Requirements for clinical use of bioelectrical impedance analysis (BIA)

Body Composition and Energy Expenditure in Youth With Spina Bifida: Protocol for a Multisite, Cross-Sectional Study

BACKGROUND

Obesity prevalence in youth with spina bifida is higher than in their typically developing peers. Obesity is associated with lifelong medical, psychological, and economic burdens. Successful prevention or treatment of obesity in individuals with spina bifida is compromised by (1) the lack of valid and reliable methods to identify body fat in a clinical setting and (2) limited data on energy expenditure that are necessary to provide daily caloric recommendations.

OBJECTIVE

The objectives of this study will be to develop 2 algorithms for use in youth with spina bifida in a clinical setting, one to model body fat and one to predict total daily energy expenditure. In addition, physical activity and dietary intake will be described for the sample.

METHODS

This multisite, prospective, national clinical study will enroll 232 youth with myelomeningocele aged 5 to 18 years (stratified by age and mobility). Participants will be enrolled for 1 week. Data obtained include 4 measures of body composition, up to 5 height measures, a ramped activity protocol, and a nutrition and physical activity screener. Participants will wear an accelerometer for the week. On the final study day, 2 samples of urine or saliva, which complete the doubly labeled water protocol, will be obtained. The analysis will include descriptive statistics, Bland-Altman plots, concordance correlation, and regression analysis.

RESULTS

The study received extramural federal funding in July 2019. Data collection was initiated in March 2020. As of April 2024, a total of 143 (female participants: n=76, 53.1%; male participants: n=67, 46.9%) out of 232 participants have been enrolled. Data collection is expected to continue throughout 2024. A no-cost extension until November 2025 will be requested for data analysis and dissemination of findings.

CONCLUSIONS

This study furthers previous pilot work that confirmed the acceptability and feasibility of obtaining alternate height, body composition, and energy expenditure measures. The findings from this study will enhance screening, prevention, and treatment of abnormal weight status by facilitating the accurate identification of youths' weight status category and recommendations of daily caloric needs for this population that is at higher risk of obesity. Furthermore, the findings have the potential to impact outcomes for youth diagnosed with disabilities other than spina bifida who experience similar challenges related to alterations in body composition or fat distribution or measurement challenges secondary to mobility issues or musculoskeletal problems.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/52779.

Association between vitamin D status, physical performance, sex, and lifestyle factors: a cross-sectional study of community-dwelling Kosovar adults aged 40 years and older

PURPOSE

Vitamin D status and its association with age-related decline in physical performance and strength have already been highlighted in various ways, but data on the situation in developing countries are scarce. This study aimed to investigate vitamin D status, its association with muscle mass and function, and other potential determinants such as age, sex, lifestyle factors (physical activity, dietary behavior), self-perceived health status, medication intake, education and financial situation in adults from Kosovo.

METHODS

This cross-sectional study included 297 participants (54.5% women), aged ≥ 40 years. Serum 25-hydroxyvitamin D (25(OH)D) concentration, hand grip strength and physical performance tests, body composition, vitamin D dietary intake and knowledge were assessed. The interaction between serum 25(OH)D status, lifestyle factors and muscle traits was investigated.

RESULTS

Vitamin D deficiency (< 50 nmol/L) was observed in 47.5% of the total population, of whom 14.7% of them were severely deficient (< 30 nmol/L). No associations were found between 25(OH)D concentration and age. Daily dietary intake of vitamin D was low (1.89 ± 0.67 µg) and 87.6% of individuals did not take vitamin D supplements. However, vitamin D supplementation was the only variable that added statistical significance (p < 0.05) to the prediction of vitamin D status (3.8%). On the other hand, age, medication intake and vitamin D level contributed significantly to the overall regression model, explaining 24.9% of the 30-s chair stand performance as an indicator of lower-body strength endurance.

CONCLUSION

Vitamin D deficiency is highly prevalent among community-dwelling adults in Kosovo and low serum 25(OH)D has been associated with low muscle strength. This implies an urgent need for the development of comprehensive prevention strategies, focusing on pharmacological (supplementation) but also on non-pharmacological strategies such as education, food fortification or lifestyle advices.

Future lines of research on phase angle: Strengths and limitations

Bioelectrical impedance analysis (BIA) is the most widely used technique in body composition analysis. When we focus the use of phase sensitive BIA on its raw parameters Resistance (R), Reactance (Xc) and Phase Angle (PhA), we eliminate the bias of using predictive equations based on reference models. In particular PhA, have demonstrated their prognostic utility in multiple aspects of health and disease. In recent years, as a strong association between prognostic and diagnostic factors has been observed, scientific interest in the utility of PhA has increased. In the different fields of knowledge in biomedical research, there are different ways of assessing the impact of a scientific-technical aspect such as PhA. Single frequency with phase detection bioimpedance analysis (SF-BIA) using a 50 kHz single frequency device and tetrapolar wrist-ankle electrode placement is the most widely used bioimpedance approach for characterization of whole-body composition. However, the incorporation of vector representation of raw bioelectrical parameters and direct mathematical calculations without the need for regression equations for the analysis of body compartments has been one of the most important aspects for the development of research in this area. These results provide new evidence for the validity of phase-sensitive bioelectrical measurements as biomarkers of fluid and nutritional status. To enable the development of clinical research that provides consistent results, it is essential to establish appropriate standardization of PhA measurement techniques. Standardization of test protocols will facilitate the diagnosis and assessment of the risk associated with reduced PhA and the evaluation of changes in response to therapeutic interventions. In this paper, we describe and overview the value of PhA in biomedical research, technical and instrumental aspects of PhA research, analysis of Areas of clinical research (cancer patients, digestive and liver diseases, critical and surgical patients, Respiratory, infectious, and COVID-19, obesity and metabolic diseases, Heart and kidney failure, Malnutrition and sarcopenia), characterisation of the different research outcomes, Morphofunctional assessment in disease-related malnutrition and other metabolic disorders: validation of PhA with reference clinical practice techniques, strengths and limitations. Based on the detailed study of the measurement technique, some of the key issues to be considered in future PhA research. On the other hand, it is important to assess the clinical conditions and the phenotype of the patients, as well as to establish a disease-specific clinical profile. The appropriate selection of the most critical outcomes is another fundamental aspect of research.

Cross-sectional and longitudinal study of the relationship between phase angle and physical function in older adults

AIM

Although the validity of the assessment in older adults has been supported by several studies, cross-sectional and longitudinal relationships between phase angle (PhA) and physical function by sex have not been clarified. This study aimed to examine (i) cross-sectional relationships and (ii) longitudinal relationships between PhA and physical function in older adults.

METHODS

A total of 816 and 445 community-dwelling older adults were included in cross-sectional and longitudinal analyses, respectively. We evaluated their physical function using grip strength, 5-repetition sit-to-stand test (5-STS), 5-meter habitual walk, Timed Up and Go test (TUG), single-leg balance with eyes open, and sit-and-reach test. A multifrequency bioelectrical impedance analyzer was used to determine the PhA at 50 kHz as well as the participants' body composition.

RESULTS

In the cross-sectional analysis, a higher PhA was significantly associated with higher grip strength, sit-and-reach, single-leg balance with eyes open, 5-STS and lower TUG in women, as well as higher grip strength, single-leg balance with eyes open, lower 5-STS and TUG in men, adjusting for age, body mass index and muscle mass. In the longitudinal analysis, there was a significant interaction between PhA and year in the TUG test (B = -0.08; 95% CI, -0.136 to -0.025; P = 0.005) in men. There was no significant interaction between the PhA value and year for the other physical functions.

CONCLUSIONS

The PhA is a useful indicator for assessing physical function in both older men and women. Furthermore, the PhA may be able to predict mobility limitation in older men. Geriatr Gerontol Int 2023; 23: 141-147.

Developing an Evidence and Theory Based Multimodal Integrative Intervention for the Management of Renal Cachexia: A Theory of Change

In this study, we aimed to develop a theoretical framework for a multimodal, integrative, exercise, anti-inflammatory and dietary counselling (MMIEAD) intervention for patients with renal cachexia with reference to how this addresses the underlying causal pathways for renal cachexia, the outcomes anticipated, and how these will be evaluated. We used a Theory of Change (ToC) approach to guide six steps. Step 1 included inputs from a workshop to obtain key stakeholder views on the potential development of a multimodal intervention for renal cachexia. Step 2 included the findings of a mixed-methods study with Health Care Practitioners (HCPs) caring for individuals with End Stage Kidney Disease (ESKD) and cachexia. Step 3 included the results from our systematic literature review on multimodal interventions for cachexia management. In step 4, we used the body of our research team's cachexia research and wider relevant research to gather evidence on the specific components of the multimodal intervention with reference to how this addresses the underlying causal pathways for renal cachexia. In steps 5 and 6 we developed and refined the ToC map in consultation with the core research team and key stakeholders which illustrates how the intervention components of MMIEAD interact to achieve the intended long-term outcomes and anticipated impact. The results of this study provide a theoretical framework for the forthcoming MMIEAD intervention for those with renal cachexia and in subsequent phases will be used to determine whether this intervention is effective. To the best of our knowledge no other multimodal intervention trials for cachexia management have reported a ToC. Therefore, this research may provide a useful framework and contribute to the ongoing development of interventions for cachexia management.

Musculoskeletal Ultrasound Shows Muscle Mass Changes during Post-Acute Care Hospitalization in Older Men: A Prospective Cohort Study

This study aimed to prospectively assess changes in muscle thickness (MT) and the cross-sectional area (CSA) of the rectus femoris (RF) muscle in a cohort of older adults, using musculoskeletal ultrasound at admission and at a 2-week follow-up during hospitalization in a post-acute care unit. Differences in frailty status and correlations of MT-RF and CSA-RF with current sarcopenia diagnostic criteria were also studied. Forty adults aged 79.5 (SD 9.5) years (57.5% women) participated, including 14 with frailty and 26 with pre-frailty. In the first week follow-up, men had a significant increase in MT (0.9 mm [95%CI 0.3 to 1.4], p = 0.003) and CSA (0.4 cm2 [95%CI 0.1 to 0.6], p = 0.007). During the second week, men continued to have a significant increase in MT (0.7 mm [95%CI 0.0 to 1.4], p = 0.036) and CSA (0.6 cm2 [95%CI 0.01 to 1.2], p = 0.048). Patients with frailty had lower values of MT-RF and CSA-RF at admission and during the hospitalization period. A moderate-to-good correlation of MT-RF and CSA with handgrip strength, fat-free mass and gait speed was observed. Musculoskeletal ultrasound was able to detect MT-RF and CSA-RF changes in older adults admitted to a post-acute care unit.

Should we overcome the resistance to bioelectrical impedance in heart failure?

INTRODUCTION

Heart failure is associated with increased neurohormonal activation that results in changes in body composition including volume overload and the loss of skeletal muscle, body fat, and bone density. Bioelectrical impedance measures body composition based on the conduction of electrical current through body fluids.

AREAS COVERED

The PubMed and Scopus databases were reviewed up to the third week of June 2020. Cross-sectional studies, retrospective observational studies, prospective observational studies, and randomized controlled trials have examined numerous bioelectrical impedance monitoring strategies to guide the diagnosis, prognosis, and treatment of heart failure. These monitoring strategies include intrathoracic impedance, lung impedance, bioelectrical impedance vector analysis, leg bioelectrical impedance, and thoracic bioreactance.

EXPERT COMMENTARY

Based on the current evidence, more studies are needed to validate bioelectrical impedance in heart failure. Lung impedance appears to be useful for guiding heart failure treatment in patients with ST-elevation myocardial infarction and improving outcomes in outpatients with heart failure. Furthermore, bioelectrical impedance has potential as a noninvasive, quantitative heart failure variable for population-based research.

Study on body composition and its correlation with obesity: A Cohort Study in 5121 Chinese Han participants

Rare reports can be found about sex- and age-specific body composition survey among Chinese population. The aim of this study is to explore the change of body composition with aging in Chinese males and females respectively.The present cross-sectional study was carried out in Central South University Xiangya School of Medicine Affiliate Haikou Hospital, on a random sample consisting of 5121 participants. Inbody720 body composition analyzer was used to detect the human body composition. Data collection was based on the assessment of anthropometric body composition measurements done with the help of bioelectric impedance. And the data were analyzed with SPSS19.0.We selected 5121 participants, 3276 males and 1845 females. A significant trend (P < 0.05) for all anthropometric indices was observed with age for both genders. Body fat in men and women were 18.33 kg and 19.82 kg, respectively. Body fat percentage in men and women were 25.74% and 34.01%, respectively. Visceral fat area in men and women were 91.98 cm and 77 cm, respectively And, with the increase of age, body fat, body fat percentages and visceral fat area also increased, both in men and in women. Meanwhile, with the increase of BMI, the body fat, body fat percentages, and visceral fat area also increased, both in men and in women.Significant trends were observed for body fat, body fat percentages and visceral fat area for both genders with age and both genders with BMI. Focusing on obesity-related lifestyle and prevent weight gain.

Novel Combined Training Approach Improves Sleep Quality but Does Not Change Body Composition in Healthy Elderly Women: A Preliminary Study

The aim of this study was to investigate the effects of a novel combined training protocol on sleep quality and body composition of healthy elderly women. The study sample consisted of 8 sedentary elderly individuals with mean (±SD) of 67 (±8) years of age, 96.0 (±7.8) mg/dL fasting blood glucose, 94.4 (±36.1) mg/dL triglycerides, 179.1 (±22.4) mg/dL total cholesterol, 57.2 (±15.7) mg/dL high-density lipoprotein (HDL), 103.1 (±25.2) mg/dL low-density lipoprotein (LDL), 125.3 (±8.4) mmHg systolic blood pressure, and 72.6 (±10.1) mmHg diastolic blood pressure. The training protocol consisted of resistance training exercises (approximately 18-minute duration) combined with aerobic exercises (approximately 26-minute duration), performed interspersed in the same session, for 8 weeks (3 times a week), with a 24-hour interval rest between each session. Continuous variables were expressed as the mean (±standard deviation) and the paired sample t-test compares baseline with final measurement. The results showed a significant improvement (p = 0.01) in quality of sleep (4.9 ± 1.5 versus 3.8 ± 1.8 for total PSQI index) without body significant improvements in the fat-free mass (59.9 ± 4.0 versus 60.5 ± 4.4; p = 0.20) and fat mass (40.1 ± 4.0 versus 39.5 ± 4.4; p = 0.20) in healthy elderly women. In this sense, the novel combined training proposed may be an effective alternative or adjunct to present therapies aimed at improving the sleep quality in this population.

Nutrition Intervention in Cancer

Nutrition intervention supports the patient with malnutrition secondary to cancer and its treatment and has been used in the primary and secondary prevention of common forms of cancer. During the emotional stress of dealing with cancer at any stage, patients derive increased quality of life and a sense of control over their lives as the result of receiving supportive advice on diet and lifestyle. Therefore, the use of nutrition intervention in cancer patients is justified in the absence of absolute proof of efficacy as long as it is done safely and with the consent of the cancer patient.

Whey protein, amino acids, and vitamin D supplementation with physical activity increases fat-free mass and strength, functionality, and quality of life and decreases inflammation in sarcopenic elderly

BACKGROUND

Interventions to attenuate the adverse effects of age-related loss of skeletal muscle and function include increased physical activity and nutritional supplementation.

OBJECTIVE

This study tested the hypothesis that nutritional supplementation with whey protein (22 g), essential amino acids (10.9 g, including 4 g leucine), and vitamin D [2.5 μg (100 IU)] concurrent with regular, controlled physical activity would increase fat-free mass, strength, physical function, and quality of life, and reduce the risk of malnutrition in sarcopenic elderly persons.

DESIGN

A total of 130 sarcopenic elderly people (53 men and 77 women; mean age: 80.3 y) participated in a 12-wk randomized, double-blind, placebo-controlled supplementation trial. All participants concurrently took part in a controlled physical activity program. We examined body composition with dual-energy X-ray absorptiometry, muscle strength with a handgrip dynamometer, and blood biochemical indexes of nutritional and health status, and evaluated global nutritional status, physical function, and quality of life before and after the 12 wk of intervention.

RESULTS

Compared with physical activity and placebo, supplementation plus physical activity increased fat-free mass (1.7-kg gain, P < 0.001), relative skeletal muscle mass (P = 0.009), android distribution of fat (P = 0.021), handgrip strength (P = 0.001), standardized summary scores for physical components (P = 0.030), activities of daily living (P = 0.001), mini nutritional assessment (P = 0.003), and insulin-like growth factor I (P = 0.002), and lowered C-reactive protein (P = 0.038).

CONCLUSION

Supplementation with whey protein, essential amino acids, and vitamin D, in conjunction with age-appropriate exercise, not only boosts fat-free mass and strength but also enhances other aspects that contribute to well-being in sarcopenic elderly. This trial was registered at clinicaltrials.gov as NCT02402608.

Nerve localization techniques for peripheral nerve block and possible future directions

BACKGROUND

Ultrasound guidance is now a standard nerve localization technique for peripheral nerve block (PNB). Ultrasonography allows simultaneous visualization of the target nerve, needle, local anesthetic injectate, and surrounding anatomical structures. Accurate deposition of local anesthetic next to the nerve is essential to the success of the nerve block procedure. Due to limitations in the visibility of both needle tip and nerve surface, the precise relationship between needle tip and target nerve is unknown at the moment of injection. Importantly, nerve injury may result both from an inappropriately placed needle tip and inappropriately placed local anesthetic. The relationship between the block needle tip and target nerve is of paramount importance to the safe conduct of peripheral nerve block.

METHODS

This review summarizes the evolution of nerve localization in regional anesthesia, characterizes a problem faced by clinicians in performing ultrasound-guided nerve block, and explores the potential technological solutions to this problem.

RESULTS

To date, technology newly applied to PNB includes real-time 3D imaging, multi-planar magnetic needle guidance, and in-line injection pressure monitoring. This review postulates that optical reflectance spectroscopy and bioimpedance may allow for accurate identification of the relationship between needle tip and target nerve, currently a high priority deficit in PNB techniques.

CONCLUSIONS

Until it is known how best to define the relationship between needle and nerve at the moment of injection, some common sense principles are suggested.

The effect of subcutaneous fat on electrical impedance myography when using a handheld electrode array: the case for measuring reactance

OBJECTIVE

Recent developments in electrical impedance myography (EIM) have led to the use of handheld electrode arrays (HEAs) for data acquisition. Although preferable for several reasons, this approach tends to be more affected by subcutaneous fat (SF) than the original approach in which the impedance-measuring electrodes are widely spaced. In this study, we seek to identify the EIM parameter least impacted by subcutaneous fat (SF) when using an HEA.

METHODS

18 normal subjects underwent 50 kHz EIM and ultrasound of the medial gastrocnemius muscles on the dominant side. Coefficients of determination (R(2) values) were calculated for each of the three major EIM variables (reactance, resistance, and phase) and SF thickness.

RESULTS

For both resistance and phase, a strong relationship to SF thickness was observed (R(2) = 0.64 and R(2) = 0.70, respectively, p < 0.001 for both). In contrast, for reactance, the relationship was non-significant, with R(2) = 0.07, p = 0.30.

CONCLUSIONS

Unlike resistance and phase, both of which are highly impacted by SF thickness, the reactance shows no significant relationship.

SIGNIFICANCE

Future clinical studies employing HEA's to perform EIM should evaluate alterations in reactance in addition to those in resistance and phase.

Pretreatment serum albumin as a predictor of cancer survival: a systematic review of the epidemiological literature

Background

There are several methods of assessing nutritional status in cancer of which serum albumin is one of the most commonly used. In recent years, the role of malnutrition as a predictor of survival in cancer has received considerable attention. As a result, it is reasonable to investigate whether serum albumin has utility as a prognostic indicator of cancer survival in cancer. This review summarizes all available epidemiological literature on the association between pretreatment serum albumin levels and survival in different types of cancer.

Methods

A systematic search of the literature using the MEDLINE database (January 1995 through June 2010) to identify epidemiologic studies on the relationship between serum albumin and cancer survival. To be included in the review, a study must have: been published in English, reported on data collected in humans with any type of cancer, had serum albumin as one of the or only predicting factor, had survival as one of the outcome measures (primary or secondary) and had any of the following study designs (case-control, cohort, cross-sectional, case-series prospective, retrospective, nested case-control, ecologic, clinical trial, meta-analysis).

Results

Of the 29 studies reviewed on cancers of the gastrointestinal tract, all except three found higher serum albumin levels to be associated with better survival in multivariate analysis. Of the 10 studies reviewed on lung cancer, all excepting one found higher serum albumin levels to be associated with better survival. In 6 studies reviewed on female cancers and multiple cancers each, lower levels of serum albumin were associated with poor survival. Finally, in all 8 studies reviewed on patients with other cancer sites, lower levels of serum albumin were associated with poor survival.

Conclusions

Pretreatment serum albumin levels provide useful prognostic significance in cancer. Accordingly, serum albumin level could be used in clinical trials to better define the baseline risk in cancer patients. A critical gap for demonstrating causality, however, is the absence of clinical trials demonstrating that raising albumin levels by means of intravenous infusion or by hyperalimentation decreases the excess risk of mortality in cancer.

Bioelectrical impedance phase angle in clinical practice: implications for prognosis in stage IIIB and IV non-small cell lung cancer

Background

A frequent manifestation of advanced lung cancer is malnutrition, timely identification and treatment of which can lead to improved patient outcomes. Bioelectrical impedance analysis (BIA) is an easy-to-use and non-invasive technique to evaluate changes in body composition and nutritional status. We investigated the prognostic role of BIA-derived phase angle in advanced non-small cell lung cancer (NSCLC).

Methods

A case series of 165 stages IIIB and IV NSCLC patients treated at our center. The Kaplan Meier method was used to calculate survival. Cox proportional hazard models were constructed to evaluate the prognostic effect of phase angle, independent of stage at diagnosis and prior treatment history.

Results

93 were males and 72 females. 61 had stage IIIB disease at diagnosis while 104 had stage IV. The median phase angle was 5.3 degrees (range = 2.9 – 8). Patients with phase angle <= 5.3 had a median survival of 7.6 months (95% CI: 4.7 to 9.5; n = 81), while those with > 5.3 had 12.4 months (95% CI: 10.5 to 18.7; n = 84); (p = 0.02). After adjusting for age, stage at diagnosis and prior treatment history we found that every one degree increase in phase angle was associated with a relative risk of 0.79 (95% CI: 0.64 to 0.97, P = 0.02).

Conclusion

We found BIA-derived phase angle to be an independent prognostic indicator in patients with stage IIIB and IV NSCLC. Nutritional interventions targeted at improving phase angle could potentially lead to an improved survival in patients with advanced NSCLC.

Bioelectrical impedance phase angle as a prognostic indicator in breast cancer

Background

Bioelectrical impedance analysis (BIA) is an easy-to-use, non-invasive, and reproducible technique to evaluate changes in body composition and nutritional status. Phase angle, determined by bioelectrical impedance analysis (BIA), detects changes in tissue electrical properties and has been hypothesized to be a marker of malnutrition. Since malnutrition can be found in patients with breast cancer, we investigated the prognostic role of phase angle in breast cancer.

Methods

We evaluated a case series of 259 histologically confirmed breast cancer patients treated at Cancer Treatment Centers of America. Kaplan Meier method was used to calculate survival. Cox proportional hazard models were constructed to evaluate the prognostic effect of phase angle independent of stage at diagnosis and prior treatment history. Survival was calculated as the time interval between the date of first patient visit to the hospital and the date of death from any cause or date of last contact/last known to be alive.

Results

Of 259 patients, 81 were newly diagnosed at our hospital while 178 had received prior treatment elsewhere. 56 had stage I disease at diagnosis, 110 had stage II, 46 had stage III and 34 had stage IV. The median age at diagnosis was 49 years (range 25 – 74 years). The median phase angle score was 5.6 (range = 1.5 – 8.9). Patients with phase angle <= 5.6 had a median survival of 23.1 months (95% CI: 14.2 to 31.9; n = 129), while those > 5.6 had 49.9 months (95% CI: 35.6 to 77.8; n = 130); the difference being statistically significant (p = 0.031). Multivariate Cox modeling, after adjusting for stage at diagnosis and prior treatment history found that every one unit increase in phase angle score was associated with a relative risk of 0.82 (95% CI: 0.68 to 0.99, P = 0.041). Stage at diagnosis (p = 0.006) and prior treatment history (p = 0.001) were also predictive of survival independent of each other and phase angle.

Conclusion

This study demonstrates that BIA-derived phase angle is an independent prognostic indicator in patients with breast cancer. Nutritional interventions targeted at improving phase angle could potentially lead to an improved survival in patients with breast cancer.

Bioelectrical impedance and strength measurements in patients with heart failure: comparison with functional class

OBJECTIVE

Patients with chronic heart failure (HF) develop important changes in body composition. Nevertheless, the usual methods of body composition assessment can be misleading in patients with HF because tissue hydration is altered. Bioelectrical impedance vector analysis (BIVA) works without making any assumption about constant soft tissue hydration. In this study, patients with HF and systolic dysfunction (HFS) and preserved systolic function (HFPSF) underwent a body composition evaluation by the BIVA method; the comparison was done between New York Heart Association (NYHA) functional classes I-II and III-IV.

METHODS

We studied 243 patients with HF, 140 (101 in NYHA I-II and 39 in III-IV) with HFS and 103 (67 in NYHA I-II and 36 in II-IV) with HFPSF. Whole-body bioelectrical impedance was measured using BodyStat QuadScan 4000, which is tetrapolar and multiple-frequency equipment.

RESULTS

In both HF categories, reactance and phase angle were significantly lower, the impedance ratio of 200 kHz to that at 5 kHz was higher, and had significantly shorter and downsloping impedance vector in the NYHA III-IV group compared with the NYHA I-II group by gender.

CONCLUSION

Bioelectrical impedance analysis allows an easier evaluation of body composition and this might be particularly useful to stratify the severity of HF.

Comparison between bioelectrical impedance analysis and body mass index methods in determination of obesity prevalence in Ahvazi women

BACKGROUND

Obesity has an increasing trend worldwide. Recently, application of body mass index (BMI) cutoff points of obesity classification for all population studies has been questioned. On the other hand, bioelectrical impedance analysis (BIA) is a safe, accurate, reliable and inexpensive method for screening the overweight and obesity in such studies.

OBJECTIVES

There were three objectives followed in this research: to determine the prevalence of obesity and overweight in married women using BMI and BIA methods; to evaluate the correlation between these methods; and to compare the women's obesity degrees according to their educational levels.

METHOD

Six hundred and thirty-seven healthy married women 18-40 years aged, who had referred to 14 health centers of the city of Ahvaz (center of Khouzestan province, south-west of Iran) were recruited in a cross-sectional design, and their socio-economic and anthropometric questionnaires were completed by the trained students. Body fat percent (%BF) and body fat mass (BFM) were measured using BIA method. BMI>25 and >30 kg/m(2) were used as criteria for determining the overweight and obese women, respectively. %BF>35% was regarded as cutoff for defining obesity.

RESULTS

Mean age+/-s.d. of the women was 26.9+/-5.8 years and majority of them were housewives with secondary educational level. Their BMI, %BF, waist-to-hip ratio, and mid-upper arm circumference means were: 25.9(4.7) kg/m(2), 27.6(7.3)%, 0.75(0.08) and 27.9(3.9) cm, respectively. Central obesity was prevalent in 21.2% of the subjects. Prevalence of obesity determined by BMI and BIA methods was 18.3 and 15.5% and women within normal ranges were detected in 44.7 and 46% of the subjects by these methods, respectively. However, thin (underweight) women were 2.6 and 14.6% of the subjects studied, respectively. About one half of the women were overweight or obese. BMI was statistically correlated with BFM (r=0.86; P<0.0001) and %BF (r=0.77; P<0.0001). Women with higher educational levels had lower body fat percentage and BMI than the other subjects with lower degrees (P<0.05).

CONCLUSION

Obesity and overweight is prevalent in about one-half of the Ahvazian married women and more than one-fifth of the subjects have central obesity. BIA and BMI methods can similarly detect the normal and obese married women but they are different in determining the underweight female subjects. Women with higher educational grades tend to have lower BMI levels.

Proton and sodium MRI assessment of fluid level in calf tissue

PURPOSE

To investigate the feasibility of using (1)H and (23)Na MRI to detect fluid levels in the lower leg muscle.

MATERIALS AND METHODS

Proton and sodium MRI was applied to detect body fluid levels in the lower leg muscles of 18 healthy young male subjects at 3T and 4T. The paradigms under investigation were a postural change from sitting upright to lying supine, and saline infusion.

RESULTS

We found that the average proton MR signal in gastrocnemius and soleus muscles were reduced following the postural change by 3.5% +/- 1.4% (P < 0.05) and rose following saline infusion by 3.7% +/- 0.9% (P < 0.01). More dramatically, the sodium MR signal decreased by 7.1% +/- 1.2% (P < 0.01) following the postural change and increased following saline infusion by 12% +/- 3.8% (P < 0.05). The ratio of intra- to extracellular fluid levels was 1.6 +/- 0.5 for the subjects based on the acquired proton and sodium data.

CONCLUSION

Our results indicate that proton and sodium MRI can be used to assess fluid levels in the lower extremities, and this technique may be applied to evaluate fluid retention.

Central obesity is associated with reduced peripheral wave reflection in Indigenous Australians irrespective of diabetes status

OBJECTIVE

To determine the influence of central obesity and type 2 diabetes on peripheral wave reflection in Indigenous Australians.

DESIGN AND METHODS

A cross-sectional study of remote Indigenous Australians with (n = 43) and without (n = 54) type 2 diabetes of similar age (47 years) and sex; using anthropometric and bioelectrical impedance measures of obesity and applanation tonometry to determine the aortic augmentation index (AI) as an index of peripheral wave reflection.

RESULTS

Indices of obesity were significantly higher in the diabetic than non-diabetic participants [body mass index (BMI): 27.3 versus 24.6 kg/m, P = 0.018; waist circumference: women 101 versus 94 cm, P = 0.008, men 102 versus 91 cm, P = 0.039]. AI was negatively related to obesity: BMI (r = -0.35, P = 0.0003), weight (r = -0.44, P < 0.0005), waist circumference (r = -0.34, P = 0.0003) and fat mass (r = -0.35, P < 0.0005). There was no significant difference in AI between the groups with and without diabetes. On multiple regression analysis, 66% of the variance in AI was explained with the following significant predictors: age, heart rate, male gender, fat mass and mean arterial pressure. Similar results were obtained when weight, waist circumference or BMI were substituted for fat mass.

CONCLUSION

When compared with Indigenous Australians without diabetes, those with type 2 diabetes do not have greater aortic pressure augmentation from peripheral wave reflection. However, obesity, irrespective of the index used, was related to lower peripheral wave reflection in both those with and without type 2 diabetes.

Role of Parenteral Nutrition in Cancer Patients Undergoing High-Dose Chemotherapy Followed by Autologous Peripheral Blood Progenitor Cell Transplantation

High-dose chemotherapy followed by autologous bone marrow or peripheral blood progenitor cell transplantation represents a recognized option in the treatment of solid tumors and hematologic diseases. Patients receiving high-dose chemotherapy are traditionally supported with parenteral nutrition with the aim to prevent malnutrition secondary to gastrointestinal toxicity and metabolic alterations induced by the conditioning regimens. Nevertheless, well-defined guidelines for its use in this clinical setting are lacking and there are several areas of controversy.

Bioelectrical impedance phase angle as a prognostic indicator in advanced pancreatic cancer

Bioelectrical impedance analysis (BIA) is an easy-to-use, non-invasive and reproducible technique to evaluate changes in body composition and nutritional status. Phase angle, determined by BIA, has been found to be a prognostic indicator in several chronic conditions, such as HIV, liver cirrhosis, chronic obstructive pulmonary disease and lung cancer, and in patients undergoing dialysis. The present study investigated the prognostic role of phase angle in advanced pancreatic cancer. We evaluated a case series of fifty-eight stage IV pancreatic cancer patients treated at Cancer Treatment Centers of America at Midwestern Regional Medical Center (Zion, IL, USA) between January 2000 and July 2003. BIA was conducted on all patients using a bioelectrical impedance analyser that operated at 50 kHz. The phase angle was calculated as capacitance (Xc)/resistance (R) and expressed in degrees. The Kaplan-Meier method was used to calculate survival. Cox proportional hazard models were constructed to evaluate the prognostic effect of phase angle independent of other clinical and nutritional variables. The correlations between phase angle and traditional nutritional measures were evaluated using Pearson and Spearman coefficients. Patients with phase angle <5.0 degrees had a median survival time of 6.3 (95% CI 3.5, 9.2) months (n 29), while those with phase angle >5.0 degrees had a median survival time of 10.2 (95% CI 9.6, 10.8) months (n 29); this difference was statistically significant (P=0.02). The present study demonstrates that phase angle is a strong prognostic indicator in advanced pancreatic cancer. Similar studies in other cancer settings with larger sample sizes are needed to further validate the prognostic significance of the phase angle.

Bioelectrical impedance phase angle in clinical practice: implications for prognosis in advanced colorectal cancer

BACKGROUND

Phase angle, determined by bioelectrical impedance analysis (BIA), detects changes in tissue electrical properties and has been found to be a prognostic indicator in several chronic conditions-such as HIV, liver cirrhosis, chronic obstructive pulmonary disease, and lung cancer-and in patients receiving dialysis.

OBJECTIVE

This study was conducted to investigate the prognostic role of phase angle in advanced colorectal cancer.

DESIGN

We evaluated a case series of 52 patients with histologically confirmed stage IV colorectal cancer. BIA was conducted on all patients and phase angle was calculated. The Kaplan-Meier method was used to calculate survival. Cox proportional hazard models were constructed to evaluate the prognostic effect of phase angle independent of other clinical and nutritional variables.

RESULTS

Patients with a phase angle < or =5.57 had a median survival of 8.6 mo (95% CI: 4.8, 12.4; n=26), whereas those with a phase angle >5.57 had a median survival of 40.4 mo (95% CI: 21.9, 58.8; n=26; P=0.0001).

CONCLUSION

Phase angle is a prognostic indicator in patients with advanced colorectal cancer. Similar studies of other cancer types with larger sample sizes are needed to further validate the prognostic significance of phase angle in cancer treatment settings.

Predonation water ingestion attenuates negative reactions to blood donation

BACKGROUND

Novice blood donors are at increased risk for unpleasant blood donation-related symptoms (e.g., dizziness, weakness, and lightheadedness), and the experience of such symptoms can contribute to a decreased likelihood of repeat donation. Recent laboratory studies suggest that water ingestion produces hemodynamic effects that may be sufficient to reduce risk of syncope and related reactions during blood donation.

STUDY DESIGN AND METHODS

Male and female volunteers were randomly assigned to ingest either 500 or 0 mL of water 30 minutes before donating blood for the first time. In addition, bioimpedance analysis was used to assess predonation chronic hydration levels in all donors. Immediately after donation, participants completed the Blood Donation Reactions Inventory to assess subjective experience of negative physiologic reactions.

RESULTS

Analysis of Blood Donation Reactions Inventory scores revealed that predonation water ingestion was associated with a 47-percent reduction of total donation-related symptoms (F [1,79]= 11.81, p = 0.001). Chronic hydration status was not related to reported reactions.

CONCLUSION

Novice blood donors responded positively to predonation water consumption, and they were able to consume 500 mL in less than 5 minutes. Results of the present study suggests that predonation water ingestion may be a simple and cost-effective strategy to enhance the donation experience and possibly increase donor retention.

The IGF-I system component concentrations that decrease with ageing are lower in obesity in relationship to body mass index and body fat

The aim of this study was to investigate the GH-IGF-I axis in healthy adults and its relationship to obesity. We studied 268 subjects: 134 men and 134 women, and determined anthropometric and body composition variables. Serum total IGF-I was measured by radioimmunoassay, serum free IGF-I concentrations by enzyme linked immunosorbant assay and serum IGFBP3 concentrations by radioimmunoassay. In men, we observed a decrease in total IGF-I, free IGF-I and IGFBP-3 throughout decades. In women, the body mass index and fat mass were higher throughout decades, and we observed a similar decrease to that in men in total IGF-I, free IGF-I and IGFBP3. In men with obesity, as measured by body fat, free IGF-I concentrations were lower than those without obesity; in women with obesity, total IGF-I concentrations and free IGF-I concentrations were lower than in those with obesity. These changes were observed in relationship to obesity when the subjects were adjusted for differences in age. We showed that in controls randomly selected, the GH-IGF-I axis component concentrations that decrease with increasing age are lower in obesity, especially in women, and that this decrease is related to body mass index and body fat.

Difficulty in losing weight by behavioral intervention for women with Trp64Arg polymorphism of the beta3-adrenergic receptor gene

OBJECTIVE

Trp64Arg mutation in the beta(3)-adrenergic receptor (beta(3)AR) gene is relatively common in Japanese people. However, it has not been clear whether persons with Trp64Arg mutation in the beta(3)AR gene tend to have obesity and difficulty in losing weight even with a restricted diet and exercise. We investigated the response of body weight and metabolic factors to behavioral intervention in Japanese women with Trp64Arg mutation in the beta(3)AR gene.

DESIGN

A 3-month behavioral intervention study using a combination of diet and exercise programs.

SUBJECTS

A total of 76 perimenopausal women with no clinical symptoms (age: 54.7+/-7.7 y, body mass index (BMI): 21.0-33.0 kg/m(2)).

MEASUREMENTS

Anthropometric measurements (weight, height, body fat, waist circumference, hip circumference, skin fold, resting energy expenditure and blood pressure) and metabolic measurements (serum levels of cholesterol, triglyceride, phospholipid, nonesterified fatty acid, glucose, insulin and leptin) and determination of the beta(3)AR genotype by polymerase chain reaction followed by BstNI digestion.

RESULTS

At the baseline of BMI, body weight, body fat, waist circumference, hip circumference, the arm skin fold, resting energy expenditure, or blood lipid and glucose profiles, there was no significant difference in participants with/without mutation of the beta(3)AR gene. The intervention yielded a body weight reduction in 69 and 48%, and induced a significant difference in weight loss (-0.74 and -0.01 kg) for women with wild-type and Trp64Arg mutation, respectively. Significant differences of anthropometric parameters were found in body weight, BMI, waist and hip circumferences and blood pressure of wild type by the intervention. However, women with Trp64Arg mutation did not show significant changes in these anthropometric parameters, except for hip circumference. A significant difference was found in high-density lipoprotein cholesterol (HDL-C) and in the low-density lipoprotein cholesterol/HDL-C ratio in both genotypes.

CONCLUSION

The results of the present study suggest that the Trp64Arg mutation of the beta(3)AR gene is associated with difficulty in losing weight through behavioral intervention, although it is not related to obesity-related phenotypes and resting energy expenditure before the intervention.

Percentage body fat ranges associated with metabolic syndrome risk: results based on the third National Health and Nutrition Examination Survey (1988-1994)

BACKGROUND

Increasing attention has focused on the association between body fatness and related metabolic risk factors. The quantitative link between percentage body fat (%BF) and the risk of metabolic syndrome is unknown.

OBJECTIVES

The objectives were to determine the risk [odds ratios (ORs)] of metabolic syndrome based on %BF in black and white men and women in the United States and to provide corresponding ranges of %BF associated with a risk equivalent to body mass index (BMI; in kg/m(2)).

DESIGN

The subjects were participants in the third National Health and Nutrition Examination Survey and were divided into those with and without the metabolic syndrome. OR equations were derived from logistic regression models for %BF and BMI, with the 25th percentile in the study population as the reference. Ranges were developed by associating %BF with the equivalent risk of metabolic syndrome based on established BMI cutoffs.

RESULTS

Four sets (men, women, black, and white) of OR curves were generated for %BF and for BMI by using data from 8259 adults. The ORs for metabolic syndrome were lower in blacks than in whites at any given %BF or BMI. The developed cutoffs for %BF differed between men and women but showed only small race and age effects. A simplified set of sex-specific %BF ranges for the risk of metabolic syndrome were developed.

CONCLUSIONS

The risk of metabolic syndrome can be established from measured %BF by using either the developed OR curves or %BF thresholds at traditional BMI cutoffs. This information should prove useful in both clinical and research settings.

History of anorexia nervosa in bulimic patients: its influence on body composition

OBJECTIVE

To analyze the body composition of a group of patients fulfilling DSM-IV criteria for bulimia nervosa (BN), comparing the patients who had a history of DSM-IV anorexia nervosa (AN) with those without such a history to determine (1) whether both groups differed in terms of body composition and (2) whether the differences between groups could be the consequence of the past condition.

METHODS

The sample consisted of 104 patients, 43 with prior AN (BN-AN group) and 61 without a history of AN (BN-nonAN). The patients were assessed using anthropometric and bioelectrical methods: height and weight, body circumferences, abdominal diameter, skinfold thickness, and body impedance analysis. In a later phase and to test the influence of current low weight on the results, two experimental groups were created: the first group was composed of the patients from the BN-AN group who had a normal body mass index (BMI range in this group, 20.1-23.4 kg/m2; n = 23); the second group consisted of 23 patients from the BN-nonAN group in the same BMI range. In both phases unpaired sample t tests were performed for statistical analysis.

RESULTS

More than 40% of the bulimic patients with a history of AN had a BMI less than 20. They had a lower percentage of body fat, lower muscle mass, and higher percentage of extracellular water. Nevertheless, most of these differences disappeared in the second phase of the analysis, when only the patients within a normal weight range were compared.

DISCUSSION

According to these results, a significant number of bulimic patients with a history of AN tend to retain some clinical traits of the past condition and could be viewed as remaining in a "subclinical anorexic status": they are thinner and seem to have less difficulties in maintaining low weight than patients without a history of AN. Nevertheless, in patients who have reached a normal weight after AN, all these differences disappear. This fact raises some important questions related to the boundaries between AN and BN, the shifting from one to another, or when AN patients really recover.

Serum leptin concentration in young adult women with ovulatory dysfunction

To investigate the functional role of leptin in human ovulation, we measured serum leptin, LH, FSH and estradiol in 16 young adult women suffering from ovulatory dysfunction with BMI ranging from 17.5 to 24.5 (group A). The control subjects included 12 women with regular ovulation and matched age and BMI (group B). We found that serum leptin concentration in group A subjects was significantly lower than that in group B subjects (4.1+/-0.5 vs. 6.1+/-0.4 ng/ml, p<0.01). The percent body fat, estradiol, LH and FSH concentrations in groups A and B were not significantly different. These results indicate that anovulatory young adult women have lower leptin concentration than women with regular ovulation, thus suggesting a key role for leptin in regular ovulation or ovulatory dysfunction.