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.     

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.     

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.     

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.     

Hypermetabolism in clinically stable patients with liver cirrhosis.

BACKGROUND: Hypermetabolism has a negative effect on prognosis in patients with liver cirrhosis. Its exact prevalence and associations with clinical data, the nutritional state, and beta-adrenergic activity are unclear. OBJECTIVE: We investigated resting energy expenditure (REE) in 473 patients with biopsy-proven liver cirrhosis. DESIGN: This was a cross-sectional study with a controlled intervention (beta-blockade) in a subgroup of patients. RESULTS: Mean REE was 7.12 +/- 1.34 MJ/d and correlated closely with predicted values (r = 0.70, P < 0.0001). Hypermetabolism was seen in 160 patients with cirrhosis (33.8% of the study population). REE was > 30% above the predicted value in 41% of the hypermetabolic patients with cirrhosis. Hypermetabolism had no association with clinical or biochemical data on liver function. REE correlated with total body potassium content (TBP; r = 0.49, P < 0.0001). Hypermetabolic patients had lower than normal body weight and TBP (P < 0.05). About 47% of the variance in REE could be explained by body composition whereas clinical state could maximally explain 3%. Plasma epinephrine and norepinephrine concentrations were elevated in hypermetabolic cirrhotic patients (by 56% and 41%, respectively; P < 0.001 and 0.01). Differences in REE from predicted values were positively correlated with epinephrine concentration (r = 0.462, P < 0.001). Propranolol infusion resulted in a decrease in energy expenditure (by 5 +/- 3%; P < 0.05), heart rate (by 13 +/- 4%; P < 0.01), and plasma lactate concentrations (by 32 +/- 12%; P < 0.01); these effects were more pronounced in hypermetabolic patients (by 50%, 33%, and 68%, respectively; each P < 0.05). CONCLUSIONS: Hypermetabolism has no association with clinical data and thus is an extrahepatic manifestation of liver disease. Increased beta-adrenergic activity may explain approximately 25% of hypermetabolism.     

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.     

Plasma levels of amino acids and hypermetabolism in patients with chronic obstructive pulmonary disease

Plasma levels of amino acids were measured by ion-exchange, high-pressure liquid chromatography in 30 ambulatory patients with chronic obstructive pulmonary disease (COPD; mean +/- SD: age 64 +/- 13 y and forced expiratory volume in 1 s [FEV1] 0.85 +/- 0.25 L) and 30 age- and sex-matched healthy control subjects with regard to nutritional status, resting energy expenditure (REE), and pulmonary function. The ratio of branched-chain amino acids to aromatic amino acids was significantly (P < 0.001) decreased in COPD patients and was significantly correlated with percentage of ideal body weight (r = 0.403, P < 0.05), percentage of arm-muscle circumference (r = 0.492, P < 0.01), and %FEV1 (r = 0.467, P < 0.05). Plasma levels of alanine and cysteine were decreased, whereas levels of glutamine, aspartic acid, serine, and ornithine were elevated in COPD patients as opposed to control subjects. The ratio of resting energy expenditure to predicted resting energy expenditure was negatively correlated with the ratio of branched-chain to aromatic amino acids (r = -0.716, P < 0.01), percentage of arm-muscle circumference (r = -0.770, P < 0.05), %FEV1 (r = -0.839, P < 0.01), and the maximal inspiratory pressure (r = -0.803, P < 0.001). Underweight COPD patients also exhibited a greater degree of hyperinflation (percentage of residual volume = 205 +/- 15 for underweight patients and 156 +/- 8 for normal-weight patients). In conclusion, a decrease in plasma levels of branched-chain amino acids in relation to hypermetabolism, possibly resulting from the severity of COPD and respiratory muscle weakness, and various disturbances in plasma amino-acid levels were found in underweight COPD patients.     

Increased contribution of protein oxidation to energy expenditure in head-injured patients

Six patients with acute head injury (initial GCS 4.8 +/- 1.7) were studied to determine the contribution of protein oxidation to resting energy expenditure (REE). Patients were studied on the second or third day post-injury and prior to implementation of nutritional support. Variables measured included REE by indirect calorimetry (normalized to percent predicted energy expenditure calculated from the Harris-Benedict equation). 24-hr urinary nitrogen excretion, calorie, and nitrogen intake. All patients received dexamethasone (39 +/- 2 mg/day) and three received pentobarbital. Mean REE was widely variable, ranging from 43 to 128% of predicted (mean, 90 +/- 31%). Mean 24-hr urinary nitrogen excretion was 16.5 +/- 5.8 g. The contribution of protein oxidation to REE was 30 +/- 4%. The contribution of protein oxidation to REE did not parallel REE (r = -0.237, p = NS) or REE expressed as percent predicted (r = -0.258, p = NS). The contribution of protein oxidation to energy expenditure is greater in acute heat trauma than previously described soft tissue injury and sepsis. The observed excessive nitrogen catabolism and increased contribution of protein oxidation to resting energy expenditure suggest accentuated protein requirements in respect to energy needs in head-injured patients.     

Resting energy expenditure in children with neonatal chronic lung disease and obstruction of the airways

Children with history of broncho-pulmonary dysplasia (BPD) often suffer from growth failure and lung sequelae. The main objective of this study was to test the role of pulmonary obstruction on resting energy expenditure (REE) and nutritional status in BPD. Seventy-one children with BPD (34 boys and 37 girls) and 30 controls (20 boys and 10 girls) aged 4-8 years were enrolled. Body composition was assessed by bio-impedancemetry measurements; REE was measured by indirect calorimetry. Predicted REE was calculated using the Schofield equation. The population of children with BPD was divided into three groups: children without obstruction of the airways, children with moderate obstruction of the airways, and children with severe obstruction. Children with BPD were significantly smaller and leaner than controls. Altered body composition (reduction of fat mass) was observed in BPD children that suffered from airway obstruction. REE was significantly lower in children with BPD compared to controls, but when adjusted for weight and fat-free mass no significant difference was observed irrespective of pulmonary status. Airway obstruction in children with BPD does not appear to be associated with an increased REE. Moreover altered REE could not explain the altered nutritional status that is still observed in BPD in later childhood. This supports the hypothesis that body composition and pulmonary function in BPD in later childhood are fixed sequelae originating from the neonatal period.     

Whole body protein turnover in malnourished cystic fibrosis patients and its relationship to pulmonary disease

To investigate the effect of pulmonary disease in cystic fibrosis (CF), total body protein synthesis and catabolism were determined in eight CF children with acute exacerbations of pulmonary infection at the time of study (CF I), a group of CF children (n = 7) with chronic but stable pulmonary disease (CF II) and a group (n = 8) of healthy children. Protein synthesis was determined by the method of Waterlow et al (1978) using a single oral dose of 15N glycine and protein catabolism derived from nitrogen balance. Protein synthesis was markedly decreased (p less than 0.001) in the CF I group (1.01 +/- 0.10 g kg-1 10 h-1) compared with that of controls (2.02 +/- 0.08) and with CF children with chronic but stable pulmonary disease (CF II) (2.36 +/- 0.17). Protein catabolism was increased (p less than 0.01) in the CF II group compared with both controls and CF I. These findings contrast strongly to studies in normal children and those with mild protein-energy malnutrition (PEM) and infection, where infection increased protein synthesis, but are consistent with the observed decrease in protein turnover where severe PEM is accompanied by infection. We conclude that repeated pulmonary infection can adversely affect protein-energy balance and that adequate nutritional support should be considered in management during and after each episode.     

Energy expenditure, nutrition status, and body composition in children with cystic fibrosis

OBJECTIVE: Undernutrition is a frequent complication in patients with cystic fibrosis (CF). Elevated energy requirements have been found to be 4% to 33% higher than in controls in some studies. Whether or not this is caused by a primary defect or energy metabolism is still a matter of controversy. To this end, we assessed energy expenditure, nutrition status, and body composition of clinically stable CF outpatients. METHODS: Fifteen clinically stable CF patients, ages 2 to 15 y, were paired with 15 healthy control children. Measurements consisted of anthropometry and body composition. Plasma tocopherol, retinol, and hair zinc content were measured. Resting energy expenditure was determined by indirect calorimetry. Physical activity and dietary intake were recorded by recall methods. RESULTS: Two children were nutritionally at risk according to the weight/height index, eight were normal, three were overweight, and two were obese. Body composition was similar in both groups. Zinc, tocopherol, and retinol levels were low in three, two, and three patients, respectively. Resting energy expenditures were 4.7 MJ/d (1127 +/- 220 kcal/d) in CF children and 4.63 MJ/d (1108 +/- 191 kcal/d) in control children (P = not significant). Physical activity level was sedentary in 86.6% of CF patients; the rest had a light physical activity pattern. Energy intake represented 141% of the estimated daily energy expenditure. CONCLUSIONS: Non-oxygen-dependent CF children, without acute respiratory infection, had resting energy expenditures comparable to those of matched controls. Total energy expenditure was similar to or slightly lower than that in healthy children. Dietary recommendations for CF patients need to be reassessed.     

Energy balance in children and young adults receiving haemodialysis for chronic renal failure

This study was designed to determine the contribution of energy expenditure to the energy imbalance seen in uraemic children. Resting energy expenditure (REE) was measured using open-circuit indirect calorimetry in eight uraemic haemodialysed subjects aged 9.3-20.4 years and in 10 healthy children. Linear correlations between REE and both body weight and fat-free mass as measured by anthropometry were found in both controls and uraemic subjects (respectively: r = 0.76 and r = 0.88 for body weight and r = 0.73 and r = 0.90 for fat-free mass). Measured REE in uraemic patients was not different from the value predicted by using actual body weight and fat-free mass in the regression equation of REE on body weight and fat-free mass in controls (paired t test: p = 0.70 and p = 0.19 respectively). These data suggest that the energy imbalance seen in uraemic children is not due to increased energy expenditure and is therefore probably due to decreased food intake.     

Resting energy expenditure in patients with end-stage liver disease and in normal population

Resting energy expenditure (REE) was measured in 10 patients with end-stage liver disease (ELD) and in 31 normal controls. Basal energy expenditure (BEE) was also predicted by the Harris-Benedict equation. In order to correlate REE to lean body mass, the 24-hr urinary creatinine was measured in patients with ELD and in normal controls and expressed as kcal/g urinary creatinine. Linear regression analysis showed a statistically significant (p less than 0.0001) correlation (r = 0.72) between the REE and the 24-hr urinary creatinine in normal controls, irrespective of age and sex. Mean BEE (1580 +/- 160 vs 1575 +/- 210) and REE (1755 +/- 215 vs 1800 +/- 330) were not significantly different between patients with ELD and controls. However, the mean REE was 1900 +/- 610 kcal/g creatinine in patients with ELD and 1180 +/- 260 (p less than 0.0001) in controls. When related to lean tissue, patients with ELD had increased energy expenditure, confirming the hypermetabolic state suggested on clinical grounds. The use of urine creatinine to estimate energy expenditure may be a simple clinical technique to predict dietary energy needs in malnourished, unstressed patients. When this estimated energy expenditure/g creatinine (EEE) is compared to measured energy expenditure/g creatinine in malnourished, stressed patients, the EEE provides an index of the extent of hypermetabolism.     

Total daily energy expenditure in wasted chronic obstructive pulmonary disease patients

OBJECTIVES: To investigate total daily energy expenditure in chronic obstructive pulmonary disease (COPD) patients during a rehabilitation programme. DESIGN: Observational study involving a case and a control group. SUBJECTS: Ten COPD patients (six with body mass index (BMI) <18.5 kg/m(2) and four with BMI >18.5 kg/m(2)) were evaluated for their energy expenditure profile. Four additional healthy age-matched volunteers were also included for methodology evaluation. INTERVENTIONS: Measurements of total daily energy expenditure (TEE), resting energy expenditure (REE) and diet-induced thermogenesis (DIT) and energy intake were undertaken by indirect calorimetry and bicarbonate-urea methods and dietary records. RESULTS: REE in COPD patients was not significantly different from that predicted by the Harris-Benedict equation. Before the exercise day the mean TEE was 1508 kcal/day and physical activity level (PAL as calculated by TEE/REE) was 1.52. On the exercise day the TEE increased to 1568 kcal/day and PAL was 1.60, but neither of these changes were significant. The energy cost of increased physical activity during rehabilitation exercise was estimated to be 191 kcal/day. No significant change was found in DIT between the two patient groups. However, overall energy balances were found to be negative (-363 kcal/day). CONCLUSION: The rehabilitation programme did not cause a significant energy demand in COPD patients. TEE in COPD patients was not greater than in free-living healthy subjects. Patients, who were underweight, did not have a higher TEE than patients with normal weight. This suggested that malnutrition in COPD patients was not due to an increased energy expenditure. On the other hand, a significant negative energy balance due to insufficient energy intake was found in seven out of 10 patients.     

Resting energy expenditure in patients with chronic obstructive pulmonary disease

Resting energy expenditure (REE) was measured in 68 patients with stable chronic obstructive pulmonary disease (COPD) and in 34 weight-stable, age-matched (65 +/- 8 y; means +/- SD) healthy control subjects. Fat-free mass (FFM) determined by bioelectrical resistance explained 84% of the variation in REE in the control group but only 34% in the COPD patients. REE could not reliably be predicted from regression equations either developed in healthy subjects or in COPD patients. REE adjusted for FFM was significantly higher (P less than 0.05) in weight-losing (n = 34) than in weight-stable (n = 34) patients (6851 +/- 781 and 6495 +/- 650 kJ/d, respectively). Pulmonary function was more compromised in weight-losing patients. Adjusted REE in weight-stable patients was significantly higher (P less than 0.01) than in the healthy control group (6131 +/- 405 kJ/d). In patients with COPD, factors in addition to FFM are important determinants of REE. A disease-related increase in REE develops, which may contribute to weight loss in COPD in combination with a lack of an adaptive response to undernutrition in weight-losing patients.     

Energy expenditure of stunted and nonstunted boys and girls living in the shantytowns of São Paulo, Brazil

BACKGROUND: Stunting increases the risk of obesity in developing countries, particularly in girls and women, but the underlying reason is not known. OBJECTIVE: Our objective was to test the hypothesis that stunted children have lower energy expenditure than do nonstunted children, a factor that has predicted an increased risk of obesity in other high-risk populations. DESIGN: A cross-sectional study was conducted in shantytown children from S?o Paulo, Brazil. Twenty-eight stunted children aged 8-11 y were compared with 30 nonstunted children with similar weight-for-height. Free-living total energy expenditure (TEE) was measured over 7 d by using the doubly labeled water method. In addition, resting energy expenditure (REE) was measured by indirect calorimetry and body composition was measured by dual-energy X-ray absorptiometry. RESULTS: There were no significant associations between stunting and any measured energy expenditure parameter, including REE adjusted for weight (f1.gif" BORDER="0"> +/- SEM: 4575 +/- 95 compared with 4742 +/- 91 kJ/d, in stunted and nonstunted children, respectively) and TEE adjusted for weight (8424 +/- 239 compared with 8009 +/- 221 kJ/d, in stunted and nonstunted children, respectively). In multiple regression models that included fat-free mass and fat mass, girls had significantly lower TEE than did boys (P: < 0.05) but not significantly lower REE (P: = 0.17). CONCLUSIONS: There was no association between stunting and energy expenditure after differences between groups in body size and composition were accounted for. However, the girls had lower TEE than did boys, which may help to explain the particularly high risk of obesity in stunted adolescent girls and women in urban areas of developing countries.     

Increased resting energy expenditure is related to plasma TNF-alpha concentration in stable COPD patients

The objective of this study was to test whether increased resting energy expenditure (REE) in chronic obstructive pulmonary disease (COPD) patients is related to increased cost of breathing and/or to increased cytokine production.In 36 non-inflammatory (CRP: 17.6 +/- 13.1 mg.l(-1), mean +/- SD; orosomucoid: 0.71 +/- 0.18 g.l(-1)), non-malnourished (BMI: 23.6 +/- 4.3 kg.m(-2)), clinically stable, non severely hypoxic COPD patients (60.5 +/- 8.9 years) we measured REE, pulmonary function and plasma cytokine concentrations (TNF-alpha, IL1 and IL6). REE was increased by 10 +/- 11% (P< 0.001) above predicted values. Plasma TNF-alpha concentration was increased in all patients (mean value 26.3 +/- 14.3 pg.ml(-1)). Excess REE (with respect to values predicted by Harris-Benedict equations) was correlated with plasma TNF-alpha concentration (P< 0.005), but not with the degree of airway obstruction, lung overinflation, or with oxygen cost of breathing. Theophylline treatment resulted in a significant increase in REE by 15%.In conclusion: non-malnourished, clinically stable, non-severely hypoxic COPD patients display an increased REE that is related with plasma TNF-alpha concentration (without apparent systemic inflammation) and to theophylline treatment, but that is independent of parameters of respiratory function.     

Energy requirements in frail elderly people: a review of the literature

This review collates studies of healthy, sick, underweight (BMI < or = 21 kg/m2) and very elderly people (> or = 90 yr), in whom resting energy expenditure (REE) was measured using indirect calorimetry. We have observed the following: (1) REE, when adjusted for differences in both body weight and fat-free mass (FFM), is similar in healthy and in sick elderly people being 20 and 28 kcal/kg of FFM per day, respectively, (2) their nutritional status influences their energy requirements given that weight-adjusted REE increases in line with a decrease in BMI, (3) total energy expenditure is lower in sick elderly people given that their physical activity level, i.e. the ratio of total energy expenditure to REE, is reduced during disease averaging at 1.36, (4) energy intake (EI) being only 1.23 x REE is insufficient to cover energy requirements in sick elderly patients, whereas the EI of healthy elderly people appears sufficient to cover requirements, and finally, (5) gender ceases to be a determinant of REE in people aged 60 yr or over, with the Harris & Benedict equation capable of accurately predicting mean REE in this population, whether healthy or sick.     

Determinants of Energy Utilization in Patients with Cystic Fibrosis

Resting energy expenditure (REE) is increased in patients with cystic fibrosis, a consequence of the work of breathing and not related to the cystic fibrosis (CF) gene. CF patients compensate, however, with reduced energy expenditure for activity and thermogenesis, thereby maintaining total energy expenditure (TEE) equivalent to that of healthy peers.     

Energy balance in children and young adultsreceiving haernodialysis for chronic renal failure

This study was designed to determine the contribution of energy expenditure tothe energy imbalance seen in uraemic children. Resting energy expenditure (REE) was measured using open-circuit indirect calorimetry in eight uraemic haemodialysed subjects aged 9.3–20.4 years and in 10 healthy children. Linear correlations between REE and both body weight and fat-free mass as measured by anthropometry were found in both controls and uraemic subjects (respectively: r = 0.76 and r = 0.88 for body weight and r = 0.73 and r = 0.90 for fat-free mass). Measured REE in uraemic patients was not different from the value predicted by using actual body weight and fat-free mass in the regression equation of REE on body weight and fat-free mass in controls (paired t test: p = 0.70 and p = 0.19 respectively). These data suggest that the energy imbalance seen in uraemic children is not due to increased energy expenditure and is therefore probably due to decreased food intake.