A Six-Month Study of Growth and Energy Expenditure in Children with Cystic Fibrosis Taking a Pulmonary Inhalation Medication (rhDNase)

Objective: To characterize the effects of recombinant human deoxyribonuclease (rhDNase) on growth velocity, body composition, resting energy expenditure (REE) and food intake in children with cystic fibrosis (CF).

Methods: A prospective, six-month pilot study was conducted in twenty-one subjects with CF (twelve male, nine female, ages 11.5±3.1 years) measured at baseline, two and six months post-baseline. Repeated measures ANOVA was used to examine the change in variables across time.

Results: The majority (75%) of subjects had minimal lung disease at baseline (FEV₁: 80%–119% predicted). As expected for growing children, weight and height gains (1.6 kg and 2.5 cm) were observed between baseline and six months (p=0.0001). No change was observed in weight z-scores from six months prior to initiation of rhDNase therapy to six months post, though a significant decline (p=0.049) in Ht z-score was observed over this twelve-month period. Triceps skinfolds and mid-arm muscle circumference increased from baseline to six months (p<0.01); respective z-scores remained stable. Energy intake remained constant during the period it was studied from baseline to two months of therapy: 120%±27% RDA. REE, though slightly elevated compared to healthy children (baseline 106%±8% predicted), remained stable throughout the study and at a level which may be expected for children with minimal lung disease. A trend (p=0.057) towards a decrease in the number of subjects requiring hospitalization for pulmonary exacerbations during the trial period was observed.

Conclusions: In summary, these pilot data from younger children with milder CF-related lung disease do not confirm anecdotal reports of improved rate of weight gain, caloric intake or decreases in the elevated REE. Future research might focus on documentation of the possible nutritional effects of rhDNase in clinical trials of children with more severe lung disease.     

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.     

Energy balance and the accuracy of reported energy intake in preadolescent children with cystic fibrosis

BACKGROUND: Suboptimal growth and nutritional status are common among children with cystic fibrosis (CF) and pancreatic insufficiency (PI). A better understanding of energy balance is required to improve prevention and treatment of malnutrition. OBJECTIVE: Our objective was to characterize energy balance and the reporting accuracy of dietary intake in children with CF by evaluating the relations between energy intake (EI), energy expenditure (EE), fecal energy loss, nutritional status, and growth. DESIGN: The subjects were participants of a 24-mo prospective study of children 6-10 y of age with CF and PI. EE, EI, fecal energy loss, and anthropometric measures were obtained at baseline and at 24 mo. RESULTS: The children (n = 69) had suboptimal growth at baseline (x +/- SD: weight-for-age z score, -0.53 +/- 1.19; adjusted height-for-age z score, -0.67 +/- 1.06; body mass index z score, -0.29 +/- 1.12), and these variables remained suboptimal at 24 mo. The median ratios of EI to EE at baseline and 24 mo were 1.15 and 1.18, respectively, which decreased to 1.09 and 1.10, respectively, when adjusted for fecal energy loss (EI(-FL):EE). At baseline, 7% of subjects were underreporters, 64% were accurate reporters, and 23% were overreporters of energy intake; the percentages were similar at 24 mo. CONCLUSIONS: Although EI(-FL):EE ratios were higher than expected at both baseline and 24 mo, this cohort showed only age-appropriate weight gain. Self-reported dietary intake data at the individual level should be interpreted with caution, and weight gain velocity may serve as an objective measure of long-term energy balance.     

Effects of Pseudomonas colonization on body composition and resting energy expenditure in children with cystic fibrosis.

BACKGROUND: To determine the extent and effects of increased metabolic demand represented by Pseudomonas colonization on body composition and resting energy expenditure in children with cystic fibrosis (CF). METHODS: The study comprised 18 stable children with CF, of whom 10 (6 male/4 female) were colonized with Pseudomonas species and 8 (4 male/4 female) were not. The groups were of similar age range and genotype. Measured resting energy expenditure (REE) was performed by open circuit indirect calorimetry and compared with predicted REE calculated from standard equations. Body composition was determined by dual-energy x-ray absorptiometry, including lean body mass (LBM), fat mass (FM), bone mineral density (BMD), and anterior-posterior spine density (APS); these were compared using z-scores. Routine pulmonary function testing assessed forced vital capacity, forced expiratory volume in 1 second (FEV1), and forced expiratory flow over middle half of vital capacity (FEF25% to 75%); these were compared as percent predicted. RESULTS: As expected, results of pulmonary function testing showed significant deterioration among the children colonized with Pseudomonas species when compared with the children who were not, while standard anthropometry showed no differences in weight, height, or weight-for-height percentile and respective z-scores. Although a trend of lower LBM was noted among the children colonized with Pseudomonas species, no significant differences were found between these children and children who were not colonized with Pseudomonas species when z-scores for LBM, FM, BMD, or APS were compared during body composition analysis. In addition, neither REE as kilocalories per day (kcal/d) nor REE expressed as a percent predicted by standard equations discriminated between subgroups of children colonized with Pseudomonas species and children who were not. However, metabolic demand, expressed as resting energy expenditure in kilocalories per kilogram (kcal/kg) of LBM (REE/LBM), revealed significant differences between children colonized with Pseudomonas species and children who were not (75.4+/-4.4 vs 58.6+/-2.9 kcal/kg, p < .05). CONCLUSIONS: The effect of Pseudomonas colonization on metabolic demand in children with CF can be accurately assessed by expressing resting energy expenditure as kilocalorie per kilogram of LBM, the active metabolic component of the body. The 50% increase in REE/LBM seen in the children colonized with Pseudomonas species represents the metabolic demand from the inflammatory burden and work of breathing resulting from the effects of the Pseudomonas colonization. The trend of a lower LBM in the children colonized with Pseudomonas species makes this finding even more dramatic.     

Variations in the measurement of resting energy expenditure in children with cystic fibrosis

OBJECTIVE: To investigate in children with cystic fibrosis (CF) and children without CF: (1) the test-retest reproducibility of a 20 min resting energy expenditure (REE) measurement; and (2) the long-term reproducibility of REE measurements in children with CF using longitudinal data. DESIGN: Cross-sectional study and longitudinal cohort. SETTING: A tertiary referral paediatric hospital. SUBJECTS: A total of 31 (11 male, 20 female) children (aged 12.8+/-3.6 y) with CF and 32 (14 male, 18 female) healthy children without CF (aged 12.2+/-2.3 y) were enrolled in the short-term reproducibility study. Long-term REE measurement reproducibility was assessed in another 14 children (5 male, 9 female) with CF, comparing their initial REE measurement with a subsequent measurement 1-2 y later. METHODS: All children had measurements of height, weight, skinfold thickness and indirect calorimetry. RESULTS: There was no statistically significant difference in REE between repeated measurements in children with CF (mean+/-s.d., 6240+/-1280 and 6220+/-1315 kJ/24 h) and in the children without CF (6040+/-956 and 6015+/-943 kJ/24 h). For the children with CF, the intraclass correlation coefficient was 0.99 and for children without CF the intraclass correlation coefficient was 0.97. The measurement errors were 119 and 177 kJ, respectively. Approximately 80% of the variation in REE in the CF group and 70% in the group without CF was explained by fat-free mass (FFM). Analysis of the longitudinal CF data show there was no difference in REE between a child's first measurement (5140+/-1140 kJ) and their subsequent measurement (5460+/-1190 kJ), after adjustment for changes in body size between the measurements. CONCLUSION: This study has demonstrated that a short-term 20 min REE measurement is reproducible and therefore valid in children with CF and children without CF. These results also indicate that in children with CF, long-term REE measurements are reproducible.     

Change in Nutrient and Dietary Intake in European Children with Cystic Fibrosis after a 6-Month Intervention with a Self-Management mHealth Tool

Cystic Fibrosis (CF) is a life-long genetic disease, causing increased energy needs and a healthy diet with a specific nutrient distribution. Nutritional status is an indicator of disease prognosis and survival. This study aimed at assessing the effectiveness of a self-management mobile app in supporting patients with CF to achieve the dietary goals set by the CF nutrition guidelines. A clinical trial was conducted in pancreatic insufficient children with CF, followed in six European CF centres, where the self-management app developed within the MyCyFAPP project was used for six months. To assess secondary outcomes, three-day food records were compiled in the app at baseline and after 3 and 6 months of use. Eighty-four subjects (mean 7.8 years old) were enrolled. Compared to baseline, macronutrient distribution better approximated the guidelines, with protein and lipid increasing by 1.0 and 2.1% of the total energy intake, respectively, by the end of the study. Consequently, carbohydrate intake of the total energy intake decreased significantly (−2.9%), along with simple carbohydrate intake (−2.4%). Regarding food groups, a decrease in ultra-processed foods was documented, with a concomitant increase in meat and dairy. The use of a self-management mobile app to self-monitor dietary intake could become a useful tool to achieve adherence to guideline recommendations, if validated during a longer period of time or against a control group.     

Elevated vitamin A intake and serum retinol in preadolescent children with cystic fibrosis

BACKGROUND: Persons with cystic fibrosis (CF) and pancreatic insufficiency (PI) are at risk of vitamin A deficiency because of steatorrhea, despite pancreatic enzyme replacement. Long-standing vitamin A supplementation may increase the risk of vitamin A toxicity. OBJECTIVE: The aim was to describe the vitamin A intake and serum retinol concentrations of preadolescent children with CF, PI, and mild-to-moderate pulmonary disease, who were cared for under current practice recommendations. DESIGN: This cross-sectional study evaluated children aged 8.0-11.9 y with CF and PI from 13 US CF centers. Dietary and supplemental vitamin A intakes were compared with the Dietary Reference Intakes (DRIs) for healthy children, CF recommendations, and data from the National Health and Nutrition Examination Survey (NHANES), 1999-2000. Serum retinol concentrations were compared with NHANES data. RESULTS: The 73 subjects with CF had a dietary vitamin A intake of 816 +/- 336 microg retinol activity equivalents (165 +/- 69% of the recommended dietary allowance), which was similar to the NHANES value. The supplement intake provided 2234 +/- 1574 microg retinol activity equivalents/d and exceeded recommendations in 21% of the subjects with CF. Total preformed retinol intake exceeded the DRI tolerable upper intake level in 78% of the subjects with CF. The serum retinol concentration was 52 +/- 13 microg/dL (range: 26-98 microg/dL), which was significantly higher than the NHANES value (37 +/- 10 microg/dL; range: 17-63 microg/dL; P < 0.001). CONCLUSION: Although supplementation helps to prevent vitamin A deficiency in children with CF and PI, their high vitamin A intakes and serum retinol concentrations suggest that usual care may result in excessive vitamin A intake and possible toxicity that would increase the risk of CF-associated liver and bone complications.     

Evaluation of body mass index percentiles for assessment of malnutrition in children with cystic fibrosis

OBJECTIVE: To compare the performance of recently released body mass index percentiles (BMIp) with standard anthropometric indexes, including height-for-age percentile (HAP), weight-for-age percentile (WAP) and percent ideal body weight (%IBW), as measures for nutritional failure in children with cystic fibrosis (CF). DESIGN: Cross-sectional analysis of growth and lung function data from 4577 children with CF reported to the German CF quality assurance (CFQA) project from 1995 to 2004. RESULTS: Frequency distribution of HAP (mean+/-s.d.: male 30.0+/-27.5; female 31.3+/-27.4) and WAP (male 28.9+/-27.0; female 29.6+/-26.7) were skewed, with significant numbers of patients below the fifth percentiles of a healthy reference population. However, because deficits occurred in both measures simultaneously, mean %IBW (male 97.0+/-12.1; female 98.1+/-12.3) assumed subjects weight close to the nominal weight-for-height at all ages. In contrast, mean BMIp was markedly reduced (male 35.7+/-27.9; female 35.6+/-27.2) and steadily declined with age. Ideal weight-for-age was significantly lower when predicted by %IBW compared with BMIp method, particularly in subjects with shorter-than-average stature. Consequently, less CF children were identified with nutritional failure according to %IBW method (male 20.5%; female 22.7%) compared with BMIp method (male 30.4%; female 28.7%). The clinical relevance of these findings was confirmed by stronger correlation of BMIp with impaired %forced expiratory volume/s, a marker for disease progression in CF. CONCLUSION: BMIp predicts nutritional failure more sensitively and accurately than conventional anthropometric indexes, at least in children with CF. Screening of CF patients by BMIp could provide an early warning sign and allow for timely therapeutic intervention.     

Energy balance in relation to cancer cachexia

The aim of the current study was to determine the contribution of increased resting energy expenditure (REE) and/or decreased energy intake (EI) to the development of weight loss in gastric and colorectal (GCR) and lung cancer patients. REE was measured in 22 GCR cancer patients and 17 lung cancer patients and was compared with REE values in 40 apparently healthy controls. REE in lung cancer patients expressed per kg fat free mass (REE/FFM) was significantly increased when compared to healthy controls (33.5 +/- 5.4 and 29.6 +/- 2.9 kcal, respectively; p < 0.01). GCR cancer patients had no elevated REE compared to these healthy controls. No significant differences in EI were established between the three groups. Eight GCR cancer patients reported a decrease in food intake compared to pre-disease intake, in contrast to only one lung cancer patient. Semi-starving GCR cancer patients showed a significant weight loss (8.7 +/- 8.1%), a low respiratory quoteint (RQ) (0.76 +/- 0.04) and a high beta-hydroxybutyrate level (259 +/- 192 mumol/l), but they showed no difference in REE compared to patients with a normal EI. The current study suggests that weight loss in GCR cancer patients is initiated by decreased food intake, whereas weight loss in lung cancer patients represents a combination of an increased REE and a relatively low EI.     

A cost-effectiveness analysis of rhDNase in children with cystic fibrosis

OBJECTIVES: This study compared the relative cost-effectiveness of daily recombinant human deoxyribonuclease (rhDNase), with alternate day rhDNase and hypertonic saline (HS) for treating children with cystic fibrosis (CF). METHODS: A randomized controlled trial with a crossover design allocated 40 CF children consecutively to 12 weeks of daily rhDNase, alternate day rhDNase, or HS. The primary outcome measure was forced expiratory volume in 1 second (FEV1), a measure of lung function. All health resource use was prospectively documented for each patient and multiplied by unit costs to give a total health service cost for each 12-week treatment period. The nonparametric bootstrap method was used to present cost-effectiveness acceptability curves and net benefit statistics for each treatment comparison, for various hypothetical levels of the decision maker's ceiling ratio. RESULTS: Compared with HS, there was a 14% improvement in FEV1 for daily rhDNase (95% Cl, 5% to 23%), and a 12% improvement (95% Cl, 2% to 22%) for alternate day rhDNase. For a ceiling ratio of 200 pounds sterling per 1% gain in FEV1, the mean net benefits of daily and alternate day rhDNase compared with HS were 1,158 pounds sterling (95% Cl, -621pounds sterling to 2,842) and 1,188 pounds sterling (95% Cl, -847 to 3,343), respectively; the mean net benefit of daily compared with alternate day rhDNase was -30 pounds sterling (95% Cl, -2,091 pounds sterling to 1,576). CONCLUSIONS: If decision makers are prepared to pay 200 pounds sterling for a 1% gain in FEV1 over a 12-week period, then on average either rhDNase strategy is cost-effective.     

Adolescent development and energy expenditure in females with cystic fibrosis

BACKGROUND AND AIMS: Poor nutrition and growth status are common in people with cystic fibrosis (CF), and females often have a worse clinical course. Relationships between sexual maturity, nutrition, resting energy expenditure (REE), and pulmonary status in females with CF and pancreatic insufficiency (PI) were evaluated. METHODS: Pre- and post-menarcheal females with CF and PI (8-29 yr) were compared to healthy females. Z-scores for growth and body composition, anthropometry and DEXA were assessed. REE was measured in all subjects and pulmonary function in CF. RESULTS: Compared to healthy females (n=28, 14.6+/-4.1 yr), females with CF (n=16, 14.7+/-4.4 yr) had lower height Z (-0.1+/-0.9 versus -0.9+/-0.9, P=0.009) and muscle area Z (0.8+/-1.3 versus -0.4+/-1.2, P=0.007), and higher REE (100+/-10 versus 110+/-11% predicted, P=0.008). Difference in REE was more pronounced for post-menarcheal girls. REE adjusted for fat and fat-free mass was significantly higher with CF (+110 calories/day), and declined with menarcheal age in all subjects. FEV1 was positively associated with BMI Z score, and negatively associated with age at menarche. CONCLUSIONS: Height and muscle stores were reduced and REE elevated in subjects with CF compared to healthy controls. Poorer growth and nutritional status and delayed menarche were associated with poorer pulmonary function in CF and were likely related to the cumulative effect of energy imbalance on growth and body composition.     

Is growth hormone a feasible adjuvant in the treatment of children after small bowel resection?

The aim of our study was to assess the metabolic consequences of short-term administration of growth hormone in children after gut resection and influence on polyamine production in red blood cells (RBC). Twelve children aged 4-60 months were studied. All children remained on parenteral nutrition and 11 also received oral feeding. Total non-protein energy intake was 429 +/- 86 kJ/kg body weight (BW)/day. Recombinant growth hormone (GH) was administered subcutaneously at a dose of 0.3 IU/kg BW/day for 10 days. Resting energy expenditure (REE; kJ/kg BW/day) was: 316.07 +/- 54.08 before and 346.04 +/- 54.40 during GH administration (P < 0.02), but daily weight gain before GH administration was significantly lower than during treatment. A significant increase of polyamine concentrations was observed in the RBC (spermidine: 30.1 +/- 15.1 and 43.8 +/- 24.9 nmol/ml packed RBC, P < 0.003; spermine: 15.6 +/- 5.1 and 19.6 +/- 10.6 nmol/ml packed RBC, P < 0.02) and in jejunal mucosa (spermidine: 172.10 +/- 142.35 nmol/g tissue and 193.92 +/- 108.15 nmol/g tissue). The authors concluded that increased polyamine concentrations in the RBC and jejunal mucosa reflect a cellular response to GH administration. The anabolic effect of GH results in higher weight gain, although increased REE may indicate increased energy requirements during GH treatment.     

Chronic Intestinal Failure in Children: An International Multicenter Cross-Sectional Survey

Background: The European Society for Clinical Nutrition and Metabolism database for chronic intestinal failure (CIF) was analyzed to investigate factors associated with nutritional status and the intravenous supplementation (IVS) dependency in children. Methods: Data collected: demographics, CIF mechanism, home parenteral nutrition program, z-scores of weight-for-age (WFA), length or height-for-age (LFA/HFA), and body mass index-for-age (BMI-FA). IVS dependency was calculated as the ratio of daily total IVS energy over estimated resting energy expenditure (%IVSE/REE). Results: Five hundred and fifty-eight patients were included, 57.2% of whom were male. CIF mechanisms at age 1–4 and 14–18 years, respectively: SBS 63.3%, 37.9%; dysmotility or mucosal disease: 36.7%, 62.1%. One-third had WFA and/or LFA/HFA z-scores < −2. One-third had %IVSE/REE > 125%. Multivariate analysis showed that mechanism of CIF was associated with WFA and/or LFA/HFA z-scores (negatively with mucosal disease) and %IVSE/REE (higher for dysmotility and lower in SBS with colon in continuity), while z-scores were negatively associated with %IVSE/REE. Conclusions: The main mechanism of CIF at young age was short bowel syndrome (SBS), whereas most patients facing adulthood had intestinal dysmotility or mucosal disease. One-third were underweight or stunted and had high IVS dependency. Considering that IVS dependency was associated with both CIF mechanisms and nutritional status, IVS dependency is suggested as a potential marker for CIF severity in children.     

Glucose metabolism in advanced lung cancer patients.

Although it is generally accepted that altered nutrient intake and metabolism are responsible for the progressive loss of body weight observed in most advanced cancer patients, there is still considerable controversy regarding the contributory role of changes in both resting energy expenditure (REE) and glucose metabolism. Several studies suggest increases in both REE and glucose appearance in advanced cancer patients compared with healthy control subjects, whereas others revealed no changes in either metabolic parameter. We measured REE with indirect calorimetry and glucose kinetics with a primed constant infusion of D-[U-14C]glucose and D-[6-3H]glucose over the last 4 h of a 24-h fast in 32 advanced lung cancer patients immediately after diagnosis and before any chemotherapy or radiotherapy and in 19 healthy volunteer subjects. REE for the lung cancer group was not significantly different from that in the control group (1535.8 +/- 78.0 vs. 1670.2 +/- 53.9 kcal/day, respectively, p = 0.151). When REE was expressed as a function of body weight, or lean body mass, no differences between the two groups were observed. The rate of glucose appearance was 9.88 +/- 0.36 mumol.kg-1.min-1 in the cancer patients and 10.15 +/- 0.53 mumol.kg-1.min-1 in control subjects (p = 0.667), of which 50.4 versus 58.2%, respectively, was oxidized. The amount of glucose recycled was 13.54 +/- 1.22% in cancer patients and 15.08 +/- 0.99% in control subjects (p = 0.394). The amount of VCO2 from direct oxidation of glucose was 23.39 +/- 0.74% in cancer patients and 27.45 +/- 1.36% in control subjects (p = 0.006).(ABSTRACT TRUNCATED AT 250 WORDS)     

Energy intake and resting metabolic rate in preschool Jamaican children with homozygous sickle cell disease

BACKGROUND: A relative energy deficiency consequent to a high resting metabolic rate (RMR) may contribute to growth impairment in persons with homozygous (SS genotype) sickle cell disease (SCD). The growth deficit in SCD emerges at an early age, but few studies have addressed the adequacy of energy intake relative to RMR in young children. OBJECTIVE: Our objective was to test the hypothesis that energy intake relative to RMR is lower in children with SCD than in control subjects. DESIGN: The dietary intake of 41 children with SCD and 31 control subjects with a normal hemoglobin genotype (AA) aged 3-6 y was assessed by weighing all food consumed during 3 d. RMR was determined with the use of indirect calorimetry. RESULTS: The RMR in the children with SCD ( +/- SD: 5.47 +/- 0.93 MJ/d) was higher than that in the control subjects (5.19 +/- 1.3 MJ/d) after adjustment for sex and weight (P = 0.04). Energy intake did not differ significantly between the 2 genotype groups. The ratio of energy intake to RMR was lower in the children with SCD ( +/- SD: 1.13 +/- 0.33) than in the control subjects (1.35 +/- 0.38) after adjustment for sex and weight (P = 0.005). CONCLUSIONS: Prepubertal children with SCD fail to compensate for their higher RMR by increasing their energy intake. This observation is consistent with a hypothesis of a relative energy deficiency in SCD.     

Regulation of energy intake may be impaired in nutritionally stunted children from the shantytowns of São Paulo, Brazil

We tested the hypothesis that nutritionally stunted children have impaired regulation of energy intake (EI), a factor that could help explain the increased risk of obesity associated with stunting in developing countries. A 3-d residency study was conducted in 56 prepubertal boys and girls aged 8-11 y from the shantytowns of Sao Paulo, Brazil. Twenty-seven of the subjects were stunted and 29 were not stunted; weight-for-height Z-scores were not significantly different between the groups. Parents of the two groups had equivalent heights and body mass indices. Measurements were made of voluntary EI from a self-selection menu, resting energy expenditure (REE) and body composition. In addition, a 753-kJ yogurt supplement was administered at breakfast on one study day (with an equal number of children receiving the supplement on each of the 3 study days) and its effect on daily EI assessed. There was no change in EI over time in either group (P: = 0.957), and no significant difference in EI between stunted and nonstunted children, even though the stunted children weighed 10% less. Energy intake per kilogram body weight was significantly higher in the stunted children (278 +/- 89 (SD), vs. 333 +/- 67 kJ/kg, P: < 0.05) and EI/REE was also significantly higher (1.91 +/- 0.34 vs. 1.68 +/- 0.38, P: < 0.05). However, the relationship between EI and body weight was not significantly influenced by stunting (P: = 0.12). There was no significant effect of the breakfast supplement on daily EI in either group although the absolute difference in EI between supplement and control days was greater in stunted than in nonstunted children (DeltaEI: +460 +/- 1574 vs. -103 +/- 1916 kJ/d, P: = 0.25). These data provide preliminary evidence consistent with the suggestion that stunted children tend to overeat opportunistically, but further studies are required to confirm these results in a larger study.     

Energy cost of physical activity in cystic fibrosis

OBJECTIVE: The purpose of this study was to compare the energy cost of standardized physical activity (ECA) between patients with cystic fibrosis (CF) and healthy control subjects. DESIGN: Cross-sectional study using patients with CF and volunteers from the community. SETTING: University laboratory. SUBJECTS: Fifteen patients (age 24.6+/-4.6 y) recruited with consent from their treating physician and 16 healthy control subjects (age 25.3+/-3.2) recruited via local advertisement. INTERVENTIONS: Patients and controls walked on a computerised treadmill at 1.5 km/h for 60 min followed by a 60 min recovery period and, on a second occasion, cycled at 0.5 kp (kilopond), 30 rpm followed by a 60 min recovery. The ECA was measured via indirect calorimetry. Resting energy expenditure (REE), nutritional status, pulmonary function and genotype were determined. RESULTS: The REE in patients was significantly greater than the REE measured in controls (P=0.03) and was not related to the severity of lung disease or genotype. There was a significant difference between groups when comparing the ECA for walking kg radical FFM (P=0.001) and cycling kg radical FFM (P=0.04). The ECA for each activity was adjusted (ECA(adj)) for the contribution of REE (ECA kJ kg radical FFM 120 min(-1)--REE kJ kg radical FFM 120 min(-1)). ECA(adj) revealed a significant difference between groups for the walking protocol (P=0.001) but no difference for the cycling protocol (P=0.45). This finding may be related to the fact that the work rate during walking was more highly regulated than during cycling. CONCLUSIONS: ECA in CF is increased and is likely to be explained by an additional energy-requiring component related to the exercise itself and not an increased REE.     

Effect of weight reduction on resting energy expenditure, substrate utilization, and the thermic effect of food in moderately obese women.

It is not known whether the decrease in the thermic effect of food (TEF) in obesity is a consequence of obesity or a factor contributing to the development of obesity. The resting energy expenditure (REE) of 24 obese, nondiabetic, postmenopausal women was 5481 +/- 110 kJ/24 h (1310 +/- 26.4 kcal/24 h). After weight loss (12.7 +/- 0.45 kg) the REE was significantly decreased (4858 +/- 94 kJ/24 h, or 1161 +/- 22.4 kcal/24 h) and equivalent to the REE of 4866 +/- 119 kJ/24 h (1163 +/- 28.5 kcal/24 h) in 24 never-obese, postmenopausal women. The TEF, expressed as a percentage of the calories ingested, was 8.2 +/- 0.50% for obese subjects, 8.7 +/- 0.57% for postobese subjects, and 9.8 +/- 0.54% for never-obese subjects. Compared with never-obese subjects, the TEF was significantly reduced in obese subjects (P = 0.043) and remained unchanged after weight loss (P = 0.341). These findings indicate that the lower TEF in the obese subjects is uncorrected by weight loss, and thus it is a contributor to obesity rather than a consequence of obesity.     

Factors associated with the increase in resting energy expenditure during refeeding in malnourished anorexia nervosa patients

BACKGROUND: In malnourished anorexia nervosa (AN) patients, body-weight gain during refeeding is slowed by an increase in resting energy expenditure (REE). OBJECTIVE: The objective of the study was to identify factors associated with the increase in REE during refeeding. DESIGN: Before and 8, 30, and 45 d after the beginning of refeeding, REE was studied by indirect calorimetry in 87 female AN patients [x +/- SD age: 23.4 +/- 7.9 y; body mass index (in kg/m2) 13.2 +/- 1.3]. Energy intake, body composition (by bioelectrical impedance analysis), physical activity, smoking behavior, abdominal pain, anxiety, depressive mood, serum thyrotropin and thyroid hormone, and urinary catecholamines were measured. REE was also evaluated in 18 patients after 1 y of recovery. RESULTS: By day 8, REE increased from 3.84 +/- 0.6 to 4.36 +/- 0.59 MJ/d (P < 0.01). This increase (13.4%) was significantly (P <0.01) greater than that expected on the basis of the increase in fat-free mass (FFM; 1.6%). Thereafter, the ratio of REE to FFM remained high and, in multivariate analysis, was significantly related to 4 factors: energy intake (P <0.01), anxiety (P <0.01), abdominal pain (P <0.05), and depressive mood (P <0.05). The ratio also increased significantly with physical activity (P <0.01) and cigarette smoking (P <0.02). This rise in REE leveled off after recovery from AN. CONCLUSION: In AN patients, the rise in REE observed during refeeding was independently linked to anxiety level, abdominal pain, physical activity, and cigarette smoking, and it contributed to resistance to weight gain.     

Effects of recombinant human leptin treatment as an adjunct of moderate energy restriction on body weight,resting energy expenditure and energy intake in obese humans

We explored the effects of recombinant human leptin (rL) as an adjunct of mild energy restriction (2092 kJ/day less than needed) in the treatment of obese humans as part of a larger multicentre trial. In a double blind, randomised, placebo (P)-controlled design, the effects of 10 mg of rL once daily vs twice daily (rL OD/BID, by s.c. injection) upon body weight, resting energy expenditure (REE) and energy intake were compared. The study groups comprised 9 (P), 15 (rL OD) and 6 (rL BID) healthy subjects (body mass index 27.5-35 kg/m2). We observed in both groups treated with rL a decline of body weight. [2.8+/-1.1 kg (P), 5.2+/-0.9 kg (rL OD), 7.9+/-1.4 kg (rL BID), p < 0.035]. No significant effects of rL treatment upon energy intake or REE were observed. However, rL tended to reduce the decline of energy expenditure associated with energy restriction, whereas the tendency of energy intake to increase back to baseline levels in placebo-treated subjects was largely prevented in subjects treated with rL. Thus, rL appears to enhance the loss of body weight in obese humans in a dose-dependent fashion if prescribed as an adjunct of energy restriction. This effect might be mediated by rL ability to counteract the behavioural and metabolic adaptations that accompany weight loss attempts.