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35 Hyperkalemia in advanced diabetes: potassium retention or cell transport adaptation? A case control study with body composition analysis
Mark L. Graber, Walton W. Shreeve, Ruimei Ma, Jean Richards and Richard N. Pierson, Jr.
36 Longitudinal measurements of total body water and body composition in healthy volunteers by online
breath deuterium measurement and other near-subject methods
Barbara Engel BSc, Patrik Spanel PhD, David Smith DSc, FRS, Ann Diskin PhD and Simon J. Davies MD, FRCP
37 Prediction of total body skeletal muscle mass from fat-free mass or intra-cellular water
Paul Deurenberg, Angelo Pietrobelli, ZiMian Wang and Steven B. Heymsfield
38 Comparison of body composition methodologies: determining what is most practical for the hospital,research laboratory or remote field study
Bert B. Boyer, Moonseong Heo, David B. Allison, Nicole T. Liebenstein, Irene S. Cho, ZiMian Wang and Steven B. Heymsfield
39 Accuracy of dietary energy reporting in young New Zealand men and women: relationships to body composition, physical activity level and ethnicity
E.C. Rush, L.D. Plank, M. Laulu, E. Mitchelson and W.A. Coward
International Journal of Body Composition Research 2004, Vol. 2 No. 3: 93-98
Mark L. Graber, Walton W. Shreeve, Ruimei Ma, Jean Richards and Richard N. Pierson, Jr.
Northport VA Medical Center, Northport, NY; Department of Medicine, SUNY at Stony Brook, NY; Brookhaven National Laboratory, Upton, NY and The Body Composition Unit, St Lukes/Roosevelt Hospital Center, New York, NY, USA
Hyperkalemia in diabetes is not uncommon, and has been thought to reflect renal retention of potassium. The goal of this study was to test this hypothesis by measuring total body potassium in hyperkalemic diabetic patients and normokalemic diabetic controls. We measured total body potassium (whole body counting of 40K), total body sodium, calcium, and chloride by neutron activation analysis, total body carbon by inelastic neutron scattering, and total body water from the distribution of 3H20. Measurements were made in 17 diabetic controls (mean plasma K = 4.47 mEq/l) and 14 diabetic patients with hyperkalemia (K = 5.26 mEq/l). All subjects were adult male Type II diabetic patients of comparable age, duration of disease, glycemic control, and end-organ complications. Total body potassium normalized by fat-free mass, total body water, or urinary creatinine was essentially identical (or slightly reduced) in the hyperkalemic subjects compared to controls. Additionally, the hyperkalemic diabetics were found to have significantly decreased body weight (77.2 kg hyperkalemics vs 92.9 kg control, P<0.001; BMI 26.7 vs 30.4 kg/m2, P = 0.002), and decreased fat-free mass (59.0 vs 66.2 kg, P < 0.05). It is concluded that the findings argue against the traditional belief that the hyperkalemia of advanced diabetes is solely renal in origin. We suggest that a fundamental defect in this disorder is a generalized derangement of cellular ion transport, resulting in cellular potassium depletion and a shift of potassium from the cell to the extracellular space. This elevates plasma potassium directly, and by depleting intracellular potassium contributes to decreased renal potassium secretion. In light of these findings of unchanged or reduced total body potassium in hyperkalemic diabetics, the routine use of diuretics to treat these patients may need to be re-examined. In addition, the findings demonstrate a novel observation in this syndrome, decreased fat and fat-free body mass.
International Journal of Body Composition Research 2004, Vol. 2 No. 3: 99-106
Barbara Engel BSc1, Patrik Spanel PhD2,3, David Smith DSc, FRS2, Ann Diskin PhD2 and Simon J. Davies MD,
1Department of Nephrology, University Hospital of North Staffordshire, Stoke-on-Trent; 2Institute of Science and Technology in Medicine, Keele University, Stoke-on-Trent, UK; 3V. Cermák Laboratory, J. Heyrovsky´ Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejskova 3, 182 23, Prague 8, Czech Republic
Rapid quantification of breath deuterium abundance by flowing afterglow mass spectrometry (FA-MS) enables accurate measurement of total body water (TBW), which combined with other techniques such as bioelectrical impedance analysis (BIA) and anthropometrics enables near-subject assessment of body composition. This study assessed the comparative reproducibility and inter-relationship of these methods in healthy subjects over 12 months. Detailed bedside composition was performed in 22 subjects, (10 male) aged 28–79 with body mass index (BMI) ranging from 21–38 at baseline and again at one year. Techniques included FA-MS deuterium dilution, BIA, skin-fold thickness (SFT) and soft tissue ultrasound measurement of fat and muscle depth. Short-term reproducibility for each method was established. Within and between technique comparisons of measurement were made from Pearson’s linear regression, coefficient of variation (CV) and Bland-Altman analysis. Weight and TBW estimated by FA-MS, BIA and SFT at baseline and one year later were highly correlated (R2 = 0.96–0.98), slope 1.02–1.03, CV = 4.5–11.6%. Systematic errors between the different methods in determining TBW were effectively identical at baseline and after one year. There was a tendency for subjects to gain weight during the study period, due to an increase, predominantly in younger women, of body water (FA-MS and SFT) and loss of upper body fat (ultrasound). BIA was relatively insensitive to these changes. It is concluded that over a 12-month period, TBW determined by FA-MS deuterium breath analysis has reproducibility similar to conventional weighing. The stability of between method errors would suggest that these techniques might be used in conjunction with each other in the longitudinal determination of body composition and so detect relatively subtle changes. The value of including an absolute determinant of TBW by FA-MS that is independent of the need to employ population derived equations, appears to be of value in the near-subject determination of body composition as required in clinical practice.
International Journal of Body Composition Research 2004, Vol. 2 No. 3: 107-113
Paul Deurenberg1, Angelo Pietrobelli2, ZiMian Wang3 and Steven B. Heymsfield3
1Nutrition Consultant, Singapore; 2Verona University Medical School, Pediatric Unit, Verona, Italy; 3Obesity Research Center, St Luke’s-Roosevelt Hospital, College of Physicians and Surgeons, Columbia University, New York, NY, USA
Skeletal muscle mass (SMM) is the largest single contributor to body composition at the tissue level, yet its measurement is not very common and requires radiological techniques like magnetic resonance imaging (MRI), computer tomography (CT), 40K counting and/or in-vivo neutron activation analysis for total body nitrogen. Today MRI and CT are regarded as reference methods. SMM predicted from anthropometry or bioelectrical impedance has a large prediction error and is only valuable for groups of subjects. Based on chemical data of 14 the reference man and on data of the chemical composition of muscle tissue, two formulas were developed to assess SMM from fat-free mass (FFM) or from intra-cellular water (ICW). The formulas (SMM (kg) = 0.566*FFM; SMM (kg) = 1.34*ICW) were validated on individual and group data reported in the literature and were also compared with SMM data calculated from 24 h creatinine excretion in a group of healthy males and females. Published individual SMM data measured by CT (34.4 ± 6.2 kg) in 17 healthy male subjects were not significant different from SMM calculated from ICW (34.7 ± 6.1 kg) and only slightly lower than SMM calculated from FFM (35.1 ± 5.5 kg). Reported group SMM data obtained by MRI in various age groups (20 years to >70 years) of both sexes were not different from SMM calculated from ICW. Skeletal muscle mass (kg) from ICW could be calculated as 1.024 ¥ SMMMRI – 0.8, with an explained variance of 0.99 and a standard error of estimate of 0.4 kg. The slope and intercept were not significantly different from one and zero respectively. In a group of 8 males SMM from FFM or from ICW was not different from SMM obtained from 24 h creatinine excretion, but in females the SMM calculated from ICW was slightly lower compared to SMM from creatinine. This bias might be due to a different than assumed water distribution over the extra and intra-cellular space in women compared to man. It is concluded that the calculation formulas provide a reliable tool to assess SMM at a group level. However, before they can be used with confidence in individuals, direct validation against reference methods like MRI is needed.
International Journal of Body Composition Research 2004, Vol. 2 No. 3: 115-124
Bert B. Boyer1,2, Moonseong Heo3, David B. Allison4, Nicole T. Liebenstein1, Irene S. Cho1, ZiMian Wang1 and Steven B. Heymsfield1
1Obesity Research Center, St. Luke’s-Roosevelt Hospital, Columbia University College of Physicians and Surgeons, New York; 2University of Alaska Fairbanks, Center for Alaska Native Health Research, Institute of Arctic Biology, Fairbanks, AK; 3Department of Psychiatry, Westchester Division, Weill Medical College of Cornell University, New York; 4Department of Biostatistics and Center for Research on Clinical Nutrition, University of Alabama at Birmingham, Birmingham, USA
The study objective was to compare the accuracy of portable and hospital or laboratory-based body composition
methods, as well as to evaluate reference methods that may be necessary for the development of population-specific
phenotyping equations in field-study settings. Subjects were healthy adults of mixed ethnicity from the
greater New York metropolitan area. Adiposity was evaluated by whole-body magnetic resonance imaging
(MRI), dual energy x-ray absorptiometry (DXA), underwater weighing (UWW), air displacement plethysmography
(ADP), isotope dilution (ID), bioimpedance analysis (BIA), and anthropometry (ANTH). Anthopometric
measurements included height, weight, and skinfolds. MRI was selected as the reference for assessing total body
adiposity. Pearson correlation coefficients with MRI-derived adipose tissue mass and fat mass measured by the
other methods were: DXA (r=0.98, n=251), ADP (r=0.98, n=73), UWW (r=0.96, n=216), ID (r=0.95,n=248), ANTH
(r=0.94, n=235), and BIA (r=0.92, n=218). Pearson correlations of %fat with MRI adiposetissue estimates resulted
in the same order. Similar results were obtained from concordance correlation coefficients between methods for
both adipose tissue % and mass as well as from Bland-Altman analysis. For mass estimates, the MRI-DXA correlation
was not significantly different from the MRI-ADP correlation but it was different from the MRI-ID, MRI-UWW,
MRI-ANTH, and MRI-BIA correlations at P<0.05 based on the bootstrap method. Nevertheless, the MRI-DXA concordance
correlation coefficient was significantly different from the others. In conclusion, DXA fat measurements
are the most highly correlated with and concordant to MRI estimates of adipose tissue mass. Although ADP may
be the only other comparable method with MRI, DXA and ADP may not be practical for field studies. In our discussion,
we compare and contrast options for field studies where more transportable methods are essential, and where cultural isolation of the population being studied may impact the comfort level of participants, the quality of phenotypes collected, and ultimately, the overall participation rate.
International Journal of Body Composition Research 2004, Vol. 2 No. 3: 125-130
1E.C. Rush, 2L.D. Plank, 1M. Laulu, 3E. Mitchelson and 4W.A. Coward
1Body Composition and Metabolism Research Centre, Auckland University of Technology; 2Department of Surgery, University of Auckland; 3School of Health Science, Unitec, Auckland, New Zealand; 4MRC, Human Nutrition Research, Cambridge, UK
Accurate determination of energy and nutrient intake in free-living people is a vital component of nutritional studies exploring the relationships between diet and disease. Our objective was to examine accuracy of reported energy intake in young adults and the potential factors that may affect accuracy. Total energy expenditure (TEE), by the doubly-labelled water technique, and resting metabolic rate (RMR), by indirect calorimetry, were measured in 78 women (39 European, 12 Maori, 27 Pacific Island) and 29 men (10 European, 10 Maori, 9Pacific Island) aged 18-27 y. Total body water was determined from the 18O dilution space and used to calculate percentage body fat (%BF), assuming a constant (73%) hydration of the fat-free mass. Energy intake was assessed from self-reported 7-day diet diaries. The ratio of TEE to RMR was calculated as an index of physical activity level. Reported energy intake averaged 77 ± 23 (SD) % of TEE and there were no gender or ethnicity differences. This proportion was significantly lower for obese than non-obese European women (0.62 ± 0.13 vs 0.86 ± 0.25, P = 0.0004) but did not differ between these groups in Maori and Pacific women or in men. Higher activity was associated with more under-reporting of energy intake. PAL and %BF were negatively correlated (r = -0.68, P<0.0001) in men and Maori women (r = -0.62, P = 0.031) but uncorrelated in European and Pacific Island women. We found significant under-reporting of energy intake in young adults across three ethnic groups. Higher under-reporting was associated with higher %BF and BMI in European women.
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