Academic potential and cognitive functioning of long-term survivors after childhood liver transplantation.

This cross-sectional study assessed intellect, cognition, academic function, behaviour, and emotional health of long-term survivors after childhood liver transplantation. Eligible children were >5 yr post-transplant, still attending school, and resident in Queensland. Hearing and neurocognitive testing were performed on 13 transplanted children and six siblings including two twin pairs where one was transplanted and the other not. Median age at testing was 13.08 (range 6.52-16.99) yr; time elapsed after transplant 10.89 (range 5.16-16.37) yr; and age at transplant 1.15 (range 0.38-10.00) yr. Mean full-scale IQ was 97 (81-117) for transplanted children and 105 (87-130) for siblings. No difficulties were identified in intellect, cognition, academic function, and memory and learning in transplanted children or their siblings, although both groups had reduced mathematical ability compared with normal. Transplanted patients had difficulties in executive functioning, particularly in self-regulation, planning and organization, problem-solving, and visual scanning. Thirty-one percent (4/13) of transplanted patients, and no siblings, scored in the clinical range for ADHD. Emotional difficulties were noted in transplanted patients but were not different from their siblings. Long-term liver transplant survivors exhibit difficulties in executive function and are more likely to have ADHD despite relatively intact intellect and cognition.

The effects of weight loss strategies on gastric emptying and appetite control.

The gastrointestinal tract plays an important role in the improved appetite control and weight loss in response to bariatric surgery. Other strategies which similarly alter gastrointestinal responses to food intake could contribute to successful weight management. The aim of this review is to discuss the effects of surgical, pharmacological and behavioural weight loss interventions on gastrointestinal targets of appetite control, including gastric emptying. Gastrointestinal peptides are also discussed because of their integrative relationship in appetite control. This review shows that different strategies exert diverse effects and there is no consensus on the optimal strategy for manipulating gastric emptying to improve appetite control. Emerging evidence from surgical procedures (e.g. sleeve gastrectomy and Roux-en-Y gastric bypass) suggests a faster emptying rate and earlier delivery of nutrients to the distal small intestine may improve appetite control. Energy restriction slows gastric emptying, while the effect of exercise-induced weight loss on gastric emptying remains to be established. The limited evidence suggests that chronic exercise is associated with faster gastric emptying, which we hypothesize will impact on appetite control and energy balance. Understanding how behavioural weight loss interventions (e.g. diet and exercise) alter gastrointestinal targets of appetite control may be important to improve their success in weight management.

Defining anthropometric cut-off levels related to metabolic risk in a group of Sri Lankan children.

BACKGROUND: Body mass index (BMI) is widely used as a measure of adiposity. However, currently used cut-off values are not sensitive in diagnosing obesity in South Asian populations. AIM: To define BMI and waist circumference (WC), cut-off values representing percentage fat mass (%FM) associated with adverse health outcomes. SUBJECTS AND METHODS: A cross-sectional descriptive study of 285 5-14 year old Sri Lankan children (56% boys) was carried out. Fat mass (FM) was assessed using the isotope (D(2)O) dilution technique based on 2C body composition model. BMI and WC cut-off values were defined based on %FM associated with adverse health outcomes. RESULTS: Sri Lankan children had a low fat free mass index (FFMI) and a high fat mass index (FMI). Individuals with the same BMI had %FM distributed over a wide range. Lean body tissue grew very little with advancing age and weight gain was mainly due to increases in body fat. BMI corresponding to 25% in males and 35% in females at 18 years was 19.2 kg/m(2) and 19.7 kg/m(2), respectively. WC cut-off values for males and females were 68.4 cm and 70.4 cm, respectively. CONCLUSION: This chart analysis clearly confirms that Sri Lankan children have a high %FM from a young age. With age, more changes occur in FM than in fat free mass (FFM). Although the newly defined BMI and WC cut-off values appear to be quite low, they are comparable to some recent data obtained in similar populations.

Validity of currently used cutoff values of body mass index as a measure of obesity in Sri Lankan children.

OBJECTIVE: The aim of the study was to determine the reliability of body mass index based (BMI) cutoff values in diagnosing obesity among Sri Lankan children. METHODS: Height, weight, waist circumference (WC) and hip circumference (HC) in 282 children were measured. Total body water was determined by deuterium dilution and fat mass (FM) derived using age and gender specific constants. A percentage FM of 30% for girls and 25% for boys were considered as cutoff levels for obesity. RESULTS: Two hundred and eighty two children (M/F: 158/124) were studied and 99 (80%) girls and 72 (45.5%) boys were obese based on % body fat. Eight (6.4%) girls and nine (5.7%) boys were obese based on International Obesity Task Force (IOTF) cutoff values. Percentage FM and WC centile charts were able to diagnose a significant proportion of children as true obese children. The FM and BMI were closely associated in both girls (r = 0.82, p < 0.001) and boys (r = 0.87, p < 0.001). Percentage FM and BMI had a very low but significant association; girls (r = 0.32, p < 0.001) and boys (r = 0.68, p < 0.001). FM had a significant association with WC and HC. BMI based cutoff values had a specificity of 100% but a very low sensitivity, varying between 8% and 23.6%. CONCLUSIONS: BMI is a poor indicator of the percentage fat and the commonly used cutoff values were not sensitive to detect cases of childhood obesity in Sri Lankan children.

Assessment of body composition in Sri Lankan children: validation of a skin fold thickness equation.

BACKGROUND: Morbidity associated with obesity is related to the fat mass (FM) of the body. The direct estimation of FM is difficult. Skin fold thickness (SFT) is a simple and cheap alternative for accurate assessment of FM, and population specific equations are necessary for accurate assessment of FM using SFT. OBJECTIVE: To develop a SFT prediction equation to estimate FM of Sri Lankan children. DESIGN, SETTING AND METHOD: Across-sectional descriptive study was done at the University Paediatric Unit of Lady Ridgeway Hospital, Colombo. Data were collected from 5 to 15 year old healthy children. Triceps, biceps, supra-iliac and subscapular SFT were measured using Harpendens skin fold caliper. Total body water was assessed using an isotope dilution method (D2O), and fat free mass calculated. FM was assessed based on 2 compartment body composition model. Multiple regression analysis was used to develop prediction equation and validated using PRESS (prediction of sum of squares) statistical technique. Independent variables were age, triceps SFT, subscapular SFT and sex. RESULTS: Prediction equation for FM [(0.68 x age) + (0.246 x triceps SFT) + (0.383 x subscapular SFT) - (1.61 x sex code) -3.45] was able to predict 76.4% of variance with a root mean squared error (RMSE) of 3.4 kg. PRESS statistics was 3.4 kg with press residuals of 1.56 kg. Bland-Altman technique showed that the majority of the residuals were within mean bias +/-1.96 SD. CONCLUSION: Results of this study provide an SFT equation for the prediction of FM in Sri Lankan children.

Assessment of body composition in Sri Lankan children: validation of a bioelectrical impedance prediction equation.

OBJECTIVE: To develop bioelectrical impedance analysis (BIA) equations to predict total body water (TBW) and fat-free mass (FFM) of Sri Lankan children. SUBJECTS/METHODS: Data were collected from 5- to 15-year-old healthy children. They were randomly assigned to validation (M/F: 105/83) and cross-validation (M/F: 53/41) groups. Height, weight and BIA were measured. TBW was assessed using isotope dilution method (D(2)O). Multiple regression analysis was used to develop preliminary equations and cross-validated on an independent group. Final prediction equation was constructed combining the two groups and validated by PRESS (prediction of sum of squares) statistics. Impedance index (height(2)/impedance; cm(2)/Omega), weight and sex code (male=1; female=0) were used as variables. RESULTS: Independent variables of the final prediction equation for TBW were able to predict 86.3% of variance with root means-squared error (RMSE) of 2.1 l. PRESS statistics was 2.1 l with press residuals of 1.2 l. Independent variables were able to predict 86.9% of variance of FFM with RMSE of 2.7 kg. PRESS statistics was 2.8 kg with press residuals of 1.4 kg. Bland Altman technique showed that the majority of the residuals were within mean bias+/-1.96 s.d. CONCLUSIONS: Results of this study provide BIA equation for the prediction of TBW and FFM in Sri Lankan children. To the best of our knowledge there are no published BIA prediction equations validated on South Asian populations. Results of this study need to be affirmed by more studies on other closely related populations by using multi-component body composition assessment.

Resting energy expenditure in children with inflammatory bowel disease.

OBJECTIVES: There is controversy in the literature regarding the effect of inflammatory bowel disease (IBD) on resting energy expenditure (REE). In many cases this may have resulted from inappropriate adjustment of REE measurements to account for differences in body composition. This article considers how to appropriately adjust measurements of REE for differences in body composition between individuals with IBD. PATIENTS AND METHODS: Body composition, assessed via total body potassium to yield a measure of body cell mass (BCM), and REE measurements were performed in 41 children with Crohn disease and ulcerative colitis in the Royal Children's Hospital, Brisbane, Australia. Log-log regression was used to determine the power function to which BCM should be raised to appropriately adjust REE to account for differences in body composition between children. RESULTS: The appropriate value to "adjust" BCM was found to be 0.49, with a standard error of 0.10. CONCLUSIONS: Clearly, there is a need to adjust for differences in body composition, or at the very least body weight, in metabolic studies in children with IBD. We suggest that raising BCM to the power of 0.5 is both a numerically convenient and a statistically valid way of achieving this aim. Under circumstances in which the measurement of BCM is not available, raising body weight to the power of 0.5 remains appropriate. The important issue of whether REE is changed in cases of IBD can then be appropriately addressed.

'Free' surfactant in gastric aspirates and bronchoalveolar lavage in children with and without reflux oesophagitis.

AIM: Dipalmitoylphosphatidycholine (DPPC) is the characteristic and main constituent of surfactant. Adsorption of surfactant to epithelial surfaces may be important in the masking of receptors. The aims of the study were to (i) compare the quantity of free DPPC in the airways and gastric aspirates of children with gastroesophageal reflux disease (GORD) to those without and (ii) describe the association between free DPPC levels with airway cellular profile and capsaicin cough sensitivity. METHODS: Children aged <14 years were defined as 'coughers' if a history of cough in association with their GORD symptoms was elicited before gastric aspirates and nonbronchoscopic bronchoalveolar lavage (BAL) were obtained during elective flexible upper gastrointestinal endoscopy. GORD was defined as histological presence of reflux oesophagitis. Spirometry and capsaicin cough-sensitivity test was carried out in children aged >6 years before the endoscopy. RESULTS: Median age of the 68 children was 9 years (interquartile range (IQR) 7.2). Median DPPC level in BAL of children with cough (72.7 microg/mL) was similar to noncoughers (88.5). There was also no significant difference in DPPC levels in both BAL and gastric aspirates of children classified according to presence of GORD. There was no correlation between DPPC levels and cellular counts or capsaicin cough-sensitivity outcome measures. CONCLUSION: We conclude that free DPPC levels in the airways and gastric aspirate is not influenced by presence of cough or GORD defined by histological presence of reflux oesophagitis. Whether quantification of adsorbed surfactant differs in these groups remain unknown. Free DPPC is unlikely to have a role in masking of airway receptors.

Airway cellularity, lipid laden macrophages and microbiology of gastric juice and airways in children with reflux oesophagitis.

BACKGROUND: Gastroesophageal reflux disease (GORD) can cause respiratory disease in children from recurrent aspiration of gastric contents. GORD can be defined in several ways and one of the most common method is presence of reflux oesophagitis. In children with GORD and respiratory disease, airway neutrophilia has been described. However, there are no prospective studies that have examined airway cellularity in children with GORD but without respiratory disease. The aims of the study were to compare (1) BAL cellularity and lipid laden macrophage index (LLMI) and, (2) microbiology of BAL and gastric juices of children with GORD (G+) to those without (G-). METHODS: In 150 children aged < 14-years, gastric aspirates and bronchoscopic airway lavage (BAL) were obtained during elective flexible upper endoscopy. GORD was defined as presence of reflux oesophagitis on distal oesophageal biopsies. RESULTS: BAL neutrophil% in G- group (n = 63) was marginally but significantly higher than that in the G+ group (n = 77), (median of 7.5 and 5 respectively, p = 0.002). Lipid laden macrophage index (LLMI), BAL percentages of lymphocyte, eosinophil and macrophage were similar between groups. Viral studies were negative in all, bacterial cultures positive in 20.7% of BALs and in 5.3% of gastric aspirates. BAL cultures did not reflect gastric aspirate cultures in all but one child. CONCLUSION: In children without respiratory disease, GORD defined by presence of reflux oesophagitis, is not associated with BAL cellular profile or LLMI abnormality. Abnormal microbiology of the airways, when present, is not related to reflux oesophagitis and does not reflect that of gastric juices.

Validity of BMI as a measure of obesity in Australian white Caucasian and Australian Sri Lankan children.

BACKGROUND: Body mass index (BMI) is used to diagnose obesity. However, its ability to predict the percentage fat mass (%FM) reliably is doubtful. Therefore validity of BMI as a diagnostic tool of obesity is questioned. AIM: This study is focused on determining the ability of BMI-based cut-off values in diagnosing obesity among Australian children of white Caucasian and Sri Lankan origin. SUBJECTS AND METHODS: Height and weight was measured and BMI (W/H2) calculated. Total body water was determined by deuterium dilution technique and fat free mass and hence fat mass derived using age- and gender-specific constants. A %FM of 30% for girls and 20% for boys was considered as the criterion cut-off level for obesity. BMI-based obesity cut-offs described by the International Obesity Task Force (IOTF), CDC/NCHS centile charts and BMI-Z were validated against the criterion method. RESULTS: There were 96 white Caucasian and 42 Sri Lankan children. Of the white Caucasians, 19 (36%) girls and 29 (66%) boys, and of the Sri Lankans 7 (46%) girls and 16 (63%) boys, were obese based on %FM. The FM and BMI were closely associated in both Caucasians (r=0.81, P<0.001) and Sri Lankans (r=0.92, P<0.001). Percentage FM and BMI also had a lower but significant association. Obesity cut-off values recommended by IOTF failed to detect a single case of obesity in either group. However, NCHS and BMI-Z cut-offs detected cases of obesity with low sensitivity. CONCLUSIONS: BMI is a poor indicator of percentage fat and the commonly used cut-off values were not sensitive enough to detect cases of childhood obesity in this study. In order to improve the diagnosis of obesity, either BMI cut-off values should be revised to increase the sensitivity or the possibility of using other indirect methods of estimating the %FM should be explored.

Impact of ethnicity upon body composition assessment in Sri Lankan Australian children.

OBJECTIVES: Obesity is a disease with excess body fat where health is adversely affected. Therefore it is prudent to make the diagnosis of obesity based on the measure of percentage body fat. Body composition of a group of Australian children of Sri Lankan origin were studied to evaluate the applicability of some bedside techniques in the measurement of percentage body fat. METHODS: Height (H) and weight (W) was measured and BMI (W/H(2)) calculated. Bioelectrical impedance analysis (BIA) was measured using tetra polar technique with an 800 microA current of 50 Hz frequency. Total body water was used as a reference method and was determined by deuterium dilution and fat free mass and hence fat mass (FM) derived using age and gender specific constants. Percentage FM was estimated using four predictive equations, which used BIA and anthropometric measurements. RESULTS: Twenty-seven boys and 15 girls were studied with mean ages being 9.1 years and 9.6 years, respectively. Girls had a significantly higher FM compared to boys. The mean percentage FM of boys (22.9 +/- 8.7%) was higher than the limit for obesity and for girls (29.0 +/- 6.0%) it was just below the cut-off. BMI was comparatively low. All but BIA equation in boys under estimated the percentage FM. The impedance index and weight showed a strong association with total body water (r(2)= 0.96, P < 0.001). Except for BIA in boys all other techniques under diagnosed obesity. CONCLUSIONS: Sri Lankan Australian children appear to have a high percentage of fat with a low BMI and some of the available indirect techniques are not helpful in the assessment of body composition. Therefore ethnic and/or population specific predictive equations have to be developed for the assessment of body composition, especially in a multicultural society using indirect methods such as BIA or anthropometry.

Acute liver failure in children: A regional experience.

OBJECTIVE: To review the outcome of acute liver failure (ALF) and the effect of liver transplantation in children in Australia. METHODOLOGY: A retrospective review was conducted of all paediatric patients referred with acute liver failure between 1985 and 2000 to the Queensland Liver Transplant Service, a paediatric liver transplant centre based at the Royal Children's Hospital, Brisbane, that is one of three paediatric transplant centres in Australia. RESULTS: Twenty-six patients were referred with ALF. Four patients did not require transplantation and recovered with medical therapy while two were excluded because of irreversible neurological changes and died. Of the 20 patients considered for transplant, three refused for social and/or religious reasons, with 17 patients listed for transplantation. One patient recovered spontaneously and one died before receiving a transplant. There were 15 transplants of which 40% (6/15) were < 2 years old. Sixty-seven per cent (10/15) survived > 1 month after transplantation. Forty per cent (6/15) survived more than 6 months after transplant. There were only four long-term survivors after transplant for ALF (27%). Overall, 27% (6/22) of patients referred with ALF survived. Of the 16 patients that died, 44% (7/16) were from neurological causes. Most of these were from cerebral oedema but two patients transplanted for valproate hepatotoxicity died from neurological disease despite good graft function. CONCLUSIONS: Irreversible neurological disease remains a major cause of death in children with ALF. We recommend better patient selection and early referral and transfer to a transplant centre before onset of irreversible neurological disease to optimize outcome of children transplanted for ALF.

Comparison of the Cosmed K4 b(2) and the Deltatrac II metabolic cart in measuring resting energy expenditure in adults.

BACKGROUND AND AIMS: The objective of the study was to compare data obtained from the Cosmed K4 b(2) and the Deltatrac II metabolic cart for the purpose of determining the validity of the Cosmed K4 b(2) in measuring resting energy expenditure. METHODS: Nine adult subjects (four male, five female) were measured. Resting energy expenditure was measured in consecutive sessions using the Cosmed K4 b(2), the Deltatrac II metabolic cart separately and the Cosmed K4 b(2) and Deltatrac II metabolic cart simultaneously, performed in random order. Resting energy expenditure (REE) data from both devices were then compared with values obtained from predictive equations. RESULTS: Bland and Altman analysis revealed a mean bias for the four variables, REE, respiratory quotient (RQ), V CO(2), V O(2) between data obtained from Cosmed K4 b(2) and Deltatrac II metabolic cart of 268+/-702 kcal/day, -0.0+/-0.2, 26.4+/-118.2 and 51.6+/-126.5 ml/min, respectively. Corresponding limits of agreement for the same four variables were all large. Also, Bland and Altman analysis revealed a larger mean bias between predicted REE and measured REE using Cosmed K4 b(2) data (-194+/-603 kcal/day) than using Deltatrac metabolic cart data (73+/-197 kcal/day). CONCLUSIONS: Variability between the two devices was very high and a degree of measurement error was detected. Data from the Cosmed K4 b(2) provided variable results on comparison with predicted values, thus, would seem an invalid device for measuring adults.

Comparison of measured sleeping metabolic rate and predicted basal metabolic rate during the first year of life: evidence of a bias changing with increasing metabolic rate.

OBJECTIVE: To compare measurements of sleeping metabolic rate (SMR) in infancy with predicted basal metabolic rate (BMR) estimated by the equations of Schofield. METHODS: Some 104 serial measurements of SMR by indirect calorimetry were performed in 43 healthy infants at 1.5, 3, 6, 9 and 12 months of age. Predicted BMR was calculated using the weight only (BMR-wo) and weight and height (BMR-wh) equations of Schofield for 0-3-y-olds. Measured SMR values were compared with both predictive values by means of the Bland-Altman statistical test. RESULTS: The mean measured SMR was 1.48 MJ/day. The mean predicted BMR values were 1.66 and 1.47 MJ/day for the weight only and weight and height equations, respectively. The Bland-Altman analysis showed that BMR-wo equation on average overestimated SMR by 0.18 MJ/day (11%) and the BMR-wh equation underestimated SMR by 0.01 MJ/day (1%). However the 95% limits of agreement were wide: -0.64 to +0.28 MJ/day (28%) for the former equation and -0.39 to +0.41 MJ/day (27%) for the latter equation. Moreover there was a significant correlation between the mean of the measured and predicted metabolic rate and the difference between them. CONCLUSIONS: The wide variation seen in the difference between measured and predicted metabolic rate and the bias probably with age indicates there is a need to measure actual metabolic rate for individual clinical care in this age group.

Fate of swallowed interleukin 8 and TNF alpha, and effect on the Wistar rat gut.

To evaluate the passage of cytokines through the gastrointestinal tract, we investigated the digestion of interleukin-8 (IL-8) and tumour necrosis factor alpha (TNF alpha), in vitro and in vivo, and their propensity to induce intestinal inflammation. We serially immuno-assayed IL-8 and TNF alpha solutions co-incubated with each of three pancreatin preparations at pH 4.5 and pH 8. We gavaged IL-8, TNF alpha and marker into 15 Wistar rats, and measured their faecal cytokine concentrations by ELISA and histologically examined their guts. IL-8 immunoreactivity was extinguished by all pancreatin preparations after 1 h of incubation at 37 degrees C. TNF alpha concentration progressively fell from 1 to 4 h with all enzyme preparations. Buffer control samples maintained their cytokine concentrations throughout incubation. No IL-8 or TNF alpha was detected in any rat faecal pellets. There was no significant proinflammatory effect of the gavaged cytokines on rat intestine. IL-8 and TNF alpha in aqueous solution could well be fully digested in the CF gut when transit time is normal and exogenous enzymes are provided, although cytokines swallowed in viscous sputum may be protected from such digestion.

Cloning and gastrointestinal expression of rat hephaestin: relationship to other iron transport proteins.

The membrane-bound ceruloplasmin homolog hephaestin plays a critical role in intestinal iron absorption. The aims of this study were to clone the rat hephaestin gene and to examine its expression in the gastrointestinal tract in relation to other genes encoding iron transport proteins. The rat hephaestin gene was isolated from intestinal mRNA and was found to encode a protein 96% identical to mouse hephaestin. Analysis by ribonuclease protection assay and Western blotting showed that hephaestin was expressed at high levels throughout the small intestine and colon. Immunofluorescence localized the hephaestin protein to the mature villus enterocytes with little or no expression in the crypts. Variations in iron status had a small but nonsignificant effect on hephaestin expression in the duodenum. The high sequence conservation between rat and mouse hephaestin is consistent with this protein playing a central role in intestinal iron absorption, although its precise function remains to be determined.

Energy expenditure and the body cell mass in cystic fibrosis.

Poor nutritional status in patients with cystic fibrosis (CF) is associated with severe lung disease, and possible causative factors include inadequate intake, malabsorption, and increased energy requirements. Body cell mass (which can be quantified by measurement of total body potassium) provides an ideal standard for measurements of energy expenditure. The aim of this study was to compare resting energy expenditure (REE) in patients with CF with both predicted values and age-matched healthy children and to determine whether REE was related to either nutritional status or pulmonary function. REE was measured by indirect calorimetry and body cell mass by scanning with total body potassium in 30 patients with CF (12 male, mean age = 13.07 +/- 0.55 y) and 18 healthy children (six male, mean age = 12.56 +/- 1.25 y). Nutritional status was expressed as a percentage of predicted total body potassium. Lung function was measured in the CF group by spirometry and expressed as the percentage of predicted forced expiratory volume in 1 s. Mean REE was significantly increased in the patients with CF compared with healthy children (119.3 +/- 3.1% predicted versus 103.6 +/- 5% predicted, P < 0.001) and, using multiple regression techniques, REE for total body potassium was significantly increased in patients with CF (P = 0.0001). There was no relation between REE and nutritional status or pulmonary disease status in the CF group. In conclusion, REE is increased in children and adolescents with CF but is not directly related to nutritional status or pulmonary disease.

Value of total body potassium in assessing the nutritional status of children with end-stage liver disease.

Malnutrition is a common problem in children with end-stage liver disease (ESLD), and accurate assessment of nutritional status is essential in managing these children. In a retrospective study, we compared nutritional assessment by anthropometry with that by body composition. We analyzed all consecutive measurements of total body potassium (TBK, n = 186) of children less than 3 years old with ESLD awaiting transplantation found in our database. The TBK values obtained by whole body counting of 40K were compared with reference TBK values of healthy children. The prevalence of malnutrition, as assessed by weight (weight Z score < -2) was 28%, which was significantly lower (chi-square test, p < 0.0001) than the prevalence of malnutrition (76%) assessed by TBK (< 90% of expected TBK for age). These results demonstrated that body weight underestimated the nutritional deficit and stressed the importance of measuring body composition as part of assessing nutritional status of children with ESLD.

Nutritional status of children with cystic fibrosis measured by total body potassium as a marker of body cell mass: lack of sensitivity of anthropometric measures.

OBJECTIVE: To investigate measures aimed at defining the nutritional status of cystic fibrosis (CF) populations, this study compared standard anthropometric measurements and total body potassium (TBK) as indicators of malnutrition. METHODS: Height, weight, and TBK measurements of 226 children with CF from Royal Children's Hospital, Brisbane, Australia, were analyzed. Z scores for height for age, weight for age, and weight for height were analyzed by means of the National Centre for Health Statistics reference. TBK was measured by means of whole body counting and compared with predicted TBK for age. Two criteria were evaluated with respect to malnutrition: (1) a z score < -2.0 and (2) a TBK for age <80% of predicted. RESULTS: Males and females with CF had lower mean height-for-age and weight-for-age z scores than the National Centre for Health Statistics reference (P <.01), but mean weight-for-height z score was not significantly different. There were no significant gender differences. According to anthropometry, only 7.5% of this population were underweight and 7.6% were stunted. However, with TBK as an indicator of nutritional status, 29.9% of males and 22.0% of females were malnourished. CONCLUSION: There are large differences in the percentage of patients with CF identified as malnourished depending on whether anthropometry or body composition data are used as the nutritional indicator. At an individual level, weight-based indicators are not sensitive indicators of suboptimal nutritional status in CF, significantly underestimating the extent of malnutrition. Current recommendations in which anthropometry is used as the indicator of malnutrition in CF should be revised.