 ± 12.1 kg, genotype 3) and body cell mass (BCM: 27.3 ± 6.8 kg vs. 24.3 ± 7.2 kg, genotype1; 27.7 ± 8.8 kg vs. 24.6 ± 7.6 kg, genotype 3) was found following treatment. PA in genotype 3 patients was significantly lowered after antiviral treatment compared to initial measurements (5.9 ± 0.7° vs. 5.4 ± 0.8°). Total body water (TBW) was significantly decreased in treated patients with genotype 1 (41.4 ± 7.9 l vs. 40.8 ± 9.5 l). PA reduction was accompanied by flu-like syndromes, whereas TBW decline was more frequently associated with fatigue and cephalgia.

Discussion

BIA offers a sophisticated analysis of body composition including BF, BCM, and TBW for HCV patients following antiviral regimens. PA reduction was associated with increased adverse effects of the antiviral therapy allowing a more dynamic therapy application.

Nutritional status in the healthy longeval population from Sardinia (Italy)

OBJECTIVES

The aim of this study was to evaluate sex- and age-related variations of the nutritional status in the aged population of central Sardinia, a geographical area with a high frequency of long-lived people, particularly men.

DESIGN

The sample consisted of 200 subjects over 70 years of age (men: N= 100, age= 81.0 +/- 7.0 years; women: N= 100, age= 81.5 +/- 7.3 years).

SETTING

Orroli (central Sardinia, Italy).

MEASUREMENTS

Mini nutritional assessment (MNA) and bioelectrical impedance vector analysis (BIVA) were used to evaluate nutritional status and body composition.

RESULTS

The indicators revealed a generally good nutritional status. The MNA results (men: 24.6 +/- 2.2; women: 23.4 +/- 2.5) showed that 64.1% of the subjects had a normal nutritional status and only a small proportion (1.2%) could be classified as malnourished. BIVA showed that most subjects (74.2%) were normal, while the prevalence of low body cell mass was 10.7% and that of dehydration 11.2%. According to the MNA, the nutritional status was significantly better in the men. Almost three-quarters of the men (73.1%) were well nourished vs. half of the women (50.6%). A worsening of the nutritional status with age was observed. The proportion of malnourished individuals, as assessed by MNA, increased from 0% to 9.1% from 70-79 to > 90 years.

CONCLUSIONS

With respect to their contemporaries from other regions, the elderly of Orroli presented a better nutritional status, a similar worsening with age and generally higher sexual dimorphism.

Changes in body composition and its relation to muscle strength in 75-year-old men and women: a 5-year prospective follow-up study of the NORA cohort in Göteborg, Sweden

OBJECTIVE

The purpose of this study was to explore the association between body composition in the elderly and subsequent changes in muscle strength during aging.

METHODS

This was a longitudinal study with a 5-y follow-up. Eighty-seven men (n = 38) and women (n = 49) from a random sample of 75-y-old subjects in the Göteborg part of the Nordic Research on Aging study who were investigated at ages 75 and 80 y and were free from any major diseases at baseline were included. Body composition was estimated from bioelectrical impedance. The maximal isometric strengths of handgrip, arm flexion, and knee extension were measured on the side of the dominant hand while a subject was in a sitting position in an adjustable dynamometer chair.

RESULTS

Fat-free mass decreased significantly (P < 0.001) in both sexes, but more in men. Percentage of body fat increased only in men (P < 0.05). Body height decreased in both sexes, but more in women (P < 0.001). Declines in muscle strengths were evident for all muscle groups in both sexes but more prominent in men. It was observed that body composition status at baseline, measured as fat-free mass and fat-free mass index, was a statistically significant predictor for decline in muscle strength, particularly in the extremities.

CONCLUSION

Fat-free mass at age 75 y was associated with lower 5-y decline in muscle strength. This finding underscores the potential importance of fat-free mass for maintaining functional ability during aging.

Body composition analysis techniques in the aged adult: indications and limitations

PURPOSE OF REVIEW

Body composition analysis allows division of the body into different compartments on the basis of differing physical properties. A variety of techniques are available for measuring body composition. This review describes the changes that occur with increasing age, their significance and also the limitations of available body composition analysis techniques when applied to the elderly.

RECENT FINDINGS

Studies have shown the development of changes in body composition with ageing that have important consequences for health. Alterations in body fat content and particularly body fat distribution are associated with adverse metabolic effects and increased cardiovascular risk. Reduced skeletal muscle mass and strength (sarcopenia) are common in the elderly with important effects on function and outcome. A range of techniques are available for measuring body composition. However, changes in body composition with ageing, particularly altered composition of the constituents of fat-free mass, and changes in fat distribution, may lead to measurement errors with standard body composition assessment methodology.

SUMMARY

Measurement of body composition provides information of importance to health and function. Techniques used for assessment should be those unaffected by age-related changes in body composition, or those that have been adapted or validated in this age group. Particular roles of these techniques in the elderly include screening or surveillance of those at risk of malnutrition, and monitoring a range of chronic illnesses that are prevalent in older individuals.

Bioelectrical impedance analysis for the evaluation of hepatic fibrosis in patients with chronic hepatitis C infection

Bioelectrical impedance analysis (BIA) is a non-invasive technique that measures electrical resistance (R) and reactance (Xc), which are then used to calculate phase angle (PA). The aim of this pilot study was to assess whether BIA can differentiate between minimal and advanced hepatic fibrosis in patients with chronic hepatitis C (HCV) infection. Twenty patients with HCV participated in this study, and were divided into minimal (Metavir 1) and advanced (Metavir 3 or 4) fibrosis groups. We obtained BIA measurements (R and Xc) in several axes and calculated PA from each pair of measurements. We found no statistically significant differences between the two groups with respect to PA, R, or Xc for the whole body, the trunk or the right upper quadrant measurements in any axis. Mean whole body PA was 7.0 and 7.1 (P = 0.9) in the minimal and advanced fibrosis groups, respectively. Bioelectrical impedance analysis did not demonstrate the ability to distinguish between minimal and advanced degrees of hepatic fibrosis in patients with chronic HCV infection.

Sarcopenic obesity: a new category of obesity in the elderly

BACKGROUND AND AIM

In elderly patients, age-related changes in body composition, as well as the increased prevalence of obesity, determine a combination of excess weight and reduced muscle mass or strength, recently defined as sarcopenic obesity (SO). This review examines the main studies regarding sarcopenic obesity in the elderly.

DATA SYNTHESIS

Definition of SO necessarily combines those of sarcopenia and obesity. The prevalence of sarcopenia and SO increases with age. Muscle and fat mass are strongly interconnected from a pathogenetic point of view. A better understanding of the mechanisms which lead from loss of muscle mass to fat gain or vice versa from fat gain to muscle loss seems to be crucial. Recent data suggest that peptides produced by adipose tissue may play an important role in the pathophysiology of SO, thus more research is needed to better characterize this new area. Obesity and sarcopenia in the elderly may potentiate each other maximizing their effects on disability, morbidity and mortality. Identifying elderly subjects with SO should be mandatory; effective treatment of sarcopenia and SO may attenuate its clinical impact.

CONCLUSION

The concept of SO may help to clarify the relationship between obesity, morbidity and mortality in the elderly.