How accurate are predictive formulas calculating energy expenditure in adolescent patients with anorexia nervosa?

BACKGROUND & AIMS: To compare resting energy expenditure, measured by indirect calorimetry, to values estimated by different predictive formulas in adolescent patients with anorexia nervosa. METHODS: We studied 22 female in-patients with a mean age of 14.7 years (SD 1.2). Resting energy expenditure was measured by indirect calorimetry (Deltatrac II MBM-200). We compared measured resting energy expenditure to values estimated by several predictive formulas [Fleisch, Harris-Benedict, FAO, Schofield-HW, Schebendach] using the intraclass correlation coefficient and the Bland-Altman method. RESULTS: Body mass index increased significantly (P<0.001). Measured resting energy expenditure increased during hospitalization (P<0.05). All formulas overestimated resting energy expenditure with respect to indirect calorimetry except the Schebendach formula. The intraclass correlation between indirect calorimetry and the formulas were poor (0.09-0.20). We observed a poor clinical agreement (Bland-Altman). CONCLUSIONS: Body mass index and resting energy expenditure increased during hospitalization. The majority of the predictive formulas overestimate resting energy expenditure in adolescent patients with anorexia nervosa. Therefore, indirect calorimetry may be a very useful tool for calculating caloric requirements in these patients.     

Can measured resting energy expenditure be estimated by formulae in daily clinical nutrition practice?

PURPOSE OF REVIEW: To recognize the fundamental factors that alter energy expenditure on a daily basis and the impact they have on the measurement of caloric consumption by the human body, through respiratory indirect calorimetry, and thus to try to determine which predictive equation best correlates with total energy expenditure generated from energy measurements. RECENT FINDINGS: The most important compartment of the body, for its metabolic activity and influence upon resting metabolic rate, is fat-free mass. Other variables affecting energy expenditure are sex, weight, height, age, body surface area, fat mass and ethnicity. Metabolic and activity factors such as the thermic effect of nutrients, facultative thermogenesis, anabolism/growth and physical activity, also contribute, comprising total daily energy expenditure. Following the pioneering work of Harris and Benedict for the estimation of energy expenditure, several authors turned their experimental interest to this area, and various recent predictive formulae were derived. These are useful and easy to apply in daily clinical nutrition practice. However, because of the cited variables upon energy expenditure, the final daily caloric estimates show inherent errors ranging from -23.5 to +22.5% upon measured caloric expenditure. These are particularly remarkable in critically ill patients who are exposed to medical and surgical interventions. SUMMARY: One has to be careful in choosing, understanding and clinically applying the results from predictive equations, bearing in mind that the original population from which the equation was derived does not always correspond to that currently being evaluated.     

Is chronic hypoxemia in patients with chronic obstructive pulmonary disease associated with more marked nutritional deficiency? A study of the fat-free mass evaluated by anthropometry and bioelectrical impedance methods

In order to determine wheter blood gases abnormalities, specially hypoxemia, are associated with more marked changes in fat-free mass in patients with chronic obstructive pulmonary disease (CPOD), nutritional assessment was performed on 16 normoxemic (PaO2 > 55 mm Hg) and 16 hypoxemic (PaO2 < 55 mm Hg) COPD patients in stable clinical condition. Body weight was expressed as percentage of the ideal body weight. Fat-free mass was estimated by anthropometry (FFM-Anthr) and by bioelectrical impedance (FFM-BI). Handgrip-strength was assessed as a measure of peripheral skeletal muscle strength. Patients were age-matched and presented similar degree of airway obstruction. Malnutrition, defined as body weight less than 90% of the ideal, was observed in 19% of the normoxemic patients and in 25% of the hypoxemic patients (p>0,05). FFM values in hypoxemic patients, estimated by both methods, were not different from those observed in normoxemic patients. No significant difference was observed on handgrip values between the two groups. No correlation was found between nutritional indices and pulmonary function and gases exchange parameters. FFM correlated positively with values of peripheral muscle function in normoxemic and hypoxemic patients. These data add further evidence to the hypothesis that hypoxemia is not a primary cause of the nutritional deficiency observed in COPD patients.     

Hypothermia in anorexia nervosa: An increase in nonshivering thermogenesis?

A variety of disturbances in thermoregulatory processes have been identified in patients with anorexia nervosa (AN). Malnutrition, loss of thermal insulation, and hypoglycemia are generally accepted as the principal underlying mechanisms. Many of these thermoregulatory aberrations, however, may persist beyond the period of malnutrition and after substantial gains in body weight (in particular, hypothermia and an absence of shivering). It is proposed that during the course of the illness a physiologic state similar to that of cold-adapted mammals may occur in AN patients. As a consequence of this aberrant physiologic state we postulate that an increase in functional nonshivering thermogenesis (NST) interferes with normal shivering responses to cold. An increase in functional brown adipose tissue is proposed to underlie the development of NST in AN patients.     

Energy expenditure in disease: time to revisit?

Knowledge of energy expenditure is especially important in disease, and may in fact help in the understanding of the pathophysiology of wasting associated with disease. Energy requirements in a clinical setting are often 'prescribed' by health professionals, either directly through enteral or parenteral feeding, or perhaps controlled through a hospital diet. Studies initially suggested an increase in energy expenditure, and thus energy requirements, as a direct result of an increase in basal metabolic rate often seen in disease. However, many problems exist in the measurement of BMR in a disease situation, due to the effects of drugs, clinical practice, feeding or possibly anxiety either as a cause of the disease or the measurement itself. These problems could in themselves contribute to the rise in metabolism seen in disease. More recently, however, with the use of tracer techniques such as doubly-labelled water and the bicarbonate-urea method, more accurate estimates of energy expenditure, and thus energy requirements, have been made. Some such measurements have in fact shown that even with an elevated BMR, free-living total energy expenditure can in fact be reduced in many disease situations, suggesting a reduced rather than an increased energy requirement. The present review investigates measurements of total energy expenditure in disease to explore the hypothesis that energy expenditure in disease, even with an elevated BMR, can in fact be reduced due to a concurrent reduction in physical activity.     

Resting energy expenditure assessment in anorexia nervosa: comparison of indirect calorimetry, a multisensor monitor and the Müller equation

The aim of this study was to compare the estimations provided by three different means of measuring the resting energy expenditure (REE) in anorexia nervosa (AN) patients. REE was measured, after 24?h of refeeding, using a portable multisensor body monitor [SenseWear Pro2 Armband (SWA)], FitMate? method and the Müller equation for individuals with body mass index 相似文献   

Energy expenditure in infants with pulmonary insufficiency: is there evidence for increased energy needs?

The observed growth failure in infants with pulmonary insufficiency is postulated to be a consequence of elevated rates of energy expenditure. Assessment of energy expenditure by the classical technique of indirect calorimetry has yielded conflicting results. The adoption of the newer, doubly labeled water technique has provided evidence to support increased rates of energy expenditure in infants with chronic lung disease, congenital heart disease and in minimally ill, extremely low birth weight infants. The doubly labeled water technique holds great promise for the detailed study of energy expenditure in a variety of clinical conditions, including very ill as well as free-living subjects.     

Decreased glutathione in patients with anorexia nervosa. Risk factor for toxic liver injury?

OBJECTIVE: To investigate glutathione and amino acids related to glutathione metabolism in patients with anorexia nervosa in order to test the hypothesis that these patients exhibit a deficiency of glutathione and therefore might be at an increased risk of developing toxic liver injury. DESIGN: Controlled observatory study and case report. SETTING: University Hospital. SUBJECTS: Subjects included 11 female patients with anorexia nervosa and 12 healthy female controls. INTERVENTIONS: Determination of fasting free and total glutathione, homocysteine, vitamins B(6) and B(12) and folic acid in plasma. RESULTS: A 14-y-old patient with a body mass index of 12.6 kg/m(2) presented with markedly elevated transaminases (ALAT >50 x upper limit of normal), and paracetamol was detected in her blood. Patients with anorexia nervosa exhibited lower circulating concentrations of free cysteine (8.9+/-1.5 vs 12.0+/-1.4 micromol/l) and free and total glutathione (5.0+/-1.3 vs 7.1+/-1.2 and 11.2+/-3.8 vs 16.2+/-5.0 micromol/l, respectively). The plasma concentrations of homocysteine (17.5+/-4.9 vs 12.0+/-3.8 micromol/l) and also of glycine (194+/-37 vs 143+/-41 micromol/l) and glutamine (422+/-51 vs 353+/-51 micromol/l) were significantly higher in patients with anorexia nervosa who were not deficient in folic acid, vitamin B(6) and B(12). CONCLUSIONS: Lower plasma concentrations of glutathione suggest lower intracellular concentrations of the tripeptide. Higher homocysteine, glycine and glutamine concentrations point to a decreased utilization of these amino acids for glutathione synthesis and an impairment of trans-sulfuration. Consequently, the capacity of patients with anorexia nervosa to detoxify electrophilic metabolites and reactive oxygen species via glutathione may be impaired.     

Resting energy expenditure in females with cystic fibrosis: is it affected by puberty?

OBJECTIVE: The aims of this study were to determine the effect of puberty and the menstrual cycle on resting energy expenditure (REE) in females with cystic fibrosis (CF). DESIGN: Cross-sectional study. All participants had measurements of REE, anthropometry and pubertal staging. The measurements in the postmenarche group were carried out both in the follicular and luteal phases of their menstrual cycle. SETTING: CF outpatient clinic at the Children's Hospital at Westmead. SUBJECTS: Fifty-six females with CF and pancreatic insufficiency (13 postmenarche) were recruited from the hospital clinic and 63 controls (21 postmenarche) were recruited through families and friends of hospital staff. RESULTS: Females with CF had a higher REE than controls (111.6+/-12.8% of predicted from controls P<0.001). There was a significant effect of menarche on REE with a decrease in the postmenarche -470 kJ/24 h compared with premenarche after adjustment for fat-free mass, fat mass and group (control or CF). There was no difference in REE between the follicular and luteal phases for either CF or controls. CONCLUSIONS: Females with CF had raised REE that appeared to be independent of menarche. This study implies all females with CF and pancreatic insufficiency may need more intensive dietary management, owing to raised REE, to maintain growth and nutritional status, and possibly improve survival.     

Fluid restriction in anorexia nervosa: a neglected symptom or new phenomenon?

OBJECTIVE: The deliberate restriction of fluids to control weight is even more dangerous than food restriction since it results in several serious medical complications. However, there has been scant attention given to the anorexia nervosa patient's manipulation of fluids. It is our clinical impression that fluid restriction in this illness is more common than previously thought. METHOD: We summarize the demographic and clinical features of six cases of anorexia nervosa and one case of eating disorder not otherwise specified (ED-NOS) (subthreshold anorexia nervosa), where fluid restriction was a major behavioral problem. We then describe two of the anorexia nervosa cases in more detail. All were treated at a dieting disorders unit affiliated with the University of Sydney. Their preadmission history, psychological and physical status on admission, results of physical investigations, the beginning of the fluid restriction, fluid and food intake throughout treatment, and the resolution of the fluid restriction were assessed. RESULTS: Patterns emerged in the relationship between eating and drinking. In all cases, food restriction was severe prior to the onset of fluid restriction but, notably, fluid intake recommenced prior to food intake. The reasons given by patients for restricting fluid were that it contained calories and that it made them feel full. Most anorexic patients equate feeling full with "feeling fat." Furthermore, they feel fully in control when they restrict fluid as well as food and this produces a strong motivation to maintain the behavior. DISCUSSION: The cases illustrate the insidious nature and serious consequences of fluid restriction and the difficulties managing dieting-disordered patients who undertake it. Careful attention must be given to assessment and clinicians should be aware of fluid restriction as an important aspect of anorexic behavior.     

Psychotherapy in anorexia nervosa: What does the absence of evidence mean?

Psychological treatment in anorexia nervosa(AN) is disheartening. Psychotherapy is the "treatment of choice" for adults though this recommendation is grounded on the absence of good quality clinical studies. This paper seeks to address the question of why improvements in the psychological treatment of AN have been thwarted, and why one of the best treatments available for adult patients is specialist supportive clinical management that has entered the stage through the backdoor of nonspecific supportive treatments originally serving as a placebo treatment assigned in randomized clinical trials to control for non-specific aspects of true psychosocial treatments. The possibility that most of the psychopathological features that characterise the AN symptoms profile could be best understood as the direct consequences of emaciation would enhance the utility of research with animal models for generating new hypothesis to improve AN treatment.