Purpose of the research: To analyse body composition of patients with Alzheimer's disease (AD) using total body and localized specific bioelectrical impedance vector analysis (specific BIVA). Method: 127 patients (50 men, 78.2 +/- 6.3 years; 77 women, 81.4 +/- 6.8 years) with mild to moderate stages of AD were selected from the Geriatric Division, SS. Trinita Hospital of Cagliari (Italy). A sample of 135 healthy age-matched individuals (74 men, 77.4 +/- 5.3 years; 61 women, 80.4 +/- 5.5 years) was chosen as control group. Anthropometric measurements were taken and body mass index (BMI) was calculated. Bioelectrical measurements were taken on the right side of the body for both the whole-body and the arm, using a BIA 101 analyser (Akern). Body composition was assessed by means of specific bioelectrical impedance vector analysis (specific BIVA). The comparison between patients and the control group was performed by two-factor analysis of variance and Hotelling's T-2 test. Results: In comparison with the control group, patients with AD showed similar anthropometric characteristics, including BMI, but lower lean tissue mass and higher percent fat mass, as indicated by the lower phase angles and longer specific vectors. The same body composition peculiarities were detected considering only the right arm. Conclusion: Patients with AD show characteristics - lower lean mass/higher percent fat mass - that can be detected by both total body and localized bioimpedance approaches. This suggests the possibility of a new, quicker and simpler procedure for body composition assessment.

Objective: The aim of this study was to demonstrate the different information provided by body mass index (BMI) in combination with specific bioelectrical impedance vector analysis (specific BIVA) in the measure of relative body fat.Methods: Anthropometric and bioelectrical values and dual -energy x-ray absorpitometry mea-surements from a sample of 1590 US adults of both sexes were retrieved from the National Health and Nutrition Examination Survey 2003-2004. The sample distribution of the BMI of each sex was divided into deciles. Quartiles were calculated for percent fat mass (FM%) after stratifying by BMI deciles. Body composition and bioelectrical characteristics of groups below the first and above the third quartile were compared using analysis of variance and the Hotelling's T-square test.Results: BMI and specific BIVA showed a different accuracy in detecting body composition variations: BMI showed similar values in groups represented by different FM percentages, whereas the bioelectrical differences were statistically significant. The mean impedance vectors corresponding to cases below the first FM% quartiles were shorter and located on the left side of the ellipses (the region of higher fat -free mass), whereas those above the third FM% quartiles were on the right and toward the upper pole (the region of higher FM%).Conclusions: Specific BIVA is a technique for the evaluation of body composition which can add relevant information regarding BMI.(C) 2016 Elsevier Inc. All rights reserved.

This review is directed to define the relationship between nutritional and psycho-functional status in patients with Alzheimer's disease, as assessed by different nutritional indicators: Mini-Nutritional Assessment (MNA), anthropometry, and body composition. Twenty-three studies met the inclusion criteria. Nutritional indicators (MNA) (73.9%), anthropometry, especially weight and body mass index (78.2%), met the criteria while body composition was less studied (17.4%). Although the majority of studies, especially when using MNA, recognized an association between nutritional and psycho-functional status, the underlying physiological mechanisms are not fully understood. There is a need for epidemiologic body composition studies to identify the risk associated with malnutrition.

Objective Specific bioelectrical impedance vector analysis ( sp BIVA) is a recently proposed technique for the analysis of body composition. The aim of this study was to apply sp BIVA to a sample of Italian and Spanish young adults and to define the new bioelectrical references for this Western Mediterranean population. Methods A sample of 440 individuals (220 from Italy, 220 from Spain; 213 men, 227 women) aged 18–30 years was considered. Anthropometric (height, weight, relaxed upper arm, waist, and calf girths) and bioelectrical (resistance, reactance; 50 kHz, 800 μA) measurements were taken. In order to verify the need for new references, specific bioelectrical values were compared to the reference values for U.S. adults and Italian elderly by tolerance ellipses and Student's t test. Results The mean specific bioelectrical values (resistivity, R sp , and reactivity, Xc sp , Ohm·cm) were: R sp (332.7 ± 41.7 Ω·cm), Xc sp (44.4 ± 6.8 Ω·cm), Z sp (335.6 ± 41.9 Ω·cm) and phase (7.6 ± 0.8°) in men; R sp (388.6 ± 60 Ω·cm), Xc sp (43.7 ± 7.5 Ω·cm), Z sp (391.0 ± 60.3 Ω·cm) and phase (6.4 ± 0.7°) in women. Italo‐Spanish bioelectrical vectors were mainly distributed (>90%) in the lower part of the tolerance ellipses for U.S. young adults, due to a shorter impedance ( P < 0.001), indicative of a lower percent fat mass. Compared to Italian elders, they were mainly located in the left side (>90%), due to a higher phase ( P < 0.001), indicative of higher body cell mass. Conclusions These population and age‐related differences indicate the need for new specific tolerance ellipses that can be used as references for assessing body composition in young adults from Western Mediterranean populations. Am. J. Hum. Biol. 27:871–876, 2015. © 2015 Wiley Periodicals, Inc.

The aim of this research was to validate a new procedure (SkanLab) for the three-dimensional estimation of total arm volume. SkanLab is based on a single structured-light Kinect sensor (Microsoft, Redmond, WA, USA) and on Skanect (Occipital, San Francisco, CA, USA) and MeshLab (Visual Computing Lab, Pisa, Italy) software. The volume of twelve plastic cylinders was measured using geometry, as the reference, water displacement and SkanLab techniques (two raters and repetitions). The right total arm volume of thirty adults was measured by water displacement (reference) and SkanLab (two raters and repetitions). The bias and limits of agreement (LOA) between techniques were determined using the Bland–Altman method. Intra- and inter-rater reliability was assessed using the intraclass correlation coefficient (ICC) and the standard error of measurement. The bias of SkanLab in measuring the cylinders volume was −21.9 mL (−5.7%) (LOA: −62.0 to 18.2 mL; −18.1% to 6.7%) and in measuring the volume of arms’ was −9.9 mL (−0.6%) (LOA: −49.6 to 29.8 mL; −2.6% to 1.4%). SkanLab’s intra- and inter-rater reliabilities were very high (ICC >0.99). In conclusion, SkanLab is a fast, safe and low-cost method for assessing total arm volume, with high levels of accuracy and reliability. SkanLab represents a promising tool in clinical applications.

OBJECTIVE:To obtain specific bioelectrical impedance vector reference values for the healthy elderly Italian population, and to study age- and sex-related differences in body composition. DESIGN:The study group consisted of 560 healthy individuals (265 men and 295 women) aged 65 to 100 y, whose anthropometric (height, weight, and calf, arm and waist circumferences) and bioelectrical measurements (resistance [R] and reactance [Xc], at 50 kHz and 800 μA) were recorded. R (Ω) and Xc (Ω) values were standardized for stature (H, m) to obtain the classic bioelectrical values. Specific values (resistivity [Rsp] and reactivity [Xcsp], Ω·cm) were obtained by multiplying R and Xc by a correction factor (A/L) that includes an estimate of the cross-sectional area of the body (A=0.45 arm area+0.10 waist area+0.45 calf area), where L=1.1H. RESULTS:Descriptive statistics were: Rsp (391.8±57.9), Xcsp (42.6±9.9), Zsp (394.2±58.2), phase angle (6.2°±1.2) in men; Rsp (462.0±80.1), Xcsp (47.9±11.2), Zsp (464.6±80.5), phase angle (5.9°±1.0) in women. The Xcsp and phase angle values showed a significant age-related decrease in both sexes, but especially in men, possibly relating to a gradual loss of muscle mass. Women's Rsp and Zsp values tended to drop, attributable to their declining proportion of fat mass. A declining sexual dimorphism was also apparent. CONCLUSIONS:Specific tolerance ellipses can be used for reference purposes for the Italian population when assessing body composition in gerontological practice and for epidemiological purposes.

Analysis of variations of nutritional status in relation to psycho-functional conditions in elderly patients with mild to moderate Alzheimer's disease (AD) by means of bioelectrical impedance vector analysis (BIVA).