Do hormonal indices of maturation explain energy expenditure differences in African American and Caucasian prepubertal children?

OBJECTIVE: To examine the relationships between hormonal indices of maturation and total, resting and physical activity-related energy expenditure (TEE, REE and AEE) in African American and Caucasian prepubertal children. DESIGN: Cross-sectional study. SUBJECTS: Sixty-four African American and 48 Caucasian prepubertal children. MEASUREMENTS: TEE (by doubly labeled water), REE (by indirect calorimetry), fat mass and fat-free mass (by dual-energy X-ray absorptiometry), fasting serum dehydroepiandrosterone-sulfate (DHEAS), androstenedione, and estrone-sulfate (by radioimmunoassay). RESULTS: Serum concentrations of hormones correlated significantly with REE and TEE (r values range from 0.33 to 0.76, P<0.001). Only androstenedione correlated significantly with AEE (r = 0.23, P<0.05). However, these correlations were no longer significant after adjusting energy expenditure components for fat-free mass. In multiple regression models, ethnicity was not a significant determinant of any energy expenditure component after adjusting for body composition and hormone concentrations. CONCLUSION: Hormonal indices of maturation do not influence energy expenditure in this group of African American and Caucasian prepubertal children.     

Physical activity levels in children and adolescents

BACKGROUND: Reference data for physical activity level (PAL) and activity-related energy expenditure (AEE) are needed for a better understanding of the effect of activity on childhood health, growth and development OBJECTIVE: Data from 17 studies measuring TDEE (TDEE) with doubly labelled water DLW were combined to construct a reference line for PAL and AEE as a function of age. DESIGN: A total of 17 studies from the literature were analyzed; 17 on girls and 16 on boys. Children were aged 3-16 y and of Caucasian origin. Weighted least-squares regression was used to obtain reference lines for PAL and AEE as a function of age and gender. The relative numbers of children per study were used as a weighting factor. Basal metabolic rate (BMR) or nonfasted (NF) resting metabolic rate and sex were included in the analysis. RESULTS: Although there was no difference in PAL between boys and girls, a significant difference in AEE was found between the two sexes. PAL: 0.025 x age+1.40. AEE (MJ/day): boys 0.30 x age+0.025; girls 0.21 x age+0.33. If BMR is measured under NF conditions, the obtained value has to be reduced by 0.21 for PAL and 0.75 MJ/day for AEE. No relation was found between AEE/kg and age. CONCLUSIONS: PAL and AEE were found to increase with age, showing the importance of age-dependent recommendations. Recommendations for AEE need to be differentiated for sex. To compare PAL and AEE between studies, the measurement conditions of BMR have to be taken into account. The increase in PAL and AEE values can be attributed to an increase in weight, because there was no relation between AEE/kg and age.     

Activity related energy expenditure in children and adolescents with Prader-Willi syndrome

OBJECTIVE: To measure activity related energy expenditure in Prader-Willi syndrome (PWS) corrected for body size. SUBJECTS: 17 PWS subjects (10 females, seven males, age 7.5-19.8 y) and 17 obese controls, matched for gender and bone age. MEAUREMENTS: Basal metabolic rate (BMR) was measured by ventilated hood and average daily metabolic rate (ADMR) was measured with doubly labelled water. Activity induced energy expenditure (AEE) was calculated as 0.9ADMR -BMR. Activity related energy expenditure was corrected for body size using the following measures: AEE per kg body weight (AEE/kg), ADMR/BMR (PAL), and the residual of the regression of ADMR on BMR (rADMR). Group differences were analyzed by analysis of covariance adjusting for bone age, fat mass (FM) and gender. RESULTS: ADMR, AEE and PAL were lower (P < 0.01) in the PWS group compared with the control group (7.14 +/- 1.72, 1.07 +/- 0.69 and 1.33 +/- 0.15 MJ/day compared with 9.94 +/- 2.64, 2.56 +/- 1.03 and 1.55 +/- 0.12 MJ/day respectively). The variance of AEE/kg and PAL was significantly explained by gender and PWS, while AEE was additionally explained by FM. The variance of rADMR was explained by PWS and not by FM or gender. CONCLUSION: Activity related energy expenditure is decreased in PWS compared with controls adjusted for bone age, FM and gender.     

Daily energy expenditure in Mexican and USA Pima indians: low physical activity as a possible cause of obesity

BACKGROUND: Obesity is caused by an imbalance between energy intake and energy expenditure. However, it is unknown whether increased physical activity protects susceptible populations against the development of obesity and type 2 diabetes. OBJECTIVE: To investigate the potential protective role of environment and physical activity against obesity by measuring total energy expenditure in Mexican and USA Pima Indians. METHODS: We compared the physical activity level of 40 (17 female and 23 male; 37+/-11 y, 66+/-13 kg) Mexican Pima Indians from a remote, mountainous area of Northwest Mexico, with 40 age-and-sex matched (17 female and 23 male; 37+/-12 y, 93+/-22 kg) Pima Indians from the Gila River Indian Community in Arizona, USA. We measured total energy expenditure (TEE) by doubly labeled water and calculated physical activity by different methods: physical activity level (PAL) as the ratio of TEE on resting metabolic rate (RMR), TEE adjusted for RMR by linear regression, activity energy expenditure adjusted for body weight (AEE), and activity questionnaire. RESULTS: Physical activity was higher in Mexican Pima Indians when compared with USA Pima Indians as assessed by PAL (1.97+/-0.34 vs 1.57+/-0.16, P<0.0001), TEE adjusted for RMR (3289+/-454 vs 2671+/-454 kcal/day, P<0.0001) and AEE adjusted for body weight (1243+/-415 vs 711+/-415 kcal/day, P<0. 0001). Questionnaires revealed more time spent on occupational activities among Mexican Pima compared with USA Pima (23.9+/-13.3 vs 12.6+/-13.9 h/week, P<0.001). CONCLUSION: These data support a significant role for physical activity in the prevention of obesity in genetically susceptible populations. International Journal of Obesity (2000)24, 55-59     

The effect of sibutramine on resting energy expenditure and adrenaline-induced thermogenesis in obese females

BACKGROUND: Sibutramine, an inhibitor of serotonin and noradrenaline uptake, reduces appetite to cause weight loss. This study tested the hypothesis that an increase in energy expenditure also contributes to this weight loss. In addition, the effects of sibutramine on adrenaline induced changes in heart rate and cardiac output were determined METHODS: Nineteen obese females randomly received either sibutramine 15 mg daily or placebo for 12 weeks along with dietary advice. Resting energy expenditure (REE) was measured and then energy expenditure was measured during a 30 min infusion of adrenaline (25 ng/min/kg IBW). Cardiac output and heart rate, measured by Duplex Colour Doppler ultrasonography, were similarly measured in the basal state and post adrenaline. All measurements were recorded at baseline and then after 12 weeks. RESULTS: Ten patients who received sibutramine reduced their weight by 8.1+/-3.8% while 9 placebo treated subjects reduced their weight by 5.1+/-4.4%, P=0.13. In absolute terms, REE decreased in placebo subjects from 1500+/-201 kcal/24 h to 1357+/-231 kcal/24 h (9.4+/-9.9%) and in sibutramine subjects from 1540+/-184 kcal/24 h to 1444+/-128 kcal/24 h (5.3+/-12.0%), P=0.77. The increased weight loss in the sibutramine group was associated with an increase in the FFM adjusted REE (2.2+/-16.1%) unlike the expected decrease (5.8+/-9.5%) in the placebo group (P=0.11). There was some suggestion (P=0.09) that the usual positive correlation between loss of weight and decline in REE was lost in the sibutramine group (r=-0.30) compared with placebo (r=0.35). There was a negative correlation between loss of FFM and decline in REE/kg FFM and (P=0.029) which was not evident in placebo (P=0.83). Adrenaline induced energy expenditure was similar in the two groups at the end of the 12 week period and there were no significant cardiovascular changes between the two groups. CONCLUSIONS: Sibutramine limits the decline in REE associated with weight loss, equivalent to about 100 kcal/d. This could allow greater numbers of people to maintain a greater degree of weight loss.     

Spontaneous physical activity in a respiratory chamber is correlated to habitual physical activity.

OBJECTIVE: During a stay in a respiratory chamber without an exercise protocol, physical activity is limited to activities of daily living, change of posture and 'fidgeting,' collectively referred to as spontaneous physical activity (SPA). SPA is quite variable among individuals and is a heritable trait. A low SPA during a chamber stay is a predictor of weight gain in men. However, it remains to be established whether physical activity in a respiratory chamber relates to physical activity under habitual, free-living conditions. The purpose of the present study was to determine whether physical activity in a chamber is correlated to habitual, free-living physical activity. DESIGN: Fifty healthy, non-diabetic Pima Indians (30 M/20 F, 30+/-6 y; 37+/-10% body fat; means+/-s.d.) completed a 24 h stay in the respiratory chamber followed by a 7 day measurement of habitual, free-living energy expenditure by doubly labeled water. Free-living physical activity was expressed as activity energy expenditure (AEE(FL); daily energy expenditure-(sleeping metabolic rate+thermic effect of food)), physical activity level (PAL(FL); daily energy expenditure/sleeping metabolic rate) and body-size independent activity units. Activity during the chamber stay was expressed as PAL(Ch), AEE(Ch), and based on radar sensor measurements, as percentage of time with activity (SPA(Radar)). RESULTS: AEE(FL) (averaging 930+/-310 kcal/day (3.89+/-1.30 MJ/day)) was correlated to AEE(CH) (averaging 440+/-160 kcal/day (1.84+/-0.67 MJ/day)) and higher in men than in women (r=0.53, P=0.003) and r=0.53, P=0.02, respectively). Likewise, PAL(FL) (averaging 1.75+/-0.21) was correlated to PAL(Ch) (averaging 1.42+/-0.10) and higher in men than in women (r=0.49, P=0.006 and r=0.42, P=0.02, respectively). Free-living activity expressed in body-size independent activity units (averaging 17.8+/-7.0) was correlated to SPA(Radar) (averaging 6.4+/-1.7) with no effect of sex (r=0.30, P=0.03). CONCLUSION: Physical activity in a respiratory chamber was correlated to habitual physical activity, whether expressed as AEE, PAL or body-size independent activity units, providing a plausible explanation for the demonstrated association between a low SPA in the chamber and weight gain. The study encourages further studies of the genetic and non-genetic determinants of SPA and non-exercise activity thermogenesis (NEAT).     

Total energy expenditure and energy requirements in healthy elderly persons.

To investigate energy requirements in healthy elderly subjects, we assessed the association of total energy expenditure (TEE) with resting metabolic rate (RMR), physical activity, body composition, and energy intake in 13 individuals (aged 56 to 78 years, six women and seven men). Free-living TEE was measured using doubly labeled water, RMR was measured by respiratory gas analysis, and energy expenditure of physical activity (EEPA) was derived from the difference between TEE and RMR, assuming the thermic response to feeding contributes 10% of TEE. Fat mass (FM) and fat-free mass (FFM) were obtained from underwater weighing, VO2max was determined from a bicycle test to exhaustion, energy intake was obtained from a 3-day food diary, and leisure time activity (LTA) was determined by structured interview. TEE was 2,406 +/- 438 kcal/d (range, 1,856 to 3,200 kcal/d, or 1.25 to 2.11 times RMR) and was related to VO2max (r = .79, P = .001), LTA (r = .74, P = .004), FFM (r = .69, P = .009), and FM (r = -.64, P = .018). The association between TEE and VO2max persisted after adjustment for FFM (partial r = .58, P = .036). EEPA was related to LTA (r = .83, P less than .0001) and FM (r = -.58, P = .039). Energy intake underestimated TEE by 31% +/- 18% in women and by 12% +/- 11% in men. Using stepwise regression, TEE was best predicted by VO2max and LTA (total adjusted r2 = .86). We conclude the following: (1) TEE varies greatly within healthy elderly subjects due to variations in physical activity; (2) VO2max has an important role in predicting energy requirements in older individuals; and (3) healthy older individuals underreport energy intake.     

Sleeping metabolic rate in relation to body mass index and body composition

OBJECTIVES: To determine whether patterns of sleeping metabolic rate (SMR) are altered in obesity. Specifically to determine the relationship between changes in SMR and body weight, body mass index (BMI, kg/m(2)), and fat-free mass (FFM); and to compare resting metabolic rate (RMR) with SMR during different periods of sleep. SUBJECTS: Eighteen healthy, pre-menopausal, obese (BMI >30, n=9) and non-obese (BMI <30, n=9), female subjects (six Caucasians and 12 African-Americans), with an average age of 36 y (range 22-45). MEASUREMENTS: Total energy expenditure (TEE or 24 h EE), metabolic rate (MR), SMR (minimum, average and maximum) and resting metabolic rate (RMR) or resting energy expenditure (REE) measured by human respiratory chamber, and external mechanical work measured by a force platform within the respiratory chamber. Physical activity index (PAL) was derived as TEE/REE. Body composition was determined by dual-energy X-ray absorptiometry (DXA). RESULTS: SMR decreased continuously during sleep and reached its lowest point just before the subject was awakened in the morning by the research staff. Although averages for RMR and SMR were similar, RMR was lower than SMR at the beginning of the sleeping period and higher than SMR in the morning hours. The rate of decrease in SMR was faster with increasing body weight (-0.829, P<0.0001), BMI (correlation factor -0.896, P<0.0001) and FFM (-0.798, P=0.001). The relationship between the slope of SMR decrease and BMI (y=-5 x 10(-6)x(2)+0.0002x-0.0028) is highly significant, with a P-value of <0.0001 and r(2) value of 0.9622. CONCLUSIONS: The rate of decline in metabolic rate during sleep is directly related to body weight, BMI and FFM. Average SMR tends to be lower than RMR in obese subjects and higher than RMR in non-obese subjects.     

Resting energy expenditure in Duchenne patients using home mechanical ventilation.

Nutritional status is both important and difficult to assess in patients with Duchenne muscular dystrophy (DMD), particularly in those requiring mechanical ventilation (MV). The current authors evaluated body composition (bio-impedancemetry), resting energy expenditure (REE; indirect calorimetry) and energy intake in 20 adult patients with DMD using home MV (nocturnal: n = 13; continuous: n = 7) and 12 age-matched healthy controls. The patients were smaller in height than the controls and had a lower body weight. Most of the reduction in body mass index was accounted for by a reduction in fat free mass (FFM). REE (kJ) was significantly reduced in the patients (4559+/-853 kJ x 24 h(-1) versus 7407+/-1312 kJ x 24 h(-1)), but the difference disappeared after correction for FFM. REE and FFM were correlated in both the controls and patients, but less strongly in the latter, the lower strength of the association being due to the patients using continuous MV (REE and FFM uncorrelated). The food intake of the patients was 1.2+/-0.4 greater than their REE. This study shows that patients with advanced forms of Duchenne muscular dystrophy have balanced energy intakes and resting energy expenditure.     

Influence of fat-free mass and functional status on resting energy expenditure in underweight elders

BACKGROUND: In underweight elders, resting energy expenditure (REE) and its relationship with fat-free mass (FFM) could be modified by sarcopenia, physical activity, and functional limitation. The aims of this study were to investigate REE and its relationship with quantity and metabolic activity of FFM and to evaluate the influence of functional status on REE in underweight elderly subjects. METHODS: Forty-eight underweight elders (BMI < 20) and 54 normal weight elderly subjects (BMI 20-30) as a control group were selected. Body composition was determined by dual energy x-ray absorptiometry (DEXA). REE was measured by indirect calorimetry. Ability in activities of daily living (ADLs) was assessed by the Katz index. RESULTS: Underweight elders had significantly lower FFM, FFM index (FFM/height(2)), and REE than healthy subjects. REE adjusted for FFM with analysis of covariance remained significantly lower in the underweight group (1287 +/- 85 vs 1715 +/- 139 kcal/day in men, and 1124 +/- 63 vs 1366 +/- 91 kcal/day in women). Katz index in the underweight group was inversely correlated with REE (r = -0.68; p <.001) even after removal of FFM, FM, and gender, by multiple regression analysis. In this model, FFM and Katz index together explained approximately 54% of REE variability. CONCLUSIONS: Underweight elderly subjects show a hypometabolism due to a reduction of both FFM quantity and its metabolic activity. Functional status in ADLs comes out as an important predictor of REE independently from FFM. The limited physical activity might be the underlying determinant of this hypometabolism, but further investigations are necessary to confirm this issue.     

Energy expenditure at age 73 and 78--a five year follow-up

There is limited knowledge concerning the energy turnover and energy requirements of the elderly. The aim of this study was to measure resting metabolic rate (RMR) and total energy expenditure (TEE), and to define activity energy expenditure (AEE) and physical activity level (PAL) in 11 78-year-old individuals. A further aim was to compare these measures with the same measures taken from the 11 subjects at age 73 years. Total body water (TBW) averaged 30.8 kg (SD 3.2) at age 73 and 28.8 kg (SD 3.5) at age 78 years ( p<0.01). RMR was measured with a ventilated-hood system and averaged 5.60 MJ/day (SD 0.66) at age 73 and 4.77 MJ/day (SD 0.32) at 78 years ( p<0.001). TEE, measured using the doubly labeled water method, averaged 9.64 MJ/day (SD 1.10) at age 73 and 8.30 MJ/day (SD 1.45) at 78 years ( p<0.05). AEE averaged 4.04 MJ/day (SD 0.44) at age 73 and 3.53 MJ/day (1.13) at 78 years (ns). PAL averaged 1.74 at both ages. TBW, TEE, and RMR decreased, whereas AEE and PAL did not change substantially during the 5-year follow-up. The PAL values indicated a physically active lifestyle for the age group.     

Energetic cost of protein turnover in healthy elderly humans

OBJECTIVE: Whole body protein turnover (PTO) and resting energy expenditure (REE) are both correlated to fat-free mass (FFM), in young and elderly subjects, and REE is positively correlated to PTO in young adults. Thus, the aim of this study was to compare the energetic cost of PTO in young (n=39, 23.4+/-3.1 y) and elderly (n=41, 67.5+/-3.6 y) healthy volunteers. MEASUREMENTS: REE (indirect calorimetry), PTO ((13)C-leucine isotopic dilution) and body composition (bioelectrical impedance analysis with age-specific equations) were measured in the postabsorptive state. RESULTS: Elderly subjects had a higher fatness (30.5+/-7.1 vs 18.2+/-5.5%, elderly vs young, P<0.001), a similar REE (0.97+/-0.13 vs 1.06+/-0.15 kcal min(-1)), and a lower PTO (1.28+/-0.22 vs 1.44+/-0.18 micromol kg(-1) min(-1), P<0.001). PTO, REE and FFM were significantly correlated and after adjustment for FFM, REE was positively correlated to PTO (r=0.61, P<0.001). The slope of this relationship was the same in both groups, while the adjusted mean REE was lower in elderly subjects (0.97+/-0.09 vs 1.05+/-0.07 kcal min(-1), P<0.01). CONCLUSION: In comparison with young subjects, the energetic cost associated with PTO in elderly subjects is not different, but the proportion of REE not associated with PTO is lower.     

Evidence for hypermetabolism in boys with constitutional delay of growth and maturation

CONTEXT: Children with constitutional delay of growth and maturation (CDGM) tend to be thin and have a growth pattern reminiscent of nutritional insufficiency. OBJECTIVE: Our objective was to compare differences in nutrition, body composition, bone mineral density, and resting and total energy expenditure (REE/TEE) in boys with CDGM and controls. We hypothesized that an imbalance between energy intake and expenditure may contribute to the pathogenesis of CDGM. DESIGN AND SETTING: We conducted an observational, cross-sectional study at an outpatient clinical research center. PATIENTS: Patients included 36 boys (8-17 yr): 12 with CDGM (short stature, delayed bone age and puberty, and no other pathology) and 12 height-matched (pre- or early-pubertal) and 12 age-matched (pubertal) healthy controls. MAIN OUTCOME MEASURES: Outcome measures included doubly labeled water studies (TEE), serum nutritional/hormonal markers, dual-energy x-ray absorptiometry, dietary analysis, and indirect calorimetry (REE). RESULTS: Nutritional markers were comparable among the groups. CDGM subjects had bone mineral density lower than age-matched controls (P < 0.01) but comparable with height-matched controls. Even though REE did not differ between groups, CDGM subjects had 25% higher caloric intake adjusted for fat-free mass (FFM) than height-matched controls (P < 0.05) and 78% higher caloric intake per kilogram FFM compared with age-matched controls (P < 0.00001). CDGM subjects had 46% (P < 0.05) and 91% (P < 0.001) higher TEE per kilogram FFM than height- and age-matched controls, respectively. CDGM subjects had lower IGF-I and testosterone than age-matched controls (P < 0.001) but levels were comparable with height-matched controls. CONCLUSIONS: Boys with CDGM have higher rates of overall energy expenditure compared with age- and size-matched controls. This increased metabolism may result in impaired tempo of growth. Additional studies are needed to determine whether augmenting nutrition to match their energy needs (with or without hormonal therapy) can improve linear and ponderal growth in patients with CDGM.     

Resting energy expenditure in chronic hepatitis C

BACKGROUND/AIMS: Hypermetabolism is considered to be of clinical interest in liver disease and in several chronic viral infections. Whether resting energy expenditure (REE) increases during chronic hepatitis C is not known. Our aims were: (a) to determine the metabolic state of patients with chronic hepatitis C, and (b) to evaluate the effects of interferon therapy on REE. METHODS: Forty-seven patients and 20 controls were studied. Sixteen patients failed to respond to interferon and 12 patients stopped the treatment during the first 2 months for various reasons. The 19 responders all received 1 year of interferon. REE (indirect calorimetry) and fat-free mass (FFM, bioelectric impedance analysis) were evaluated before (day 0) and after 90, 180, and 360 days of interferon. The virus load was evaluated in patients before treatment. RESULTS: On day 0, REE expressed as a ratio of FFM (REE/FFM) was higher in patients than in controls (129.2 +/- 14.7 vs 117.9 +/- 9.6 kJ kg FFM(-1) 24 h(-1), p<0.01), and was positively correlated with the viral load (r=0.45, p=0.01). On day 90, REE/FFM had significantly decreased in responders but it did not decrease in non-responders (p<0.01). In responders, REE/FFM on days 180 and 360 was similar to that of the controls. CONCLUSIONS: Chronic hepatitis C induces hypermetabolism that is normalized by interferon therapy in responders. The underlying mechanisms of chronic hepatitis C-induced hypermetabolism and its clinical relevance remain to be determined.     

Effect of weight loss on resting energy expenditure in obese prepubertal children.

To assess the effect of weight loss on resting metabolic rate (RMR), the energy expenditure of eight obese prepubertal children (age 9 +/- 1 years; weight 48.7 +/- 9.1 kg; BMI 25.3 +/- 3.9) and of 14 age-matched children of normal body weight (age 9 +/- 1 years; weight 28.8 +/- 5.6 kg; BMI 16.5 +/- 1.7) was measured by indirect calorimetry. The obese children were reinvestigated after a mean weight loss of 5.4 +/- 1.2 kg induced by a six-months mixed hypocaloric diet. Before slimming, the obese group showed a higher daily energy intake than the control group (10.40 +/- 3.45 MJ/day vs 7.97 +/- 2.02 MJ/day respectively; P less than 0.05) but a similar value was observed per unit fat-free mass (FFM) (0.315 +/- 0.032 MJ/kgFFM/day vs 0.329 +/- 0.041 MJ/kgFFM/day respectively). The average RMR of the obese children was greater than that of the control group (5217 +/- 531 kJ/day vs 4477 +/- 506 kJ/day) but similar after adjusting for FFM (4728 +/- 3102 kJ/day vs 4899 +/- 3102 kJ/day). Weight loss resulted in a reduction in RMR (5217 +/- 531 kJ/day vs 4874 +/- 820 kJ/day), each kg of weight loss being accompanied by a decrease of RMR of 64 kJ (15.3 kcal) per day. The changes in RMR induced by weight loss paralleled the changes in FFM. No difference was found in average RQ in obese children vs controls (0.85 +/- 0.03 vs 0.87 +/- 0.03 respectively) and in the obese children before and after weight loss (0.87 +/- 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)     

Association of fatigue with an acute phase response in sarcoidosis.

The pathophysiological explanation for fatigue, one of the most common symptoms in sarcoidosis, still has to be elucidated. It was hypothesized that the presence of fatigue is associated with an acute phase response in sarcoidosis. A cross-sectional study was performed in 38 sarcoidosis patients. Resting energy expenditure (REE) was measured in the fasting state by indirect calorimetry using a ventilated hood and adjusted for fat-free mass (FFM). Patients with fatigue (n=25) also suffered more frequently from other symptoms, such as exercise intolerance (p=0.01), the need for sleep (p=0.02) and weight loss (p=0.01), compared to those without fatigue (n=13). However, no relationship was found between fatigue and serum angiotensin-converting enzyme (sACE) or lung function impairment. Patients with fatigue had higher levels of C-reactive protein (CRP) (11.4+/-6.8 microg x mL(-1), p<0.0001) and REE adjusted for FFM (33.0+/-3.7 kcal x kg FFM(-1), p<0.003) compared to those without fatigue (3.2+/-2.2 mg x mL(-1); 29.2+/-2.8 kcal x kg FF(-1)). Furthermore, REE/FFM was significantly related to CRP (r=0.54, p=0.001). This study confirms the presence of an acute phase response as indicated by metabolic derangements and a moderate increase in C-reactive protein levels in sarcoidosis, particularly in those patients with constitutional symptoms. Future studies should focus on the clinical relevance and therapeutic implications of these findings.     

Effect of a high-protein, energy-restricted diet on weight loss and energy expenditure after weight stabilization in hyperinsulinemic subjects

OBJECTIVE: To determine the effect of replacing some dietary carbohydrate with protein, during energy restriction, on weight loss, total energy expenditure (TEE), resting energy expenditure (REE), respiratory quotient (RQ), and the thermic effect of feeding (TEF) in subjects with hyperinsulinemia. DESIGN: Parallel, clinical intervention study of 12 weeks energy restriction (6.5 MJ/day) and 4 weeks energy balance (8.2 MJ/day) in two groups of subjects randomly assigned to either a high-protein (HP) diet (27% of energy (%E) as protein, 45%E as carbohydrate) or a lower-protein (LP) diet (16%E as protein, 57%E as carbohydrate). SUBJECTS: A total of 36 obese nondiabetic volunteers with hyperinsulinemia (10 males/26 females, aged 34-65 y, BMI 28-43 kg/m(2), fasting insulin 12-45 mU/l). MEASUREMENTS: Body weight and composition, TEE, REE, and RQ were measured at baseline and at week 16. In addition, the TEF to an HP or LP meal was determined for 3 h, at baseline and at week 16. RESULTS: After 16 weeks, weight loss was similar in response to each diet; the overall decrease was 7.9+/-0.6 kg (P<0.001), of which 6.8+/-0.5 kg was fat (P<0.001). REE fell similarly with each diet; the overall decrease was 719+/-106 kJ/day (P<0.001). The TEF was 2% greater after the HP than after the LP meal at baseline (P<0.01) and 0.8% greater at week 16 (P=0.35). After 16 weeks, the TEF was not reduced in either dietary group. There was no change in TEE after 16 weeks. CONCLUSION: In subjects with hyperinsulinemia an energy-restrictive diet containing an increased protein-to-carbohydrate ratio does not enhance weight loss or significantly affect energy expenditure. Caloric restriction, rather than the macronutrient composition of the diet, is the most important determinant of weight loss.     

Resting energy expenditure and nutritional status in children with juvenile rheumatoid arthritis.

OBJECTIVE: Undernutrition is frequently encountered in children with juvenile rheumatoid arthritis (JRA). We assessed resting energy expenditure (REE) in relation to nutritional status and body composition in patients with JRA. METHODS: We selected 33 children (age 6 to 18 yrs) with JRA (13 oligoarticular, 10 polyarticular, 10 systemic JRA) and 17 controls matched for age and sex. Nutritional status was assessed for height, weight, and fat-free mass (FFM), and REE was measured with indirect calorimetry. RESULTS: Nutritional status in the patients with systemic JRA was diminished compared to the controls for height (140 vs. 159 cm; p<0.01) and FFM (28 vs. 38 kg; p = 0.03). Oligo and polyarticular patients with JRA had normal height and FFM. No significant differences existed in crude REE among the groups. However, after correcting REE for body weight and FFM, the patients with systemic JRA, compared to controls, had 18% higher REE per kg body weight (159 vs. 134 kJ/kg/day; p<0.01) and 21% higher REE per kg FFM (196 vs. 162 kJ/kg/day; p<0.01). Oligo and polyarticular JRA patients had 8% increased values for REE per kg body weight or FFM, but these differences were not statistically significant. CONCLUSION: Patients with systemic JRA show stunting, low FFM, and a significantly increased REE when nutritional status is taken into account. These data suggest that assessment of individual energy requirements should include correction for fat-free mass in the treatment of malnutrition in patients with systemic JRA.     

Assessment of growth hormone secretion in normal stature children using 24-hour integrated concentration of GH and pharmacological stimulation

The integrated concentration of serum GH (IC-GH) is used for the assessment of spontaneous GH secretion. In order to use the IC-GH as a diagnostic tool a normative reference range needs to be established. We determined the IC-GH by continuous blood withdrawal in 119 children of normal height, weight and growth rate. Although the mean IC-GH increased with pubertal status, 4.4 +/- 1.2 micrograms/L at Tanner I (n = 36), 5.5 +/- 2.1 micrograms/L at Tanner II-III (n = 43), and 5.8 +/- 1.6 at Tanner IV-V (n = 40) (P less than 0.03), there was a considerable overlap of individual IC-GH levels between the pubertal groups. Gender affected the mean IC-GH level slightly, but not the range. Although the mean IC-GH of girls tended to be higher than that of boys this difference was not statistically significant. Ninety five percent of the IC-GH values were above the 3.2 micrograms/L level. The response to pharmacological stimulation (clonidine, insulin, or arginine) was also evaluated in 68 of the subjects. The peak GH response to pharmacological stimulation (micrograms/L) with clonidine 21.0 +/- 10.7 (n = 66) was significantly higher than to either arginine 13.1 +/- 6.1 (n = 23) or insulin 14.2 +/- 6.3 (n = 19) (P less than 0.01). The peak response to clonidine increased significantly with pubertal status (P less than 0.001) and there was an interactive effect of gender and pubertal stage where the GH response of prepubertal boys exceeded that of prepubertal girls but the response of pubertal girls exceeded that of pubertal boys (P less than 0.02). The peak stimulated GH levels was correlated with IC-GH in this subgroup r = 0.52, P less than 0.0001). This study provides a large normative data base for IC-GH and the GH provocative tests in normally growing children of varying pubertal status.