Bioimpedance vector analysis and conventional bioimpedance to assess body composition in older adults with dementia

A screening method for mild cognitive impairment in elderly individuals combining bioimpedance and MMSE

We investigated a screening method for mild cognitive impairment (MCI) that combined bioimpedance features and the Korean Mini-Mental State Examination (K-MMSE) score. Data were collected from 539 subjects aged 60 years or older at the Gwangju Alzheimer's & Related Dementias (GARD) Cohort Research Center, A total of 470 participants were used for the analysis, including 318 normal controls and 152 MCI participants. We measured bioimpedance, K-MMSE, and the Seoul Neuropsychological Screening Battery (SNSB-II). We developed a multiple linear regression model to predict MCI by combining bioimpedance variables and K-MMSE total score and compared the model's accuracy with SNSB-II domain scores by the area under the receiver operating characteristic curve (AUROC). We additionally compared the model performance with several machine learning models such as extreme gradient boosting, random forest, support vector machine, and elastic net. To test the model performances, the dataset was divided into a training set (70%) and a test set (30%). The AUROC values of SNSB-II scores were 0.803 in both sexes, 0.840 for males, and 0.770 for females. In the combined model, the AUROC values were 0.790 (0.773) for males (and females), which were significantly higher than those from the model including MMSE scores alone (0.723 for males and 0.622 for females) or bioimpedance variables alone (0.640 for males and 0.615 for females). Furthermore, the accuracies of the combined model were comparable to those of machine learning models. The bioimpedance-MMSE combined model effectively distinguished the MCI participants and suggests a technique for rapid and improved screening of the elderly population at risk of cognitive impairment.

Reduced body cell mass and functions in lower extremities are associated with mild cognitive impairment and Alzheimer's dementia

This study examined the alterations of segmental body composition in individuals with Alzheimer's pathology (AD), including mild cognitive impairment (MCI) and dementia. A multifrequency bioimpedance analysis (BIA) was used to provide segmental water and impedance variables from 365 cognitively normal (CN), 123 MCI due to AD, and 30 AD dementia participants. We compared the BIA variables between the three groups, examined their correlations with neuropsychological screening test scores, and illustrate their 95% confidence RXc graphs. AD dementia participants were older, more depressive, and had worse cognitive abilities than MCI due to AD and CN participants. Although the BIA variables showed weak partial correlations with the cognitive test scores, we found patterns of an increasing water content in lean mass, increasing extra to intracellular water ratio, and decreasing reactance and phase angle in the lower extremities with effect sizes ranging from 0.26 to 0.51 in the groups of MCI and dementia due to AD compared with CN individuals. The RXc graphs upheld the findings with a significant displacement downward and toward the right, dominantly in the lower extremities. Individuals with AD pathology exhibit a reduced body cell mass or cell strength, an abnormal cellular water distribution, and an overhydration status in lean mass, especially in the lower extremities.

Phase Angle as a Prognostic Indicator of Survival in Institutionalized Psychogeriatric Patients

Phase angle (PhA) has been evidenced to be a useful survival indicator and predictor of morbi-mortality in different pathologies, but not in psychogeriatric patients. The aim of this study was to evaluate the clinical utility of PhA as a prognostic indicator of survival in a group of institutionalized psychogeriatric patients. A survival study was conducted on 157 patients (46.5% dementia, 43.9% schizophrenia). Functional impairment stage, frailty, dependence, malnutrition (MNA), comorbidity, polypharmacy, BMI, and waist circumference were registered. Body composition was analyzed using a 50-kHz whole-body BIA; PhA was recorded. The association between mortality and standardized-PhA was evaluated through univariate and multivariate Cox regression models and ROC-curve. The risk of death decreased when Z-PhA, BMI, and MNA were higher. Mortality increases with age, frailty, and dependence. The risk of death was statistically significantly lower (56.5%) in patients with schizophrenia vs. dementia (89%). The Z-PhA cut-off point was -0.81 (Sensitivity:0.75; Specificity:0.60). Mortality risk was multiplied by 1.09 in subjects with a Z-PhA < -0.81, regardless of age, presence of dementia, and BMI. PhA presented a remarkable clinical utility as an independent indicator of survival in psychogeriatric patients. Moreover, it could be useful to detect disease-related malnutrition and to identify subjects eligible for an early clinical approach.

Body Composition and COPD: A New Perspective

The proportion of obese or overweight patients in COPD patients is increasing. Although BMI, WC and other easy to measure indicators have been proven to be related to the risk of COPD, they cannot accurately reflect the distribution and changes of body composition, ignoring the body composition (such as fat distribution, muscle content, water content, etc.), the relationship between it and disease risk may be missed. By analyzing the correlation between different body composition indexes and COPD patients, we can provide new research ideas for the prognosis judgment or intervention of COPD disease.

Segmental Bioimpedance Variables in Association With Mild Cognitive Impairment

Objective

To examine the changes in body composition, water compartment, and bioimpedance in mild cognitive impairment (MCI) individuals.

Methods

We obtained seven whole-body composition variables and seven pairs of segmental body composition, water compartment, and impedance variables for the upper and lower extremities from the segmental multi-frequency bioelectrical impedance analysis (BIA) of 939 elderly participants, including 673 cognitively normal (CN) people and 266 individuals with MCI. Participants’ characteristics, anthropometric information, and the selected BIA variables were described and statistically compared between the CN participants and those with MCI. The correlations between the selected BIA variables and neuropsychological tests such as the Korean version of the Mini-Mental State Examination and Seoul Neuropsychological Screening Battery – Second Edition were also examined before and after controlling for age and sex. Univariate and multivariate logistic regression analyses with estimated odds ratios (ORs) were conducted to investigate the associations between these BIA variables and MCI prevalence for different sexes.

Results

Participants with MCI were slightly older, more depressive, and had significantly poorer cognitive abilities when compared with the CN individuals. The partial correlations between the selected BIA variables and neuropsychological tests upon controlling for age and sex were not greatly significant. However, after accounting for age, sex, and the significant comorbidities, segmental lean mass, water volume, resistance, and reactance in the lower extremities were positively associated with MCI, with ORs [95% confidence interval (CI)] of 1.33 (1.02–1.71), 1.33 (1.03–1.72), 0.76 (0.62–0.92), and 0.79 (0.67–0.93), respectively; with presumably a shift of water from the intracellular area to extracellular space. After stratifying by sex, resistance and reactance in lower extremities remained significant only in the women group.

Conclusion

An increase in segmental water along with segmental lean mass and a decrease in body cell strength due to an abnormal cellular water distribution demonstrated by reductions in resistance and reactance are associated with MCI prevalence, which are more pronounced in the lower extremities and in women. These characteristic changes in BIA variables may be considered as an early sign of cognitive impairment in the elderly population.

Association of Drug Application and Hydration Status in Elderly Patients

Due to multifactorial reasons, such as decreased thirst and decreased total body water, elderly patients are vulnerable to dehydration. Mild cognitive impairment (MCI) or dementia increase the risk of dehydration and, in turn, dehydration decreases cognitive performance. The study aims to identify and assess differences in hydration status, taking into account patients' drug treatment and diseases, using bioelectrical impedance vector analysis (BIVA), thereby revealing unfavorable aspects of prognosis. 447 geriatric patients (241 women, 206 men) including information on medication and bioelectrical impedance analysis (BIA) were investigated, which allowed studying the association between 40 drugs and the hydration status. First, patients were divided into disease groups. Renal disease and diuretic treatment were significantly different in both sexes, whereas cardiovascular patients differed exclusively for females. Next, drug enrichment was examined in either hyperhydrated or dehydrated patients. Simvastatin, candesartan, bisoprolol, amlodipine, olmesartan, furosemide, torasemide, allopurinol, mirtazapine, pantoprazole, cholecalciferol, and resveratrol showed enrichment depending on hydration status. This study demonstrated that patients can be differentiated and stratified by BIVA, taking into account medication and disease associated with hydration status. Although patients diagnosed with MCI and therefore treated with resveratrol, BIVA still showed evaluated dehydration. This is unfavorable in terms of prognosis and requires special attention.

Effects of Resistance Training with Different Pyramid Systems on Bioimpedance Vector Patterns, Body Composition, and Cellular Health in Older Women: A Randomized Controlled Trial

Bioelectrical impedance vector analysis (BIVA) and phase angle (PhA) have been widely used to monitor changes in health-related parameters in older adults, while resistance training (RT) is one of the potential strategies to mitigate the adverse effects of aging. The purpose of this study was to compare the effects of the crescent pyramid RT system with two repetition zones on BIVA patterns and PhA. Fifty-five older women (≥60 years) were randomly assigned into three groups: control (CON, n = 18), narrow pyramid (NPR, n = 19), and wide pyramid (WPR, n = 18). The RT was performed for eight weeks, three times per week, in eight exercises for the whole body with three sets of 12/10/8 (NPR) or 15/10/5 repetitions (WPR). Bioimpedance spectroscopy (50 kHz frequency) was assessed. After the intervention period, both training groups showed significant changes in BIVA patterns compared to CON (p < 0.001); resistance decreased and reactance increased, which resulted in a BIVA-vector displacement over time (p < 0.001). Changes in PhA were greater for WPR (∆% = 10.6; effect size [ES] = 0.64) compared to NPR (∆% = 5.3; ES = 0.41) and CON (∆% = −6.4; ES = −0.40). The results suggest that the crescent pyramid RT system with both repetition zones (WPR and NPR) is effective for inducing improvements in BIVA patterns and PhA in older women, although WPR elicits greater increases in PhA than NPR.

Phase Angle Evaluation of Lung Disease Patients and Its Relationship with Nutritional and Functional Parameters

BACKGROUND

This study aimed to determine the value of phase angle (PhA) in patients with chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH) and its association with nutritional and functional parameters.

METHODS

A cross-sectional study of 77 patients under follow-up at the pulmonary outpatient clinic of a public hospital. Anthropometric measurements and functional assessments of physical and pulmonary capacity were performed, and a regular physical activity questionnaire was administered.

RESULTS

The sample consisted of 38 patients with COPD (mean age, 63.8 ± 9.9 years; 68.4% female) and 39 patients with PH (mean age, 46.6 ± 14.4 years; 79.5% female). There was no difference in anthropometric measurements between patients with COPD and PH. Patients with COPD had mild to moderate limitations of pulmonary function, while patients with PH had only mild limitations (p < 0.01). Although the median distance covered in the 6-minute walk test (6MWT) was different between the COPD and PH groups (p < 0.05), it was considered adequate for these populations. Mean PhA was within the range considered adequate in patients with COPD (6.3°±1°) and PH (6.2°±0.8°) (p > 0.05). In the statistical analyses, although the correlations were weak, adequate PhA correlated with fat free mass index, 6MWT, disease staging, forced vital capacity, and forced expiratory volume in the first second.

CONCLUSION

The anthropometric profile of both patient groups was very similar, and PhA values were within the expected range. Despite weak correlations, PhA is a clinical component to be followed and investigated in patients with lung disease.

Bioimpedance analysis as an indicator of muscle mass and strength in a group of elderly subjects

OBJECTIVE

To assess the association between whole-body and calf impedance vectors and muscle mass and strength in a group of elderly individuals.

MATERIAL AND METHODS

We carried out a cross-sectional observational study on a sample of 113 elderly people. Anthropometric parameters (weight, height and body circumferences) were determined. Body composition was evaluated using conventional bioimpedance analysis (BIA) and vector bioimpedance analysis (BIVA) (whole-body and calf BIVAs), and muscle strength was determined (manual dynamometry). The results were analyzed using the Student t-test or the Mann-Whitney U, and the correlations using the Pearson or Spearman test. To compare BIVA results among the subgroups established, the Mahalanobis distance (dM) was calculated and the Hotelling T² statistic was used. Statistical significance was set to p < 0.05.

RESULTS

Nearly half the sample was overweight. Based on waist circumference, 66.7% of the males and 94.9% of the females showed risk of metabolic complications; calf circumference indicated no risk of disability or skeletal muscle mass depletion. However, BIA and dynamometry detected risk of sarcopenia in more than half the subjects. Whole-body BIVA results agreed with those of the BIA, given that most impedance vectors in both sexes were to the right of major axis of the tolerance ellipses. This shows cell mass depletion. While the whole-body BIVA distinguished the subjects having loss of muscle mass and strength, the specific BIVA (calf) only did so in individuals with muscle mass loss.

CONCLUSIONS

Whole-body BIVA detects loss of muscle mass and strength, while calf BIVA only distinguishes subjects having muscle mass loss. The localized BIVA might be an alternative to conventional BIA or whole-body BIVA to assess body composition in the elderly.

Applicability of the direct parameters of bioelectrical impedance in assessing nutritional status and surgical complications of women with gynecological cancer

BACKGROUND/OBJECTIVES

Bioelectrical impedance vector analysis (BIVA) has been considered a promising technique in monitoring the nutritional and hydration status of patients with different types of diseases. The aim of this study was to assess the nutritional status provided by direct parameters of bioelectrical impedance analysis (BIA), BIVA and phase angle (PA), in patients with cervical and endometrial cancer undergoing surgical treatment, associating to other parameters of nutritional status and surgical outcomes.

SUBJECTS/METHODS

In a prospective cohort, 208 women eligible to surgical treatment, admitted from January to December 2015, were enrolled. Patients were assessed according to the body mass index (BMI), Patient Generated Subjective Global Assessment (PG-SGA) and BIA. The PA was categorized as below and above percentiles 25 and 50 of studied population.

RESULTS

According to BMI and PG-SGA, most of them were classified as obese (69%) and well nourished (84%), respectively. PA was significantly lower in patients with endometrial cancer, PG-SGA B or C, and in those who remained longer in hospital. PA below 25th percentile was also associated with surgical complications. Comparison of BIVA detachment of our population with a reference population showed significant impedance vector displacement, characterized by decreased reactance value and increased resistance value in our group of patients.

CONCLUSIONS

PA was associated with other parameters of nutritional status and surgical outcomes. BIVA was associated with nutritional status and length of hospital, but did not present significant result for surgical complications.

Nutritional status and body composition by bioelectrical impedance vector analysis: A cross sectional study in mild cognitive impairment and Alzheimer's disease

AIMS

Analysis of nutritional status and body composition in Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI).

METHODS

A cross-sectional study was performed in a University-Hospital setting, recruiting 59 patients with AD, 34 subjects with MCI and 58 elderly healthy controls (HC). Nutritional status was assessed by anthropometric parameters (body mass index; calf, upper arm and waist circumferences), Mini Nutritional Assessment (MNA) and body composition by bioelectrical impedance vector analysis (BIVA). Variables were analyzed by analysis of variance and subjects were grouped by cognitive status and gender.

RESULTS

Sociodemographic variables did not differ among the three groups (AD, MCI and HC), except for females' age, which was therefore used as covariate in a general linear multivariate model. MNA score was significantly lower in AD patients than in HC; MCI subjects achieved intermediate scores. AD patients (both sexes) had significantly (p<0.05) higher height-normalized impedance values and lower phase angles (body cell mass) compared with HC; a higher ratio of impedance to height was found in men with MCI with respect to HC. With BIVA method, MCI subjects showed a significant displacement on the RXc graph on the right side indicating lower soft tissues (Hotelling's T2 test: men = 10.6; women = 7.9;p < 0,05) just like AD patients (Hotelling's T2 test: men = 18.2; women = 16.9; p<0,001).

CONCLUSION

Bioelectrical parameters significantly differ from MCI and AD to HC; MCI showed an intermediate pattern between AD and HC. Longitudinal studies are required to investigate if BIVA could reflect early AD-changes in body composition in subjects with MCI.

Different displacement of bioimpedance vector due to Ag/AgCl electrode effect

BACKGROUND/OBJECTIVES

Bioelectrical impedance vector analysis (BIVA) is increasingly used in clinical research to assess soft tissue hydration. It is known that physical characteristics of electrodes, such as low intrinsic impedance, low electrode/skin contact impedance and type of gel, affect the reliability of noninvasive bioimpedance assessments. The aim of this study was to determine the effect of intrinsic impedance of electrode on the bioimpedance vector displacement in RXc graph.

SUBJECTS/METHODS

The intrinsic impedance is measured in nine pregelled disposable Ag/AgCl electrodes usually used for bioimpedance measures. The BIVA method is performed on 35 healthy volunteers using a 50 kHz phase-sensitive bioimpedance analyzer (BIA 101 Anniversary) with the lowest intrinsic impedance electrode and highest. The individual bioimpedance vector is plotted on the bivariate normal interval of reference population. The differences in the mean bioimpedance vectors obtained with each electrode are plotted, with their 95% confidence ellipses, on the dRXc graph. The paired one-sample Hotelling's T²-test is used to compare the differences of the mean bioimpedance vectors.

RESULTS

We found large variability in intrinsic resistance (11-665 Ω) and reactance (0.25-2.5 Ω) values of the electrodes analyzed and significant displacement (P<0.05) of bioimpedance vector positions in healthy adults according to the paired one-sample Hotelling's T²-test.

CONCLUSIONS

A robust study of all physical characteristics of commercial Ag/AgCl electrodes is necessary to reach consensus on pregelled Ag/AgCl electrodes valid for bioimpedance measurement. This information will enable BIVA users to avoid systemic errors when performing BIVA assessments, specifically when these measurements are used for clinical interpretations.

Association of Grip Strength, Upper Arm Circumference, and Waist Circumference with Dementia in Older Adults of the WiSE Study: A Cross-Sectional Analysis

OBJECTIVE

We examined the associations of handgrip strength, upper arm circumference, and waist circumference with dementia among Singapore older adults.

DESIGN

Cross-sectional epidemiological study.

SETTING

Residential homes, day care centres, nursing homes and institutions.

PARTICIPANTS

2,565 men and women aged 60 years and above who participated in the Well-being of the Singapore Elderly (WiSE) study in 2013.

MEASUREMENTS

Socio-demographic correlates, dietary habits, health behaviours, grip strength, upper arm circumference, and waist circumference were collected. Grip strength was measured using a hand dynamometer with the dominant hand. Upper arm circumference was measured using a measuring tape around the thickest part of the upper arm while waist circumference measured in centimetres was measured at the narrowest part of the body between the chest and hips for women, and measured at the level of the umbilicus for men. Dementia was diagnosed using the 10/66 dementia diagnostic criteria.

RESULTS

Mean grip strength was 13.07 kg (SE=0.60) for people with dementia and 21.98 kg (SE=0.26) for people without dementia. After adjusting for all factors, grip strength remained significantly associated with dementia (p <0.0001). Upper arm circumference was associated with dementia (p <0.0001) but this association was only significant in the univariate analysis. Waist circumference was not significantly associated with dementia.

CONCLUSIONS

Lower grip strength was independently associated with dementia in the older adult population in Singapore. Further research needs to be done to ascertain whether this association exists for specific types of dementia and look into the relationship of other anthropometric measurements with dementia in Singapore.