Nutritional and hydration status in elderly subjects: Clinical rating versus bioimpedance analysis

The relationship between sarcopenia, sarcopenia related quality of life and ultrasound findings of the rectus femoris muscle in older outpatients

PURPOSE

Skeletal muscle ultrasonography stands out as a promising method for detecting sarcopenia. We aimed to evaluate the relationship between sarcopenia, sarcopenia related quality of life and US findings of the Rectus Femoris muscle.

METHODS

A total of 300 older individuals were included in this cross-sectional study. Sarcopenia was diagnosed according to the European Working Group on Sarcopenia in Older People 2 criteria. Rectus F muscle thickness, cross-sectional area, fascicle length, pennation angle, stiffness and echogenicity were measured by an experienced radiologist using a B-mode US device. Quality of life was determined with the Sarcopenia- Quality of life questionnaire. Correlation analysis, receiver operating analysis, sensitivity and specificity analysis were performed.

RESULTS

The median age of participants was 72. 191 (63.9%) and 109 (36.1%) of the participants were male and female, respectively. The prevalence of sarcopenia was 15.6%. Fascicle length, cross-sectional area and thickness showed the highest sensitivity (81%) and specificity (87%) for men. Fascicle length and pennation angle showed the highest sensitivity (87%) and specificity (66%) for women. Rectus Femoris ultrasound parameters differed across SarQoL quartiles, and higher Sarcopenia- Quality of life scores were associated with better ultrasound parameters. All ultrasound parameters had positive correlations with Sarcopenia- Quality of life.

CONCLUSION

Different Rectus Femoris ultrasound parameters are useful for detecting sarcopenia according to gender. A combination of these parameters can increase diagnosis accuracy. Ultrasound parameters are associated with sarcopenia related quality of life.

Hydration Status Assessment in Older Patients

BACKGROUND

Hydration disturbances are common in old age: the reported prevalence of dehydration in elderly patients ranges from 19% to 89%, depending on the definition and the population in question. However, the clinical assessment of patients' hydration status is difficult. In this review, we discuss the diagnostic value of currently used methods that may or may not be suitable for assessing older patients' hydration status.

METHODS

We conducted a selective literature search for relevant studies concerning patients aged 65 and above. Of the 355 articles retrieved by the initial search, a multistep selection process yielded 30 that were suitable for inclusion in this review.

RESULTS

107 different methods for the diagnostic assessment of dehydration in older persons were evaluated on the basis of the reviewed publications. High diagnostic value, especially for the determination of hyperosmolar dehydration, was found for serum osmolality, serum sodium concentration, inferior vena cava ultrasonography, a history (from the patient or another informant) of not drinking between meals, and axillary dryness. On the other hand, a variety of clinical signs such as a positive skin turgor test, sunken eyes, dry mouth, tachycardia, orthostatic dysregulation, and dark urine were found to be of inadequate diagnostic value.

CONCLUSION

Only five of the 107 methods considered appear to be suitable for determining that a patient is dehydrated. Thus, the available scientific evidence indicates that all clinicians should critically reconsider their own techniques for assessing hydration status in elderly patients. To optimize the clinical assessment of patients' hydration status, there seems to be a need for the rejection of unsuitable methods in favor of either newly developed criteria or of a combination of the best criteria already in use.

Nutritional Predictors of Mortality after 10 Years of Follow-Up in Patients with Chronic Kidney Disease at a Multidisciplinary Unit of Advanced Chronic Kidney Disease

Nutritional monitoring in advanced chronic kidney disease (ACKD) units provides personalized care and improves clinical outcomes. This study aimed to identify mortality risk factors in chronic kidney disease (CKD) patients on nutritional follow-up in the multidisciplinary ACKD unit. A retrospective cross-sectional observational study was conducted in 307 CKD patients’ stage 3b, 4−5 followed-up for 10 years. Clinical and nutritional monitoring was performed by malnutrition-inflammation score (MIS), biochemical parameters (s-albumin, s-prealbumin, and serum C-reactive protein (s-CRP), body composition measured by bioelectrical impedance analysis (BIA), anthropometry, and handgrip strength measurements. The sample was classified into non-survivors, survivors, and censored groups. Of the 307 CKD patients, the prevalence of protein-energy wasting (PEW) was 27.0% using MIS > 5 points, s-CRP > 1 mg/dL was 19.20%, and 27.18% died. Survivors had higher significant body cell mass (BCM%) and phase angle (PA). Survival analyses significantly showed that age > 72 years, MIS > 5 points, s-prealbumin ≤ 30 mg/dL, PA ≤ 4°, and gender-adjusted handgrip strength (HGS) were associated with an increased risk of mortality. By univariate and multivariate Cox regression, time on follow-up (HR:0.97), s-prealbumin (HR:0.94), and right handgrip strength (HR:0.96) were independent predictors of mortality risk at 10 years of follow-up in the ACKD unit. Nutritional monitoring in patients with stage 3b, 4−5 CKD helps to identify and treat nutritional risk early and improve adverse mortality prognosis.

Nutritional Status, Body Composition, and Inflammation Profile in Older Patients with Advanced Chronic Kidney Disease Stage 4-5: A Case-Control Study

Nutritional status is a predictor of adverse outcomes and mortality in patients with advanced chronic kidney disease (ACKD). This study aimed to explore and evaluate risk factors related to nutritional status, body composition, and inflammatory profile in patients with ACKD compared with age- and sex-matched controls in a Mediterranean cohort of the Spanish population. Out of 200 volunteers recruited, 150 participants (64%) were included, and a case-control study was conducted on 75 ACKD patients (stages 4−5), matched individually with controls at a ratio of 1:1 for both age and sex. At enrolment, demographic, clinical, anthropometric, and laboratory parameters were measured. Bioimpedance analysis (BIA) was used to assess both body composition and hydration status. ACKD patients had lower body cell mass (BCM%), muscle mass (MM%) phase angle (PA), s-albumin, and higher C-reactive protein (s-CRP) than controls (at least, p < 0.05). PA correlated positively with BCM% (cases: r = 0.84; controls: r = 0.53, p < 0.001), MM% (cases: r = 0.65; controls: r = 0.31, p < 0.001), and inversely with s-CRP (cases: r = −0.30, p < 0.001; controls: r = −0.31, p = 0.40). By univariate and multivariate conditional regression analysis, total body water (OR: 1.186), extracellular mass (OR: 1.346), s-CRP (OR: 2.050), MM% (OR: 0.847), PA (OR: 0.058), and s-albumin (OR: 0.475) were significantly associated among cases to controls. Nutritional parameters and BIA-derived measures appear as prognostic entities in patients with stage 4−5 ACKD compared to matched controls in this Mediterranean cohort.

Nutrition Assessment and Interventions for the Prevention and Treatment of Malnutrition in Older Adults: An Evidence Analysis Center Scoping Review

Older adults living in the community or long-term residence such as a nursing home are at increased risk for malnutrition due to factors such as depression and isolation. The purpose of this scoping review is to identify the best available research that evaluates the validity and reliability of nutrition assessment tools, and the effectiveness of nutrition interventions to prevent or treat malnutrition among older adults. A literature search was conducted in Medline, Embase, CINAHL, and Cochrane Central databases to identify clinical trials, published in the English language, evaluating assessment and intervention methods aimed to treat or prevent malnutrition among older adults living in the community or their long-term residence such as nursing homes. Articles were screened by 2 reviewers, then data were extracted and narratively synthesized. The literature search retrieved 20,937 articles and 197 articles were included in narrative synthesis. A total of 73 assessment articles were identified, 36 of which were validity and reliability trials. A total of 122 intervention articles were identified, the majority of which were randomized controlled trials. A few of the most commonly evaluated interventions were oral nutrition supplements, medical nutrition therapy, fortification and enrichment, and nutrition education. Several systematic reviews were identified, however, that did not meet the criteria of this review. There is a need to conduct systematic reviews for nutrition assessment and intervention trials to guide development of evidence-based nutrition practice recommendations for older adults living in the community or their long-term residence.

Sarcopenia measured with paraspinous muscle using computed tomography for predicting prognosis in elderly pneumonia patients

Background:

In the elderly, diagnostic findings of pneumonia are often atypical. Computed tomography was recommended for the diagnosis of pneumonia in elderly patients. Recently, the usage of computed tomography as a screening tool for pneumonia in emergency departments has increased. Sarcopenia is defined as the loss of skeletal muscle mass and strength with aging. In this study, the association between sarcopenia and prognosis measured through computed tomography was evaluated compared to CURB-65.

Methods:

This study was conducted on patients diagnosed with pneumonia through computed tomography from 1 March 2018 to 31 March 2020. The paraspinous muscle size and attenuation were measured at a level located at the T12 pedicle level on axial computed tomography images. Paraspinous muscle size was presented as paraspinous muscle index. Differences in the prognostic performance among the paraspinous muscle size and attenuation, and CURB-65 were evaluated by the area under the receiver operating characteristic curve.

Results:

A total of 509 patients were included and 132 patients (25.9%) were admitted to the ICU, and 58 patients (11.4%) died in hospital. Paraspinous muscle index was the significant factor for predicting in-hospital mortality and ICU admission. The area under the receiver operating characteristic value of paraspinous muscle index for prediction of mortality was 0.738 and CURB-65 was 0.707. The area under the receiver operating characteristic of paraspinous muscle index and CURB-65 for predicting ICU admission were 0.766 and 0.704, respectively.

Conclusion:

As a method of measuring sarcopenia, paraspinous muscle index was superior to CURB-65 in elderly pneumonia patients. The use of computed tomography in predicting prognosis for elderly pneumonia patients will ease the economic burden.

Fluid Intake Monitoring Systems for the Elderly: A Review of the Literature

Fluid intake monitoring is an essential component in preventing dehydration and overhydration, especially for the senior population. Numerous critical health problems are associated with poor or excessive drinking such as swelling of the brain and heart failure. Real-time systems for monitoring fluid intake will not only measure the exact amount consumed by the users, but could also motivate people to maintain a healthy lifestyle by providing feedback to encourage them to hydrate regularly throughout the day. This paper reviews the most recent solutions to automatic fluid intake monitoring both commercially and in the literature. The available technologies are divided into four categories: wearables, surfaces with embedded sensors, vision- and environmental-based solutions, and smart containers. A detailed performance evaluation was carried out considering detection accuracy, usability and availability. It was observed that the most promising results came from studies that used data fusion from multiple technologies, compared to using an individual technology. The areas that need further research and the challenges for each category are discussed in detail.

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.

The use of bioelectrical impedance vector analysis for a nutritional evaluation of older adults in the community

INTRODUCTION

The body composition of an older adult person is characterized by an increase in body fat, as well as by a reduction in both muscle mass and total body water. The bioelectrical impedance vector analysis (BIVA) overcomes the limits imposed by bioelectrical impedance, since it only requires the resistance (R) and reactance (Xc) values, standardized by the individual's height, which makes the method more individualized and accurate. The aim of this study was to evaluate the body composition using the BIVA of the community-living older adults, with regard to sex and body mass index (BMI) classification, and compare the results with the reference population.

METHODS

Cross-sectional study with the community-living older adults of both sexes. Bioimpedance was carried out and the R and Xc data analyzed, based on height, and plotted on RXc graphs.

RESULTS

One hundred and forty-four older adults (n = 33 men; n = 111 women; mean age of 80.2 ± 9.2 years) participated in the study. Low weight (<23 kg/m²) was the most prevalent in BMI classification. The older adult women presented a higher average BMI, body fat percentage and R/Height values, while the older adult men presented a higher average for fat-free mass and the phase angle (p < 0.05). The older adult, regardless of their BMI, located in the right quadrant, indicated cachexia; those with low weight were dehydrated, and those with overweight (BMI ≥ 28 kg/m²) presented hyperhydration.

CONCLUSION

The majority of the older adults with normal weight or overweight has impedance vectors indicating loss of muscle mass and water imbalance (dehydration or hyperhydration).

Is mini-nutritional assessment a reliable tool in detecting malnutrition in elderly with body weight excess?

PURPOSE

The rising proportion of elderly population in high-income societies has resulted in increasing number of subjects with chronic disabling diseases and nutritional deficiency. Elderly's nutritional status is usually assessed through the mini-nutritional assessment (MNA^®). However, its effectiveness may be influenced by weight excess or obesity. We tested the performance of MNA^® questionnaire in subjects aged ≥ 65 years from Northern Sardinia, Italy, according to overweight/obesity, and we tried to identify the factors associated with malnutrition.

METHODS

A modified version of MNA^® (mMNA) test, not including BMI, was compared with the conventional MNA^® (cMNA) test, and the overall test performance was assessed by calculating sensitivity, specificity and accuracy. In addition, indexes of cognitive health, disability, comorbidity and polypharmacy were compared between patients with concordant and discordant MNA tests.

RESULTS

cMNA^® sensitivity, specificity and accuracy were 67%, 99% and 84% compared with the mMNA test, due to malnourished patients misclassified as normal because of excess weight. Predictors of malnutrition were: depression (p < 0.0001), disability (p < 0.0001) and polypharmacy (p < 0.0001). Interestingly, the average scores of the "global", "subjective" and "dietary" components of the cMNA^®, were significantly lower compared with the corresponding scores of the mMNA.

CONCLUSIONS

Excess of weight, a condition progressively rising in the elderly population, may reduce the performance of cMNA^® test in detecting malnutrition.

LEVEL OF EVIDENCE

Level III, case‒control analytic study.

Personalized hydratation status in endurance and ultra-endurance: A review

This review aims to investigate the physiological mechanisms that underlie the hydro-electrolyte balance of the human body and the most appropriate hydration modalities for individuals involved in physical and sports activities, with a focus on ultra-endurance events. The role of effective hydration in achieving optimal sports performance is also investigated. An adequate pre-hydration is essential to perform physical and sporting activity in a condition of eu-hydration and to mantain physiologic levels of plasma electrolyte. To achieve these goals, athletes need to consume adequate drinks together with consuming meals and fluids, in order to provide an adequate absorption of the ingested fluids and the expulsion of those in excess through diuresis. Therefore, there are important differences between individuals in terms of sweating rates, the amount of electrolytes loss and the specific request of the discipline practiced and the sporting event to pursue.

The Role of Imaging Biomarkers in the Assessment of Sarcopenia

BACKGROUND

The diagnosis of sarcopenia through clinical assessment has some limitations. The literature advises studies that include objective markers along with clinical assessment in order to improve the sensitivity and specificity of current diagnostic criteria. The decrease of muscle quality precedes the loss of quantity, so we studied the role magnetic resonance imaging biomarkers as indicators of the quantity and quality of muscle in sarcopenia patients.

METHODS

a cross-sectional analysis was performed to analyze what MR-derived imaging parameters correlate better with sarcopenia diagnostic criteria in women of 70 years of age and over (independent walking and community-dwelling women who were sarcopenic in accordance with EWGSOP criteria with muscle mass adjusted to Spanish population were chosen).

RESULTS

The study included 26 women; 81 ± 8 years old. A strong correlation was obtained between cineanthropometric variables (BMI; thigh perimeter and fat mass) and imaging biomarkers (muscle/fat ratio, fatty infiltration, muscle T2*, water diffusion coefficient, and proton density fat fraction) with coefficients around 0.7 (absolute value).

CONCLUSIONS

Knowing the correlation of clinical parameters and imaging-derived muscle quality indicators can help to identify older women at risk of developing sarcopenia at an early stage. This may allow taking preventive actions to decrease disability, morbidity, and mortality in sarcopenia patients.

Anthropometry, bioimpedance and densitometry: Comparative methods for lean mass body analysis in elderly outpatients from a tertiary hospital

OBJECTIVES

To evaluate lean mass index (LMI) measured by bioimpedance (BIA) and anthropometry compared to densitometry (DXA) in elderly outpatients from a tertiary care hospital.

METHODS

Participants were over 60-year-old men, presenting no dementia or disability, from a tertiary geriatric ambulatory. LMI obtained by BIA, anthropometry and DXA were submitted to Baumgartner, Janssen and Delmonico calculations respectively. Sarcopenia was calculated as LMI by DXA and handgrip strength. Data were analyzed by T student's test, ANOVA for repeated measures and pos hoc Bonferroni test, Pearson's correlation test, regression equation and Bland Altman analysis, ROC curve and contingency table 2 × 2 for sensitivity, specificity and predictive values.

RESULTS

A total of 92 participants completed the study. Most of them were married, aged 72.9 ± 6.6, lived a sedentary lifestyle, presented multiple morbidities, and in use of polypharmacy. Appendicular lean mass was lower in sarcopenic participants when compared to that in nonsarcopenic ones (20.2 kg/m² and 23 kg/m² respectively, p < 0.0001). BIA sensitivity, specificity and correlation to DXA were 37%, 98% and r = 0.81 (p < 0.001), and for anthropometry 67%, 92% and r = 0.77 (p < 0.0001) respectively. Bland Altman's analysis showed congruence between methods and DXA (anthropometry: bias = -0,05 ± 0,66, limits of agreement (LoA) = -1.37 and 1.26; BIA: bias = 2,2; LoA = 0,7 and 3,7).

CONCLUSION

Aging and multiple chronic and degenerative morbidities affect LM in vulnerable elderly patients. Both anthropometry and BIA, are accurate to measure LMI independently in this population but Anthropometry presented better agreement to DXA than Bioimpedance and has the advantage of lower price, easier application and cheaper equipment to be applied.

Somatotype and Bioimpedance Vector Analysis: A New Target Zone for Male Athletes

Background: Bioelectrical impedance vector analysis (BIVA) is a body composition assessment method based on the interpretation of the raw bioimpedance parameters. While it was initially proposed in clinical settings, its use in the sports field has grown considerably. The aim of this study was: (i) to explore the role of somatotype on BIVA patterns and (ii) to propose a new target zone to improve BIVA analysis in ball games athletes. Methods: One hundred and sixty-four male volleyball, soccer, and rugby players (age 26.2 ± 4.4 yrs; body mass index (BMI) 25.4 ± 2.4 kg/m2) were included in this study. Somatotype and BIVA were measured from anthropometric and bioelectrical data, respectively. Results: Forty-six athletes were classified with an endomorphic mesomorphic somatotype, 26 showed a balanced mesomorphy, 55 were ectomorphic mesomorph, 10 resulted as mesomorph ectomorphs, 13 with a mesomorphic ectomorph somatotype, and in 14 athletes a balanced ectomorphy was assessed. The results of the Hotelling’s T2 test showed significant differences in BIVA patterns for the endomorphic mesomorph group (p < 0.001) in comparison with all the other groups, while mesomorphic balanced athletes presented a more inclined vector compared to the athletes with a balanced ectomorphy (p < 0.003). In addition, the endomorphic mesomorph group showed a greater BMI (p < 0.001) with respect to the athletes grouped in the other somatotype categories. Discriminant analysis revealed two significant functions (p < 0.001). The first discriminant function primarily represented differences based on the bioelectrical standardized resistance parameter (R/H) measure, while the second function reflected differences based on the bioelectrical standardized reactance parameter (Xc/H). Conclusions: Athletes presenting a higher endomorphic component have a lower vector, whereas those with a larger mesomorphic component display higher vector inclinations on the R-Xc graph. We propose a new target zone to improve the interpretation of BIVA analysis in athletes engaged in team sports.

The Association of Hydration Status with Physical Signs, Symptoms and Survival in Advanced Cancer-The Use of Bioelectrical Impedance Vector Analysis (BIVA) Technology to Evaluate Fluid Volume in Palliative Care: An Observational Study

BACKGROUND

Hydration in advanced cancer is a controversial area; however, current hydration assessments methods are poorly developed. Bioelectrical impedance vector analysis (BIVA) is an accurate hydration tool; however its application in advanced cancer has not been explored. This study used BIVA to evaluate hydration status in advanced cancer to examine the association of fluid status with symptoms, physical signs, renal biochemical measures and survival.

MATERIALS AND METHODS

An observational study of 90 adults with advanced cancer receiving care in a UK specialist palliative care inpatient unit was conducted. Hydration status was assessed using BIVA in addition to assessments of symptoms, physical signs, performance status, renal biochemical measures, oral fluid intake and medications. The association of clinical variables with hydration was evaluated using regression analysis. A survival analysis was conducted to examine the influence of hydration status and renal failure.

RESULTS

The hydration status of participants was normal in 43 (47.8%), 'more hydrated' in 37 (41.1%) and 'less hydrated' in 10 (11.1%). Lower hydration was associated with increased symptom intensity (Beta = -0.29, p = 0.04) and higher scores for physical signs associated with dehydration (Beta = 10.94, p = 0.02). Higher hydration was associated with oedema (Beta = 2.55, p<0.001). Median survival was statistically significantly shorter in 'less hydrated' patients (44 vs. 68 days; p = 0.049) and in pre-renal failure (44 vs. 100 days; p = 0.003).

CONCLUSIONS

In advanced cancer, hydration status was associated with clinical signs and symptoms. Hydration status and pre-renal failure were independent predictors of survival. Further studies can establish the utility of BIVA as a standardised hydration assessment tool and explore its potential research application, in order to inform the clinical management of fluid balance in patients with advanced cancer.

Acoustical Method of Whole-Body Hydration Status Monitoring

An acoustical handheld hydration monitor (HM) for assessing the water balance of the human body was developed. Dehydration is a critical public health problem. Many elderly over age of 65 are particularly vulnerable as are infants and young children. Given that dehydration is both preventable and reversible, the need for an easy-to-perform method for the detection of water imbalance is of the utmost clinical importance. The HM is based on an experimental fact that ultrasound velocity in muscle is a linear function of water content and can be referenced to the hydration status of the body. Studies on the validity of HM for the assessment of whole-body hydration status were conducted in the Appalachian State University, USA, on healthy young adults and on elderly subjects residing at an assisted living facility. The HM was able to track changes in total body water during periods of acute dehydration and rehydration in athletes and day-to-day and diurnal variability of hydration in elderly. Results of human studies indicate that HM has a potential to become an efficient tool for detecting abnormal changes in the body hydration status.

Risk of malnutrition in a sample of nonagenarians: Specific versus classic bioelectrical impedance vector analysis

OBJECTIVES

The aims were to describe the body composition and the risk of malnutrition in a sample of nonagenarians and to identify what bioelectrical impedance vector analysis (BIVA) approach (classic or specific) is more correlated with either the risk of malnutrition or various anthropometric parameters.

METHODS

In the Mugello area (Italy), a representative sample of nonagenarians was enrolled in a survey aimed at investigating various health issues, including those related to nutritional status. The nutritional status was investigated using body mass index (BMI), mid-upper arm circumference (MUAC), calf circumference (CC), Malnutrition Universal Screening Tool (MUST), and BIVA. Two different approaches were used for the BIVA data analysis: the classic method and the specific method.

RESULTS

All measurements were obtained from 321 nonagenarians (65.7% of the enrolled sample; 92 men and 229 women); 74.8% of the subjects were at low risk of malnutrition according to MUST, 62.5% exhibited CC values higher than 31 cm, and 86.8% exhibited MUAC values higher than 22 cm. The bioelectrical parameters varied with nutritional status, independent of the nutritional indicator used; the parameters also varied based on sex and BIVA approach. The bioelectrical parameters obtained by the specific BIVA approach were more strongly correlated with MUST score, MUAC, and CC values compared with the parameters calculated using the classic approach.

CONCLUSIONS

Our study produced findings relevant to particular aspects of population aging. Above all, the specific BIVA was more effective at assessing nutritional status based on both anthropometric parameters and the risk of malnutrition.

Are segmental MF-BIA scales able to reliably assess fat mass and lean soft tissue in an elderly Swedish population?

BACKGROUND AND AIMS

The assessment of body composition is an important measure to monitor the process of healthy aging and detect early signs of disease. Dual X-ray absorptiometry (DXA) is considered a valid technique for the assessment of body composition but is confined to the clinical environment. Multi-frequency bio-electrical impedance analysis (MF-BIA) might be a versatile alternative to DXA. We aimed to assess whether a segmental MF-BIA scale can be an accurate and reliable tool for the monitoring of body composition in the elderly and whether the presence of metallic prostheses can influence the agreement between the two techniques.

SUBJECTS AND METHODS

Weight and height were measured in 92 healthy subjects (53 women) aged 80-81 years from the H70 Gerontological and Geriatric study in Gothenburg. Total and segmental fat mass (FM) and lean soft tissue (LST) were estimated by DXA (Lunar Prodigy, Scanex, Sweden) and segmental MF-BIA (MC-180MA, Tanita, Japan). Bland-Altman analyses were performed to assess the agreement between the two techniques. The prediction of DXA-FM by MF-BIA was compared to that of the body mass index (BMI).

RESULTS AND DISCUSSION

MF-BIA showed a significant underestimation of FM and an overestimation of LST that was larger in men than in women. Smaller but significant deviations were found for appendicular LST and SMM. MF-BIA was not superior to BMI at predicting DXA-FM. The lack of agreement between MF-BIA and DXA was not due to the presence of metal prostheses or diagnoses such as hypertension and edema. The prediction equations applied by the device used in this study should be adapted to the elderly population and details about the reference population(s) should be disclosed.

Clinical symptoms, signs and tests for identification of impending and current water-loss dehydration in older people

BACKGROUND

There is evidence that water-loss dehydration is common in older people and associated with many causes of morbidity and mortality. However, it is unclear what clinical symptoms, signs and tests may be used to identify early dehydration in older people, so that support can be mobilised to improve hydration before health and well-being are compromised.

OBJECTIVES

To determine the diagnostic accuracy of state (one time), minimally invasive clinical symptoms, signs and tests to be used as screening tests for detecting water-loss dehydration in older people by systematically reviewing studies that have measured a reference standard and at least one index test in people aged 65 years and over. Water-loss dehydration was defined primarily as including everyone with either impending or current water-loss dehydration (including all those with serum osmolality ≥ 295 mOsm/kg as being dehydrated).

SEARCH METHODS

Structured search strategies were developed for MEDLINE (OvidSP), EMBASE (OvidSP), CINAHL, LILACS, DARE and HTA databases (The Cochrane Library), and the International Clinical Trials Registry Platform (ICTRP). Reference lists of included studies and identified relevant reviews were checked. Authors of included studies were contacted for details of further studies.

SELECTION CRITERIA

Titles and abstracts were scanned and all potentially relevant studies obtained in full text. Inclusion of full text studies was assessed independently in duplicate, and disagreements resolved by a third author. We wrote to authors of all studies that appeared to have collected data on at least one reference standard and at least one index test, and in at least 10 people aged ≥ 65 years, even where no comparative analysis has been published, requesting original dataset so we could create 2 x 2 tables.

DATA COLLECTION AND ANALYSIS

Diagnostic accuracy of each test was assessed against the best available reference standard for water-loss dehydration (serum or plasma osmolality cut-off ≥ 295 mOsm/kg, serum osmolarity or weight change) within each study. For each index test study data were presented in forest plots of sensitivity and specificity. The primary target condition was water-loss dehydration (including either impending or current water-loss dehydration). Secondary target conditions were intended as current (> 300 mOsm/kg) and impending (295 to 300 mOsm/kg) water-loss dehydration, but restricted to current dehydration in the final review.We conducted bivariate random-effects meta-analyses (Stata/IC, StataCorp) for index tests where there were at least four studies and study datasets could be pooled to construct sensitivity and specificity summary estimates. We assigned the same approach for index tests with continuous outcome data for each of three pre-specified cut-off points investigated.Pre-set minimum sensitivity of a useful test was 60%, minimum specificity 75%. As pre-specifying three cut-offs for each continuous test may have led to missing a cut-off with useful sensitivity and specificity, we conducted post-hoc exploratory analyses to create receiver operating characteristic (ROC) curves where there appeared some possibility of a useful cut-off missed by the original three. These analyses enabled assessment of which tests may be worth assessing in further research. A further exploratory analysis assessed the value of combining the best two index tests where each had some individual predictive ability.

MAIN RESULTS

There were few published studies of the diagnostic accuracy of state (one time), minimally invasive clinical symptoms, signs or tests to be used as screening tests for detecting water-loss dehydration in older people. Therefore, to complete this review we sought, analysed and included raw datasets that included a reference standard and an index test in people aged ≥ 65 years.We included three studies with published diagnostic accuracy data and a further 21 studies provided datasets that we analysed. We assessed 67 tests (at three cut-offs for each continuous outcome) for diagnostic accuracy of water-loss dehydration (primary target condition) and of current dehydration (secondary target condition).Only three tests showed any ability to diagnose water-loss dehydration (including both impending and current water-loss dehydration) as stand-alone tests: expressing fatigue (sensitivity 0.71 (95% CI 0.29 to 0.96), specificity 0.75 (95% CI 0.63 to 0.85), in one study with 71 participants, but two additional studies had lower sensitivity); missing drinks between meals (sensitivity 1.00 (95% CI 0.59 to 1.00), specificity 0.77 (95% CI 0.64 to 0.86), in one study with 71 participants) and BIA resistance at 50 kHz (sensitivities 1.00 (95% CI 0.48 to 1.00) and 0.71 (95% CI 0.44 to 0.90) and specificities of 1.00 (95% CI 0.69 to 1.00) and 0.80 (95% CI 0.28 to 0.99) in 15 and 22 people respectively for two studies, but with sensitivities of 0.54 (95% CI 0.25 to 0.81) and 0.69 (95% CI 0.56 to 0.79) and specificities of 0.50 (95% CI 0.16 to 0.84) and 0.19 (95% CI 0.17 to 0.21) in 21 and 1947 people respectively in two other studies). In post-hoc ROC plots drinks intake, urine osmolality and axillial moisture also showed limited diagnostic accuracy. No test was consistently useful in more than one study.Combining two tests so that an individual both missed some drinks between meals and expressed fatigue was sensitive at 0.71 (95% CI 0.29 to 0.96) and specific at 0.92 (95% CI 0.83 to 0.97).There was sufficient evidence to suggest that several stand-alone tests often used to assess dehydration in older people (including fluid intake, urine specific gravity, urine colour, urine volume, heart rate, dry mouth, feeling thirsty and BIA assessment of intracellular water or extracellular water) are not useful, and should not be relied on individually as ways of assessing presence or absence of dehydration in older people.No tests were found consistently useful in diagnosing current water-loss dehydration.

AUTHORS' CONCLUSIONS

There is limited evidence of the diagnostic utility of any individual clinical symptom, sign or test or combination of tests to indicate water-loss dehydration in older people. Individual tests should not be used in this population to indicate dehydration; they miss a high proportion of people with dehydration, and wrongly label those who are adequately hydrated.Promising tests identified by this review need to be further assessed, as do new methods in development. Combining several tests may improve diagnostic accuracy.

Validation analysis of a geriatric dehydration screening tool in community-dwelling and institutionalized elderly people

Dehydration is common among elderly people. The aim of this study was to perform validation analysis of a geriatric dehydration-screening tool (DST) in the assessment of hydration status in elderly people. This tool was based on the DST proposed by Vivanti et al., which is composed by 11 items (four physical signs of dehydration and seven questions about thirst sensation, pain and mobility), with four questions extra about drinking habits. The resulting questionnaire was evaluated in a convenience sample comprising institutionalized (n = 29) and community-dwelling (n = 74) elderly people. Urinary parameters were assessed (24-h urine osmolality and volume) and free water reserve (FWR) was calculated. Exploratory factor analysis was used to evaluate the scale’s dimensionality and Cronbach’s alpha was used to measure the reliability of each subscale. Construct’s validity was tested using linear regression to estimate the association between scores in each dimension and urinary parameters. Two factors emerged from factor analysis, which were named “Hydration Score” and “Pain Score”, and both subscales showed acceptable reliabilities. The “Hydration Score” was negatively associated with 24-h urine osmolality in community-dwelling; and the “Pain Score” was negatively associated with 24-h urine osmolality, and positively associated with 24-h urine volume and FWR in institutionalized elderly people.

An analysis of electrical impedance measurements applied for plant N status estimation in lettuce (Lactuca sativa)

Nitrogen plays a key role in crop yields. Hence, farmers may apply excessive N fertilizers to crop fields, inducing environmental pollution. Crop N monitoring methods have been developed to improve N fertilizer management, most of them based on leaf or canopy optical-property measurements. However, sensitivity to environmental interference remains an important drawback. Electrical impedance has been applied to determine the physiological and nutritional status of plant tissue, but no studies related to plant-N contents are reported. The objective of this article is to analyze how the electrical impedance response of plants is affected by their N status. Four sets of lettuce (Lactuca sativa L.) with a different N-source concentrations per set were used. Total nitrogen and electrical impedance spectra (in a 1 to 100 kHz frequency range) were measured five times per set, three times every other day. Minimum phase angles of impedance spectra were detected and analyzed, together with the frequency value in which they occurred, and their magnitude at that frequency. High and positive correlation was observed between plant N content and frequency values at minimum phase angle with no significant variations detected between days of measurement. These results suggest that electrical impedance can be sensitive to plant N status.

Predictors of survival within 2 years of inpatient rehabilitation among older adults

BACKGROUND

Restoring functional independence in elderly people with disabilities is one of the main purposes of a geriatric rehabilitation unit. However, the rehabilitation period may also represent a useful circumstance to identify predictors of long-term health outcomes. The aim of this study was to evaluate a broad spectrum of characteristics in geriatric patients admitted to a rehabilitation unit in order to identify possible predictors of long-term survival.

METHODS

This cross-sectional and prospective study was carried out in an Evaluation and Rehabilitation unit in Northern Italy. 243 persons aged 65 or older were enrolled over a period of 12 months (2007-8) and followed for 2 years. Possible predictors of survival were identified among a large spectrum of demographic, clinical (Charlson Index, lab data), nutritional (Mini-Nutritional Short-Form, bio-impedance analysis), and respiratory (spirometry) features. Logistic regression models were used to evaluate the association between patients' characteristics and survival.

RESULTS

189 (86.3%) participants were alive after 2 years of follow-up. Younger age, better functional status at discharge, a lower Charlson Index score, higher hemoglobin and albumin values at discharge, lower basal fasting glucose, creatinine, TNF-α levels, and extra-cellular water, as well as higher cholesterol, vital capacity (VC), and inspiratory capacity were significantly associated with survival. In the multivariate model, higher VC (OR=6.2; 95%CI=1.6-24.6) and albumin (OR=3.7; 95%CI=1.2-11.8) were associated with survival, whereas the Charlson Index and male gender showed an inverse correlation (OR=0.77; 95%CI=0.60-0.99 and OR=0.23; 95%CI=0.10-0.95, respectively).

CONCLUSION

VC was identified as one of the best predictors of survival along with higher albumin and lower Charlson Index score within 2 years of inpatient rehabilitation among older adults.

Impact of the -174 G > C IL-6 polymorphism on bioelectrical parameters in obese subjects after laparoscopic adjustable gastric banding

BACKGROUND

Recent data demonstrated that the -174 G > C IL-6 polymorphism may account for differences in the therapeutic response to laparoscopic adjustable gastric banding (LAGB) surgery.

OBJECTIVE

We investigated the impact of -174 G > C IL-6 polymorphism on weight loss, body composition, and fluid distribution changes in obese subjects after LAGB.

DESIGN AND OUTCOME MEASURES

Twenty obese subjects were selected and studied at baseline and 3 months after LAGB. Genetic assessment of -174 G > C IL-6 polymorphism and anthropometric and bioelectrical impedance analysis were performed.

RESULTS

At baseline, C(+) carriers had a lower extracellular water (ECW) and higher intra-CW, phase angle (PA), reactance X(c), and X(c)/height. LAGB surgery determined significant reductions in weight and BMI. After LAGB, in C(-) carriers, significant decreases in weight, BMI, and ECW and increases in BCM, BCMI, ICW, PA, and X(c)/H were highlighted. In C(+) carriers, significant reductions in weight, BMI, ICW, and PA and increases in ECW, Na/K, resistance (R), and R/height were obtained. Significant higher reductions in BMI and X(c)/H were observed in C(+) with respect to C(-) carriers.

CONCLUSIONS

Genotyping of genetic variants, for example, the -174 G > C polymorphism of IL-6, gives the opportunity to predict therapeutic response, in terms of body composition outcomes after LAGB.

Comparison of nutritional parameters among adult and elderly hemodialysis patients

AIM

The aim of this study was to compare the nutritional biochemical parameters, prealbumin levels, and bioimpedance analysis parameters of adult and elderly hemodialysis (HD) patients.

METHODS

This prospective cross-sectional study included 50 adult HD patients (42.0 % female). Nutritional status was assessed by post-dialysis multifrequency bioimpedance analysis (BIA), serum prealbumin and other nutritional biochemical parameters.

RESULTS

Mean age of patients was 57.4±15.1 years (range: 30-83 years) and mean dialysis duration was 68.3 ± 54.5 months (range: 3-240 months). When the patients were divided into two groups according to age of patients (<65 and ≥65), prealbumin (p=0.003), blood urea nitrogen (BUN) (p=0.000), serum creatinine (p=0.013), albumin (p=0.016), protein catabolic rate per normalized body weight (nPCR) (p=0.001), intracellular water (ICW)/total body weight (0.003) , body fat mass (p00.000), lean body mass (p=0.031), lean dry mass (p=0.001), illness marker (p=0.005), basal metabolism (p=0.007), body mass index (BMI) (p=0.028), body fat mass index (BFMI) (p=0.000), fat free mass index (FFMI) (p=0.040) values were significantly different between the groups. In the elderly patients (age ≥65), body fat mass, illness marker, BMI, BFMI were higher compared to adult patients (age <65). Additionally, in the elderly patients, prealbumin, BUN, creatinine, albumin, nPCR, ICW/ total body weight, lean body weight, lean dry weight, basal metabolism and FFMI were lower than adult patients.

CONCLUSIONS

Our results indicate that BFMI were higher, albumin, prealbumin, nPCR and lean body mass and FFMI were lower in elderly patients compared to adults. These results imply that elderly HD patients may be prone sarcopenic obesity and may require special nutritional support.

Prevalence of malnutrition in orally and tube-fed elderly nursing home residents in Germany and its relation to health complaints and dietary intake

Objective. To investigate the prevalence of malnutrition in orally and tube-fed nursing home (NH) residents in Germany and its relation to common health complaints and dietary intake. Methods. In 350 NH residents, subjects' characteristics, Mini Nutritional Assessment (MNA), and several health problems were inquired with the nursing staff using standardised interviews. In a subset of 122 residents, dietary intake was assessed by 3-day weighing records. Results. 7.7% of the participants were tube fed. 24.1% of orally nourished and 57.7% of tube-fed residents were malnourished (MNA < 17 p.). Malnutrition was significantly related to nausea/vomiting, constipation, pressure ulcers, dehydration, infections, antibiotic use, and hospitalisation. Mean daily energy intake was 1535 ± 413 kcal and mean protein intake was 54.2 ± 0.9 g/d irrespective of the nutritional state. Conclusion. In Germany, malnutrition is widespread among NH residents and is related to common health problems. The MNA rather reflects health condition than currently reduced dietary intake.