Accuracy of direct segmental multi-frequency bioimpedance analysis in the assessment of total body and segmental body composition in middle-aged adult population

Background & aims

Body composition measurement is a valuable tool for assessing nutritional status and physical fitness in a variety of clinical settings. Although bioimpedance analysis (BIA) can easily assess body composition, its accuracy remains unclear. We examined the accuracy of direct segmental multi-frequency BIA technique (DSM-BIA) in assessing different body composition parameters, using dual energy X-ray absorptiometry (DEXA) as a reference standard.

Methods

A total of 484 middle-aged participants from the Leiden Longevity Study were recruited. Agreements between DSM-BIA and DEXA for total and segmental body composition quantification were assessed using intraclass correlation coefficients and Bland–Altman plots.

Results

Excellent agreements were observed between both techniques in whole body lean mass (ICC female = 0.95, ICC men = 0.96), fat mass (ICC female = 0.97, ICC male = 0.93) and percentage body fat (ICC female = 0.93, ICC male = 0.88) measurements. Similarly, Bland–Altman plots revealed narrow limits of agreements with small biases noted for the whole body lean mass quantification but relatively wider limits for fat mass and percentage body fat quantifications. In segmental lean muscle mass quantification, excellent agreements between methods were demonstrated for the upper limbs (ICC female≥0.91, ICC men≥0.87) and lower limbs (ICC female≥0.83, ICC male≥0.85), with good agreements shown for the trunk measurements (ICC female = 0.73, ICC male = 0.70).

Conclusions

DSM-BIA is a valid tool for the assessments of total body and segmental body composition in the general middle-aged population, particularly for the quantification of body lean mass.     

Weight cycling is associated with body weight excess and abdominal fat accumulation: A cross-sectional study

Background & aims

To investigate the association between history of multiple weight loss diets followed by weight regain, namely weight cycling (WCy), and both body weight excess and abdominal fat accumulation.

Methods

A one-day cross-sectional survey (“Obesity-Day”) including 914 participants (605F:309M). Anthropometric variables (body mass index [BMI], waist circumference [WC] and waist-to-height ratio [WtHR]), covariates and WCy (≥5 intentional weight loss episodes of ≥5 kg followed by rapid return to pre-diet or higher body weight) were assessed by a self-administered questionnaire, interview and physical examination.

Results

Data on central fat accumulation (by WC and WtHR) were available in a representative sub-group (n = 600). WCy was reported by 119 participants (13.0%) of total population and by 79 (13.2%) of those with available data on central fat accumulation. At multivariable linear regressions WCy was independently associated with higher BMI (P = .004), WC (P = .011) and WtHR (P = .008). Sensitivity analyses, performed after excluding those being on a diet at the time of assessment, confirmed these findings.

Conclusions

A history of WCy appears related to body weight excess and abdominal fat accumulation. These findings support the importance of designing adequate weight loss programs to achieve long-term weight maintenance and to prevent undesirable and unhealthy weight accumulation.     

Influence of resting energy expenditure on weight gain in adolescents taking second-generation antipsychotics

Background & aims

: Weight gain is an undesirable side effect of second-generation antipsychotics (SGAs). We performed this study to examine the influence of SGAs on resting energy expenditure (REE) and the relationship of REE to weight gain in adolescent patients.

Methods

Antipsychotic-naïve or quasi-naïve (<72 h of exposure to antipsychotics) adolescent patients taking olanzapine, quetiapine, or risperidone in monotherapy were followed up for one year. We performed a prospective study (baseline, 1, 3, 6, and 12 months after treatment) based on anthropometric measurements, bioelectrical impedance analysis, and indirect calorimetry (Deltatrac™ II MBM-200) to measure REE. We also analyzed metabolic and hormonal data and adiponectin concentrations.

Results

Forty-six out of the 54 patients that started treatment attended at least 2 visits, and 16 completed 1 year of follow-up. Patients gained 10.8 ± 6.2 kg (60% in the form of fat mass) and increased their waist circumference by 11.1 ± 5.0 cm after 1 year of treatment. The REE/kg body mass ratio decreased (p = 0.027), and the REE/percentage fat-free mass (FFM) ratio increased (p = 0.007) following the fall in the percentage of FFM during treatment. Weight increase was significantly correlated with the REE/percentage FFM ratio at all the visits (1–3–6–12 months) (r = 0.69, p = 0.004 at 12 months).

Conclusions

SGAs seem to induce a hypometabolic state (reflected as decreased REE/kg body mass and increased REE/percentage FFM). This could explain, at least in part, the changes in weight and body composition observed in these patients.     

Body weight and body composition of depot medroxyprogesterone acetate users

Objectives

Weight gain is a concern with the contraceptive depot-medroxyprogesterone acetate (DMPA); however, this issue remains controversial. The objective of this study was to compare body weight (BW) and body composition (BC) in DMPA and copper intrauterine device (IUD) users at baseline and after one year of use.

Study Design

We enrolled new DMPA users and age and weight matched new IUD users into this prospective study. Weight and height were measured, BC (fat and lean mass) was evaluated using dual-energy X-ray absorptiometry, and physical activity was assessed at baseline and at 12 months. Student's paired t test and the Wilcoxon paired test for matched samples were used.

Results

Ninety-seven women were enrolled for the study; 26 matched pairs continued using the initial method for at least one year, and completed the baseline and 12 month assessments. An increase of 1.9 kg occurred in BW (p=.02) in DMPA users at 12 months of use, resulting from an increase in fat mass of 1.6 kg (p=.03). Weight remained stable in IUD users; however, there was an increase in lean mass at 12 months of use (p=.001). The number of women practicing physical activity increased in this group. There was a significant difference between the groups regarding the variation in the percentage of central fat (p=.04).

Conclusion

Weight gain in the DMPA group after the first year of use resulted from an increase in fat mass. Weight remained stable in the IUD group; however, an increase in lean mass and a reduction in localized abdominal fat mass occurred, possibly because more users were practicing physical activity.

Implications statement

There was a greater increase in body weight in DMPA users compared to TCu380A IUD users in the first year of use of the contraceptive method. Furthermore, the weight increase in users of DMPA occurred principally as the result of an increase in fat mass. Physical activity probably could increase the lean mass in the users of TCu380A IUD.     

The increase in physical performance and gain in lean and fat mass occur in prepubertal children independent of mode of school transportation. One year data from the prospective controlled Pediatric Osteoporosis Prevention (POP) Study

Background

The aim of this 12-month study in pre-pubertal children was to evaluate the effect of school transportation on gain in lean and fat mass, muscle strength and physical performance.

Methods

Ninety-seven girls and 133 boys aged 7-9 years from the Malmö Pediatric Osteoporosis Prevention Study were included. Regional lean and fat mass were assessed by dual energy X-ray absorptiometry, isokinetic peak torque of knee extensors and flexors by a computerised dynamometer and physical performance by vertical jump height. Level of physical activity was assessed by accelerometers. The 12-month changes in children who walked or cycled to school were compared with changes in those who travelled by bus or car.

Results

There were no differences in baseline or annual changes in lean or fat mass gain, muscle strength or physical performance between the two groups. All children reached the internationally recommended level of 60 minutes per day of moderate or high physical activity by accelerometers.

Conclusion

The choice of school transportation in pre-pubertal children seems not to influence the gain in lean and fat mass, muscle strength or functional ability, probably as the everyday physical activity is so high that the mode of school transportation contributes little to the total level of activity.

     

The four-compartment model of body composition in obese Chilean schoolchildren,by pubertal stage: Comparison with simpler models

ObjectivesWe assessed the agreement of body fat and fat-free mass measured by simpler methods against the four-compartment model (4C).MethodsIn 60 obese schoolchildren (body mass index ≥95th percentile) between the ages of 8 and 13 y who were recruited from one school in Chile, multicompartmental body composition was estimated with the use of isotopic dilution, plethysmography (BodPod), radiographic absorptiometry (DEXA), and anthropometric equations. These results were compared to those of the 4C model, which is considered the gold standard.ResultsFor body fat, the 4C model showed the best agreement with DEXA for boys in Tanner stages I and II (r = 0.971) and with isotopic dilution for boys in Tanner stages III and IV (r = 0.984). The best agreement in girls occurred with isotopic dilution, regardless of pubertal stage (r = 0.948 for Tanner stages I and II; r = 0.978 for Tanner stages III and IV). Both isotopic dilution and the Huang, Ellis, and Deurenberg anthropometric equations underestimated body fat in boys; by contrast, DEXA, BodPod, and the Slaughter equation overestimated body fat in boys. All of the equations underestimated body fat in girls. For fat-free mass in both boys and girls, the 4C model showed the best agreement with isotopic dilution, regardless of pubertal stage. The Huang equation showed the best agreement for boys (r = 0.730 for Tanner stages I and II; r = 0.695 for Tanner stages III and IV) and for girls in Tanner stages I and II (r = 0.884). The Ellis equation had the best agreement for girls in Tanner stages III and IV (r = 0.917).ConclusionsFor obese Chilean children of both sexes, isotopic dilution and DEXA were the two-compartment methods that had the best agreement with the gold-standard 4C model for both body fat and fat-free mass; these were followed by the Huang and Ellis anthropometric equations.     

Depression scores predict adherence in a dietary weight loss intervention trial

Background & aims

Depression has a complex association with cardiometabolic risk, both directly as an independent factor and indirectly through mediating effects on other risk factors such as BMI, diet, physical activity, and smoking. Since changes to many cardiometabolic risk factors involve behaviour change, the rise in depression prevalence as a major global health issue may present further challenges to long-term behaviour change to reduce such risk. This study investigated associations between depression scores and participation in a community-based weight management intervention trial.

Methods

A group of 64 overweight (BMI > 27), otherwise healthy adults, were recruited and randomised to follow either their usual diet, or an isocaloric diet in which saturated fat was replaced with monounsaturated fat (MUFA), to a target of 50% total fat, by adding macadamia nuts to the diet. Subjects were assessed for depressive symptoms at baseline and at ten weeks using the Beck Depression Inventory (BDI-II). Both control and intervention groups received advice on National Guidelines for Physical Activity and adhered to the same protocol for food diary completion and trial consultations. Anthropometric and clinical measurements (cholesterol, inflammatory mediators) also were taken at baseline and 10 weeks.

Results

During the recruitment phase, pre-existing diagnosed major depression was one of a range of reasons for initial exclusion of volunteers from the trial. Amongst enrolled participants, there was a significant correlation (R = −0.38, p < 0.05) between BDI-II scores at baseline and duration of participation in the trial. Subjects with a baseline BDI ≥10 (moderate to severe depression symptoms) were more likely to dropout of the trial before week 10 (p < 0.001). BDI-II scores in the intervention (MUFA) diet group decreased, but increased in the control group over the 10-week period. Univariate analysis of variance confirmed these observations (adjusted R² = 0.257, p = 0.01). Body weight remained static over the 10-week period in the intervention group, corresponding to a relative increase in the control group (adjusted R² = 0.097, p = 0.064).

Conclusions

Depression symptoms have the potential to affect enrolment in and adherence to dietbased risk reduction interventions, and may consequently influence the generalisability of such trials. Depression scores may therefore be useful for characterising, screening and allocating subjects to appropriate treatment pathways.     

A Worksite Program for Overweight Middle-Aged Men Achieves Lesser Weight Loss With Exercise Than With Dietary Change

Objective To compare changes in total and regional body composition using dual energy X-ray absorptiometry (DEXA) after subjects lost weight through change in diet or exercise.Design A 12-month, randomized, controlled study of two weight-loss interventions — low-fat diet ad libitum or moderate, unsupervised exercise — in free-living, middle-aged men. Compliance was determined at monthly measurement sessions through food records and activity logs; DEXA scans were performed every 3 months.Subjects/setting Fifty-eight overweight men (mean body mass INDEX=29.0±2.6; mean AGE=43.4±5.7 years) recruited from a national corporation were assigned randomly to diet, exercise, or control groups.Interventions One group reduced dietary fat to 26.4% of energy intake but kept activity unchanged; another group self-selected aerobic exercise (three sessions per week at 65% to 75% maximum heart rate) but kept diet unchanged. A control group maintained weight.Main outcome measures At 12 months, measurements of weight, total and regional fat mass and lean mass, energy intake, and percentage dietary fat; physical activity indexes. Statistical analyses Results were analyzed using paired t tests and analysis of variance.Results Mean weight loss was 6.4±3.3 kg in dieters and 2.6+3.0 kg in exercisers; control subjects maintained weight. DEXA scans revealed that 40% of dieters’ weight loss was lean tissue; more than 80% of weight lost by exercisers was fat. Exercisers maintained limb lean tissue and lost fat mass.Conclusions Greater total weight and lean tissue loss occurred when subjects lost weight through a low-fat diet consumed ad libitum than when subjects participated in unsupervised aerobic exercise. Use of DEXA enabled identification of progressive total and regional changes in fat and lean tissue. J Am Diet Assoc. 1997; 97:37–42.     

Effect of time interval between food intake and exercise on substrate oxidation during exercise in obese and lean children

Background & aims

Exercise induces adaptations in fat metabolism favourable to the treatment of obesity. However, time interval between meal and exercise alters substrate bioavailability and oxidation during exercise. The aim of this study was therefore to investigate the effect of time interval between food intake and exercise on substrate oxidation rates in obese and lean children.

Methods

The metabolic responses to exercise of nine obese children (10.3 ± 1.8 years; %body fat: 36.1 ± 6.1) and seven lean children (9.2 ± 1.6 years; %body fat: 22.2 ± 4.1) were compared 1 h (time interval 1, TI1) and 3 h (TI3) after a standardized breakfast.

Results

Despite significantly lower plasma glucose and insulin concentrations and large effect size suggesting a higher plasma FFA availability (lean, 1.43, obese 0.98), fat oxidation was not significantly increased in TI3 compared to TI1 in both lean and obese children. Fat oxidation contributed marginally to energy expenditure during exercise (<20%) in both conditions and groups but was moderately increased during TI3 compared to TI1 in lean children (effect size: 0.54).

Conclusions

The low contribution of fat oxidation to energy expenditure during exercise in obese and lean children fed 3 h before exercise questions the efficacy of moderate intensity exercise to favourably affect fat balance.     

An effective lifestyle intervention in overweight children: one-year follow-up after the randomized controlled trial on "Obeldicks light"

Background & aims

Lifestyle interventions address primarily obese children, while interventions tailored to overweight but not obese children are scarce. The effectiveness of the lifestyle intervention “Obeldicks light” based on physical activity training, nutrition education, and behavior counseling for overweight children and their parents has been demonstrated by a randomized controlled trial. Here, we present the 12 months follow-up analysis of these children after end of intervention.

Methods

Degree of overweight (BMI and SDS-BMI), waist circumference, skinfold thickness, bioimpedance analyses (BIA), and blood pressure were determined in 76 overweight (BMI>90^th≤97^th percentile) children (mean age 11.8 ± 1.8years, 67% females, mean BMI 24.3 ± 1.9 kg/m²) participating in the evaluation study of “Obeldicks light” at onset of intervention (T0), end of 6 months intervention (T1), 6 months after end of intervention (T2) and 12 months after end of intervention (T3). Comparisons were performed on an intention-to-treat approach.

Results

The drop-out rate was 4% in the intervention period and additional 3% during follow-up. The children reduced significantly (p < 0.001) their SDS-BMI in the intervention period between T0 and T1 (−0.27 ± 0.23; p < 0.001). This SDS-BMI reduction remained stable at T2 (T0-T2:-0.26 ± 0.31; p < 0.001) and T3 (T0-T3:-0.26 ± 0.39; p < 0.001). SDS-BMI reductions were independent from age and gender. Body fat measured by skinfold thickness and BIA, waist circumference, and blood pressure decreased significantly in the intervention period and remained stable in the follow-up period as well.

Conclusions

The lifestyle intervention “Obeldicks light” was effective in reducing degree of overweight, fat mass, waist circumference, and blood pressure both at end of intervention and in a 12 months follow-up period.     

Postoperative loss of skeletal muscle mass, complications and quality of life in patients undergoing cardiac surgery

Objective

The objective of this study was to describe postoperative undernutrition in terms of postoperative losses of appendicular skeletal muscle mass (ASMM) with respect to complications, quality of life, readmission, and 1-y mortality after cardiac surgery.

Methods

Patients undergoing cardiac surgery were prospectively followed. ASMM was measured 2 wk before and 2 mo after surgery using dual-energy X-ray absorptiometry. ASMM consists of arm skeletal muscle mass (SMM) and leg SMM. The association between ≥5% of ASMM decrease and postoperative outcome was analyzed using the chi-square test. A similar approach was used to analyze arm SMM and leg SMM decreases separately.

Results

Twenty-nine patients were included (23 male, 34.5% ≥65 y old). Postoperatively, seven patients (24.1%) lost ≥5% ASMM. When analyzed separately, a ≥5% decrease in leg SMM was associated with a decrease in experienced vitality (odds ratio 13.0, 95% confidence interval 1.32-128.11, P = 0.03). In contrast, a ≥5% loss of arm SMM was associated with fewer in-hospital complications (odds ratio 0.20, 95% confidence interval 0.04-0.98, P = 0.04). These patients were characterized by a higher preoperative fat-free mass index (kilograms per meter squared; P = 0.01).

Conclusions

The results suggest that a preoperatively higher fat-free mass index indicates better ability to cope with operative stress, resulting in fewer complications. In addition, postoperative loss of muscle mass was associated with decreased vitality. We advocate further research investigating the effect of preoperative and postoperative nutritional intervention combined with physical exercise programs to increase lean body mass and thereby improve postoperative recovery after cardiac surgery.     

Evaluation of the knowledge of primary healthcare patients in Poland on the prevention of hypertension: a community study

Objectives

To investigate the knowledge of Poles on the prevention of arterial hypertension (HT) and identify the main souces of knowledge in order to make health promotion activities more effective, and thus increase the efficiency and efficacy of the Polish healthcare system.

Study design

Community study.

Methods

This questionnaire study included 180 subjects (120 primary healthcare patients without a history of diagnosed HT and 60 primary care physicians).

Results

The knowledge of most surveyed patients was insufficient (43%, n = 52) or sufficient (40%, n = 48) for the effective prevention of HT; 17% (n = 20) of the respondents had knowledge that was definitely sufficient, and none of the respondents had knowledge that was definitely insufficient. The patients reported that primary care physicians were the most common source of health information (67%, n = 80). Primary care physicians were also the most trusted source of information.

Conclusions

Patients’ knowledge on smoking, diet and exercise is sufficient for the effective prevention of HT. The areas of insufficient knowledge for the development of HT and possible organ complications are drinking alcohol, stress, genetic factors and diabetes.     

Malnutrition syndrome, but not body mass index, is associated to worse prognosis in heart failure patients

Background & aims

Many studies have suggested that obese patients with chronic heart failure have a better prognosis than leaner patients. The main purpose of this study was to assess the prognostic value of body mass index in patients with chronic heart failure, independently of other poor prognosis parameters.

Methods

This retrospective study included 405 heart failure patients. Anthropometric, body composition, clinical, biochemical, and echocardiographic data were collected from all patients. Patients were classified as: underweight (<20 kg/m²), normal (20–24.9 kg/m²), overweight (25–29.9 kg/m²), and obese (≥30 kg/m²). The endpoints were all-cause and cardiovascular mortality.

Results

Cox regression analysis on all-cause mortality showed that normal weight patients were at significantly lower risk of death [RR = 0.231 (CI_95% 0.085–0.627)] as compared with obese patients, while underweight and overweight categories did not show a significantly different risk compared with the reference category. Age, gender, ejection fraction, systolic heart failure, angiotensin II receptor blockers use, hemoglobin levels, and handgrip strength were independent predictors of all-cause mortality. Cardiovascular deaths showed the same trend.

Conclusion

A lower body mass index does not predict all-cause and cardiovascular mortality among chronic heart failure patients, independently of other nutritional, body composition, and clinical status parameters.     

Body composition differences between adults with multiple sclerosis and BMI-matched controls without MS

BackgroundPersons with multiple sclerosis (MS) have many health conditions related to overweight and obesity, but little is known about how body composition among those with MS compares to those without MS at the same weight.ObjectiveTo compare differences in whole body and regional body composition between persons with and without MS matched for sex and body mass index (BMI).MethodsPersons with MS (n = 51) and non-MS controls (n = 51) matched for sex and BMI. Total mass, lean mass, fat mass, and percent body fat (%BF) of total body and arm, leg, and trunk segments were assessed using dual-energy X-ray absorptiometry (DXA).ResultsMen with MS had significantly less whole body lean mass (mean difference: 9933.5 ± 3123.1 g, p < 0.01) and higher fat mass (mean difference: 6079.0 ± 2137.4 g, p = .01) and %BF (mean difference: 9.43 ± 2.04%, p < 0.01) than BMI-matched non-MS counterparts. Further, men with MS had significantly lower lean mass in the arm (p = 0.02) and leg (p < 0.01) and higher fat mass in the arm (p = 0.01), leg (p = 0.03) and trunk (p = 0.03) than men without MS. Men with MS had significantly higher %BF in all three regions (p < 0.01) than men without MS. There were no differences between women with and without MS.ConclusionsWe observed significant differences in whole body and regional body composition between BMI-matched men with and without MS. Additional research is needed to further explore differences in body composition, adipose distribution, and the impact of these differences on the health and function of men with MS.     

Physical activity, walking and leanness: an analysis of the Northern Ireland Sport and Physical Activity Survey (SAPAS)

Objective

To report on the contribution walking makes to total weekly physical activity and the relationship between the volume and intensity of walking and leanness in a representative sample of the Northern Ireland population.

Method

4563 adults participated in this cross-sectional survey of physical activity behaviour. Self-reported height and weight was used to determine inverse body mass index (iBMI) as a measure of leanness. Data across all domains of physical activity including self-reported volume and intensity of walking (in bouts of 10 min or more) were analysed to determine their contribution to leanness using ANCOVA, having controlled for age, gender, socio-economic and smoking status.

Results

Over 68% of the participants reported walking > 10 minutes during the previous week but only 24% report walking at a brisk or fast pace. Time walking at a brisk or fast pace for personal transport was identified as having the strongest positive association with being lean (F_1,4256 = 10.45, β = 0.051 cm² kg^− 1 min^− 1 (SE = 0.016),P = 0.001).

Conclusions

In addition to increasing the amount of walking and the percentage of people walking regularly, public health messages encouraging an increase in walking pace may be valuable to increase the proportion of the population meeting physical activity guidelines and gaining associated health benefits.     

Exploring the Role of Muscle Mass,Obesity, and Age in the Relationship Between Muscle Quality and Physical Function

BackgroundDivergent conclusions emerge from the literature regarding the relationship between muscle quality (defined as muscle strength per unit of muscle mass) and physical function. These contrasted results may be due to the influence of factors such as age, obesity, and muscle mass itself. Consequently, the aim of the present study was to explore the role of these factors in the relationship between muscle quality (MQ) and physical function.MethodsData are from 312 individuals (97 men and 215 women) aged 50 years and older. Body composition (dual energy X-ray absorptiometry) and knee extension strength of the right leg (1 repetition maximum) were assessed. Appendicular lean body mass index (AppLBMI) and MQ (knee extension strength /right leg lean mass) were calculated. A composite score of physical function was created based on the timed up-and-go, alternate step, sit-to-stand, and balance tests.ResultsMQ was significantly associated with physical function when AppLBMI (β = 0.179; P = .004) and body mass index (BMI) (β = 0.178; P = .003), but not age (β = 0.065; P = .26), were included in regression analysis. AppLBMI (β = 0.221; P < .001), BMI (β = 0.234; P < .001), and age (β = 0.134; P = .018) significantly interacted with MQ to determine physical function.ConclusionsOur results show that muscle mass, obesity, and age influence the relationship between MQ and physical function, suggesting that these factors should be taken into account when interpreting MQ. Even so, higher levels of MQ were associated with higher physical function scores. Nutritional and physical activity interventions may be designed in this regard.     

Postprandial protein metabolism but not a fecal test reveals protein malabsorption in patients with pancreatic exocrine insufficiency

Background & aims

Pancreatic exocrine insufficiency (PEI) impairs fat absorption, but few data are available on protein absorption. We investigated this question in patients with chronic pancreatitis, both in the absence and presence of enzyme therapy, using a stable isotope sensitive method.

Methods

Eleven patients with sustained PEI and regular enzyme substitution were investigated at hospital, after a washout period without enzyme substitution, and later after reintroduction of substitution. The digestibility and postprandial metabolism of dietary protein were characterized after the ingestion of a semi-synthetic single meal containing 20 g ¹⁵N-labeled casein.

Results

At baseline, 20 ± 8% of dietary nitrogen was transferred to the metabolic pools vs. 24.5 ± 7% under enzyme treatment (P = 0.04). After treatment, the transfer of dietary nitrogen tended to increase in plasma amino acids, and increased significantly in plasma proteins and the deamination pool. In contrast, the fecal excretion of dietary nitrogen did not demonstrate any treatment effect. In patients not receiving insulin for diabetes, the treatment stimulated insulin secretion.

Conclusions

Protein malabsorption was mostly undetectable using standard fecal tests. The study of the postprandial fate of dietary protein revealed a moderate increase of its transfer to metabolic pools after enzyme substitution.     

Oral sensitivity to oleic acid is associated with fat intake and body mass index

Background & aims

Taste sensitivity to fatty acids influences food ingestion and may regulate fat intake and body weight status. Fatty acids are detected via homologous receptors within the mouth and gastrointestinal (GI) tract, where attenuated sensitivity may be associated with greater fat intake and BMI. This study aimed to extend observations surrounding fatty acid taste, specifically the types of foods consumed and dietary behaviours that may be associated with fatty acid taste sensitivity.

Methods

51 subjects (41 female; BMI, 21.4 ± 0.46 kg/m², age, 20 ± 0.52 yrs, 10 male; BMI, 23.6 ± 1.4 kg/m², age, 22 ± 1 yrs) were screened for oral sensitivity to oleic acid (3.8 mM) using triplicate sensory evaluations, and classified as hypersensitive; (3/3 correct identifications), or hyposensitive, (<3/3). Fat-taste perception (using sensory-matched custards made with 0, 2, 6, 10% oil), recent diet (4-day diet record) and food habits and behaviours (food habits and behaviours questionnaire) were also established.

Results

75% (n = 38) of subjects were classified as hyposensitive to oleic acid and these subjects differed from those who were classified as hypersensitive. Hyposensitive subjects consumed significantly more energy, fat, saturated fat, fatty foods (butter, meat, dairy), had greater BMI and were less perceptive of small changes in the fat content of custard (all P < 0.05), compared to hypersensitive subjects.

Conclusion

An inability to perceive low concentrations of fatty acids in foods was associated with greater consumption of fatty foods, specifically butter, meat, dairy, and increasing BMI.     

Reducing glucose infusion safely prevents hyperglycemia in post-surgical children

Background & aims

To investigate the effects of two different glucose infusions on glucose homeostasis and amino acid metabolism in post-surgical children.

Methods

This randomized crossover study evaluated glucose and amino acid metabolism in eight children (age 9.8 ± 1.9 months, weight 9.5 ± 1.1 kg) admitted to a pediatric intensive care unit in a tertiary university hospital after surgical correction for non-syndromal craniosynostosis. Patients were randomized to receive low (LG; 2.5 mg kg⁻¹ min⁻¹) and standard (SG; 5.0 mg kg⁻¹ min⁻¹) glucose infusion in a crossover setting. After a bolus (4 g kg⁻¹) of deuterium oxide, we conducted a primed, constant, 8 h tracer infusion with [6,6-²H₂]Glucose, [1-¹³C]Leucine, [ring-²H₅]Phenylalanine and [3,3-²H₂]Tyrosine.

Results

SG resulted in hyperglycemia (defined as > 6.1 mmol L⁻¹), while during LG plasma glucose levels were normoglycemic (5.9 ± 0.6 vs. 7.5 ± 1.7 mmol L⁻¹; LG vs. SG respectively, p = 0.02). Hypoglycemia did not occur during LG infusion. Endogenous glucose production was not fully suppressed during the hyperglycemic state under SG and increased with reduced glucose infusion (2.6 ± 1.5 vs. 1.1 ± 1.4 mg kg⁻¹ min⁻¹; LG vs. SG; p = 0.05). Whole body protein balance derived from leucine and phenylalanine kinetics was slightly negative but not further affected with a decrease in glucose infusion.

Conclusions

The current recommended glucose infusion induces hyperglycemia in post-surgical children. A reduced glucose infusion safely reduced high glucose levels, while children were capable to sustain normoglycemia with increased endogenous glucose production. The reduced glucose infusion did not exacerbate the mild catabolic state in which the patients were.     

Muscle protein synthesis in cancer patients can be stimulated with a specially formulated medical food

Objective

Maintenance of muscle mass is crucial to improving outcome and quality of life in cancer patients. Stimulating muscle protein synthesis is the metabolic basis for maintaining muscle mass, but in cancer patients normal dietary intake has minimal effects on muscle protein synthesis. Adding leucine to high protein supplements stimulates muscle protein synthesis in healthy older subjects. The objective was to determine if a specially formulated medical food, high in leucine and protein, stimulates muscle protein synthesis acutely in individuals with cancer to a greater extent than a conventional medical food.

Design

A randomized, controlled, double-blind, parallel-group design was used in 25 patients with radiographic evidence of cancer. Patients were studied before their cancer treatment was started or 4 weeks after their treatment was completed or halted. The fractional rate of muscle protein synthesis (FSR) was measured using the tracer incorporation technique with L-[ring-¹³C₆]-phenylalanine. The experimental group (n = 13) received a medical food containing 40 g protein, based on casein and whey protein and enriched with 10% free leucine and other specific components, while the control group (n = 12) was given a conventionally used medical food based on casein protein alone (24 g). Blood and muscle samples were collected in the basal state and 5h hours after ingestion of the medical foods.

Results

The cancer patients were in an inflammatory state, as reflected by high levels of C-reactive protein (CRP), IL-1β and TNF-α, but were not insulin resistant (HOMA). After ingestion of the experimental medical food, plasma leucine increased to about 400 μM as compared to the peak value of 200 μM, after the control medical food (p < 0.001). Ingestion of the experimental medical food increased muscle protein FSR from 0.073 (SD: 0.023) to 0.097 (SD: 0.033) %/h (p = 0.0269). In contrast, ingestion of the control medical food did not increase muscle FSR; 0.073 (SD: 0.022) and 0.065 (SD: 0.028) %/h.

Conclusions

In cancer patients, conventional nutritional supplementation is ineffective in stimulating muscle protein synthesis. This anabolic resistance can be overcome with a specially formulated nutritional supplement.