Resting energy expenditure and body composition in bedridden institutionalized elderly women with advanced-stage pressure sores

BACKGROUND: Our study investigated nutritional status, body composition, and resting energy expenditure (REE) in elderly patients with advanced-stage pressure sores (PS), in addition to researching any hypermetabolic condition and its relationship with PS size. METHODS: The study involved 52 institutionalized bedridden elderly women (aged 83.7 +/- 6.3 years), divided into two groups: 23 with advanced-stage (stage 3 and 4) PS and 29 without PS. Albumin, prealbumin, and retinol-binding protein were measured in all patients, and fat-free mass (FFM) and fat mass (FM) were obtained by dual-energy x-ray absorptiometry (DEXA). REE was measured by indirect calorimetry and predicted with the Harris-Benedict formula. PS area and volume were also measured. RESULTS: The elderly women with and without PS were comparable in age, FFM, and FM. Mean albumin, prealbumin, and retinol-binding protein values were lower in cases with PS. Unadjusted mean REE was significantly higher in patients with PS (1212.3 +/- 236.7 vs 1085.5 +/- 161.3 kcal/d; p <.05), even after adjusting for FFM or expressed per kilogram of body weight (25.8 +/- 6.7 vs 21.1 +/- 4.0 kcal/d/kg; p <.01). Hypermetabolism, i.e., a measured REE > 110% of the predicted REE, was seen in 74% of patients with PS and 38% of controls. The difference between measured and predicted REE (DeltaREE) correlated with PS volume (r = 0.58; p <.01), but not with area. CONCLUSION: Advanced-stage PS in elderly women are associated with a hypermetabolic state that is influenced by the volume of the PS.     

Loss of total body potassium during rapid weight loss does not depend on the decrease of potassium concentration in muscles. Different methods to evaluate body composition during a low energy diet

OBJECTIVE: The aim of the study was to elucidate whether combustion of skeletal muscle glycogen during a very low calorie diet (VLCD) was associated with decreased muscle potassium content. A comparison between different methods was also performed to evaluate body composition during a VLCD and a low calorie diet (LCD). DESIGN: Dietary treatment of obese women by VLCD and LCD. Measurements after 1 and 2 weeks of VLCD and 6 months of LCD. SUBJECTS: Fifteen perimenopausal obese women aged 46.5+/-1.3 y and 15 of 48.0+/-0.7 y of age. MEASUREMENTS: Skeletal muscle biopsies under local anaesthesia. Body composition measurements by means of deal-energy X-ray absorptiometry (DEXA), and measurements of total body potassium (40K) and total body nitrogen (TBN). Measurements of electrolytes and glycogen concentration in muscle samples. RESULTS: In the first study (1 week of VLCD) skeletal muscle glycogen decreased (P<0.01), but muscle potassium increased (P<0.01). Muscle sodium decreased (P<0.01), while muscle magnesium was unaltered. Body weight decreased by 2.9+/-0.5 kg and 40K decreased. Fat-free mass (FFM) calculated from 40K and DEXA decreased by 2.7 vs 1.9 kg (P<0.001). Body fat measured with DEXA decreased by 1.1 kg (P<0.01), but not body fat calculated from 40K. TBN decreased by 0.03+/-0.01 kg (P<0.05) and FFM calculated from TBN by 2.9+/-0.5 kg (P<0.002). In the second study, 6 months on the LCD resulted in 17.0+/-2.0 kg weight reduction and this was mainly due to reduced body fat, 14. 0+/-2.0 kg measured with DEXA and from 40K (P<0.001). The decrease in FFM was slight. CONCLUSION: One week of VLCD resulted in muscle glycogen depletion but increased muscle potassium content in spite of decreased total body potassium. FFM contributed to the main part of body weight loss during short periods of severe energy restriction, but remained unchanged during long-term dietary treatment. Body fat became mostly responsible for the body weight loss during long-term LCD. Calculations of changes of FFM from 40K and TBN seem to overestimate the FFM decrease associated with short-term VLCD. International Journal of Obesity (2000)24, 101-107     

Long-term effects of consumption of a novel fat emulsion in relation to body-weight management

OBJECTIVE: To assess weight maintenance after weight loss by consumption of yoghurt with a novel fat emulsion (Olibra) including effects on body composition, resting energy expenditure (REE), fat oxidation, hunger feelings and satiety hormones. DESIGN: A randomized, placebo-controlled, double-blind, parallel design. A 6-week weight loss period (2.1 MJ/day) was followed by 18 weeks weight maintenance with test (Olibra) or placebo yoghurt. SUBJECTS: Fifty overweight women (age: 18-58 years, body mass index (BMI) 25-32 kg/m2). MEASUREMENTS: In weeks 1, 7 and 25, a satiety test with questionnaires and blood samples for analysis of satiety hormones. In weeks 2, 8 and 26, REE, body weight and body composition. RESULTS: During weight maintenance after significant body weight reduction, there was no significant increase in body weight in the test group (1.1+/-3.4 kg); the placebo group did gain weight (3.0+/-3.1 kg, P<0.001). Compared to the placebo group, the test group was less hungry 4 h after yoghurt consumption in week 25 (P<0.05) and showed increased glucagon like peptide-1 values 180 min after yoghurt consumption (week 25 vs week 1, P<0.05). Measured REE as a function of fat-free mass (FFM) was significantly higher than predicted REE (P<0.05) in week 26 for the test group, but not for the placebo group. Fat mass (FM) was significantly more decreased in the test group (6.5+/-4.1 kg) compared to the placebo group (4.1+/-3.6 kg) (week 26 vs week 2, P<0.05). CONCLUSION: Consumption of Olibra yoghurt improved weight maintenance compared to placebo, which can be explained by the relatively higher REE as a function of FFM, relatively higher decrease in FM and the relatively lower increase in hunger.     

Effect of organ and tissue masses on resting energy expenditure in underweight, normal weight and obese adults

BACKGROUND: In normal-weight subjects, resting energy expenditure (REE) can be accurately calculated from organ and tissue masses applying constant organ-specific metabolic rates. This approach allows a precise correction for between-subjects variation in REE, explained by body composition. Since a decrease in organ metabolic rate with increasing organ mass has been deduced from interspecies comparison including human studies, the validity of the organ- and tissue-specific REE calculation remains to be proved over a wider range of fat-free mass (FFM). DESIGN: In a cross-sectional study on 57 healthy adults (35 females and 22 males, 19-43 y; 14 underweight, 25 intermediate weight and 18 obese), magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA) were used to assess the masses of brain, internal organs, skeletal muscle (MM), bone and adipose tissue. REE was measured by indirect calorimetry (REEm) and calculated from detailed organ size determination by MRI and DXA (REEc1), or in a simplified approach exclusively from DXA (REEc2). RESULTS: We found a high agreement between REEm and REEc1 over the whole range of FFM (28-86 kg). REE prediction errors were -17 +/- 505, -145 +/- 514 and -141 +/- 1058 kJ/day in intermediate weight, underweight and obese subjects, respectively (n.s.). Regressing REEm on FFM resulted in a significant positive intercept of 1.6 MJ/day that could be reduced to 0.5 MJ/day by adjusting FFM for the proportion of MM/organ mass. In a multiple regression analysis, MM and liver mass explained 81% of the variance in REEm. DXA-derived REE prediction showed a good agreement with measured values (mean values for REEm and REEc2 were 5.72 +/- 1.87 and 5.82 +/- 1.51 MJ/day; difference n.s.). CONCLUSION: Detailed analysis of metabolically active components of FFM allows REE prediction over a wide range of FFM. The data provide indirect evidence for a view that, for practical purposes within humans, the specific metabolic rate is constant with increasing organ mass. Nonlinearity of REE on FFM was partly explained by FFM composition. A simplified REE prediction algorithm from regional DXA measurements has to be validated in future studies.     

Age-related differences in metabolic adaptations following resistance training in women

The purpose of this study was to determine whether aging alters changes in resting metabolic rate, body composition and insulin sensitivity in response to resistance training (RT) in women. The impact of a 6-month controlled RT program on fat-free mass (FFM), resting energy expenditure (REE), and glucose disposal was examined in 19 younger (27.8+/-3.5 yr; range 18-35) and 12 older (66.6+/-4.9 yr, range 55-70) non-obese caucasian women. For younger women, the RT program increased body weight (59.1+/-6.2 to 60.8+/-6.1 kg, p<0.05) due to an increase in FFM (39.2+/-3.7-40.4+/-3.2 kg, p<0.05). REE increased from 1379+/-114 to 1451+/-140 kcal day(-1), p<0.0001), and glucose disposal (from 364.1+/-91.1 to 402.1+/-87.8 mg min(-1), p<0.05). Neither fat mass nor VO2max changed significantly. On the other hand, older women lost fat mass (24.0+/-4.6-23.2+/-5.4 kg, p<0.05) and tended to gain FFM (from 37.3+/-4.0-38.0+/-4.3 kg, +1.9%; p=0.057), whereas no change occurred in body weight, REE, VO(2)max or glucose disposal. Thus, younger women showed greater metabolic changes in body composition, REE and insulin sensitivity in response to RT than older women. These results suggest an age-related alteration in metabolic changes in response to a 6-month RT program in previously untrained women.     

Different cycle ergometer outcomes in severely obese men and women without documented cardiopulmonary morbidities before bariatric surgery

STUDY OBJECTIVES: The number of severely obese patients undergoing bariatric surgery is increasing. No incremental cycle ergometer data are available in this category of patients. The current study was undertaken to provide information and to compare outcomes between severely obese men and women during physical exercise. DESIGN: Cross-sectional study. PARTICIPANTS: Twenty-two men and 34 women, all with a body mass index (BMI) of at least 40 kg/m(2), were selected from among persons participating in a dedicated weight management program that was carried out in the outpatient clinic of a large teaching hospital. MEASUREMENTS AND RESULTS: Body composition was estimated with bioelectrical impedance. Oxygen uptake (Vo(2)) was obtained by breath-by-breath minute ventilation (ventilated hood) and was measured under resting energy expenditure (REE) conditions. Endurance was measured with an incremental cycle ergometer test. Male and female groups were balanced for mean (+/- SD) age (42.7 +/- 7.6 vs 41.8 +/- 8.9 years, respectively), BMI (43.0 +/- 4.9 vs 41.3 +/- 5.2 kg/m(2), respectively), and fat weight (55.5 +/- 14.0 vs 56.8 +/- 2.2 kg, respectively). Fat-free mass (FFM), FFM index, fasting blood glucose level, insulin level, REE, and Vo(2) at rest and during subjective maximal endurance were higher in the male group. However, maximal Vo(2) (women, 119 +/- 19% predicted; men, 92 +/- 16% predicted) and anaerobic threshold were higher in the female group (women, 64 +/- 12% predicted; men, 48 +/- 76% predicted, respectively; p < 0.0001). CONCLUSIONS: Severely obese men were more carbohydrate-intolerant and sustained less physical endurance than was predicted according to standards in comparison with obese women. The cycle ergometer data indicated that male gender was associated with less physical fitness.     

Resting energy expenditure should be measured in patients with cirrhosis, not predicted.

Measurements of resting energy expenditure (REE) can be used to determine energy requirements. Prediction formulae can be used to estimate REE but have not been validated in cirrhotic patients. REE was measured, by indirect calorimetry, in 100 cirrhotic patients and 41 comparable healthy volunteers, and the results compared with estimates predicted using the Harris-Benedict, Schofield, Mifflin, Cunningham, and Owen formulae, and the disease-specific Müller formula. The mean (+/- 1 SD) measured REE in the healthy volunteers (1,590 +/- 306 kcal/24 h) was significantly greater than the mean Harris-Benedict, Mifflin, Cunningham, and Owen predictions but comparable with the mean Schofield prediction; individual predicted values varied widely from measured values (95% limits of agreement, -460 to +424 kcal). The mean measured REE in the cirrhotic patients was significantly greater than in the healthy volunteers (23.2 +/- 3. 8 cf 21.9 +/- 2.9 kcal/kg/24 h; P <.05). The mean measured REE in the cirrhotic patients (1,660 +/- 337 kcal/24 h) was significantly different from mean predicted values (Harris-Benedict, 1,532 +/- 252 kcal/24 h, P <.0001; Schofield, 1,575 +/- 254 kcal/24 h, P <.0005; Mifflin, 1,460 +/- 254 kcal/24 h, P <.0001; Cunningham, 1,713 +/- 252 kcal/24 h, P <.05; Owen, 1,521 +/- 281 kcal/24 h, P <.0001; Müller, 1,783 +/- 204 kcal/24 h, P <.0001); individual predicted values varied widely from measured values (95% limits of agreement, -632 to +573 kcal). Simple regression analysis showed that fat-free mass (FFM) was the strongest predictor of measured REE in the cirrhotic patients, accounting for 52% of the variation observed. However, a population-specific prediction equation, derived using stepwise regression analysis, which incorporated FFM, age, and Pugh's score, accounted for only 61% of the observed variation in measured REE. REE should, therefore, be measured in cirrhotic patients, not predicted.     

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.     

Laparoscopic gastric banding and body composition in morbid obesity

BACKGROUND AND AIM: Gastric banding induced considerable and rapid weight loss in morbid obesity. Nevertheless data on changes in body composition following gastric banding are scanty. In this study, we evaluated the 2-year changes in body composition in a small group of morbidly obese women treated by laparoscopic adjustable gastric banding (LAGB) associated with a well balanced low-calorie diet. METHODS AND RESULTS: We studied 20 premenopausal morbid obese women with BMI ranging from 35 to 57 (kg/m2) before, and 6, 12 and 24 months after laparoscopic adjustable gastric banding (LAGB). A well balanced 5.4 MJ/day hypocaloric diet was prescribed after surgery. Total body water (TBW), fat-free mass (FFM) and fat mass (FM) were investigated using conventional bioelectrical impedance analysis (BIA). Tissue hydration was also assessed by impedance vector analysis and the RXc graph method. The subjects showed a total weight loss of 28% of baseline body weight. In the first 6 months after surgery, patients lost 18.5+/-5.9 kg of body weight (17.6+/-6.2 kg of FM and 0.7+/-1.4 kg of FFM). From 6 to 12 months, a further 12.5+/-7.5 kg of body weight was lost (10.5+/-8.2 kg of FM and 2.2+/-3.8 kg of FFM). During the last 12 months, weight loss was 3.0+/-2.3 kg (1.9+/-3.7 kg of FM and 1.1+/-2.9 kg of FFM). The weight loss observed after LAGB was mainly due to a decrease in FM, whereas TBW, FFM and BCM were only slightly and non-significantly reduced. No changes in body hydration status were observed after surgery. CONCLUSIONS: LAGB associated with a well balanced low-calorie diet achieved a satisfactory 2-year weight loss, while sparing FFM and not causing body fluid alterations.     

Serum leptin concentration in moderate and severe obesity: relationship with clinical, anthropometric and metabolic factors

OBJECTIVE: To study clinical, anthropometric and metabolic determinants of serum leptin concentrations in a series of patients with a wide range of obesity. SUBJECTS: 400 patients, 116 males and 284 females, aged 44+/-12.3 years with body mass index (BMI) ranging from 31 to 82 kg/m2 (mean 41.4+/-7.1). MEASUREMENTS: Energy intake by 7-day recall, resting energy expenditure (REE) by indirect calorimetry, body composition determined by bioelectrical impedance; C index, an anthropometric index of abdominal fat distribution, and waist-hip ratio (WHR), blood glucose serum leptin concentrations, total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, uric acid, and insulin concentrations HOMA IRI (homeostastis model assessment of insulin resistance index). RESULTS: Leptin concentrations were higher in obese than in normal subjects and in females than in males without differences between diabetic and non-diabetic patients; leptin concentrations were not related to age and showed a strong negative association with energy intake only in the group of women with BMI less than 40. Leptin concentrations showed a direct correlation with BMI and body fat values (expressed either as percentage of total body mass or absolute fat mass) independent of age and sex. After adjustment for fat mass, leptin values higher than predicted were found in women whereas concentrations lower than predicted were found predominantly in men. Leptin showed an inverse correlation with WHR and C-index, the latter persisting also after correction for gender and fat mass. REE, but not REE/kg fat-free mass (FFM) was inversely related to leptin also after correction for sex and absolute fat mass. Leptin concentrations were directly associated with HOMA IRI, insulin and HDL cholesterol and inversely associated with triglycerides and uric acid. The relationship of leptin with HOMA IRI was still evident after adjusting for sex but was lost when absolute fat mass was added to the model; HDL cholesterol and triglycerides appeared to be variables independent of leptin concentrations even when both sex and fat mass were added to the model. CONCLUSIONS: In a large group of obese patients (half of whom had severe obesity, gender, BMI and fat mass accounted for the largest proportion of serum leptin concentrations variability. We found that in obese subjects there is an effect of fat distribution on leptin concentrations and that, after excluding variability due to absolute fat mass, patients with a greater amount of abdominal fat have relatively low leptin concentrations which in turn relates to a metabolic profile compatible with an increased cardiovascular risk. Women with milder obesity may retain some degree of control of food intake by leptin.     

Body composition in prepubertal girls: comparison of six methods

OBJECTIVE: To compare estimates of fat mass (FM), fat-free mass (FFM) and percentage body fat (%fat) by six different methods in prepubertal girls. DESIGN: Cross-sectional study. SUBJECTS: Normal-weight, multi-ethnic, prepubertal girls (age=8.5+/-0.4 y, n=101). MEASUREMENTS: Body composition was measured in each child by anthropometry (skinfold thickness using Slaughter equation), dual-energy X-ray absorptiometry (DXA), total body potassium (TBK), isotope dilution for total body water measurement (TBW), multifrequency bioelectrical impedance spectroscopy (BIS), and total body electrical conductivity (TOBEC). RESULTS: TOBEC and skinfold thickness yielded the lowest values of FM followed by DXA, TBK, TBW and BIS, with BIS giving the highest value of FM. All methods were significantly different for FFM, FM and %fat (P<0.001), except FFM by DXA and TBK. The Bland-Altman limits of agreement among the methods reveal that they are not directly interchangeable for FM, FFM, or %fat. The largest mean difference for FM was between TOBEC and BIS (-2.90 kg), whereas the smallest mean difference was between TOBEC and skinfold thickness (-0.14 kg). For FFM, the largest mean difference was also between TOBEC and BIS (2.83 kg), but the smallest mean difference for FFM was between DXA and TBK (-0.03 kg). For %fat, the mean differences were larger, -10.5% for TOBEC and BIS and+9.7% for skinfold thickness and BIS. The closest two techniques for %fat were TOBEC and skinfold thickness (mean difference of -0.62%) and DXA and TBK (-1.81%). CONCLUSIONS: We found that estimates of body composition in prepubertal 8-y-old girls are highly method-dependent and that the six methods studied (DXA, TBK, TBW, TOBEC, BIS and anthropometry) are not directly interchangeable.     

Effect of chronic treatment with beta-blockers on resting energy expenditure in obese hypertensive patients during a low-calorie and physical training program

BACKGROUND AND AIM: To evaluate whether chronic treatment with beta-blockers influences resting energy expenditure (REE) and weight loss after a period of diet and physical activity in obese hypertensive patients. METHODS AND RESULTS: Seventy-eight obese hypertensive patients (24 males and 54 females) aged 53.7 +/- 11.1 years with mean BMI of 42.4 +/- 5.8 kg/m2 were enrolled. Thirty-eight patients were using beta-blockers while 40 patients who had not received beta-blockers in the past 6 months were the control group. REE was measured with indirect calorimetric method. Total body fat mass, total body fat-free mass (FFM) and total body water (W) were determined by bioelectrical impedance analysis. Patients and controls underwent a structured physical training program and a hypocaloric diet for a period of 31.6 +/- 10.6 days. Measured REE in patients taking beta-blockers was 1818 +/- 309 kcal/24 h and 1853 +/- 348 kcal/24 h in patients not taking beta-blockers; p = non significant. Weight and BMI loss were similar between the two groups and were respectively -6.43 +/- 2.62 kg and -2.42 +/- 0.91 kg/m2 in the beta-blocker group and -7.49 +/- 3.10 kg, -2.78 +/- 1.03 kg/m2 in the non beta-blocker group. Body composition was similar in the two groups. In the comparison between patients treated with selective beta 1-adrenoceptors blockers and non selective beta-blockers we found a significant difference in REE (1704 +/- 283 vs 1974 +/- 278; p = 0.012) and in weight loss (-5.6 +/- 2.4 vs -7.5 +/- 2.7; p = 0.048) at the end of study. CONCLUSIONS: Beta-blockers are not associated with a lower REE in obese subjects compared to other antihypertensive treatment. Use of non selective beta-adrenergic blockers is associated with a higher REE and weight loss compared to use of selective beta 1-adrenergic blockers. Non selective beta-blockers could be indicated among first choice drugs in hypertensive severely obese subjects without contraindications to beta-blockade.     

Differences in body composition between Tongans and Australians: time to rethink the healthy weight ranges?

OBJECTIVE: The prevalence of obesity varies considerably between countries when compared using the common international standard. This study investigated body size and body composition in Tongan and Australian Caucasian adults. DESIGN: Cross-sectional comparative study. SUBJECTS: A total of 543 Tongans and 393 Australians. MEASUREMENTS: Weight, height, waist and hip circumference, four skinfolds, midarm circumference, elbow breadth, and body composition by bioelectrical impedance using sex- and ethnic-specific regression equations. RESULTS: Tongan women (mean body mass index (BMI)+/-s.e.=32.6+/-0.4 kg/m2) were larger than Australian women (BMI=25.8+/-0.4 kg/m2), with more fat-free mass (FFM; 52.2+/-0.4; 42.6+/-0.3 kg), fat mass (37.1+/-0.7; 26.6+/-0.8 kg) and percentage body fat (%fat) (40.5+/-0.4; 37.0+/-0.5%), respectively. Tongan men also had higher BMI (Tongan= 30.3+/-0.3 kg/m2; Australian=26.5+/-0.3 kg/m2), FFM (70.2+/-0.5; 62.3+/-0.6 kg) and fat mass (23.5+/-0.6; 20.7+/-0.7 kg). When compared with Australians within the same BMI range, Tongans had significantly higher FFM, elbow width, midarm muscle area and significantly lower %fat. The %fat at BMIs of 25 and 30 kg/m2 in Australian women was equivalent to the %fat found in Tongan women at 28.8 and 35.1 kg/m2, respectively. BMIs of 25 and 30 kg/m2 in Australian men corresponded with 27.5 and 35.8 kg/m2 in Tongan men. Skinfold thicknesses, waist, hip and WHR measurements suggested differences in fat distribution and body shape between ethnic groups, particularly in women. CONCLUSION: These results suggest that the standard healthy weight ranges recommended for international use may not be appropriate standards for use in the Tongan population.     

The effect of gender and body composition method on the apparent decline in lean mass-adjusted resting metabolic rate with age

BACKGROUND: Declining resting energy expenditure (REE) is a hallmark of normal aging, but the cause of this decline remains controversial. Some, but not all, studies have shown that the decline in REE with age is eliminated after adjustment for fat-free mass (FFM). METHODS: We examined the effect of four body composition methods used to assess FFM (underwater weighing [UWW], bioimpedance analysis [BIA], tritium dilution, and total body potassium [TBK]) on the relationship between REE and age in 30 healthy men and 101 healthy women aged 18 to 87 years. RESULTS: The decline in REE with age was significant in women (-80.3 kJ/d/y, p < .004) but not in men (-46.9 kJ/d/y, p = .328). After adjustment for FFM, the decline in REE with age persisted when FFM was measured by BIA, UWW, or tritium dilution, but no decline was seen when TBK was used to adjust for FFM. In both women and men, fat mass was significantly associated with REE after adjusting for age and FFM. CONCLUSION: It is the decline in cell mass with age, detectable by TBK but not by other methods, rather than any metabolic alteration, that explains the decline in FFM-adjusted REE with age.     

Composition of weight loss in severely obese women: a new look at old methods.

Seven severely obese, outpatient dieters lost weight (mean +/- SEM, 14 +/- 1 kg), and the composition of weight lost was determined by six different models. Total body water (TBW), total body potassium (TBK), and body density, bone mineral content, and fat as determined by dual photon absorptiometry (DPA) were measured while subjects were weight-stable, before and after weight loss. Fat loss was calculated by three two-compartment models (2C-TBW, 2C-TBK, and hydrodensitometry [2C-HD]), one three-compartment model (HD with correction for water content of fat-free mass [FFM], 3C), and one four-compartment model (HD with correction for water and mineral content of FFM, 4C), and was measured directly by DPA. Mean composition of weight loss was similar for all models (mean weight lost as fat: 89% for DPA, 91.5% for 4C, 89% for 3C, 88.6% for 2C-HD, and 87% for 2C-TBW) except 2C-TBK (weight lost as fat, 66%). There was a much wider range of individual values for the 2C-TBW and 2C-TBK models (17% to 138% and 18% to 93%, respectively) than for the multicompartment models (63% to 112%) and DPA (76% to 107%). Almost opposite results were obtained for the same individual when using the 2C-TBK and 2C-TBW models. The discrepancy between these models was due to the inverse relationship between changes in TBW and TBK in the group as a whole (r = -.34, NS). In addition, TBK loss was found to be dependent on the initial level of hyperinsulinemia, calculated as the area under the 2-hour oral glucose tolerance curve.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Physiologic changes after diet combined with structured aerobic exercise or lifestyle activity

Moderate intensity physical activity achieved through changes in lifestyle may promote weight management. However, little is known about changes in physiologic and metabolic variables when patients lose weight using moderate intensity lifestyle activity instead of traditional structured vigorous aerobic exercise. To compare changes in resting metabolic energy expenditure (REE), fat mass (FM), and fat-free mass (FFM) associated with a 12-week weight loss program combined with either: (1) aerobic exercise (AER); or (2) lifestyle activity (LIFE), we randomized 39 overweight adults (mean body mass index [BMI] = 30.9 +/- 2.8 kg/m(2)) to either diet plus AER (N = 18) or diet plus LIFE (N = 21). Both groups consumed a self-selected diet of 1,200 to 1,800 kcal/d (5,021 to 7,531 kJ/d). The AER group performed vigorous aerobic exercise for up to 45 minutes 3 to 4 d/wk. The LIFE group accumulated 30 minutes of moderate intensity physical activity on most days of the week. Compliance with the respective protocols was monitored on a weekly basis. REE was measured before and after treatment via open-circuit spirometry. The AER group decreased body weight by 8.4% (P<.001)while the LIFE had a reduction of 6.7% (P <.001) after treatment. Over the course of the interventions, the AER and LIFE groups experienced 10.9% (P <.001) and 10.2% (P <.001) reductions in REE, respectively. Aerobic exercise did not prevent reductions in REE to a greater extent than did lifestyle activity in patients consuming a reduced calorie diet. Change in REE was not related to changes in FFM or FM for either group, and there were no differences between groups in reductions of REE, weight, FM, or FFM. A program of diet plus lifestyle physical activity may be a suitable alternative for dieting adults who have difficulty adhering to a program of vigorous activity.     

Resting metabolic rate, body composition, and serum leptin concentrations in a free-living elderly population

OBJECTIVE: The present study investigated the relationship between serum leptin concentrations and resting metabolic rate (RMR) in a large study group of elderly individuals with special consideration of body composition and body fat distribution as possible confounders. DESIGN AND METHODS: The subjects were 122 women (age: 69+/-6 years, body mass index (BMI): 26.3+/-3.6 kg/m(2)) and 82 men (age: 69+/-5 years, BMI: 26.0+/-2.6 kg/m(2)). RMR was measured by indirect calorimetry and body composition by the bioelectrical impedance method. Serum leptin levels were determined by radioimmunoassay. RESULTS: There was a strong correlation between fat mass (FM) and serum leptin levels in both sexes. An age-related decline in leptin levels adjusted for FM was observed only in the women. After adjustment of RMR for both fat-free mass (FFM) and FM, leptin levels were not associated with RMR. In stepwise multiple regression analysis, FFM was the main predictor of RMR, explaining 35.8% and 47.6% of the variance of RMR in men and women respectively. FM did not explain variance in RMR in men, but accounted for 2.6% of the variance in RMR in women. Waist-hip-ratio and age influenced RMR only in males, explaining 5.7% and 4.0% of the variance in RMR respectively. CONCLUSION: Leptin is not a significant predictor of RMR in the elderly, but body composition and distribution of body fat are significantly associated with RMR.     

No effect of gender on different components of daily energy expenditure in free living prepubertal children

BACKGROUND: There are limited and controversial data on the influence of gender on metabolic rate in prepubertal children. OBJECTIVE: To assess the effect of gender on resting energy expenditure (REE), activity-related energy expenditure (AEE), total energy expenditure (TEE) and physical activity level (PAL) in free-living prepubertal children. DESIGN: Cross-sectional study. SUBJECTS: 40 prepubertal children (24 boys, 16 girls, 4-11 y old (mean age: 7.0 +/- 1.2 y), BMI 13.1-32.0 kg/m2). MEASUREMENTS: Energy expenditure was measured by the combination of indirect calorimetry and individually calibrated 24 h heart rate monitoring. Body composition was assessed by anthropometrics and bioelectrical impedance analysis. Socio-cultural and socio-economic factors, as well as activities of daily living, were estimated by questionnaire for the parents. Boys and girls were matched for fat-free mass (FFM, boys: 25.9 +/- 8.5 kg; and girls: 24.4 +/- 4.5 kg, n.s.) and fat mass (FM, boys: 11.6-5.9 kg; and girls: 10.8 +/- 3.3 kg, n.s.). RESULTS: We found no sex difference in REE, AEE and TEE. PAL was 1.4 +/- 0.3 for boys and 1.2 +/- 0.4 for girls. REE and TEE were significantly related to FFM (r=0.62, r=0.81, r=0.60). FFM was found to be the most significant determinant of REE (r2=0.70). REE accounted for the largest part of the variance in TEE (r2=0.46). Gender had no significant effect. CONCLUSIONS: There is no effect of gender on energy expenditure in prepubertal children.     

The relationship between active ghrelin levels and human obesity involves alterations in resting energy expenditure

Ghrelin is a gastric hormone that exerts a stimulatory effect on appetite and fat accumulation. Ser(3) octanoylation is regarded as a prerequisite for ghrelin biological activity, although des-octanoylated forms may retain biological functions in vitro. Circulating ghrelin levels are usually low in obesity and in states of positive energy balance. Hence, the aim of our study was to analyze plasma active and serum total ghrelin levels in 20 obese (ages, 22-42 yr; body mass index, 41.3 +/- 1.1 kg/m(2)) and 20 lean subjects (ages, 22-43 yr; body mass index, 22.4 +/- 0.6 kg/m(2)) as well as their relationship to measures of glucose homeostasis, body fat, and resting energy expenditure (REE). The measured/predicted REE percentage ratio was calculated to subdivide groups into those with positive (> or = 100% ) and negative (<100%) ratio values. In obese patients, plasma active (180 +/- 18 vs. 411 +/- 57 pg/ml; P < 0.001) and serum total ghrelin levels (3650 +/- 408 vs. 5263 +/- 643 pg/ml; P < 0.05) were significantly lower when compared with lean subjects. Hence, ghrelin activity, defined as the proportion of active over total ghrelin levels, was similarly reduced in the obese state (6.1 +/- 0.9% vs. 8.4 +/- 1%; P < 0.05). There was a significant correlation between active and total ghrelin (r = 0.62; P < 0.001), and between total ghrelin and insulin (r = -0.53; P < 0.001) or insulin resistance using the homeostatis model of assessment-insulin resistance (r = -0.49; P < 0.001) approach. Significantly higher active ghrelin levels (214 +/- 22 vs. 159 +/- 30 pg/ml; P < 0.05) and ghrelin activity (8 +/- 1.7% vs. 4.9 +/- 0.9%; P < 0.05) were observed in patients with positive compared with negative measured/predicted REE ratio values. Our study shows that obesity is associated with an impairment of the entire ghrelin system. The observation that ghrelin is further decreased in cases of abnormal energy profit adds new evidence to the relationship between ghrelin activity and energy balance in obesity.