Energy metabolism in acute and chronic renal failure

Energy metabolism was measured by indirect calorimetry in 86 patients with various forms of renal failure and in 24 control subjects. In patients with acute renal failure with sepsis, oxygen consumption, carbon dioxide production, and resting energy expenditure were increased (P less than 0.05). In other groups with renal failure (acute renal failure without sepsis, chronic renal failure with conservative treatment or hemodialysis, and severe untreated azotemia) these indices were not different from those of control subjects. Urea nitrogen appearance was decreased in patients with chronic renal failure undergoing conservative treatment, in those with severe untreated azotemia, and in hemodialysis patients (P less than 0.05). We conclude that renal failure has no influence on energy expenditure as long as septicemia is absent. Reduced urea nitrogen appearance rates in chronic renal failure are due to a reduced energy and protein intake. Wasting is a consequence of decreased food intake but not of hypermetabolism in chronic renal failure.     

Affect of serum leptin on nutritional status in renal disease

Protein-energy malnutrition is a major comorbid condition in persons with renal disease. A variety of interventions have been implemented to supplement protein and energy intake in malnourished patients with renal disease, but the prevalence of protein-energy malnutrition remains high. Leptin, a hormone secreted by adipose tissue, decreases food intake via neuroendocrine systems in the hypothalamus in persons with normal renal function. Serum leptin levels are elevated in patients with chronic renal insufficiency and end-stage renal disease, and experimental evidence suggests a possible role for leptin in the development of protein-energy malnutrition in this population. Release of leptin from adipocytes may be stimulated by cytokines mediating the inflammatory response, which is frequently pronounced in patients with end-stage renal disease receiving hemodialysis and peritoneal dialysis. This article provides an overview of research conducted on serum leptin levels in different stages of renal disease, and the relationship among serum leptin, body composition, biochemical indexes, and markers of inflammation in persons with end-stage renal disease. Effects of intradialytic parenteral nutrition and anabolic factors on leptin levels and nutritional status are briefly reviewed.     

腹膜透析病人营养不良发生机制的初步探讨

目的: 探讨腹膜透析病人营养不良的发生机制。方法: 采用多中心前瞻性队列研究。对维持腹膜透析治疗的44例病人进行近2年的随访研究。按随访期间膳食蛋白摄入量(DPI)分为两组,即保持在0.78 g/(kg·d)以下者和曾出现0.78g/(kg·d)以上者。将随访期间综合性主观评估(SGA)水平发生动态变化的22例按SGA的变化分为两组,即营养状况好转组和恶化组,比较随访期间营养指标和残余肾功能的变化情况,以及高容量负荷状态和心血管事件的发生状况。结果: 以SGA评定营养状况,较低DPI组病人横断面研究时营养不良发生率为43.5％,而随访后为60.9％;较高DPI病人横断面研究时营养不良发生率为57.1％,而随访后为28.6％。营养状况恶化组病人在随访期间残余肾功能显著下降,高容量负荷状态和新发心血管系统事件的出现率明显高于营养状况好转组病人(P<0.05)。结论:在腹膜透析病人中,单纯低水平的蛋白质摄入并不一定导致营养不良的发生,而残余肾功能的变化、高容量负荷状态和心血管系统疾病与低蛋白质摄入共同作用,可能导致腹膜透析病人营养不良的发生与恶化。     

A cross-sectional study comparing the nutritional status of peritoneal dialysis and hemodialysis patients in Korea.

OBJECTIVE: This study was performed to compare the nutritional status of peritoneal dialysis (PD) and hemodialysis (HD) patients in Korea and to validate the nutritional assessment method. DESIGN: For nutritional assessment, we used five nutrition-related indicators, including percentage unplanned weight loss, percentage ideal body weight (IBW), serum albumin, appetite and intake, and any gastrointestinal symptoms affecting intake. A 1-month food frequency interview was conducted by clinical dietitians using food models to estimate energy and protein intake. The validity of the nutritional assessment method was tested by objective measures. PATIENTS/SETTING: A cross-sectional study was conducted in our center for 51 PD patients and 169 HD patients who met the study criteria. In the study, HD patients typically underwent dialysis three times per week, and most PD patients performed four 2-L dialysis exchanges every day. RESULTS: Our data showed a higher incidence of malnutrition in PD patients than in HD patients (33% v 18%) and in diabetics than in nondiabetics. Age, height, and dietary energy intake of the two groups were comparable. In PD patients, however, duration of dialysis treatment (23.9 +/- 19.1 months v 41.8 +/- 31.7 months, P < 0.001) and serum albumin (35.2 +/- 5.0 g/L v 39. 7 +/- 3.4 g/L, P < 0.0001) were significantly lower, whereas percentage IBW (108.1% +/- 12.4% v 96.2% +/- 11.6%, P < 0.0001) and dietary protein intake (1.12 +/- 0.34 g/kg IBW v 0.98 +/- 0.31 g/kg IBW, P < 0.05) were significantly higher than in HD patients. In malnourished PD and HD patients, percentage IBW, serum albumin, dietary energy, and protein intake were significantly lower than in well-nourished counterparts. CONCLUSION: A higher incidence of malnutrition was observed in PD patients than in HD patients. Nutritional profile of PD patients was different from that of HD patients. Higher body weight and lower serum albumin in PD patients did not seem to be related to dietary energy and protein intake. The five nutritional indicators can be used as a simple inexpensive and reliable method for the early detection of malnutrition in dialysis patients.     

Energy balance in predialysis patients on a low-protein diet.

OBJECTIVE: To determine if energy intake on a low-protein diet (0.6 g protein/kg ideal body weight (ibw)/d) with 70% animal protein (Diet A) or 30% animal protein (Diet B) meets energy expenditure derived from measured resting energy expenditure and activity levels. DESIGN: Patients already on a conventional low-protein diet with 70% animal protein kept a 5-day weighed dietary intake, with a 3-day activity diary, and had their resting metabolic rate (RMR) measured. Patients then switched to a diet with 30% animal protein for a minimum of 2 weeks (range, 2 to 16 weeks) and repeated the weighed intake and RMR measurement. SETTING: Predialysis hospital outpatients. PATIENTS: Seven patients were recruited, 5 male. Mean age, 56 years (range, 43 to 78 years); mean serum creatinine 300 micromol/L (range, 180 to 560 micromol/L). INTERVENTION: Indirect calorimetry used to measure RMR. MAIN OUTCOME MEASURE: RMR compared with standard formulae and total energy expenditure compared with dietary intake. RESULTS: Mean RMR was 5.76 MJ/d (1,385 kcal/d) or 84.9 kJ/kg ibw/d (20.3 kcal/kg ibw/d); which was 108% to 113% of that predicted by standard formulae. Total energy expenditure (RMR plus activity) was 8.35 MJ/d (1,996 kcal/d) or 123.3 kJ/kg/d (29.5 kcal/kg ibw/d). Mean energy intake was 116.3 (27.8 kcal/kg ibw/d) on Diet A and 131.2 (31.4 kcal/kg ibw/d) on Diet B (P = .096) with 3 of the 7 patients meeting their energy expenditure on Diet A and 4 on Diet B. CONCLUSION: RMR of patients with chronic renal failure is within expected range for healthy individuals, and the activity of these relatively fit patients similar to healthy individuals with light to moderate activity. Energy intake on the low-protein diets failed to meet energy expenditure in 4 patients on Diet A and 3 patients on Diet B. Low energy intake may contribute to the development of malnutrition in some patients.     

Impairment of small intestinal protein assimilation in patients with end-stage renal disease: extending the malnutrition-inflammation-atherosclerosis concept

BACKGROUND: Protein malnutrition is a common finding in renal disease. Recently, we showed that impaired protein assimilation (digestion and absorption) may contribute to protein malnutrition in nondiabetic patients with chronic renal failure. OBJECTIVE: The aim of the present study was to evaluate whether these findings can be extended to the dialysis population. Moreover, relations with indexes of the malnutrition-inflammation-atherosclerosis (MIA) syndrome were investigated. DESIGN: Protein assimilation was evaluated in 24 healthy control subjects and in 40 patients with end-stage renal disease (ESRD; 14 treated with peritoneal dialysis and 26 with hemodialysis) by means of a [13C]protein breath test, quantification of the generation rate of p-cresol, or both methods. Both approaches provide reliable information on the efficiency of protein assimilation. Breath test results were expressed as the maximum percentage recovery per hour of the administered dose of 13C (%max) and as the cumulative percentage recovery at the end of the test (%cum end). Several indexes of nutritional status, inflammation, and atherosclerosis were assessed. RESULTS: Compared with the control subjects, ESRD patients had significantly lower breath-test derived indexes of protein assimilation [%max=3.75 +/- 0.30 compared with 4.90 +/- 0.25, P=0.006; %cum end=12.41 (5.74-23.22) compared with 16.87 (9.42-22.99), P=0.020] and a higher 24-h p-cresol generation rate corrected for dietary protein intake [3.89 (0.48-11.60) compared with 2.81 (0.21-11.20) mg p-cresol/g urea nitrogen; P=0.028]. The presence of impaired protein assimilation was associated with indexes of the MIA syndrome. CONCLUSION: Our study provides evidence that protein assimilation is impaired in ESRD patients. Moreover, this disorder is associated with the severity of the MIA syndrome.     

Protein intake in renal and hepatic disease

The kidney and the liver play a central role in protein metabolism. Synthesis of albumin and other proteins occurs mainly in the liver, whereas protein breakdown and excretion are handled through an intricate interaction between these two organ systems. Thus, disease states of either the liver and/or the kidney invariably result in clinically relevant disturbances of protein metabolism. Conversely, metabolic processes regulated by these two organs are directly affected by dietary protein intake. Of particular importance in this respect is the maintenance of acid/base homeostasis. Finally, both the amount and composition of ingested proteins have a direct impact on renal function, especially in a state of diseased kidneys. Consequently, dietary protein intake is of paramount importance in patients with chronic nephropathy and renal insufficiency. Limitation of ingested protein, particularly from animal sources, is crucial in order to slow the progression of chronic kidney disease and impaired renal function. In contrast, patients with chronic renal failure undergoing renal replacement therapy by hemodialysis or peritoneal dialysis, have an increased protein demand. The syndrome of "protein-energy malnutrition" is a relevant factor for morbidity and mortality in this population and requires early detection and vigorous treatment. Protein intake in patients with cirrhosis of the liver should not be diminished as has been earlier suggested but rather increased to 1.0 - 1.2 g/kg body weight/day, in order to prevent protein malnutrition. Moderate restriction depending on protein tolerance (0.5 - 1.2 g/kg body weight/day), with the possible addition of branched chain amino acids (BCAA), has been recommended only in patients with advanced hepatic encephalopathy. Proteins of plant origin are theoretically superior to animal proteins.     

Resting energy expenditure of patients with gynecologic malignancies.

To evaluate resting energy expenditure compared to predicted energy expenditure in patients with cervical or ovarian carcinoma who require specialized nutritional support.

Women with biopsy-proven cervical or ovarian carcinoma referred to the Nutrition Support Service were studied. Resting energy expenditure was measured by indirect calorimetry and compared to predicted energy expenditure (PEE) as determined by the Harris-Benedict equation for females.

Sixty one patients were studied. Patients with ovarian cancer (n = 31) had a significantly higher measured resting energy expenditure (% PEE) than patients with cervical cancer (109 +/? 18% vs. 98 +/? 16%, p < 0.02, respectively). This difference in measured resting energy expenditure between groups could not be explained by differences in the extent of disease, nutritional status, body temperature, or nutrient intake between groups. A greater proportion of patients with ovarian cancer were hypermetabolic (> 110% of predicted) in comparison to patients with cervical cancer (55% vs. 13%, p < 0.01, respectively). Measured resting energy expenditure varied between 53% and 157% of predicted for the entire population.

Ovarian cancer patients are more hypermetabolic than cervical cancer patients. The Harris-Benedict equation for females is a unreliable estimate of caloric expenditure in patients with cervical or ovarian cancer receiving specialized nutritional support.     

腹膜透析联合血液透析对慢性肾衰竭患者钙磷代谢及生化指标的影响

目的探讨腹膜透析联合血液透析对慢性肾衰竭患者钙磷代谢及生化指标的影响。方法选取2018年1月至2019年12月我院收治的64例慢性肾衰竭患者,根据治疗方法不同分为对照组(n=31)和观察组(n=33)。对照组采用血液透析治疗,观察组采用腹膜透析联合血液透析治疗。比较两组患者治疗前、治疗6个月后钙磷代谢及生化指标[尿素氮(BUN)、血肌酐(Scr)、血红蛋白(Hb)、白蛋白(ALB)]水平。结果治疗6个月后,观察组的血清钙水平高于对照组,磷水平低于对照组(P<0.05)。治疗6个月后,观察组的BUN、Scr水平低于对照组,Hb、ALB水平高于对照组(P<0.05)。结论腹膜透析联合血液透析可有效调节慢性肾衰竭患者的钙磷代谢水平,改善其生化指标,值得临床推广。     

Nutritional status in patients with diabetes and chronic kidney disease: a prospective study

BACKGROUND: A poor nutritional status reduces the life expectancy of diabetes patients undergoing hemodialysis. OBJECTIVE: The study objective was to specify the nutritional outcome in patients with chronic kidney disease (CKD) and well-controlled diabetes. DESIGN: Forty-five diabetes patients with CKD were enrolled in a cooperative-care program designed to control glucose, blood pressure, LDL cholesterol, and the albumin excretion rate (AER). Their glomerular filtration rate (GFR), body composition, serum albumin (SA), and resting energy expenditure were assessed and compared at baseline and 2 y later. RESULTS: Thirty-five patients did not start dialysis. Their glycated hemoglobin, blood pressure, LDL cholesterol, and AER improved; their GFR declined slowly (-3.3 mL x min(-1) x 1.73 m(-2) x y(-1)). Their body mass index (BMI), lean body mass, and SA increased. The GFR decline was correlated negatively with the initial BMI (r = -0.37, P < 0.05) and positively with the initial GFR (r = 0.34, P < 0.05). Ten patients started hemodialysis: except for higher total body water (P < 0.05) and extracellular volume (P < 0.01), their initial nutritional status did not differ significantly from that of 10 patients with comparable baseline severe CKD but without dialysis. At the second evaluation, patients on hemodialysis lost lean body mass, and their SA was lower than that of the patients with severe CKD (P = 0.05); lean body mass was unchanged and SA was higher (P = 0.01) in the patients with severe CKD. No significant difference was detected for resting energy expenditure. CONCLUSIONS: Nutritional status improved in CKD patients with well-controlled diabetes without dialysis, and it deteriorated in patients who started dialysis. A high initial BMI was associated with a slower decline in GFR.     

杭州市腹膜透析和血液透析治疗费用与疗效的比较研究

为比较腹膜透析和血液透析的费用和效果,对浙江大学附属第一医院和杭州市中医院的腹膜透析和血液透析者进行问卷调查。结果显示：（1）腹透者花费的年透析费用和因透析发生的年总医疗费用低于血透者;（2）腹透者可以间隔较长的时间到医院就诊,对于患者的治疗比较方便;（3）腹膜透析对生命质量的改善优于或至少不低于血液透析;（4）腹透并发症住院率高于血透。故建议积极推广腹膜透析,同时提高腹膜透析服务质量,降低其并发症发生率。     

维持性血液透析患者营养评定及营养不良膳食危险因素分析

目的了解维持性血液透析患者营养状况及发生营养不良的常见膳食危险因素,为针对性营养干预提供依据。方法采用主观全面评定法评估116名维持性血液透析患者的营养状态,同时采用连续4日24小时膳食回顾法了解实际摄入内容,并进行必要的人体测量及营养生化指标检测。结果12.1%(14例)的患者为C级,属重度营养不良;40.5%(47例)的患者为B级,属轻中度营养不良。人体测量和营养生化指标检测结果显示,单一指标营养不良的发生率为20%～80%。膳食回顾分析结果显示,维持性血液透析患者的热能、蛋白质、脂肪和锌、硒等微量元素摄入均明显低于膳食推荐摄入量(P<0.05)。危险因素相关性分析结果表明,患者的年龄、透析时间和碳水化合物摄入量与营养不良发生显著相关(P<0.05)。结论维持性血液透析患者营养不良发生比例很高,热能和多种营养素摄入不足。年龄、透析时间和热能摄入不足可能是导致营养不良的重要原因。     

Nutrition and lung function in cystic fibrosis patients: review

Complex interactions between nutrition, skeletal and respiratory muscle function and energy expenditure in cystic fibrosis patients exist. Malnutrition significantly contributes to muscle weakness in patients with chronic obstructive pulmonary disease of the adult or in cystic fibrosis in childhood. Together with a measurable increase in resting energy expenditure the malnutrition, as a consequence of pancreatic insufficiency, leads to pulmonary deterioration. Whether pulmonary disease, pancreatic insufficiency, increased energy expenditure or insufficient intake of nutrition are the starters for the destructive circle or whether the basic defect is responsible for some of the components interacting with each other remains to be determined.     

Energy and substrate metabolism in patients with active Crohn's disease

The aim of the study was to evaluate the possible contribution of changes in energy metabolism and substrate oxidation rates to malnutrition in Crohn's disease and to assess the effect of enteral nutrition on these parameters. Energy metabolism was evaluated by indirect calorimetry in 32 patients with active Crohn's disease and 19 age- and sex-matched healthy individuals. Measurements were done in the postabsorptive state. Seven out of 32 patients received enteral nutrition via a nasogastric tube. In these patients, resting energy metabolism was determined at d 0 (postabsorptive), 7, 14 (during full enteral nutrition) and 15 (postabsorptive). Resting energy expenditure was not significantly different between patients and controls, whereas the respiratory quotient (RQ) was lower in patients (0.78 +/- 0.05 vs. 0.86 +/- 0.05; P < 0.05). During enteral nutrition in 7 patients with Crohn's disease, the RQ increased on d 7 compared with d 0 and remained high even after cessation of enteral nutrition (d 0, 0.78 +/- 0.03; d 7, 0.91 +/- 0.04; d 15, 0. 84 +/- 0.05; P < 0.05; d 7 and 15 vs. d 0). No effects of enteral nutrition on resting energy expenditure were found. Active Crohn's disease is associated with changes in substrate metabolism that resemble a starvation pattern. These changes appear not to be specific to Crohn's disease but to malnutrition and are readily reversed by enteral nutrition. Enteral nutrition did not affect resting energy expenditure. Wasting is a consequence of malnutrition but not of hypermetabolism in Crohn's disease.     

Energy metabolism and substrate oxidation in patients with Crohn's disease

Weight loss and malnutrition are common features in patients with Crohn's disease. This study was designed to evaluate diet-induced thermogenesis and substrate oxidation in patients with Crohn's disease. Twenty-three patients (17 women, 6 men; age 34 +/- 2 y) and 17 healthy control subjects (13 women, 4 men; age 36 +/- 3 y) were studied. Resting energy expenditure and fasting substrate oxidation were measured by indirect calorimetry in the morning after an overnight fast. After a standard homogenized test meal (10 kcal/kg), indirect calorimetry was performed every 30 min for 3 h to measure the diet-induced thermogenesis and the postprandial substrate oxidation. In the fasting state, resting energy expenditure was significantly higher in patients than in control subjects (1433 +/- 43 versus 1279 +/- 53 kcal/24 h). Lipid oxidation was higher in patients with Crohn's disease than in control subjects (1.17 +/- 0. 07 versus 0.61 +/- 0.11 mg. kg(-1). min(-1), P < 0.01). Postprandially, diet-induced thermogenesis was significantly lower in patients with Crohn's disease than in control subjects (4.6% +/- 0.5 versus 6.3% +/- 0.5 of energy intake, P < 0.01). Lipid oxidation was significantly higher in patients with Crohn's disease than in control subjects (0.78 +/- 0.05 versus 0.56 +/- 0.08 mg. kg(-1). min(-1), P < 0.05), and glucose oxidation was lower in patients with Crohn's disease than in control subjects. In patients with Crohn's disease, lipid oxidation positively correlates with the disease activity evaluated by the Crohn's Disease Activity Index (r = 0.48, P150), fasting and postprandial lipid oxidation was significantly higher than in patients with inactive Crohn's disease (P < 0.05). In conclusion, patients with Crohn's disease have increased fat oxidation, which correlates with disease activity and this may explain the reduced fat stores in patients with Crohn's disease.     

Delayed nephrologist referral and inadequate vascular access in patients with advanced chronic kidney failure

We sought to determine whether late referral to a nephrologist in patients with chronic renal failure influences the adequacy of vascular access for hemodialysis. We analyzed data describing all health care encounters for all Medicare and Medicaid patients with end-stage renal failure in New Jersey between January 1991 and June 1996. Patients were required to have been diagnosed with renal disease at least 1 year prior to onset of hemodialysis. In the resulting cohort of 2,398 incident hemodialysis patients, 35% had their first nephrologist consultation < or =90 days prior to initiation of dialysis. After controlling for demographic characteristics, socio-economic status and underlying renal disease, we found that patients who were referred to a nephrologist >90 days prior to onset of hemodialysis were 38% more likely to have undergone predialysis vascular access surgery than those who were referred to a nephrologist < or =90 days before dialysis [OR: 1.38; 95% CI (1.15; 1.64)]. Similarly, patients referred late were 42% more likely to require central venous access for hemodialysis compared to those seen by a nephrologist early [OR: 1.42; 95% CI (1.17; 1.71)]. Inadequate development of vascular access for renal replacement therapy in patients with late nephrologist referral unnecessarily contributes to the burden of disease experienced by this vulnerable patient population.     

The work results in a recently created pediatric dialysis unit

Results of the first period of two working years in a dialysis unit, at a provincial pediatric hospital, are exposed. A total of 26 patients, 20 children and 6 adults, was submitted to hemodialysis and peritoneal dialysis. Within the first, male sex prevailed and age groups more often submitted to dialysis were those under one year old and school children aged 5-14 years. A total of 370 peritoneal dialysis and 264 hemodialysis was performed to children. In the case of peritoneal dialysis, 11.1% was performed by puncture catheter, for acute patients, and the remainder 88.9% by fixed Tenckhoff's catheter, for patients with chronic renal insufficiency. Diseases that more often require the use of dialytic methods were, in first place, acute renal insufficiency, followed by chronic renal insufficiency and, in second place, obstructive uropathies. At the end of the research, 56.0% of the patients assisted in the dialysis unit was cured, with renal transplantations presenting a good evolution or under periodical dialysis waiting for transplantation. Emphasis is made on the most frequent complications occurred during the performance of the fore-mentioned procedures.     

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.     

The organization and funding of the treatment of end-stage renal disease in Australia

Treatment rates for end-stage renal disease have risen over the last 25 years in Australia, from 3,181 patients in 1981 to 14,221 patients (707 per million) in 2004. Access to dialysis services is largely through the national public insurance system, with more than 85% of services provided by public hospitals for outpatient (68%) or home-based (32%) care. Annual payment rates per patient are around AU$53,500 for hemodialysis (78% of patients). Total recurrent health expenditure on all chronic kidney disease was AU$647 million, or 1.3% of the total recurrent health expenditure that could be allocated by disease.      

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.