Total Energy Expenditure and Functional Status in Older Adults: A Doubly Labelled Water Study.

OBJECTIVES: Higher total energy expenditure in free living conditions, regardless of any activity, has been strongly associated with a lower risk of mortality in healthy older adults. Also, a good performance in physical and functional tests is a marker of good functional prognosis. However, it is not yet clear what is the association between total energy expenditure and the performance in physical and functional tests. The objective of this study was to verify the association between the total energy expenditure of older adults measured by doubly labelled water and the performance in functional tests. DESIGN: Cross-sectional study. SETTINGS AND PARTICIPANTS: Fifty-six older people were recruited from health services linked to the participating institutions. MEASUREMENTS: Socio-demographic, anthropometric and clinical characteristics were assessed through the application of a structured questionnaire. Body composition was evaluated by isotopic dilution of deuterium oxide and functional status was assessed by the gait speed test, 6-minute walk test and handgrip strength. Total energy expenditure (GET) was assessed using the doubly labelled water method and the physical activity profile was verified using an activity monitor based on accelerometery. RESULTS: The results showed that the highest total energy expenditure correlated with the best performance in the gait speed tests (r = 0.266; p = 0.047), 6-minute walk test (r = 0.424; p = 0.001) and maximum handgrip strength (r = 0.478; p = 0.000). Multivariate regression analysis in a model adjusted for sex and fat-free mass revealed an association between total energy expenditure and the 6-minute walk test (ß = 1.790; t = 2.080; p = 0.044) and the number of sedentary events ( ß = 6.389; t = 2.147; p = 0.038). CONCLUSION: The results of this study suggest that, in clinical practice, older individuals with lower gait speed, worse performance in the 6-minute walk test and lower handgrip strength, may have lower total energy expenditure, being the stimulus for its increase important for the prevention of possible problems related to low energy expenditure.

Maximum Walking Speed Can Improve the Diagnostic Value of Frailty among Community-Dwelling Older Adults a Cross-Sectional Study.

This study investigates the diagnostic accuracy of the combination of usual walking speed (UWS) and maximum walking speed (MWS) to identify frailty in community-dwelling older adults. A population-based study with 758 participants aged 65 and older was conducted. Frailty syndrome was determined using the Fried phenotype. UWS and MWS were evaluated in a 4.6-meter path. Both measures were categorized using the 1.0 m/s cut points, and participants were categorized into three groups: those with "very good", "good" and "insufficient" walking reserve capacity (WRC). Of all participants, 9% were identified as frail and 47% as prefrail. The "insufficient" WRC presented a low sensitivity of 0.55, high specificity of 0.91 and moderately useful likelihood ratios (LR+ 6.57, LR- 0.48) to identify frailty. Based on Fagan's nomogram, an elder's corresponding post-test probability of being frail with an "insufficient" WRC would be around 40%, which substantially increased the diagnostic accuracy of frailty.

Body Mass Index and Its Relationship with Disability, Chronic Diseases and Frailty in Older People: A Comparison of the Lipschitz and Who Classifications.

BACKGROUND: Anthropometric parameters are closely associated with the pathophysiology of frailty and with clinic and functional parameters assessed for its diagnosis. OBJECTIVE: To evaluate the possible association of the nutritional status of older people as assessed by Body Mass Index (BMI) and functional disability, self-reported chronic diseases and frailty, comparing the use of two different classifications of BMI. DESIGN: Cross-sectional study. SETTING: The sample was selected among community-dwelling older people from the city of Ribeirão Preto/ Brazil. PARTICIPANTS: 326 independent older people (mean age 73.8±6.4 years) who participated in the FIBRA (Frailty in Brazilian Older People) study. MEASUREMENTS: Weight and height were collected for BMI analysis and frailty criteria were applied according to Fried et al. Participants were also evaluated for self-reported activities of daily living (Katz Index and Lawton and Brody Scale), and the presence of chronic diseases. RESULTS: The prevalence of frailty was 12.3%. Regardless of the classification of BMI applied, most of the sample was classified as overweight (50.9% and 39.3% in the Lipschitz and WHO classifications, respectively). For both classifications, low weight was the only BMI classification associated with frailty status (OR Lipschitz: 4.12(1.53-11.14); OR WHO: 6.21 (1.26-30.58). Comorbidities and dependence in activities of daily living (ADLs) were associated with BMI ≥ 30kg.m2. CONCLUSION: Regardless of the classification adopted, low weight is associated with frailty. However, when the WHO stratification is employed, high BMI is also associated to increased functional disability and the presence of comorbidities, coexisting factors of frailty.

Misreport of energy intake assessed with food records and 24-h recalls compared with total energy expenditure estimated with DLW.

BACKGROUND/OBJECTIVES: The accuracy of dietary assessment methods has rarely been validated using precise techniques. The objective of this work was to evaluate the validity of energy intake (EI) estimated with food records (FRs) and 24-h recalls (24hRs) against total energy expenditure (EE) estimated by the doubly labeled water (DLW) method. In addition, the magnitude of EI under-reporting was assessed along with its associated characteristics. SUBJECTS/METHODS: The studied group included 83 adults between 20 and 60 years of age who were recruited from a population-based sample. Within-person variation-adjusted means of EI estimated from two FRs and three 24hRs were compared with EE estimated using the DLW method multiple-point protocol. The Wilcoxon signed-rank test was used to assess the differences between EI and EE, whereas Bland-Altman and survival-agreement plots assessed the agreement between the estimates. RESULTS: The mean EE (2540 kcal) was greater than the mean reported EI for both dietary assessment methods (FR: 1774 kcal; 24hR: 1658 kcal, P<0.01). The frequency of under-reporting was lower (20%) for EI estimated with the 24hR than that estimated with the FR (32%). Men presented lower magnitude of under-reported EI than women did. For women, differences between EI and EE were lower with FR than with 24hR. Overall, FR and 24hR showed similar performance. The mean under-reported EI was ~30% for both methods. CONCLUSIONS: Irregular meal habits, smoking and low education were associated with the under-report of EI. Both FR and 24hR are subjected to bias suggesting the need of refining the procedures applied in dietary assessment methods.

Bioelectrical impedance with different equations versus deuterium oxide dilution method for the inference of body composition in healthy older persons.

BACKGROUND: There is no consensus regarding the accuracy of bioimpedance for the determination of body composition in older persons. OBJECTIVE: This study aimed to compare the assessment of lean body mass of healthy older volunteers obtained by the deuterium dilution method (reference) with those obtained by two frequently used bioelectrical impedance formulas and one formula specifically developed for a Latin-American population. DESIGN: A cross-sectional study. PARTICIPANTS: Twenty one volunteers were studied, 12 women, with mean age 72±6.7 years. SETTING: Urban community, Ribeirão Preto, Brazil. MEASUREMENT: Fat free mass was determined, simultaneously, by the deuterium dilution method and bioelectrical impedance; results were compared. In bioelectrical impedance, body composition was calculated by the formulas of Deuremberg, Lukaski and Bolonchuck and Valencia et al. RESULTS: Lean body mass of the studied volunteers, as determined by bioelectrical impedance was 37.8±9.2 kg by the application of the Lukaski e Bolonchuk formula, 37.4±9.3 kg (Deuremberg) and 43.2±8.9 kg (Valencia et. al.). The results were significantly correlated to those obtained by the deuterium dilution method (41.6±9.3 Kg), with r=0.963, 0.932 and 0.971, respectively. Lean body mass obtained by the Valencia formula was the most accurate. CONCLUSION: In this study, lean body mass of older persons obtained by the bioelectrical impedance method showed good correlation with the values obtained by the deuterium dilution method. The formula of Valencia et al., developed for a Latin-American population, showed the best accuracy.

Body composition measures of obese adolescents by the deuterium oxide dilution method and by bioelectrical impedance.

The objectives of the present study were to describe and compare the body composition variables determined by bioelectrical impedance (BIA) and the deuterium dilution method (DDM), to identify possible correlations and agreement between the two methods, and to construct a linear regression model including anthropometric measures. Obese adolescents were evaluated by anthropometric measures, and body composition was assessed by BIA and DDM. Forty obese adolescents were included in the study. Comparison of the mean values for the following variables: fat body mass (FM; kg), fat-free mass (FFM; kg), and total body water (TBW; %) determined by DDM and by BIA revealed significant differences. BIA overestimated FFM and TBW and underestimated FM. When compared with data provided by DDM, the BIA data presented a significant correlation with FFM (r = 0.89; P < 0.001), FM (r = 0.93; P < 0.001) and TBW (r = 0.62; P < 0.001). The Bland-Altman plot showed no agreement for FFM, FM or TBW between data provided by BIA and DDM. The linear regression models proposed in our study with respect to FFM, FM, and TBW were well adjusted. FFM obtained by DDM = 0.842 x FFM obtained by BIA. FM obtained by DDM = 0.855 x FM obtained by BIA + 0.152 x weight (kg). TBW obtained by DDM = 0.813 x TBW obtained by BIA. The body composition results of obese adolescents determined by DDM can be predicted by using the measures provided by BIA through a regression equation.

Body composition measures of obese adolescents by the deuterium oxide dilution method and by bioelectrical impedance

The objectives of the present study were to describe and compare the body composition variables determined by bioelectrical impedance (BIA) and the deuterium dilution method (DDM), to identify possible correlations and agreement between the two methods, and to construct a linear regression model including anthropometric measures. Obese adolescents were evaluated by anthropometric measures, and body composition was assessed by BIA and DDM. Forty obese adolescents were included in the study. Comparison of the mean values for the following variables: fat body mass (FM; kg), fat-free mass (FFM; kg), and total body water (TBW; percent) determined by DDM and by BIA revealed significant differences. BIA overestimated FFM and TBW and underestimated FM. When compared with data provided by DDM, the BIA data presented a significant correlation with FFM (r = 0.89; P < 0.001), FM (r = 0.93; P < 0.001) and TBW (r = 0.62; P < 0.001). The Bland-Altman plot showed no agreement for FFM, FM or TBW between data provided by BIA and DDM. The linear regression models proposed in our study with respect to FFM, FM, and TBW were well adjusted. FFM obtained by DDM = 0.842 x FFM obtained by BIA. FM obtained by DDM = 0.855 x FM obtained by BIA + 0.152 x weight (kg). TBW obtained by DDM = 0.813 x TBW obtained by BIA. The body composition results of obese adolescents determined by DDM can be predicted by using the measures provided by BIA through a regression equation.

Body composition assessment of undernourished older subjects by dual-energy x-ray absorptiometry and bioelectric impedance analysis.

BACKGROUND: The prevention and treatment of diseases related to changes in body composition require accurate methods for the measurement of body composition. However, few studies have dealt specifically with the assessment of body composition of undernourished older subjects by different methodologies. OBJECTIVES: To assess the body composition of undernourished older subjects by two different methods, dual energy x-ray absorptiometry (DXA) and bioelectric impedance (BIA), and to compare results with those of an eutrophic group. DESIGN: The study model was cross-sectional; the study was performed at the University Hospital of the School of Medicine of Ribeirão Preto, University of São Paulo, Brazil. PARTICIPANTS: Forty-one male volunteers aged 62 to 91 years. The groups were selected on the basis of anamnesis, physical examination and nutritional assessment according to the Mini Nutritional Assessment (MNA) score. Body composition was assessed by DXA and BIA. RESULTS: Body weight, arm and calf circumference, body mass index (BMI), fat free mass (FFM) and fat mass (FM) were significantly lower in the undernourished group as compared to the eutrophic group. There were no significant differences between FFM and FM mean values determined by DXA and BIA in both groups, but the agreement between methods in the undernourished group was less strong. CONCLUSION: Our results suggest caution when BIA is to be applied in studies including undernourished older subjects. This study does not support BIA as an accurate method for the individual assessment of body composition.

Prediction of fat-free mass by bioelectrical impedance analysis in older adults from developing countries: a cross-validation study using the deuterium dilution method.

OBJECTIVE: Several limitations of published bioelectrical impedance analysis (BIA) equations have been reported. The aims were to develop in a multiethnic, elderly population a new prediction equation and cross-validate it along with some published BIA equations for estimating fat-free mass using deuterium oxide dilution as the reference method. DESIGN AND SETTING: Cross-sectional study of elderly from five developing countries. METHODS: Total body water (TBW) measured by deuterium dilution was used to determine fat-free mass (FFM) in 383 subjects. Anthropometric and BIA variables were also measured. Only 377 subjects were included for the analysis, randomly divided into development and cross-validation groups after stratified by gender. Stepwise model selection was used to generate the model and Bland Altman analysis was used to test agreement. RESULTS: FFM = 2.95 - 3.89 (Gender) + 0.514 (Ht2/Z) + 0.090 (Waist) + 0.156 (Body weight). The model fit parameters were an R2, total F-Ratio, and the SEE of 0.88, 314.3, and 3.3, respectively. None of the published BIA equations met the criteria for agreement. The new BIA equation underestimated FFM by just 0.3 kg in the cross-validation sample. The mean of the difference between FFM by TBW and the new BIA equation were not significantly different; 95% of the differences were between the limits of agreement of -6.3 to 6.9 kg of FFM. There was no significant association between the mean of the differences and their averages (r= 0.008 and p= 0.2). CONCLUSIONS: This new BIA equation offers a valid option compared with some of the current published BIA equations to estimate FFM in elderly subjects from five developing countries.

Salt and insulin sensitivity after short and prolonged high salt intake in elderly subjects.

Salt sensitivity and insulin resistance are correlated with higher cardiovascular risk. There is no information about changes in salt sensitivity (SS) and insulin sensitivity (IS) after a chronic salt overload in humans. The aim of this study was to evaluate these parameters in the elderly. Seventeen volunteers aged 70.5 +/- 5.9 years followed a low-salt diet (LSD) for 1 week and a high-salt diet (HSD) for 13 weeks. We evaluated SS after one week (HSD1) and after 13 weeks (HSD13), and subjects' IS and lipids on their usual diet (UD) at HSD1, and at HSD13. Blood pressure (BP) was measured at each visit and ambulatory blood pressure monitoring (ABPM) was performed twice. SS was the same at HSD1 and HSD13. Systolic BP was lower on LSD than on UD (P = 0.01), HSD1 (P < 0.01) and HSD13 (P < 0.01). When systolic and diastolic BP were evaluated by ABPM, they were higher at HSD13 during the 24-h period (P = 0.03 and P < 0.01) and during the wakefulness period (P = 0.02 and P < 0.01) compared to the UD. Total cholesterol was higher (P = 0.04) at HSD13 than at HSD1. Glucose and homeostasis model assessment (HOMA) were lower at HSD1 (P = 0.02 and P = 0.01) than at HSD13. Concluding, the extension of HSD did not change the SS in an elderly group. The higher IS found at HSD1 did not persist after a longer HSD. A chronic HSD increased BP as assessed by ABPM.

Salt and insulin sensitivity after short and prolonged high salt intake in elderly subjects

Salt sensitivity and insulin resistance are correlated with higher cardiovascular risk. There is no information about changes in salt sensitivity (SS) and insulin sensitivity (IS) after a chronic salt overload in humans. The aim of this study was to evaluate these parameters in the elderly. Seventeen volunteers aged 70.5 ± 5.9 years followed a low-salt diet (LSD) for 1 week and a high-salt diet (HSD) for 13 weeks. We evaluated SS after one week (HSD1) and after 13 weeks (HSD13), and subjects’ IS and lipids on their usual diet (UD) at HSD1, and at HSD13. Blood pressure (BP) was measured at each visit and ambulatory blood pressure monitoring (ABPM) was performed twice. SS was the same at HSD1 and HSD13. Systolic BP was lower on LSD than on UD (P = 0.01), HSD1 (P < 0.01) and HSD13 (P < 0.01). When systolic and diastolic BP were evaluated by ABPM, they were higher at HSD13 during the 24-h period (P = 0.03 and P < 0.01) and during the wakefulness period (P = 0.02 and P < 0.01) compared to the UD. Total cholesterol was higher (P = 0.04) at HSD13 than at HSD1. Glucose and homeostasis model assessment (HOMA) were lower at HSD1 (P = 0.02 and P = 0.01) than at HSD13. Concluding, the extension of HSD did not change the SS in an elderly group. The higher IS found at HSD1 did not persist after a longer HSD. A chronic HSD increased BP as assessed by ABPM.

Characteristics of women who frequently under report their energy intake: a doubly labelled water study.

BACKGROUND/OBJECTIVES: We applied three dietary assessment methods and aimed at obtaining a set of physical, social and psychological variables that can discriminate those individuals who did not underreport ('never under-reporters'), those who underreported in one dietary assessment method ('occasional under-reporters') and those who underreported in two or three dietary assessment methods ('frequent under-reporters'). PARTICIPANTS/METHODS: Sixty-five women aged 18-57 years were recruited for this study. Total energy expenditure was determined by doubly labelled water, and energy intake was estimated by three 24-h diet recalls, 3-day food records and a food frequency questionnaire. A multiple discriminant analysis was used to identify which of those variables better discriminated the three groups: body mass index (BMI), income, education, social desirability, nutritional knowledge, dietary restraint, physical activity practice, body dissatisfaction and binge-eating symptoms. RESULTS: Twenty-three participants were 'never under-reporters'. Twenty-four participants were 'occasional under-reporters' and 18 were 'frequent under-reporters'. Four variables entered the discriminant model: income, BMI, social desirability and body dissatisfaction. According to potency indices, income contributed the most to the total discriminant power, followed in decreasing order by social desirability score, BMI and body dissatisfaction. Income, social desirability and BMI were the characteristics that mainly separated the 'never under-reporters' from the under-reporters (occasional or frequent). Body dissatisfaction better discriminated the 'occasional under-reporters' from the 'frequent under-reporters'. CONCLUSIONS: 'Frequent under-reporters' have a greater BMI, social desirability score, body dissatisfaction score and lower income. These four variables seemed to be able to discriminate individuals who are more prone to systematic under reporting.

Effect of fluid and food intake on the body composition evaluation of elderly persons.

BACKGROUND: Several studies have shown that liquid and food intake interfere with the evaluation of body composition in adults. However, since there are no reports about this interference in the elderly population, the need to fast for this evaluation may be dispensable. OBJECTIVES: The objective of the present study was to assess the influence of liquid and solid food on the measurement of body composition by bioelectrical impedance analysis (BIA) and by dual energy X-ray absorptiometry (DXA). DESIGN: Forty-one male volunteers aged 62 to 87 years participated in the study. The subjects were submitted to evaluation of body composition by DXA and BIA under fasting conditions and 1 hour after the ingestion of breakfast (500 ml of orange juice and one 50 g bread roll with butter). RESULTS: There was no significant difference in the variables fat-free mass (FFM) or fat mass (FM) between the fasting condition and the evaluation performed 1 hour after the meal as measured by BIA or DXA. There was also no significant difference when the same variables were compared between methods. CONCLUSION: In the present study, the ingestion of 500 ml orange juice and of one bread roll with butter by elderly subjects did not affect the results of the parameters of body composition determined by BIA or DXA. Thus, these exams could be performed without the rigor of fasting, often poorly tolerated by the elderly.

Effects of arginine supplementation on the humoral and innate immune response of older people.

OBJECTIVE: To evaluate whether oral supplementation with arginine affects the humoral and innate immune response after vaccination against Streptococcus pneumoniae in a group of people aged 60 y and older, free-living in the community. DESIGN: A randomized controlled trial with one supplemented group and one control group. SETTING: Older persons living in the community. SUBJECTS: A total of 29 adults aged 60 y and older. INTERVENTIONS: The older people were randomized into two groups, one with arginine supplementation (15 g/day) for 4 weeks after pneumococcal vaccine. The control group received only the vaccine. Anthropometric measurements and immune system function parameters: neutrophil chemotaxis and phagocytosis, natural killer cell activity, determination of serum pneumococcal polysaccharide antibodies and serum C3 and C4. RESULTS: Neutrophil phagocytosis and the serum concentration of complement (C3 and C4) did not differ between groups. IgG antibodies against pneumococcal polysaccharide serotypes 1, 5 and 6B increased in both groups. The following parameters increased in the arginine-supplemented group compared to the nonsupplemented group: neutrophil chemotaxis (34 vs 19 units of migration, P = 0.002), natural killer cell cytotoxicity (23.3 vs 13.4 10 M/Ul 40%, P = 0.011) and IgG against antigen 5 (12.3 vs 6.2 mug/ml, P = 0.044). CONCLUSIONS: This study suggests that, after the pneumococcal vaccine, the intake of arginine increased neutrophil chemotaxis, natural killer cytotoxicity and serum concentration of IgG against antigen 5 in older people. These results suggest that arginine supplementation may enhance the immune response elicited by the pneumococcal vaccine in older people. SPONSORSHIP: Supported in part by CAPES and FAEPA.

Mini-nutritional assessment score and the risk for undernutrition in free-living older persons.

BACKGROUND: Many scales have been proposed for the brief nutritional assessment of older persons, with the goal of increasing undernutrition detection and the detection of nutritional risk. The Mini-Nutritional Assessment (Guigoz et al., 1994) has been increasingly used worldwide, but its efficacy has been assessed in few countries. OBJECTIVES: This study aimed to assess, through complete clinical evaluation, anthropometric measurements and laboratorial tests, the nutritional state of older persons living in the community and compare the results with the score obtained by the application of the Mini Nutritional Assessment. DESIGN: Forty-two persons aged 60 years or older (55% women, mean age 70.9 years) were studied. All volunteers were submitted to a criterious clinical evaluation, anthropometric measures and laboratorial testing (serum albumin, hemoglobin, lymphocite count, iron and unsatured iron binding capacity). RESULTS: Twenty-seven volunteers (64%) were considered eutrophic, 12 volunteers were considered obese (28,6%) and three volunteers were considered undernourished. Thirteen volunteers were classified as in risk of undernutrition by the Mini-Nutritional Assessment score, 29 scored within the normal range and no volunteer was considered to be undernourished. The Mini Nutritional Assessment score was significantly associated with age and with the unsatured iron binding capacity. When compared to the final nutritional diagnosis, the questionnaire showed 100% sensibility and 74.3% specificity. CONCLUSION: This study detected a prevalence of undernutrition in the elderly living in the community similar to those described in developed countries. In this population, the Mini Nutritional Assessment showed to be specially efficient for the detection of nutritional risk.

Obese women on a low energy rice and bean diet: effects of leucine, arginine or glycine supplementation on protein turnover.

This study examined if leucine, arginine or glycine supplementation in adult obese patients (body mass index of 33 +/- 4 kg/m(2)) consuming a Brazilian low energy and protein diet (4.2 MJ/day and 0.6 g protein/kg) affects protein and amino acid metabolism. After four weeks adaptation to this diet, each subject received supplements of these amino acids (equivalent to 0.2 g protein kg(-1) day(-1)) in random order. On the seventh day of each amino acid supplementation, a single-dose 15N-glycine study was carried out. There were no significant differences in protein flux, synthesis or breakdown. The protein flux (grams of nitrogen, gN/9 h) was 55 +/- 24 during the nonsupplemented diet intake and 39 +/- 10, 44 +/- 22 and 58 +/- 35 during the leucine-, glycine- and arginine-supplemented diet intake, respectively; protein synthesis (gN/9 h) was 57 +/- 24, 36 +/- 10, 41 +/- 22 and 56 +/- 36, respectively; protein breakdown (gN/9 h) was 51 +/- 24, 34 +/- 10, 32 +/- 28 and 53 +/- 35, respectively; kinetic balance (gN/9 h) was 3.2 +/- 1.8, 4.1 +/- 1.7, 3.4 +/- 2.9 and 3.9 +/- 1.6. There was no difference in amino acid profiles due to leucine, arginine or glycine supplementation. The present results suggest that 0.6 g/kg of dietary protein is enough to maintain protein turnover in obese women consuming a reduced energy diet and that leucine, arginine or glycine supplementation does not change kinetic balance or protein synthesis.

Obese women on a low energy rice and bean diet: effects of leucine, arginine or glycine supplementation on protein turnover

This study examined if leucine, arginine or glycine supplementation in adult obese patients (body mass index of 33 + or - 4 kg/m²) consuming a Brazilian low energy and protein diet (4.2 MJ/day and 0.6 g protein/kg) affects protein and amino acid metabolism. After four weeks adaptation to this diet, each subject received supplements of these amino acids (equivalent to 0.2 g protein kg-1 day-1) in random order. On the seventh day of each amino acid supplementation, a single-dose 15N-glycine study was carried out. There were no significant differences in protein flux, synthesis or breakdown. The protein flux (grams of nitrogen, gN/9 h) was 55 + or - 24 during the nonsupplemented diet intake and 39 + or - 10, 44 + or - 22 and 58 + or - 35 during the leucine-, glycine- and arginine-supplemented diet intake, respectively; protein synthesis (gN/9 h) was 57 + or - 24, 36 + or - 10, 41 + or - 22 and 56 + or - 36, respectively; protein breakdown (gN/9 h) was 51 + or - 24, 34 + or - 10, 32 + or - 28 and 53 + or - 35, respectively; kinetic balance (gN/9 h) was 3.2 + or - 1.8, 4.1 + or - 1.7, 3.4 + or - 2.9 and 3.9 + or - 1.6. There was no difference in amino acid profiles due to leucine, arginine or glycine supplementation. The present results suggest that 0.6 g/kg of dietary protein is enough to maintain protein turnover in obese women consuming a reduced energy diet and that leucine, arginine or glycine supplementation does not change kinetic balance or protein synthesis

A physiological manoeuvre to improve the positivity of the gastro-oesophageal reflux scintigraphic test.

One of the best examinations used routinely to detect gastro-oesophageal reflux (GOR) is scintigraphy and attempts are continuously being made to improve the performance of the test. We have tested a new manoeuvre to improve the results. Three hundred and twenty eight patients (190 males and 138 females, aged 1 month to 84 years, average 4.47 years) were studied after a 12 h fast period with 100 MBq of 99Tcm-phytate, 50 ml volume, directly delivered into the stomach in a mixture of orange juice. All patients were strongly suspected of having GOR. Conventional acquisition was done for 20 min, at a rate of one frame every 20 s. In the middle of the examination, small children were put in the upright position and held there for a few seconds or released in a way that allowed movement; adults were asked to stand up and walk a few metres. The test was then continued for the remaining 10 min. The global index of positivity was 64.6% (76 positive cases in the first half of the examination and 134 positive cases only after the manoeuvre). The mean of GOR episodes observed in the positive cases without the manoeuvre was 0.5 per patient, significantly different from the mean of 1.59 noted after the manoeuvre (P<0.01). In 28 cases the manoeuvre increased either the intensity or the frequency of reflux previously detected without it. We believe that this manoeuvre should be performed in all scintigraphic tests aiming to detect GOR. In the present series, the manoeuvre increased the frequency of GOR episodes.