Accurate Determination of Energy Needs in Hospitalized Patients

Energy, Protein, Carbohydrate, and Lipid Intakes and Their Effects on Morbidity and Mortality in Critically Ill Adult Patients: A Systematic Review

The guidelines for nutritional support in critically ill adult patients differ in various aspects. The optimal amount of energy and nutritional substrates supplied is important for reducing morbidity and mortality, but unfortunately this is not well known, because the topic is complex and every patient is individual. The aim of this review was to gather recent pertinent information concerning the nutritional support of critically ill patients in the intensive care unit (ICU) with respect to the energy, protein, carbohydrate, and lipid intakes and the effect of their specific utilization on morbidity and mortality. Enteral nutrition (EN) is generally recommended over parenteral nutrition (PN) and is beneficial when administered within 24-48 h after ICU admission. In contrast, early PN does not provide substantial advantages in terms of morbidity and mortality, and the time when it is safe and beneficial remains unclear. The most advantageous recommendation seems to be administration of a hypocaloric (<20 kcal · kg^-1 · d^-1), high-protein diet (amino acids at doses of ≥2 g · kg^-1 · d^-1), at least during the first week of critical illness. Another important factor for reducing morbidity is the maintenance of blood glucose concentrations at 120-150 mg/dL, which is accomplished with the use of insulin and lower doses of glucose of 1-2 g · kg^-1 · d^-1, because this prevents the risk of hypoglycemia and is associated with a better prognosis according to recent studies. A fat emulsion is used as a source of required calories because of insulin resistance in the majority of patients. In addition, lipid oxidation in these patients is ∼25% higher than in healthy subjects.

Resting energy expenditure in critically ill patients: Evaluation methods and clinical applications

Patients on intensive care present systemic, metabolic, and hormonal alterations that may adversely affect their nutritional condition and lead to fast and important depletion of lean mass and malnutrition. Several factors and medical conditions can influence the energy expenditure (EE) of critically ill patients, such as age, gender, surgery, serious infections, medications, ventilation modality, and organ dysfunction. Clinical conditions that can present with EE change include acute kidney injury, a complex disorder commonly seen in critically ill patients with manifestations that can range from minimum elevations in serum creatinine to renal failure requiring dialysis. The nutritional needs of this population are therefore complex, and determining the resting energy expenditure is essential to adjust the nutritional supply and to plan a proper diet, ensuring that energy requirements are met and avoiding complications associated with overfeeding and underfeeding. Several evaluation methods of EE in this population have been described, but all of them have limitations. Such methods include direct calorimetry, doubly labeled water, indirect calorimetry (IC), various predictive equations, and, more recently, the rule of thumb (kcal/kg of body weight). Currently, IC is considered the gold standard.

Total Parenteral and Enteral Nutrition in the ICU: Evolving Concepts

Appropriate nutrition in the hospital setting, particularly in critically ill patients, has long been tied to improving clinical outcomes. During critical illness, inflammatory mediators and cytokines lead to the creation of a catabolic state to facilitate the use of endogenous energy sources to meet increased energy demands. This process results in increasing the likelihood of overfeeding. The literature has revealed exponential advances in understanding the molecular basis of nutritional support and evolution of clinical protocols aimed at treating artificial nutritional support as a therapeutic intervention, preventing loss of lean body mass and metabolic deterioration to improve clinical outcomes in the critically ill.

Considerations When Using Predictive Equations to Estimate Energy Needs Among Older, Hospitalized Patients: A Narrative Review

The aim of this narrative review was to summarize the accuracy of predictive equations used to estimate energy expenditure in older, hospitalized adults. More than 50% of patients admitted to intensive care units are older adults. Currently accepted prediction equations used to determine energy intake in the older, hospitalized patient were not specifically developed for the aging population. Rates of multimorbidity, polypharmacy and malnutrition, conditions that influence energy expenditure, are higher in older adults compared to younger adults. For these reasons, current equations may not accurately assess energy needs in this population. As the evidence demonstrating the importance of nutritional supplementation in older, hospitalized adults grows, more accurate energy assessment methods that account for age-related conditions are needed to predict nutritional requirements.

Prevalence of Pressure Ulcer and Nutritional Factors Affecting Wound Closure Success in Thailand

Introduction:

The authors aimed to estimate the prevalence of pressure ulcers and to explore the nutritional effects of the prognostic factors on successful pressure ulcer closure in a public tertiary care hospital in Thailand.

Patients and Methods:

The study was a retrospective cohort analysis of seven-year census (2008 - 2014) at Surin hospital in Thailand. There were 424 of total 240,826 patients aged over than 15 years admitted to surgery, orthopedics and medicine wards during the study period with documented pressure ulcers (ICD 10TM). We analyzed four hundred and ten patients after excluding 14 patients with non-pressure ulcers (due to burning/ diabetic/ ischemic neuropathic ulcers, and less than 24 hours of admission) and loss medical record. We selected independent factors from demographic data, nutritional factors, pressure ulcer characteristics, and management data. The outcome of interest was successful pressure ulcer closure. The analysis method was the semi-parametric Cox regression model and reported as Hazard Ratios (HR) with 95% confidence interval (95% CI).

Results:

The total hospital admission was 240,826 patients between 2008 - 2014. 410 patients were developing pressure ulcers, of these, 7% (28/410) success in ulcer closure, and 77% (314/410) failure in closure requiring for additional procedures (excisional debridement). The rest of patients (16%, 68/410) was non-operative care. The prevalence of pressure ulcers was 1.7 per 1,000 person-year. The multivariable model found that only the Nottingham Hospital Screening Tool (NS) score was a statistically significant nutritional variable, and additional subgroup analysis of two models of sepsis and spinal cord co-morbidities was also significant. Adjusted hazard ratios (HR) for NS score = 0.355 (95% CI: 0.187, 0.674), p=0.002), for sepsis = 0.312 (95% CI: 0.140, 0.695), p=0.004), and for spinal cord co-morbidity = 0.420 (95% CI: 0.184, 0.958), p=0.039).

Conclusions:

The annual prevalence was 1.7 per 1,000 persons. NS score was strongly associated with ulcer closure success.

Predicting resting energy expenditure in underweight, normal weight, overweight, and obese adult hospital patients

Background

When indirect calorimetry is not available, predictive equations are used to estimate resing energy expenditure (REE). There is no consensus about which equation to use in hospitalized patients. The objective of this study is to examine the validity of REE predictive equations for underweight, normal weight, overweight, and obese inpatients and outpatients by comparison with indirect calorimetry.

Methods

Equations were included when based on weight, height, age, and/or gender. REE was measured with indirect calorimetry. A prediction between 90 and 110% of the measured REE was considered accurate. The bias and root-mean-square error (RMSE) were used to evaluate how well the equations fitted the REE measurement. Subgroup analysis was performed for BMI. A new equation was developed based on regression analysis and tested.

Results

513 general hospital patients were included, (253 F, 260 M), 237 inpatients and 276 outpatients. Fifteen predictive equations were used. The most used fixed factors (25 kcal/kg/day, 30 kcal/kg/day and 2000 kcal for female and 2500 kcal for male) were added. The percentage of accurate predicted REE was low in all equations, ranging from 8 to 49%. Overall the new equation performed equal to the best performing Korth equation and slightly better than the well-known WHO equation based on weight and height (49% vs 45% accurate). Categorized by BMI subgroups, the new equation, Korth and the WHO equation based on weight and height performed best in all categories except from the obese subgroup. The original Harris and Benedict (HB) equation was best for obese patients.

Conclusions

REE predictive equations are only accurate in about half the patients. The WHO equation is advised up to BMI 30, and HB equation is advised for obese (over BMI 30). Measuring REE with indirect calorimetry is preferred, and should be used when available and feasible in order to optimize nutritional support in hospital inpatients and outpatients with different degrees of malnutrition.

Pilot Study to Explore the Accuracy of Current Prediction Equations in Assessing Energy Needs of Patients with Newly Diagnosed Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is rare, yet it is the most common brain malignancy and has a poor prognosis. In regard to GBM, there is a dearth of research on resting energy expenditure (REE) and the accuracy of extant prediction equations. The aim of this cross-sectional study was to compare measured REE (mREE) to commonly used prediction equations in newly diagnosed GBM patients. REE was collected by indirect calorimetry in 20 GBM patients. Calculated REE was derived from Harris-Benedict (again with weight adjusted for obesity), Mifflin-St Jeor, and the 20 kcal/kg body weight ratio method. Paired t-tests and Bland-Altman analyses were used to compare group means, evaluate the bias, and find the limits of agreement. Clinical accuracy was assessed by determining the percentage of patients with predicted REE within ±10% of mREE. Subjects were evenly distributed with regard to gender, primarily Caucasian, and largely overweight or obese and had a mean age of 57 years. All equations overestimated mREE. Mifflin-St Jeor and adjusted Harris-Benedict had the narrowest limits of agreement and accurately predicted 60% and 65% of subjects, respectively. Clinicians should be aware of the discrepancy between commonly used prediction equations and REE. More research is needed to verify these findings and decipher the cause and significance in the GBM population.

ACG Clinical Guideline: Nutrition Therapy in the Adult Hospitalized Patient

The value of nutrition therapy for the adult hospitalized patient is derived from the outcome benefits achieved by the delivery of early enteral feeding. Nutritional assessment should identify those patients at high nutritional risk, determined by both disease severity and nutritional status. For such patients if they are unable to maintain volitional intake, enteral access should be attained and enteral nutrition (EN) initiated within 24-48 h of admission. Orogastric or nasogastric feeding is most appropriate when starting EN, switching to post-pyloric or deep jejunal feeding only in those patients who are intolerant of gastric feeds or at high risk for aspiration. Percutaneous access should be used for those patients anticipated to require EN for >4 weeks. Patients receiving EN should be monitored for risk of aspiration, tolerance, and adequacy of feeding (determined by percent of goal calories and protein delivered). Intentional permissive underfeeding (and even trophic feeding) is appropriate temporarily for certain subsets of hospitalized patients. Although a standard polymeric formula should be used routinely in most patients, an immune-modulating formula (with arginine and fish oil) should be reserved for patients who have had major surgery in a surgical ICU setting. Adequacy of nutrition therapy is enhanced by establishing nurse-driven enteral feeding protocols, increasing delivery by volume-based or top-down feeding strategies, minimizing interruptions, and eliminating the practice of gastric residual volumes. Parenteral nutrition should be used in patients at high nutritional risk when EN is not feasible or after the first week of hospitalization if EN is not sufficient. Because of their knowledge base and skill set, the gastroenterologist endoscopist is an asset to the Nutrition Support Team and should participate in providing optimal nutrition therapy to the hospitalized adult patient.

Clinical Guide for the Use of Metabolic Carts: Indirect Calorimetry--No Longer the Orphan of Energy Estimation

Critically ill patients often require nutrition support, but accurately determining energy needs in these patients is difficult. Energy expenditure is affected by patient characteristics such as weight, height, age, and sex but is also influenced by factors such as body temperature, nutrition support, sepsis, sedation, and therapies. Using predictive equations to estimate energy needs is known to be inaccurate. Therefore, indirect calorimetry measurement is considered the gold standard to evaluate energy needs in clinical practice. This review defines the indications, limitations, and pitfalls of this technique and gives practice suggestions in various clinical situations.

Microbial cell preparation in enteral feeding in critically ill patients: A randomized, double-blind, placebo-controlled clinical trial

Gut failure is a common condition in critically ill patients in the intensive care unit (ICU). Enteral feeding is usually the first line of choice for nutrition support in critically ill patients. However, enteral feeding has its own set of complications such as alterations in gut transit time and composition of gut eco-culture. The primary aim of this study was to investigate the effect of microbial cell preparation on the return of gut function, white blood cell count, C-reactive protein levels, number of days on mechanical ventilation, and length of stay in ICU. A consecutive cohort of 60 patients admitted to the ICU in University Malaya Medical Centre requiring enteral feeding were prospectively randomized to receive either treatment (n = 30) or placebo (n = 30). Patients receiving enteral feeding supplemented with a course of treatment achieved a faster return of gut function and required shorter duration of mechanical ventilation and shorter length of stay in the ICU. However, inflammatory markers did not show any significant change in the pretreatment and posttreatment groups. Overall, it can be concluded that microbial cell preparation enhances gut function and the overall clinical outcome of critically ill patients receiving enteral feeding in the ICU.

Energy expenditure in mechanically ventilated patients: The weight of body weight!

BACKGROUND & AIMS

Optimal nutritional care for intensive care unit (ICU) patients requires precise determination of energy expenditure (EE) to avoid deleterious under- or overfeeding. The reference method, indirect calorimetry (IC), is rarely accessible and inconstantly feasible. Various equations for predicting EE based on body weight (BW) are available. This study aims at determining the best prediction strategy unless IC is available.

METHODS

Mechanically ventilated patients staying ≥72 h in the ICU were included, except those with contraindications for IC measurements. IC and BW measurements were routinely performed. EE was predicted by the ESPEN formula and other predictive equations using BW (i.e. anamnestic (AN), measured (MES), adjusted for cumulated water balance (ADJ), calculated for a body mass index (BMI) of 22.5). Comparisons were made using Pearson correlation and Bland & Altman plots.

RESULTS

85 patients (57 ± 19 y, 61 men, SAPS II 43 ± 16) were included. Correlations between IC and predicted EE using the ESPEN formula with different BW (BW_AN, BW_MES, BW_ADJ, and BW_BMI22.5) were 0.44, 0.40, 0.36, and 0.47, respectively. Bland & Altman plots showed wide and inconsistent variations. Predictive equations including body temperature and minute ventilation showed the best correlations, but when using various BWs, differences in predicted EE were observed.

CONCLUSION

No EE predictive equation, regardless of the BW used, gives statistically identical results to IC. If IC cannot be performed, predictive equations including minute ventilation and body temperature should be preferred. BW has a significant impact on estimated EE and the use of measured BW_MES or BW _{BMI 22.5} is associated with the best EE prediction. Clinical trial registration number on ClinicalTrial.gov: NCT02552446. Ethical committee number: CE-14-070.

Nutritional status, assessment, requirements and adequacy of traumatic brain injury patients

Traumatic Brain Injury (TBI) has been considered as a serious public health problem. Each year, traumatic brain injuries are contributing to a substantial number of cases of permanent disability and deaths and it can be classified according to the severity into penetrating and closed head injury. Symptoms, beside to be unconscious can be defined as vomiting, nausea, headache, dizziness, lack of motor coordination, difficulty in balancing, blurred vision and lightheadedness, bad taste in the mouth, ringing in the ears, fatigue and lethargy as well as changes in sleep patterns. The brain is known to be the functional regulator for all the metabolic activities inside the body and TBI patients mostly have a complex metabolic alterations including aberrant cellular metabolism, abnormal metabolic processes, changes in hormones functions and inflammatory cascade. The TBI patient's status needed to be assessed medically and nutritionally since the medical status of the patients can affect the nutrition part. Data from the four assessment tools are needed to be correctly used and interpreted in order to make a proper nutritional diagnosis, clinical assessment, biochemistry as well as anthropometric measurements. Regardless the methods used for assessing TBI patients, having adequate intake and medical care can lead to a reduction in hospital costs, numbers of day hospitalized, numbers of hours of mechanical ventilation and in the overall infection rates.

Mechanically Ventilated, Cardiothoracic Surgical Patients Have Significantly Different Energy Requirements Comparing Indirect Calorimetry and the Penn State Equations

BACKGROUND

Nutrition equations have been validated with indirect calorimetry for determining energy needs in intensive care unit (ICU) populations. This study tested the hypothesis that mechanically ventilated cardiothoracic surgical patients would have significantly different energy requirements when determined by indirect calorimetry vs the Penn State equations.

MATERIALS AND METHODS

This single-center, retrospective cohort analysis of consecutive cardiothoracic surgical patients adhered to a prospectively designed protocol for indirect calorimetry energy measurements. Energy needs were estimated by Penn State equations 2010 and 2003b and then indirect calorimetry.

RESULTS

Analyzed patients (n = 71) had a mean ± SD difference of 556 ± 543 calories/d between indirect calorimetry and Penn State formulae, as well as a mean ± SD percentage caloric difference of 32% ± 31% (95% confidence interval [CI], -20 to 87) with a range of 1311 calories (minimum difference, -379; maximum difference, 933). There was a 10% or greater difference in resting metabolic rate between indirect calorimetry and the Penn State equations in 89% of patients (95% CI, 79%-95%). Based on Lin's concordance correlation of 0.20 (95% CI, 0.09-0.32), the strength of agreement between the resting metabolic rates determined by indirect calorimetry compared with the Penn State equations was poor within this patient sample. Indirect calorimetry performance showed a 10% increase in caloric need in 77% of patients and was associated with a nutrition prescription change in 66%.

CONCLUSIONS

Mechanically ventilated cardiothoracic surgical ICU patients appear to have higher energy requirements by indirect calorimetry than those determined by Penn State equations. Future studies targeting indirect calorimetry in relation to clinical outcomes are needed.

Energy requirements and the use of predictive equations versus indirect calorimetry in critically ill patients

Nutrition support has been shown to have a positive impact on critically ill patients who meet their defined goals of nutrition therapy. However, inappropriate energy assessment can contribute to under- or overfeeding resulting in deleterious effects. Thus, assessment of energy expenditure in critically ill patients is crucial to prevent negative impacts from inappropriate feeding. Currently, the optimal energy requirement and appropriate energy assessment in these patients is controversial. Indirect calorimetry or predictive equations have been suggested to evaluate energy expenditure in critically ill patients. Indirect calorimetry is a gold standard for evaluating energy expenditure, but it is not always available and has some limitations. Many predictive equations, therefore, have been developed to predict energy expenditure in critically ill patients. However, these equations cannot be used generally in these patients since they were developed in a unique patient population. Many studies compared measured energy expenditure with predictive energy expenditure, but the data regarding accuracy is not robust. Therefore, clinicians should consider using these equations carefully based on the current supporting data. Indirect calorimetry is recommended for use in evaluating energy expenditure in critically ill patients if it is available.

Energy expenditure in acute posttraumatic amputation: comparison of four methods for assessment

BACKGROUND

Adequate energy intake is a component of successful recovery after injury, yet little is known about the energy requirements in the acute period following traumatic amputation. The purpose of this study was to compare the clinical applicability of resting energy expenditure (REE) measured by a handheld calorimeter and estimated by 3 different predictive equations to that measured by the gold standard, indirect calorimetry using a metabolic cart, during the acute postamputation period of inpatient hospitalization.

MATERIALS AND METHODS

Indirect calorimetry measured using both a metabolic cart and handheld calorimeter and predicted by 3 equations were used to assess energy needs of eligible subjects admitted to Brooke Army Medical Center with traumatic amputation(s). REE measured by the handheld calorimeter and estimated using 3 predictive equations (Mifflin St. Jeor, Ireton-Jones 1992, and the American College of Chest Physicians [ACCP]) were compared to the gold standard metabolic cart. Each measure was assessed for significant differences and level of clinical acceptability defined as ± 10% REE by metabolic cart.

RESULTS

Thirteen male service members with traumatic amputation(s) were included. The majority of subject's measurements using the handheld calorimeter (n = 9, 69%) and 3 predictive equations (Mifflin St. Jeor [n = 7, 54%], Ireton-Jones 1992 [n = 8, 62%], ACCP [n = 7, 54%]) fell outside of the ± 10% range of clinical acceptability.

CONCLUSION

Use of the metabolic cart for measuring energy needs remains optimal in this population.

Low calorie and carbohydrate diet: to improve the cardiovascular risk indicators in overweight or obese adults with prediabetes

Our objective was to evaluate the effects of a moderate calorie and carbohydrate-restricted diet on cardiovascular risk indicators in overweight or obese patients with prediabetes. A clinical trial was conducted in which 86 subjects presenting with overweight or obesity and prediabetes received a personalized diet of 1,200 to 1,700 calories with a distribution of 50 % carbohydrates, 20 % proteins, and 30 % fat. Body weight, fat mass, and lean mass were measured through bioimpedance. Glucose, total cholesterol, high density lipoprotein cholesterol and low density cholesterol, and triglycerides were measured. The measurements were taken at the beginning of, and at, 6 and 12 months during the intervention, and the differences were compared by paired Student's t and χ(2) tests. At 12 months, a significant reduction was noticed in body weight in patients with overweight and obesity (72.4 ± 7.8-69.6 ± 7.5 kg) (85.7 ± 14.8-80.2 ± 12.7 kg) with body mass index (28.2 ± 0.8-27.2 ± 2.1 kg/m(2)) (34.3 ± 3.5-32.1 ± 3.2 kg/m(2)), systolic (120.9 ± 14.2-112.4 ± 11.5 mmHg) (124.1 ± 11.9-115.7 ± 14.0 mmHg), diastolic blood pressures (79.0 ± 9.3-71.8 ± 8.3 mmHg) (80.4 ± 9.0-73.7 ± 13.1 mmHg), glucose (106.0 ± 8.9-95.9 ± 7.5 mg/dL) (107.3 ± 7.0-97.0 ± 8.2 mg/dL), and significant improvement on lipid profile (p < 0.05). The restrictions in the calorie and carbohydrate diet decrease the cardiovascular risk indicators in overweight or obese adults with prediabetes.

Taxa metabólica basal de homens residentes na cidade de Goiânia

INTRODUÇÃO: A Taxa Metabólica Basal (TMB) é a quantidade de energia necessária para o corpo humano manter os processos fisiológicos normais e a homeostase. Atualmente, a TMB é calculada a partir de equações baseadas na população norte-americana e/ou europeia. OBJETIVO: Comparar as equações de Harris-Benedict, Food and Agriculture Organization e Institute of Medicine com a calorimetria indireta em indivíduos do sexo masculino residentes na cidade de Goiânia. MÉTODOS: A determinação da TMB foi feita pela análise direta de gases, utilizando o analisador VO2000. Foram avaliados 44 voluntários do sexo masculino, com média de idade 29,8 anos (Desvio padrão - DP = 6,21), estatura 1,79 m (DP = 0,06), peso 77,79 kg (DP = 8,49), IMC 24,30 kg/m2 (DP = 1,96), gordura corporal 15,84% (DP = 4,49), circunferência da cintura 80,48 cm (DP = 5,89). RESULTADOS: Foi observada diferença significante (p < 0,05) para os valores da TMB estimada pelas equações de Harris-Benedict (1.824,7, DP = 138,2 kcal/dia) e Food and Agriculture Organization (1.821,8, DP = 115,4 kcal/dia), quando comparado ao valor obtido pela calorimetria indireta (1.709,8, DP = 329,7 kcal/dia). Esse valor não foi significantemente diferente do obtido pela equação do Institute of Medicine (1.791, DP = 329 kcal/dia). CONCLUSÃO: As equações Harris-Benedict e Food and Agriculture Organization podem superestimar a TMB de homens jovens, sadios, com características semelhantes as do presente estudo. As equações do Institute of Medicine, por sua vez, resultam em valores estimados de TMB mais próximos aos mensurados.

Nutrition therapy for critically ill and injured patients

BACKGROUND

Nutrition support has undergone significant advances in recent decades, revolutionizing the care of critically ill and injured patients. However, providing adequate and optimal nutrition therapy for such patients is very challenging: it requires careful attention and an understanding of the biology of the individual patient's disease or injury process, including insight into the consequent changes in nutrients needed.

OBJECTIVE

The objective of this article is to review the current principles and practices of providing nutrition therapy for critically ill and injured patients.

METHODS

Review of the literature and evidence-based guidelines.

RESULTS

The evidence demonstrates the need to understand the biology of nutrition therapy for critically ill and injured patients, tailored to their individual disease or injury, age, and comorbidities.

CONCLUSION

Nutrition therapy for critically ill and injured patients has become an important part of their overall care. No longer should we consider nutrition for critically ill and injured patients just as "support" but, rather, as "therapy", because it is, indeed, a key therapeutic modality.

The use of indirect calorimetry in the intensive care unit

PURPOSE OF REVIEW

This review evaluates whether improvements have occurred in the value of predictive equations for use in designing nutritional therapeutic regimens in the ICU. The report also seeks to determine whether emerging strategies for nutrition therapy in the ICU change the need for an accurate measurement of energy requirements by indirect calorimetry.

RECENT FINDINGS

Predictive equations remain problematic for use in the critically ill patient. Inaccuracy of predictive equations introduces error in the design of a nutritional therapy regimen. The epidemic of obesity renders the calculations of requirements by predictive equations increasingly inaccurate at extremes of BMI. Certain patient populations appear to be hypometabolic, contradicting the traditional notion that critical illness increases energy expenditure. More recent data indicates that determination of which patients benefit from nutritional therapy may be based both on assessment of nutrition risk and delivery of sufficient nutrition therapy.

SUMMARY

The role of indirect calorimetry in the ICU should be expected to increase in the near future, as predictive equations may be too inaccurate to identify the appropriate goals of nutrition therapy.

Triiodothyronine (T3) and metabolic rate in adolescents with eating disorders: Is there a correlation?

AIM

To examine the correlation between T3 and resting energy expenditure (REE) in adolescent patients with eating disorders (ED) to assess whether T3 can be used to predict metabolic rate suppression and recovery.

METHODS

A retrospective chart review was performed on patients with ED (Anorexia Nervosa [AN], Bulimia Nervosa [BN], and Eating Disorder NOS [EDNOS]), aged 11-22 years, who had T3 and REE measured within 1 month (N=38 AN, 32 BN/EDNOS). REE was measured by indirect calorimetry (IC) and represented as the percentage of expected REE (%EREE) predicted by the Harris-Benedict equation. Pearson correlation coefficients were calculated to examine the relationship between T3 and %EREE and how each correlates with anthropometric data, laboratory values, and diagnosis.

RESULTS

T3 was significantly correlated with %EREE in the AN group but not in the total population or BN/EDNOS group. In the total study population, T3 alone correlated significantly with weight, Body Mass Index (BMI), BMI percentile, %Ideal Body Weight (%IBW), %Maximum Weight Lost (%MWL), LH, and estradiol. In the AN group, T3 and %EREE both correlated with BMI, BMI percentile, LH, and estradiol; however, only T3 correlated with %IBW and %MWL. In the BN/EDNOS group, T3 correlated with BMI, BMI percentile, %IBW, and estradiol while %EREE correlated with none.

CONCLUSION

In patients with AN, T3 correlated significantly with markers of malnutrition and %EREE and may serve as a surrogate measure when IC is unavailable. Following T3 during treatment of AN may assist clinicians in assessing metabolic suppression and recovery and help guide caloric prescriptions and goal weights.

Comparison of five equations for estimating resting energy expenditure in Chinese young, normal weight healthy adults

BACKGROUND

Most resting energy expenditure (REE) predictive equations for adults were derived from research conducted in western populations; whether they can also be used in Chinese young people is still unclear. Therefore, we conducted this study to determine the best REE predictive equation in Chinese normal weight young adults.

METHODS

Forty-three (21 male, 22 female) healthy college students between the age of 18 and 25 years were recruited. REE was measured by the indirect calorimetry (IC) method. Harris-Benedict, World Health Organization (WHO), Owen, Mifflin and Liu's equations were used to predictREE (REEe). REEe that was within 10% of measured REE (REEm) was defined as accurate. Student's t test, Wilcoxon Signed Ranks Test, McNemar Test and the Bland-Altman method were used for data analysis.

RESULTS

REEm was significantly lower (P < 0.05 or P < 0.01) than REEe from equations, except for Liu's, Liu's-s, Owen, Owen-s and Mifflin in men and Liu's and Owen in women. REEe calculated by ideal body weight was significantly higher than REEe calculated by current body weight ( P < 0.01), the only exception being Harris-Benedict equation in men. Bland-Altman analysis showed that the Owen equation with current body weight generated the least bias. The biases of REEe from Owen with ideal body weight and Mifflin with both current and ideal weights were also lower.

CONCLUSIONS

Liu's, Owen, and Mifflin equations are appropriate for the prediction of REE in young Chinese adults. However, the use of ideal body weight did not increase the accuracy of REEe.

Resting energy expenditure of morbidly obese patients using indirect calorimetry: a systematic review

The increasing proportion of acutely ill hospital patient admissions presenting with a morbidly obese body mass index (BMI ≥ 40 kg m(-2) ) as a comorbidity is an emerging clinical concern. Suboptimal food intake and malnutrition is prevalent in the acute care hospital setting. The energy requirements necessary to prevent malnutrition in acutely ill patients with morbid obesity remains unclear. The aim of this systematic review was to identify studies in the literature that have used indirect calorimetry to measure the resting energy expenditure of patients with morbid obesity to establish their minimum energy requirements and the implications for optimal feeding practices in acutely ill hospitalized patients. A total of 20 studies from PubMed, Cochrane Library and Embase met the inclusion criteria and were reviewed. All articles were graded using the Australian National Health and Medical Research Council levels of evidence and given a quality rating using the American Dietetic Association recommendations. Studies were categorized according to the mean BMI of its subjects. The most commonly measured resting energy expenditures for morbidly obese patients are between 2,000 and 3,000 kcal d(-1) (8,400-12,600 kJ d(-1) ). Activity and injury factors of acutely ill morbidly obese patients could result in significantly greater energy requirements for this patient group and are unlikely to be met by standard hospital menus. Establishing the minimum energy requirements for this population group will help inform adequate and accurate energy provision in the acute setting. Outcomes of underfeeding and overfeeding in morbidly obese patients warrant further research.