Professional Interpretation Of Bia
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View Professional Interpretation Of Bia as PDF for free.
More details
- Words: 2,551
- Pages: 5
PROFESSIONAL INTERPRETATION OF BIOELECTRICAL IMPEDENDCE ANALYSIS (BIA) BIA is increasingly used to estimate body composition in dietetic practice, largely due to its simple, quick, non‐invasive nature and portability (Lukaski, 1985). Although different BIA meters will record different results on individuals, using the correct equations for the population studied can produce consistent intra‐group data (Oldman, 1996). The most salient feature of BIA is its reproducibility on individual patients on serial testing showing changes over time with altered nutrition therapy and/or activity. The reference groups for testing were HIV and Renal patients (Stall et al 1995, Madore et al 1994 & Zabetakis et al 1994). Reproducibility makes BIA an ideal clinical tool (Ghosh et al 1997). The electrical impedance of the body is measured by introducing a small alternating electrical current (for example: 800A: 50KHz, varies with equipment used) into the body and measuring the potential difference that results (Foster KR and Lukaski HC, 1996). Fat free mass contains electrolytes and acts as a conductor, whereas fat mass does not and acts as an insulator. BIA has been validated against other body composition methods and in healthy adults (Khaled et al, 1988). In addition, BIA continues to be researched and validated in a variety of populations and conditions. Please check this manual by condition to look for disease specific standards and normal values. Systems Measuring Fat Free Mass/Lean Body Mass and Fat Mass There are two types of BIA meters available containing validated equations or computer software. One type of system measures resistance/impedance only and may or may not use electrodes. The meters may be hand held or are 'step‐on' scales. These systems provide a measure of fat free mass and fat mass. They are used primarily in weight loss programs to assess and monitor changes in body fat. Some will state the number of pounds/kg of fat and fat free mass, which may be more useful than percent body fat alone. Percent body fat and BMI have been criticized because they are not a reflection of the other components of the human body. Muscle mass and bone weight can vary greatly in individuals and by race. High quality diets and excellent fitness programs will produce fat loss and minimal loss of muscle mass. It is not possible to determine the loss of active cell mass with these systems therefore it is prudent to combine this test with a MAMA test. Because BIA may underestimate body fat in abdominal obesity, it is wise to collect serial waist circumference data. 'Applied Body Composition Assessment`, (Heyward) includes detailed information on current equations from experts in the field by race, age and for obese subjects. Software for the text is also available from Human Kinetics. These equations will not provide the detailed clinical output outlined below. Systems Measuring Clinical Nutritional Indicators The second type of system requires a patient to lie supine with electrode placement on the right hand and foot or on body segments (Lukaski, 1996), provides a large array of information. These systems may measure resistance and reactance in the body. Resistance being the opposition of the conductor to the flow of the current (Lukaski, 1996). Reactance is associated with several types of polarization (separation
of charges or electrochemical gradients) that may be produced by cell membranes and tissue interfaces. Capacitance causes the administered current to lag behind the voltage and creates a phase shift that is represented by the phase angle (Lukaski, 1996). The clinical systems may have more than one frequency setting (5 to 200 kHz) to improve accuracy when testing very thin or very obese subjects (Hannan, 1995 & Lukaski, 1996). BIA Testing The ideal test time is in the morning before breakfast and before having had a physical workout or if later in the day, at least four hours since the last meal with no workout, coffee or alcohol during the day of the test (Heyward, 1996). This assures a more accurate body fat mass measure but in not necessary if the goal is to test random hydration. Good hydration is essential for very muscular subjects because of the water content of muscle. Lukaski (1985) reported dehydration increases resistance (approximately 40 ohms) resulting in an underestimation of fat free mass and overestimation of fat mass. Morning test results may be slightly different from those taken after lunch. Using a consistent time of day for repeat tests with individual patients is advised. Lower hydration scores may also be recorded at the end of the week in the active working population. In general follow the guidelines and use electrodes and supplies recommended by the manufacturer. When developing equations for a specific population group use a meter that provides both resistance and reactance scores. Height, weight, sex and age are usually entered into the programs. Where height and weight are not available some research is underway to use a resistance/impedance or reactance measure alone (e.g. frail elderly or critically ill patients) (Olde et al 1997). BIA Test Interpretation The following is an explanation of the type of information seen on a software printout. Equations used in software are patented and will vary slightly from system to system. Total Body Water (TBW) is an estimate of total hydration level, including intracellular and extracellular water (Kushner et al, 1986). It should be available in litres and as a percent with a normal range. For optimal hydration this reading should be in the upper half of the normal range and vary with age, sex and body fat. If not, check the patient's fluid intake. The more obese a subject, the lower the percent total hydration and this may be normal for them given a good fluid intake. However litre volumes will be normal or high normal. Clinicians have mistakenly tried increased the fluid intake of obese individuals to improve this score. In general percent TBW will go up as weight goes down. Intracellular Water (ICW) is an estimate of the water in active tissue and should be provided in litres and as a percent of a normal range (near 60% of TBW). ICW will be in the high range with a large amount of muscle in a well hydrated subject and may a proxy for muscle mass. Drops in this compartment indicate lower hydration or a loss of active cell mass in catabolic patients. Nutrition plans are implemented to restore or increase ICW litre volume. Extracellular Water (ECW) is water in tissues and plasma and should be provided in litres and as a percent of a normal range (near 40% of TBW). It should be close to the low normal range in males and
may be in the low or mid range for females. Subjects with very low body fat will have a lower ECW and subjects with high body fat will have an associated high ECW. Women on OCA have consistently higher scores while women not on OCA may have more varied scores. Heyward (1996) discusses women's cycles in detail. In catabolic patients the litre volume in this compartment will increase with poor cell membrane transport. Nutrition plans or medication may be implemented to reduce ECW litre volume (Coodley et al 1995). Body Cell Mass (BCM) is an estimate of total pounds/kg of all active cells. The percent BCM will be in the normal range if the subject is close to his/her ideal body weight. It appears as a low percent in obese subjects but the pounds/kg will be high normal in the active obese individual and low in the catabolic obese patient. Many overweight subjects have very high BCM in pounds/kg even though their percent BCM does not appear to be in the normal range. It is important to maintain or improve BCM when writing nutrition care plans or exercise program. As body fat is lost, BCM percent will come into the normal range. BCM declines in catabolic patients or with drops or changes in physical activity or with conditions producing muscle loss. Nutrition plans are implemented to maintain, restore or increase BCM, ICW litre volume and to prevent excess gain of ECW. Extracellular Tissue (ECT)/Extracellular Mass (ECM) is an estimate of the mass of all other non‐muscle inactive tissues including ligaments, bone and ECW. ECT is usually higher than BCM but will be lower than BCM in very anabolic subjects with normal or low ECW(BCM/ECT ratio >1. German researchers (Fischer & Ott, 1990) have used a ratio of ECM/BCM (.7 ‐ 1.0 normal range) to monitor improvements in nutrition in HIV patients. Increasing scores on serial tests were consistent with a decline in status. Fat Free Mass (FFM)/Lean Body Mass (LBM) is an estimate of the entire mass that is not fat. It should be available in pounds/kg and may be presented as a percent with a normal range. This compartment will change with hydration and loss or gain of BCM. This alone is not as sensitive a measure when trying to determine loss of body cell mass. Fat Mass (FM) is an estimate of pounds/kg of body fat and percentage body fat. The notion comparing pounds/kg of Fat Mass with BCM has revealed a clinical comparison measure for practice (FM/BCM ratio). Qualitative assessment of clinical data on satisfaction with body size, showed women are content with the same number of pounds of fat mass as BCM and men are content with half as much Fat Mass as BCM independent of percent body fat (BIA unpublished observations, Schneider (1996‐99). The client goal for women is to reach a ratio of FM/BCM of 1.0. For men the ratio would be .5). Athletic individuals are not satisfied with this high a ration and may have lower pounds of body fat than these standards depending on their sport and the body weight requirement. Percent body fat alone as a measure continues to discourage large framed, physically active individuals and reduces satisfaction with body image because of unrealistic normal values well established in the popular press. In fact clinical BIA data collected (Schneider, 1996‐99) on large numbers of men and women with ideal body weight, shows that both men and women carry 40 to 45 pounds (18 to 20 kg) of body fat for a wide range of heights. Using the FM/BCM ratio is a more positive way to present information to patients and allow active goal setting in relation to BCM maintenance and gradual loss or gain of body fat. More qualitative/quantitative research is being carried out on this subject.
Phase Angle (PA) is believed to be associated with both nutrition and physical fitness. For example a stroke patient with one source of nutrition (via mouth), will have a higher phase angle on his/her active side of the body than on the inactive side of the body. It is believed that the phase angle may indicate the presence of fully functional cell membrane transport systems. Phase angle scores are between 3 and 10 degrees and vary with age, sex, race, physical activity and the presence of health and disease. Scores rise in the teen age years from 5 to 7 as growth becomes complete. Similar individual scores may continue until the forth and fifth decade when scores begin to drop and gradually reduced to the 4‐6 range in seniors. Scores of 8 or 9 are rare, only seen in well nourished physically active subjects such as body builders. High scores may be seen in well nourished obese subjects. Research is being carried out to determine variations by race. In catabolic patients, there will be an associated drop in ICW, BCM and an increase in ECW, which will be improved effectively with an implemented nutrition plan (Scalfi et al, 1999). Studies on HIV and renal patients found the phase angle was correlated with serum albumin, pre albumin, creatinine and was the most predictive indicator of impending mortality in critically ill patients (Cherlow et al, 1997; Ott et al, 1995). More research is being done in Canada and the U.S. to determine applications by age, sex, race, rehabilitation programs and specific catabolic conditions and nutrition interventions with monitoring of several assessment variables to determine the best practices.
References 1. Gupta, D., Christopher, G.L. et al. The relationship between bioelectrical impedance phase angle and subjective global assessment in advanced colorectal cancer. Nutrition Journal 7:19doi:10.1186/1475‐2891‐7‐19, 2008. 2. Susanne Hengstermann, Andreas Fischer, MD, Elisabeth Steinhagen‐Thiessen, MD, PhD and Ralf‐ Joachim Schulz, MD, PhD, Nutrition Status and Pressure Ulcer: What We Need for Nutrition Screening. Journal of Parenteral and Enteral Nutrition, Vol. 31, No. 4, 288‐294 (2007) 3. Heyward, V., and Wagner, D. Applied Body Composition Assessment, Second Edition, Human Kinetics, Champaign IL, 2004. 4. Kyle, U.G., Bosaeus, I. Et al. ESPEN Guidelines 2004, Bioelectrical Impedance Analysis Part 1: review of principles and methods. Clinical Nutrition 23, 1226‐1243, 2004. 5. Kyle, U.G., Bosaeus, I. Et al. ESPEN Guidelines 2004, Bioelectrical Impedance Analysis Part 2: utilization in clinical practice. Clinical Nutrition 23, 1430‐1453, 2004. 6. Barbosa‐Silva, M.C.G., Barros, A.J.D. et al. Bioelectrical Impedance Analysis: population reference values for phase angle by age and sex. American Journal of Clinical Nutrition, 82;49‐ 52, 2005. 7. Roche A, Heymsfield S, Lohman T, Human Body Composition, Human Kinetics, Champaign IL, 1996. 8. American Journal of Clinical Nutrition, Bioelectrical Impedance, Supplement. September 1996. 9. Cherlow GM, Lazarus JM, Lew NL et al. Bioimpedance norms for the hemodialysis population. Kidney Int. Dec;52(6):1617‐21, 1997. 10. Coodley EL, Segal JL, Smith DH et al. Bioelectrical Impedance analysis as an assessment of diuresis in congestive heart failure. Ann Pharmacother, Nov; 29(11):1091‐5. 1995
11. Foster KR and Lukaski HC. Whole‐body impedance‐‐‐what does it measure? AJCN 1996;64:388S‐ 96S. 1996. 12. Ghosh S, Meister D, Cowen S, Hannan WJ, Ferguson A. Body composition at the bedside. Eur J Gastroenterology Hepatol, 9(8):783‐8. 1997. 13. Hannan WJ, Cowen CE, Plester KC et al. Comparison of bio‐impedance spectroscopy and multi‐ frequency BIA for the assessment of extracellular and total body water in surgical patients. Clinical Science, 89:651‐658, 1995. 14. Kushner R. Schoeller DA. Estimation of total body water by bioelectrical impedance analysis. AJCN,44 417‐424, 1986. 15. Lukaski HC. et al, Assessment of fat free mass using bioelectrical impedance measurement of the human body. AJCN;41:810. 1985. 16. Lukaski HC. Biological indexes considered in the derivation of the bioelectrical impedance analysis. AJCN, 64:397S‐404S, 1996. 17. Madore F, Wuest M, Ethier JH. Nutritional evaluation of hemodialysis patients using an impedance index. Clin Nephrol, 41:377‐82, 1994. 18. Olde Rikkert MG, Deurenberg P, Jansen RW. Validation of multi‐frequency BIA in detecting changes in fluid balance of geriatric patients. Journal of the American Geriatric Society, Nov:45(11):1345‐51, 1997. 19. Oldham NM. How should BIA be performed, and how can measurement be standardized? Overview of bioelectrical impedance analyzers. AJCN, 64:405S‐12S, 1996. 20. Ott M; Fischer H; Polat H; Helm EB; Frenz M; Caspary WF; Lembcke B. Bioelectrical impedance analysis as a predictor of survival in patients with human immunodeficiency virus infection. J Acquir Immune Defic Syndr Hum Retrovirol, May 1;9(1):20‐5, 1995. 21. Scalfi L, Marra M, Caldara A et al. Changes in bioimpedance after stable refeeding or undernourished anorexic patients. Int J Obes Relat Metab Disord. Feb;23(2):133‐7, 1999. 22. Stall S, Ginsberg NS, Lynn RI, Zabetakis PM. Bioelectrial Impedance Analysis and Dual X‐Ray Absorptiometry to monitor nutritional status. Perit Dial Int, 15(5) (Supp), 1995. 23. Zabetakis PM, Stall S, Frapf R et al. Body Composition and nutritional indices in peritoneal dialysis. Perit Dial Int, 14:523, 1994.
of charges or electrochemical gradients) that may be produced by cell membranes and tissue interfaces. Capacitance causes the administered current to lag behind the voltage and creates a phase shift that is represented by the phase angle (Lukaski, 1996). The clinical systems may have more than one frequency setting (5 to 200 kHz) to improve accuracy when testing very thin or very obese subjects (Hannan, 1995 & Lukaski, 1996). BIA Testing The ideal test time is in the morning before breakfast and before having had a physical workout or if later in the day, at least four hours since the last meal with no workout, coffee or alcohol during the day of the test (Heyward, 1996). This assures a more accurate body fat mass measure but in not necessary if the goal is to test random hydration. Good hydration is essential for very muscular subjects because of the water content of muscle. Lukaski (1985) reported dehydration increases resistance (approximately 40 ohms) resulting in an underestimation of fat free mass and overestimation of fat mass. Morning test results may be slightly different from those taken after lunch. Using a consistent time of day for repeat tests with individual patients is advised. Lower hydration scores may also be recorded at the end of the week in the active working population. In general follow the guidelines and use electrodes and supplies recommended by the manufacturer. When developing equations for a specific population group use a meter that provides both resistance and reactance scores. Height, weight, sex and age are usually entered into the programs. Where height and weight are not available some research is underway to use a resistance/impedance or reactance measure alone (e.g. frail elderly or critically ill patients) (Olde et al 1997). BIA Test Interpretation The following is an explanation of the type of information seen on a software printout. Equations used in software are patented and will vary slightly from system to system. Total Body Water (TBW) is an estimate of total hydration level, including intracellular and extracellular water (Kushner et al, 1986). It should be available in litres and as a percent with a normal range. For optimal hydration this reading should be in the upper half of the normal range and vary with age, sex and body fat. If not, check the patient's fluid intake. The more obese a subject, the lower the percent total hydration and this may be normal for them given a good fluid intake. However litre volumes will be normal or high normal. Clinicians have mistakenly tried increased the fluid intake of obese individuals to improve this score. In general percent TBW will go up as weight goes down. Intracellular Water (ICW) is an estimate of the water in active tissue and should be provided in litres and as a percent of a normal range (near 60% of TBW). ICW will be in the high range with a large amount of muscle in a well hydrated subject and may a proxy for muscle mass. Drops in this compartment indicate lower hydration or a loss of active cell mass in catabolic patients. Nutrition plans are implemented to restore or increase ICW litre volume. Extracellular Water (ECW) is water in tissues and plasma and should be provided in litres and as a percent of a normal range (near 40% of TBW). It should be close to the low normal range in males and
may be in the low or mid range for females. Subjects with very low body fat will have a lower ECW and subjects with high body fat will have an associated high ECW. Women on OCA have consistently higher scores while women not on OCA may have more varied scores. Heyward (1996) discusses women's cycles in detail. In catabolic patients the litre volume in this compartment will increase with poor cell membrane transport. Nutrition plans or medication may be implemented to reduce ECW litre volume (Coodley et al 1995). Body Cell Mass (BCM) is an estimate of total pounds/kg of all active cells. The percent BCM will be in the normal range if the subject is close to his/her ideal body weight. It appears as a low percent in obese subjects but the pounds/kg will be high normal in the active obese individual and low in the catabolic obese patient. Many overweight subjects have very high BCM in pounds/kg even though their percent BCM does not appear to be in the normal range. It is important to maintain or improve BCM when writing nutrition care plans or exercise program. As body fat is lost, BCM percent will come into the normal range. BCM declines in catabolic patients or with drops or changes in physical activity or with conditions producing muscle loss. Nutrition plans are implemented to maintain, restore or increase BCM, ICW litre volume and to prevent excess gain of ECW. Extracellular Tissue (ECT)/Extracellular Mass (ECM) is an estimate of the mass of all other non‐muscle inactive tissues including ligaments, bone and ECW. ECT is usually higher than BCM but will be lower than BCM in very anabolic subjects with normal or low ECW(BCM/ECT ratio >1. German researchers (Fischer & Ott, 1990) have used a ratio of ECM/BCM (.7 ‐ 1.0 normal range) to monitor improvements in nutrition in HIV patients. Increasing scores on serial tests were consistent with a decline in status. Fat Free Mass (FFM)/Lean Body Mass (LBM) is an estimate of the entire mass that is not fat. It should be available in pounds/kg and may be presented as a percent with a normal range. This compartment will change with hydration and loss or gain of BCM. This alone is not as sensitive a measure when trying to determine loss of body cell mass. Fat Mass (FM) is an estimate of pounds/kg of body fat and percentage body fat. The notion comparing pounds/kg of Fat Mass with BCM has revealed a clinical comparison measure for practice (FM/BCM ratio). Qualitative assessment of clinical data on satisfaction with body size, showed women are content with the same number of pounds of fat mass as BCM and men are content with half as much Fat Mass as BCM independent of percent body fat (BIA unpublished observations, Schneider (1996‐99). The client goal for women is to reach a ratio of FM/BCM of 1.0. For men the ratio would be .5). Athletic individuals are not satisfied with this high a ration and may have lower pounds of body fat than these standards depending on their sport and the body weight requirement. Percent body fat alone as a measure continues to discourage large framed, physically active individuals and reduces satisfaction with body image because of unrealistic normal values well established in the popular press. In fact clinical BIA data collected (Schneider, 1996‐99) on large numbers of men and women with ideal body weight, shows that both men and women carry 40 to 45 pounds (18 to 20 kg) of body fat for a wide range of heights. Using the FM/BCM ratio is a more positive way to present information to patients and allow active goal setting in relation to BCM maintenance and gradual loss or gain of body fat. More qualitative/quantitative research is being carried out on this subject.
Phase Angle (PA) is believed to be associated with both nutrition and physical fitness. For example a stroke patient with one source of nutrition (via mouth), will have a higher phase angle on his/her active side of the body than on the inactive side of the body. It is believed that the phase angle may indicate the presence of fully functional cell membrane transport systems. Phase angle scores are between 3 and 10 degrees and vary with age, sex, race, physical activity and the presence of health and disease. Scores rise in the teen age years from 5 to 7 as growth becomes complete. Similar individual scores may continue until the forth and fifth decade when scores begin to drop and gradually reduced to the 4‐6 range in seniors. Scores of 8 or 9 are rare, only seen in well nourished physically active subjects such as body builders. High scores may be seen in well nourished obese subjects. Research is being carried out to determine variations by race. In catabolic patients, there will be an associated drop in ICW, BCM and an increase in ECW, which will be improved effectively with an implemented nutrition plan (Scalfi et al, 1999). Studies on HIV and renal patients found the phase angle was correlated with serum albumin, pre albumin, creatinine and was the most predictive indicator of impending mortality in critically ill patients (Cherlow et al, 1997; Ott et al, 1995). More research is being done in Canada and the U.S. to determine applications by age, sex, race, rehabilitation programs and specific catabolic conditions and nutrition interventions with monitoring of several assessment variables to determine the best practices.
References 1. Gupta, D., Christopher, G.L. et al. The relationship between bioelectrical impedance phase angle and subjective global assessment in advanced colorectal cancer. Nutrition Journal 7:19doi:10.1186/1475‐2891‐7‐19, 2008. 2. Susanne Hengstermann, Andreas Fischer, MD, Elisabeth Steinhagen‐Thiessen, MD, PhD and Ralf‐ Joachim Schulz, MD, PhD, Nutrition Status and Pressure Ulcer: What We Need for Nutrition Screening. Journal of Parenteral and Enteral Nutrition, Vol. 31, No. 4, 288‐294 (2007) 3. Heyward, V., and Wagner, D. Applied Body Composition Assessment, Second Edition, Human Kinetics, Champaign IL, 2004. 4. Kyle, U.G., Bosaeus, I. Et al. ESPEN Guidelines 2004, Bioelectrical Impedance Analysis Part 1: review of principles and methods. Clinical Nutrition 23, 1226‐1243, 2004. 5. Kyle, U.G., Bosaeus, I. Et al. ESPEN Guidelines 2004, Bioelectrical Impedance Analysis Part 2: utilization in clinical practice. Clinical Nutrition 23, 1430‐1453, 2004. 6. Barbosa‐Silva, M.C.G., Barros, A.J.D. et al. Bioelectrical Impedance Analysis: population reference values for phase angle by age and sex. American Journal of Clinical Nutrition, 82;49‐ 52, 2005. 7. Roche A, Heymsfield S, Lohman T, Human Body Composition, Human Kinetics, Champaign IL, 1996. 8. American Journal of Clinical Nutrition, Bioelectrical Impedance, Supplement. September 1996. 9. Cherlow GM, Lazarus JM, Lew NL et al. Bioimpedance norms for the hemodialysis population. Kidney Int. Dec;52(6):1617‐21, 1997. 10. Coodley EL, Segal JL, Smith DH et al. Bioelectrical Impedance analysis as an assessment of diuresis in congestive heart failure. Ann Pharmacother, Nov; 29(11):1091‐5. 1995
11. Foster KR and Lukaski HC. Whole‐body impedance‐‐‐what does it measure? AJCN 1996;64:388S‐ 96S. 1996. 12. Ghosh S, Meister D, Cowen S, Hannan WJ, Ferguson A. Body composition at the bedside. Eur J Gastroenterology Hepatol, 9(8):783‐8. 1997. 13. Hannan WJ, Cowen CE, Plester KC et al. Comparison of bio‐impedance spectroscopy and multi‐ frequency BIA for the assessment of extracellular and total body water in surgical patients. Clinical Science, 89:651‐658, 1995. 14. Kushner R. Schoeller DA. Estimation of total body water by bioelectrical impedance analysis. AJCN,44 417‐424, 1986. 15. Lukaski HC. et al, Assessment of fat free mass using bioelectrical impedance measurement of the human body. AJCN;41:810. 1985. 16. Lukaski HC. Biological indexes considered in the derivation of the bioelectrical impedance analysis. AJCN, 64:397S‐404S, 1996. 17. Madore F, Wuest M, Ethier JH. Nutritional evaluation of hemodialysis patients using an impedance index. Clin Nephrol, 41:377‐82, 1994. 18. Olde Rikkert MG, Deurenberg P, Jansen RW. Validation of multi‐frequency BIA in detecting changes in fluid balance of geriatric patients. Journal of the American Geriatric Society, Nov:45(11):1345‐51, 1997. 19. Oldham NM. How should BIA be performed, and how can measurement be standardized? Overview of bioelectrical impedance analyzers. AJCN, 64:405S‐12S, 1996. 20. Ott M; Fischer H; Polat H; Helm EB; Frenz M; Caspary WF; Lembcke B. Bioelectrical impedance analysis as a predictor of survival in patients with human immunodeficiency virus infection. J Acquir Immune Defic Syndr Hum Retrovirol, May 1;9(1):20‐5, 1995. 21. Scalfi L, Marra M, Caldara A et al. Changes in bioimpedance after stable refeeding or undernourished anorexic patients. Int J Obes Relat Metab Disord. Feb;23(2):133‐7, 1999. 22. Stall S, Ginsberg NS, Lynn RI, Zabetakis PM. Bioelectrial Impedance Analysis and Dual X‐Ray Absorptiometry to monitor nutritional status. Perit Dial Int, 15(5) (Supp), 1995. 23. Zabetakis PM, Stall S, Frapf R et al. Body Composition and nutritional indices in peritoneal dialysis. Perit Dial Int, 14:523, 1994.
