静息能量测定在儿童危重患者中的应用

静息能量是评估患者能量消耗的主要指标,而儿童危重患者的能量消耗易受多种因素影响,不同疾病状态下的静息能量消耗有所不同;目前,间接能量测定是衡量机体能量代谢的“金标准”,利用间接测热法可准确掌握患者的能量消耗,利于优化营养支持,提供个体化营养治疗。     

Resting energy expenditure in children newly diagnosed with stage IV neuroblastoma

Children with stage IV neuroblastoma (NBIV) are often malnourished at time of diagnosis, observed as high as 50%. The emphasis of this study was to determine whether an increased resting energy expenditure (REE) is a causative factor. Our hypothesis was that children diagnosed with NBIV have an increased REE, which normalizes with cancer treatment. Changes in nutritional status from time of diagnosis in response to nutritional support were examined. REE and nutritional evaluation were obtained three times: at diagnosis before starting treatment, where tumor burden is expected to be highest; after two courses of chemotherapy, where some response to treatment is expected; and after surgical excision of the primary tumor, where there was presumably minimal residual disease. Ten subjects completed the study. Results showed that REE was not increased, and there was no significant difference between phases (p = 0.29). Fifty percent of our subjects were malnourished at diagnosis. Because REE is not increased in NBIV, it is concluded that malnutrition seen in NBIV is not due to increased energy needs, but is likely due to decreased intake because of the intra-abdominal mass and malignant malaise.     

Resting energy expenditure is not increased in prepubertal children with Alagille syndrome

Increased resting energy expenditure (REE) is a possible explanation for the negative energy balance seen in children with Alagille syndrome (AGS). We evaluated 16 subjects with AGS and 37 healthy controls and did not find a significant difference in REE (101% +/- 12%, 105% +/- 13%, respectively).     

Resting energy expenditure and prediction equations in young children with failure to thrive

OBJECTIVE: To compare predicted and measured resting energy expenditure (REE) in young children (birth to 3 years) with failure to thrive (FTT). METHODS: REE (kcal/d) was measured by indirect calorimetry and compared with predicted REE from 3 sex and age group equations: World Health Organization (WHO), Schofield weight-based (SCH-WT), and Schofield weight- and height-based (SCH-WT-HT). The clinical characteristics associated with inaccuracy of predicted REE were examined. RESULTS: Forty-five subjects (47% female) were evaluated. Their clinical characteristics (mean +/- SD) included age 1.2 +/- 0.7 years, length/height z score -2.1 +/- 1.3, weight z score -2.7 +/- 1.0, and measured REE 438 +/- 111 kcal/d. All prediction equations were within 10% accuracy <50% of the time. However, SCH-WT-HT did not significantly differ from measured REE (450 +/- 138 vs 438 +/- 111 kcal/d, P =.2) and was least likely to underestimate REE. Younger age and more severe growth failure (based on weight, length/height, or both) were associated with underestimation of REE by prediction equations. CONCLUSION: REE should be measured in young infants and children with moderate to severe FTT when knowledge of caloric needs is required for optimal clinical care. The SCH-WT-HT equation was least likely to underestimate REE and is therefore preferred when REE cannot be measured in this group of children.     

Total energy expenditure and body composition in early infancy

In adults greater energy expenditure, primarily on physical activity, is associated with greater leanness. Such an association has proved more difficult to demonstrate in infants, partly due to the difficulty of measuring fatness and free living energy expenditure in this age group. Stable isotope techniques now make such investigations more viable. OBJECTIVE: The relationship between body composition and energy expenditure was investigated in 12 week infants. METHODS: Total energy expenditure and fat mass were estimated using the doubly labelled water technique. SUBJECTS: 92 normal healthy infants. RESULTS: Fat mass was correlated with both triceps and subscapular skinfold thicknesses (p < 0.001). After controlling for body size, age was a significant predictor of fat mass (p = 0.003), whereas total energy expenditure was not (p = 0.463). CONCLUSIONS: The cross sectional link between activity level and fatness in young infants, reported previously, does not persist when energy expenditure is considered.     

Total energy expenditure and body composition in early infancy.

In adults greater energy expenditure, primarily on physical activity, is associated with greater leanness. Such an association has proved more difficult to demonstrate in infants, partly due to the difficulty of measuring fatness and free living energy expenditure in this age group. Stable isotope techniques now make such investigations more viable. OBJECTIVE: The relationship between body composition and energy expenditure was investigated in 12 week infants. METHODS: Total energy expenditure and fat mass were estimated using the doubly labelled water technique. SUBJECTS: 92 normal healthy infants. RESULTS: Fat mass was correlated with both triceps and subscapular skinfold thicknesses (p < 0.001). After controlling for body size, age was a significant predictor of fat mass (p = 0.003), whereas total energy expenditure was not (p = 0.463). CONCLUSIONS: The cross sectional link between activity level and fatness in young infants, reported previously, does not persist when energy expenditure is considered.     

健康新生儿静息能量消耗的研究

目的　检测我国健康新生儿静息能量消耗值 (REE) ,评估不同因素对其的影响。方法通过开放式间接能量测定仪 (DeltatracTMⅡ ,芬兰 )对 15 4例出生体重 2 5 0 0～ 3 999g的健康新生儿 (男75名 ,女 79名 )进行REE检测 ,与Schofield预计公式所得的预计值进行比较 ,同时比较性别和分娩方式对新生儿REE的影响。结果　健康新生儿的REE平均实测值为 ( 2 0 1 8± 2 5 4)kJ/ (kg·d) ,预计值为 :( 2 2 6 1± 4 8)kJ/ (kg·d) ,两者之间差异有显著性 ,预计值比实测值高出 12 0 4%。性别及分娩方式对新生儿REE无影响。结论　现有的预计公式并不适用于临床估算新生儿能量消耗 ,对新生儿进行间接能量测定是了解其能量消耗的较好方法。本研究推荐中国健康新生儿 (出生体重 2 5 0 0～ 3 999g)静息能量消耗值为 ( 2 0 1 8± 2 5 4)kJ/ (kg·d) ,95 %可信区间为 ( 15 2 0～ 2 5 1 6)kJ/ (kg·d)。     

Resting energy expenditure in insulin resistance falls with decompensation of insulin secretion in obese children

BACKGROUND: Low resting energy expenditure (REE) and respiratory quotient (RQ) have been shown in adults to predispose to obesity and diabetes mellitus. AIM: To correlate REE and RQ in 73 obese children and young adults (body mass index [BMI] 37 +/- 10 kg/m2) with measures of insulin secretion and resistance (IR) indices, percent carbohydrate and fat oxidation, and prolactin and leptin levels. DESIGN: During a 3-day admission, REE and RQ were determined by indirect calorimetry. Blood chemistries and oral glucose tolerance test (OGTT) were obtained, and intravenous glucose tolerance test (IVGTT) modified by tolbutamide was conducted after an overnight fast, permitting calculation of acute insulin response (AIR), insulin resistance (SiIVGTT), and disposition index (DI). RESULTS: Patients fell into two groups according to their SiIVGTT: those with normal insulin sensitivity (NIS) and those with insulin resistance (IR). IR patients were subdivided on the basis of DI (cut-off value 0.13 min(-1)) into compensated (CIR) or decompensated (DIR) groups. CIR patients had higher RQ, REE corrected by BMI, AIR, and carbohydrate oxidation and lower fat oxidation than NIS and DIR patients. REE correlated positively with BMI, leptin, and AIR, and negatively with SiIVGTT. CONCLUSIONS: Findings in the CIR and DIR groups support the correlation of REE with metabolic changes consistent with an increased risk of diabetes mellitus.     

Resting energy expenditure of children attending a rehabilitation programme following head injury

STATEMENT OF PURPOSE: Increased resting energy expenditure following head injury is well documented, but whether this increase extends into rehabilitation and whether this is affected by changes in body composition have not been studied. The aim of this study was to determine whether children attending a rehabilitation program following head injury had altered energy expenditure and body composition. METHODS: Measurements of resting energy expenditure by indirect calorimetry were performed in 21 head injured children (mean age 10.2 +/- 3.8 years). Measurement of body composition was performed using total body potassium. RESULTS: Measured resting energy expenditure values were widely distributed, ranging from 52.3-156.4% of predicted values, yet the mean percentage predicted using Schofield weight, Schofield weight and height and World Health Organization predictive equations were 97.5%, 97.4% and 98.6%, respectively. Mean percentage of expected total body potassium for weight, height and age for head injured children were 85.1 +/- 15.5%, 89.1 +/- 14.1% and 86.9 +/- 15.9%, thus all showed significant depletion. CONCLUSIONS: During rehabilitation, using predictive equations to estimate resting energy expenditure in this group revealed a small bias on average but very large bias at the individual level. Head injured children had altered resting energy expenditure and body composition.     

Resting energy expenditure in disorders of propionate metabolism

OBJECTIVES: During intercurrent illness children with methylmalonic acidemia were found to have increased resting energy expenditure (REE). We measured REE in children with disorders of propionate metabolism (methylmalonic and propionic acidemia) when they were well and compared the values with those predicted by the Schofield equation. STUDY DESIGN: Prospective study in tertiary care facility. REE was measured with open-circuit indirect calorimetry under standardized conditions. Predicted REE values were calculated with the Schofield equation. Fourteen subjects with propionic acidemia (n = 3) and methylmalonic acidemia (n = 11) were studied. RESULTS: The median REE was 690 kcal/d (range 186 to 1687 kcal/d), which is significantly reduced, representing 80% +/- 18% of that predicted by the Schofield height and weight equation (P <.01). REE was significantly lower in female compared with male patients for unknown reasons. There were no differences with age or neurologic state. REE was not further reduced in those with chronic renal failure. CONCLUSION: REE in patients with disorders of propionate metabolism is reduced when they are well.     

Body composition and components of energy expenditure in children with end-stage liver disease

BACKGROUND: Better understanding of body composition and energy metabolism in pediatric liver disease may provide a scientific basis for improved medical therapy aimed at achieving optimal nutrition, slowing progression to end-stage liver disease (ESLD), and improving the outcome of liver transplantation. METHODS: Twenty-one children less than 2 years of age with ESLD awaiting liver transplantation and 15 healthy, aged-matched controls had body compartment analysis using a four compartment model (body cell mass, fat mass, extracellular water, and extracellular solids). Subjects also had measurements of resting energy expenditure (REE) and respiratory quotient (RQ) by indirect calorimetry. Nine patients and 15 control subjects also had measurements of total energy expenditure (TEE) using doubly labelled water. RESULTS: Mean weights and heights were similar in the two groups. Compared with control subjects, children with ESLD had higher relative mean body cell mass (33 +/- 2% vs 29 +/- 1% of body weight, P < 0.05), but had similar fat mass, extracellular water, and extracellular solid compartments (18% vs 20%, 41% vs 38%, and 7% vs 13% of body weight respectively). Compared with control subjects, children with ESLD had 27% higher mean REE/body weight (0.285 +/- 0.013 vs 0.218. +/- 0.013 mJ/kg/24h, P < 0.001), 16% higher REE/unit cell mass (P < 0.05); and lower mean RQ (P < 0.05). Mean TEE of patients was 4.70 +/- 0.49 mJ/24h vs 3.19 +/- 0.76 in controls, (P < 0.01). CONCLUSIONS: In children, ESLD is a hypermetabolic state adversely affecting the relationship between metabolic and nonmetabolic body compartments. There is increased metabolic activity within the body cell mass with excess lipid oxidation during fasting and at rest. These findings have implications for the design of appropriate nutritional therapy.     

Decreased energy expenditure is caused by abnormal body composition in infants with Prader-Willi Syndrome

OBJECTIVE: Infants with Prader-Willi syndrome (PWS) are hypotonic and underweight before the onset of childhood obesity. This study evaluates body composition in the PWS infant and its relationship to energy expenditure. STUDY DESIGN: Sixteen infants and toddlers with PWS (mean age, 12.4+/-6 months; eight female subjects) underwent analysis of body composition with dual-energy x-ray absorptiometry and deuterium dilution, and energy expenditure with both doubly labeled water and indirect calorimetry. RESULTS: Percent body fat was significantly increased (male subjects, P<.001; female subjects, P<.001) and fat-free mass (FFM) was significantly decreased (male subjects, P<.001; female subjects, P=.04) in infants with PWS when compared with age-matched published data for normal infants. Meanwhile, total energy expenditure was significantly decreased (male subjects, P=.025; female subjects, P<.001) in infants with PWS when compared with published normative data. There was a normal relationship between FFM and total energy expenditure in infants with PWS. CONCLUSION: Compared with published data for infants without PWS, infants with PWS demonstrate increased percent body fat, decreased FFM, and decreased energy expenditure. Importantly, total energy expenditure per kilogram of FFM appears similar in infants with and without PWS. We conclude that lower energy expenditure in infants with PWS is caused by decreased FFM.     

Resting energy expenditure and substrate oxidation rates in cystic fibrosis

The resting energy expenditure (REE) and substrate oxidation rates in 16 patients with cystic fibrosis who had mild chest disease and 11 healthy controls were measured using indirect calorimetry. The mean REE (% predicted) in the patients with cystic fibrosis was 11% greater than in the controls. Five patients with cystic fibrosis were hypermetabolic but only one of these had a clinically significant reduction of respiratory function. A greater proportion of REE was derived from carbohydrate oxidation in the cystic fibrosis patients (43.5% v 29.9%). However, the 24 hour dietary intake of carbohydrate was greater in the cystic fibrosis group (49.6 v 45.8% of energy intake). These data suggest that a high dietary intake of carbohydrate may contribute to the increased oxidation of carbohydrate in these cystic fibrosis patients. All patients with cystic fibrosis, including those with apparently mild lung disease, should continue to receive a high energy diet.     

Measured and predicted total body water in children with myelomeningocele

OBJECTIVE: Children with myelomeningocele (MMC) have an altered body composition and an atypical distribution of total body water (TBW). The aim of the present study was to determine the accuracy of current predictive equations, based on bioelectrical impedance analysis (BIA), in determining TBW when compared with measured TBW using deuterium dilution. METHODS: Fourteen children with MMC were measured for whole body BIA and TBW (using deuterium dilution and the Plateau method). Total body water was predicted using equations based on the resistance and characteristic frequency from BIA measurements and heights of subjects. RESULTS: The mean measured TBW was 15.46 +/- 8.28 L and the mean predictions for TBW using equations based on the resistance and characteristic frequency from BIA measurements and heights of subjects were 18.29 +/- 8.41 L, 17.72 +/- 11.42 L and 12.51 +/- 7.59 L, respectively. The best correlation was found using characteristic frequency. The limits of agreement between measured and predicted TBW values using Bland-Altman analysis were large. CONCLUSIONS: The present study suggests that the prediction of TBW in children with MMC can be made accurately using the equation of Cornish et al. based on BIA measurements of characteristic frequency.     

Energy expenditure and body composition in patients with anorexia nervosa

Blood biochemistry, body composition, and resting energy expenditure were studied in 25 patients with anorexia nervosa admitted to hospital during a period of 18 months. The patients' ages ranged from 12.9 to 17.2 years, and the abnormal feeding history from 3 to 12 months. Blood chemistry values were in the normal range, but fat body mass and lean body mass were reduced and extracellular water volume was expanded beyond normal values. Resting energy expenditure was reduced to 49% to 91% of values predicted by the Harris-Benedict equations. Substrate use after overnight fast indicated an abnormally high use of carbohydrates. Significant correlations were found between extracellular water volume and triceps skin-fold thickness, mid-arm muscle circumference and lean body mass, and substrate use and weight loss as a percentage of initial weight. We suggest that these simple anthropometric measurements can be used to assess and monitor the refeeding of patients with anorexia nervosa.     

Resting energy expenditure and substrate oxidation rates in cystic fibrosis.

The resting energy expenditure (REE) and substrate oxidation rates in 16 patients with cystic fibrosis who had mild chest disease and 11 healthy controls were measured using indirect calorimetry. The mean REE (% predicted) in the patients with cystic fibrosis was 11% greater than in the controls. Five patients with cystic fibrosis were hypermetabolic but only one of these had a clinically significant reduction of respiratory function. A greater proportion of REE was derived from carbohydrate oxidation in the cystic fibrosis patients (43.5% v 29.9%). However, the 24 hour dietary intake of carbohydrate was greater in the cystic fibrosis group (49.6 v 45.8% of energy intake). These data suggest that a high dietary intake of carbohydrate may contribute to the increased oxidation of carbohydrate in these cystic fibrosis patients. All patients with cystic fibrosis, including those with apparently mild lung disease, should continue to receive a high energy diet.     

Changes in body composition and energy expenditure after six weeks' growth hormone treatment.

Changes in body composition and energy expenditure were assessed in 15 children after six weeks of human growth hormone (hGH) treatment. Body composition measurements were made by stable isotope labelled water (H2(18)O) dilution, bioelectrical impedance, and skinfold thickness techniques. Energy expenditure was assessed both by indirect ventilated hood calorimetry (resting energy expenditure) and the stable isotope doubly labelled water (2H2(18)O) technique (free living daily total energy expenditure). Mean increases in weight of 0.96 kg and fat free mass of 1.37 kg and a mean decrease in fat mass of 0.41 kg were observed. Significant increases both in resting energy expenditure and free living daily energy expenditure were detected. Absolute changes in fat mass and resting energy expenditure were correlated. The data suggest (i) that the increase in the fat free mass is the most significant early clinical measure of hGH response and (ii) that hGH increases the metabolic activity of the fat free mass. Monitoring such changes may be predictive of the efficacy of hGH in promoting growth.     

Resting energy expenditure in obese children aged 4 to 15 years: measured versus predicted data

AIM: To measure the relationship of resting energy expenditure (REE) and body composition, and to compare REE data calculated from anthropometric parameters using published equations with measurements obtained by indirect calorimetry (IC) in a population of obese paediatric patients. METHODS: The study included 82 healthy obese paediatric subjects (49 boys, 33 girls; body mass index 29.6 +/- 5.0 kg/m , age 1 1.4 +/- 2.6 y, weight 72.4 +/- 20.9 kg, height 155 +/- 14 cm). REE was measured by IC, body composition was determined by dual energy X-ray absorptiometry (DXA). Bootstrap analysis was performed to validate the step-down linear regression analysis results. RESULTS: Lean body mass (LBM) and weight were identified as the most significant determinants of REE. LBM was the best single predictor (r = 0.78; p < 0.001) for REE. Regression equations are given in the text. Prediction of REE on the basis of published anthropometric formulas was strongly dependent from the equation used. Some equations tend to underestimate REE in the population studied with a considerable systematic error. CONCLUSION: In the present paper we show that (1) the published equations to predict REE in obese subjects yield scattered data and some are even biased by a systematic error, and that (2) the inclusion of DXA-derived LBM improves accuracy and precision of predicted REE in boys and girls aged from 4 to 10 y and in boys from 11 to 15 y.     

Body composition and energy expenditure in adolescents with cerebral palsy or myelodysplasia

We measured body composition, resting metabolic rate (RMR), and total energy expenditure (TEE) in a group of adolescents with cerebral palsy (CP) and myelodysplasia (M) aged 13- to 20-y-old using indirect calorimetry and the doubly labeled water method. Fat-free mass (FFM), RMR, and TEE were significantly lower in both the CP and M groups than comparable measurements in a control group of normal adolescent males and females. The ratio of TEE to RMR did not differ between controls and ambulatory M and CP subjects. However, TEE/RMR was significantly lower in the nonambulatory M and CP subjects than in controls (p less than 0.01). Our data indicate that energy requirements are reduced in both populations because both FFM and activity are decreased. Although energy requirements were decreased in both groups, the relationships between FFM and body weight differed. FFM and body weight were significantly correlated with RMR only in the M group. These data suggest that the type of paralysis in a handicapped population may affect resting energy expenditure.     

Total and resting energy expenditure in children with sickle cell disease

OBJECTIVE: To investigate energy balance in children with sickle cell disease (SCD) as the possible cause of impaired growth and undernutrition. STUDY DESIGN: Growth, resting (REE), total (TEE), and activity-related (AEE) energy expenditure and dietary intake were examined in 36 African American children with SCD (20 girls and 16 boys) and 30 control subjects (15 girls and 15 boys) of similar age (mean, 11.2 years) and ethnicity. TEE was measured by means of the doubly labeled water technique and REE by indirect calorimetry. AEE was calculated as TEE minus REE. Fat free mass (FFM) was calculated from skinfold prediction equations. RESULTS: REE was significantly increased (131 kcal/d) in children with SCD (P =.001), after adjusting for sex and FFM. Children with SCD tended to have lower TEE (214 kcal/d) than control subjects, but there was no difference after adjusting for FFM and sex (P =.57). Children with SCD had significantly (P =.025) lower AEE (268 kcal/d) but only marginally (P =.08) lower AEE after adjusting for FFM and sex. CONCLUSIONS: The elevated REE and lower AEE, in combination with poor growth status, indicate chronic energy deficiency in children with SCD. Further studies are needed to determine the best approaches to the treatment and prevention of undernutrition in children with SCD.