Energy and the maintenance of the body cell mass

The impact of image and performance enhancing drugs on atrial structure and function in resistance trained individuals

BACKGROUND

Image and performance enhancing drugs (IPEDs) are commonly used in resistance trained (RT) individuals and negatively impact left ventricular (LV) structure and function. Few studies have investigated the impact of IPEDs on atrial structure and function with no previous studies investigating bi-atrial strain. Additionally, the impact of current use vs. past use of IPEDs is unclear.

METHODS

Utilising a cross-sectional design, male (n = 81) and female (n = 15) RT individuals were grouped based on IPED user status: current (n = 57), past (n = 19) and non-users (n = 20). Participants completed IPED questionnaires, anthropometrical measurements, electrocardiography, and transthoracic echocardiography with strain imaging. Structural cardiac data was allometrically scaled to body surface area (BSA) according to laws of geometric similarity.

RESULTS

Body mass and BSA were greater in current users than past and non-users of IPEDs (p < 0.01). Absolute left atrial (LA) volume (60 ± 17 vs 46 ± 12, p = 0.001) and right atrial (RA) area (19 ± 4 vs 15 ± 3, p < 0.001) were greater in current users than non-users but this difference was lost following scaling (p > 0.05). Left atrial reservoir (p = 0.008, p < 0.001) and conduit (p < 0.001, p < 0.001) strain were lower in current users than past and non-users (conduit: current = 22 ± 6, past = 29 ± 9 and non-users = 31 ± 7 and reservoir: current = 33 ± 8, past = 39 ± 8, non-users = 42 ± 8). Right atrial reservoir (p = 0.015) and conduit (p = 0.007) strain were lower in current than non-users (conduit: current = 25 ± 8, non-users = 33 ± 10 and reservoir: current = 36 ± 10, non-users = 44 ± 13). Current users showed reduced LV diastolic function (A wave: p = 0.022, p = 0.049 and E/A ratio: p = 0.039, p < 0.001) and higher LA stiffness (p = 0.001, p < 0.001) than past and non-users (A wave: current = 0.54 ± 0.1, past = 0.46 ± 0.1, non-users = 0.47 ± 0.09 and E/A ratio: current = 1.5 ± 0.5, past = 1.8 ± 0.4, non-users = 1.9 ± 0.4, LA stiffness: current = 0.21 ± 0.7, past = 0.15 ± 0.04, non-users = 0.15 ± 0.07).

CONCLUSION

Resistance trained individuals using IPEDs have bi-atrial enlargement that normalises with allometric scaling, suggesting that increased size is, in part, associated with increased body size. The lower LA and RA reservoir and conduit strain and greater absolute bi-atrial structural parameters in current than non-users of IPEDs suggests pathological adaptation with IPED use, although the similarity in these parameters between past and non-users suggests reversibility of pathological changes with withdrawal.

Starvation causes changes in the intestinal transcriptome and microbiome that are reversed upon refeeding

BACKGROUND

The ability of animals and their microbiomes to adapt to starvation and then restore homeostasis after refeeding is fundamental to their continued survival and symbiosis. The intestine is the primary site of nutrient absorption and microbiome interaction, however our understanding of intestinal adaptations to starvation and refeeding remains limited. Here we used RNA sequencing and 16S rRNA gene sequencing to uncover changes in the intestinal transcriptome and microbiome of zebrafish subjected to long-term starvation and refeeding compared to continuously fed controls.

RESULTS

Starvation over 21 days led to increased diversity and altered composition in the intestinal microbiome compared to fed controls, including relative increases in Vibrio and reductions in Plesiomonas bacteria. Starvation also led to significant alterations in host gene expression in the intestine, with distinct pathways affected at early and late stages of starvation. This included increases in the expression of ribosome biogenesis genes early in starvation, followed by decreased expression of genes involved in antiviral immunity and lipid transport at later stages. These effects of starvation on the host transcriptome and microbiome were almost completely restored within 3 days after refeeding. Comparison with published datasets identified host genes responsive to starvation as well as high-fat feeding or microbiome colonization, and predicted host transcription factors that may be involved in starvation response.

CONCLUSIONS

Long-term starvation induces progressive changes in microbiome composition and host gene expression in the zebrafish intestine, and these changes are rapidly reversed after refeeding. Our identification of bacterial taxa, host genes and host pathways involved in this response provides a framework for future investigation of the physiological and ecological mechanisms underlying intestinal adaptations to food restriction.

Supplementation with Qter® and Creatine improves functional performance in COPD patients on long term oxygen therapy

BACKGROUND

Skeletal muscle dysfunction and poor functional capacity are important extra-pulmonary manifestations of chronic obstructive pulmonary disease (COPD), especially in COPD patients on long-term O₂ therapy (LTOT). Beside the role of pulmonary rehabilitation, the effect of nutritional interventions is still controversial, and there are knowledge gaps on the effective role of nutraceutical supplementation on hard endpoints. The aim of this study was to investigate the effects of nutritional supplementation with Coenzyme Q10 (QTer^®) - a powerful antioxidant with the potential to reduce oxidative stress and improve mitochondrial function - and Creatine on functional, nutritional, and metabolomic profile in COPD patients on long-term O₂ therapy.

METHODS

One-hundred and eight patients with COPD from 9 Italian hospitals were enrolled in this double-blinded randomized placebo-controlled clinical study. At baseline and after 2 months of therapy, the patients underwent spirometry, 6-minute walk test (6MWT), bioelectrical impedance analysis, and activities of daily living questionnaire (ADL). Also, dyspnea scores and BODE index were calculated. At both time points, plasma concentration of CoQ10 and metabolomic profiling were measured.

FINDINGS

Ninety patients, who randomly received supplementation with QTer^® and Creatine or placebo, completed the study. Compared with placebo, supplemented patients showed improvements in 6MWT (51 ± 69 versus 15 ± 91 m, p < 0.05), body cell mass and phase angle, sodium/potassium ratio, dyspnea indices and ADL score. The CoQ10 plasma concentration increased in the supplementation group whereas it did not change in the placebo group. The metabolomics profile also differed between groups. Adverse events were similar in both groups.

INTERPRETATION

These results show that in patients with COPD, dietary supplementation with CoQ10 and Creatine improves functional performance, body composition and perception of dyspnea. A systemic increase in some anti-inflammatory metabolites supports a pathobiological mechanism as a reason for these benefits. Further trials should help clarifying the role of QTer^® and Creatine supplementation in patients with COPD.

Prevalence of rheumatoid cachexia assessed by bioelectrical impedance vector analysis and its relation with physical function

Rheumatoid arthritis (RA) patients frequently have changes in their body composition, with a decrease in muscle mass and an increase in fat mass, a syndrome that is termed rheumatoid cachexia (RC). The prevalence of this nutritional alteration is not well known; there is as yet no consensus, seeing as it depends on the methods, techniques, and cutoff points that are used for its diagnosis. The main aim of this study was to identify RC through assessment by bioelectrical impedance vector analysis (BIVA) and its association with metabolic causes, physical function, and the main disease status, among others. The prevalence of RC was identified in those subjects who fell outside the right lower quadrant of the reference curve of RXc graph of BIVA. Clinical, anthropometric, biochemical and physical activity, emotional status, and diet markers were also evaluated. Ninety-four patients were included (92.55% women). The prevalence of RC assessed by BIVA was 21.28%. BIVA-cachexia patients had a lesser value of handgrip strength vs. patients without BIVA-cachexia 10.2 kg (7.2-13.4) vs. 14.7 kg (9.6-19), p = 0.0062. Disability and folic acid with methotrexate consumption are related to BIVA-cachexia ((OR 4.69, 95% CI 1.33, 16.54, p = 0.016) and (OR 0.19, 95%CI 0.058, 0.651, p = 0.008), respectively). BIVA could represent a valuable tool to assess presence of RC. It is important that RA patients have physical therapy to improve their nutritional status.

How Much and What Type of Protein Should a Critically Ill Patient Receive?

Protein loss, manifested as loss of muscle mass, is observed universally in all critically ill patients. Depletion of muscle mass is associated with impaired function and poor outcomes. In extreme cases, protein malnutrition is manifested by respiratory failure, lack of wound healing, and immune dysfunction. Protecting muscle loss focused initially on meeting energy requirements. The assumption was that protein was being used (through oxidation) as an energy source. In healthy individuals, small amounts of glucose (approximately 400 calories) protect muscle loss and decrease amino acid oxidation (protein-sparing effect of glucose). Despite expectations of the benefits, the high provision of energy (above basal energy requirements) through the delivery of nonprotein calories has failed to demonstrate a clear benefit at curtailing protein loss. The protein-sparing effect of glucose is not clearly observed during illness. Increasing protein delivery beyond the normal nutrition requirements (0.8 g/k/d) has been investigated as an alternative solution. Over a dozen observational studies in critically ill patients suggest that higher protein delivery is beneficial at protecting muscle mass and associated with improved outcomes (decrease in mortality). Not surprisingly, new Society of Critical Care Medicine/American Society for Parenteral and Enteral Nutrition guidelines and expert recommendations suggest higher protein delivery (>1.2 g/kg/d) for critically ill patients. This article provides an introduction to the concepts that delineate the basic principles of modern medical nutrition therapy as it relates to the goal of achieving an optimal management of protein metabolism during critical care illness, highlighting successes achieved so far but also placing significant challenges limiting our success in perspective.

Ω-3 Fatty Acid Supplements for Cancer-Associated Weight Loss

Omega-3 fatty acids have been tested for the treatment of cancer anorexia/weight loss, a syndrome that predicts a poor prognosis among cancer patients with incurable disease. This review focuses on both the preclinical and clinical data of omega-3 fatty acids for treating this syndrome. Overall, the promise of the former does not seem to be borne out completely in the latter. This review includes a discussion of how these data might be interpreted and explained to cancer patients who are striving to cope with this syndrome.

Body composition of children with cancer during treatment and in survivorship

BACKGROUND

Malnutrition as assessed with the use of body-composition measurements is a poorly understood short- and long-term complication of childhood cancer.

OBJECTIVES

We aimed to evaluate the body composition of 2 childhood cancer cohorts as follows: 1) children currently undergoing cancer treatment and 2) childhood cancer survivors. We also aimed to compare the prevalence of obesity and undernutrition between the cancer groups and investigate the impact of cancer type on body composition.

DESIGN

Eighty-two children during the treatment of cancer and 53 childhood cancer survivors were involved in the study. Height, weight, body cell mass, percentage of fat, fat mass index, and fat-free mass index were assessed. Subjects were compared with age- and sex-matched healthy controls.

RESULTS

The on-treatment group had a higher percentage of fat (P = 0.0001) and fat mass index (P = 0.0001) and a significantly lower body cell mass index (P = 0.0001) and fat-free mass index (P = 0.003) than did matched controls. The survivor group had a significantly higher percentage of fat (P = 0.03) and fat mass index (P = 0.04) and significantly lower body cell mass index (P = 0.0001) than did matched controls. The prevalence of undernutrition was high in both groups with 48% (95% CI: 36%, 60%) of the on-treatment group and 53% (95% CI: 40%, 66%) of the survivors considered undernourished. According to the percentage of fat cutoffs, significantly more on-treatment patients were obese (55%; 95% CI: 40%, 60%) than were survivors (26%; 95% CI: 14%, 38%) (P = 0.005). There were no statistically significant differences in body composition between cancer types in either the on-treatment or the survivor group.

CONCLUSIONS

Overnutrition and undernutrition are major concerns in the short and long term for children with cancer. Children treated for cancer have increased fat mass and decreased body cell mass, which are evident during treatment and in survivorship. This trial was registered at http://www.ANZCTR.org.au as ACTRN12614001279617 and ACTRN12614001269628.

Sex differences in the relation of body composition to cardiovascular parameters and functions in Korean adolescents: a school-based study

OBJECTIVE

Obesity in adolescence is associated with increased cardiovascular risk. The patterns of obesity and body composition differ between boys and girls. It is uncertain how body composition correlates with the cardiovascular system and whether such correlations differ by sex in adolescents.

METHODS

Body composition (fat-free mass (FFM), adipose mass, waist circumference (WC)) and cardiovascular parameters and functions were studied in 676 healthy Korean adolescents aged 12-16 years. Partial correlation and path analyses were done.

RESULTS

WC correlated with stroke volume (SV) and cardiac output (CO), systolic blood pressure (SBP) and pulse pressure (PP), cardiac diastolic function (ratio of early to late filling velocity (E/A ratio)), and vascular function (pulse wave velocity (PWV)) in boys. Adipose mass was related to SV, CO, SBP, PP, left ventricular mass (LVM), and PWV in girls - and to E/A ratio in both sexes. FFM affected SV, CO, SBP, and PP in both sexes and LVM in boys. Cardiac systolic functions had no relation with any body composition variable in either sex.

CONCLUSION

In adolescence, the interdependence of the cardiovascular system and the body composition differs between sexes. Understanding of those relations is required to control adolescent obesity and prevent adult cardiovascular disease.

Body composition of children with cancer

BACKGROUND

Nutritional status, as represented by body composition, is an important consideration in the treatment of pediatric cancer patients because it is linked to poor outcomes. Little is known about how a child's body composition responds to cancer and treatment.

OBJECTIVES

We aimed to compare the body composition of children undergoing treatment of cancer with that of healthy controls and to compare body composition between children with hematologic malignancies and children with solid tumors.

DESIGN

This cross-sectional study measured height, weight, body cell mass, fat-free mass, and fat mass in 48 children undergoing treatment of cancer and blood-related disorders and in age-matched healthy controls.

RESULTS

Patients with cancer had a significantly lower body cell mass index z score (body cell mass/height raised to the power of 2.5 for females and 3 for males) than did controls (P = 0.0001), and 45% of the patients with cancer were considered malnourished according to body cell mass. Subjects with cancer had a significantly higher percentage of body fat (P = 0.0001) and fat mass (P = 0.0001) than did controls; however, there was no significant difference in fat-free mass (P = 0.09). On the basis of percentage fat, 77% of subjects with cancer were considered obese. No difference in body composition was observed between cancer types.

CONCLUSIONS

This study showed that children undergoing treatment of all types of cancer have a significantly lower body cell mass and a significantly higher fat mass than do healthy controls. Nutritional support is suggested for all children undergoing treatment of cancer.

Body composition of children with chronic and end-stage renal failure

AIM

Protein energy malnutrition is common in children with chronic renal failure (CRF) and may negatively impact on clinical outcome. Although the aetiology of malnutrition is multifactorial, descriptive information on body composition may guide nutritional interventions aimed at optimising nutritional status.

METHODS

This prospective cohort study in children with CRF was conducted from April 1999 to November 2000. Patients were categorised according to their glomerular filtration rate (GFR) into CRF and end-stage renal failure (ESRF). Body composition was assessed based on anthropometry, total body potassium (TBK), total body protein (TBP) and dual X-ray absorptiometry (DEXA).

RESULTS

Fifteen patients (10 male, 5 female; mean age: 13.4 +/- 4.3 years) were studied, including eight patients with CRF (mean GFR: 17.0 +/- 7.2 mL/min/1.73 m(2)) and seven patients with ESRF (mean GFR: 6.4 +/- 1.7 mL/min/1.73 m(2)). Patients in both groups (n = 15) had deficits in height and TBP (mean z-score height-for-age: -1.19 +/- 1.05, P < 0.01; mean z-score TBP: -0.71 +/- 0.71, P < 0.05). There were no significant differences in weight, height, fat-free mass, TBK and TBP between patients with CRF and ESRF.

CONCLUSIONS

Linear growth impairment and decreased TBP are common in children with chronic and ESRF. TBK and DEXA may underestimate the degree of malnutrition in these patients.

The nutritional status of children with cystic fibrosis

The importance of nutritional intervention for children with cystic fibrosis (CF) is well recognised. It would be expected that the increase in knowledge over the past decade would be reflected in improvements in nutritional status for the CF paediatric population. The aim of the present paper was to evaluate the nutritional status of children with CF, cross-sectionally and longitudinally. Body cell mass adjusted for gender and size (BCM/Htp) was measured in sixty-four children with CF to represent nutritional status and expressed as a Z-score. The cross-sectional results showed a mean BCM/Htp Z-score of 0·54 (sd 1·21), with males having a slightly higher Z-score than females but with a larger variation. At the initial measurement, only one female and one male were considered sub-optimally nourished. The longitudinal analysis after 2 years showed that the mean population had a significantly decreased BCM/Htp Z-score; however, when each gender was analysed separately, this decrease was significant only in the males. At the final measurement, only two females and three males were considered sub-optimally nourished. It is evident from our results that children with CF are well nourished, with only a small percentage considered malnourished. It appears that nutritional status decreases with age, with this decline being more evident in males. These results signify that although children with CF are better nourished with current treatment support, intervention needs to continue throughout a CF patient's life to counteract the changes that occur with age.

Energy balance in patients with advanced NSCLC, metastatic melanoma and metastatic breast cancer receiving chemotherapy--a longitudinal study

Chemotherapy exerts a variable effect on nutritional status. It is not known whether loss of body fat or fat-free mass (FFM) during chemotherapy relates to diminished dietary intake, failure to meet elevated energy requirements, or to the presence of an acute-phase response. We sought to determine prospective measurements of body mass and composition, resting energy expenditure, energy and protein intake, and C-reactive protein over a course of chemotherapy in 82 patients with advanced cancer. There was a large dropout from the study. Prospective measurements were obtained in 19 patients with non-small-cell lung cancer (NSCLC), 12 with metastatic melanoma and 10 with metastatic breast cancer. There were significant increases in energy intake among patients with metastatic breast cancer, 873 (266–1480) kJ (mean 95% CI; P<0.01), and metastatic melanoma, 2513 (523–4503) kJ (P<0.01). Breast cancer patients gained percentage body fat over the course of treatment, 2.1 (0.8–3.5%). Gain or loss of body fat correlated to mean energy intake throughout chemotherapy in patients with NSCLC (Rs=0.751; P<0.01) and metastatic breast cancer (Rs=0.617; P<0.05). The ability to meet or exceed energy requirements led to gains in body fat among patients with metastatic breast cancer and NSCLC, but did not prevent loss of FFM in these groups.

Nutritional status and energy expenditure in children pre-bone-marrow-transplant

The aims of this study were to establish the nutritional status of children pre-BMT and to determine whether predictive methods of assessing nutritional status and resting energy expenditure (REE) are accurate in this population. We analysed the body cell mass (BCM) (n=26) and REE (n=24) in children undergoing BMT. BCM was adjusted for height (BCM/HT(p)) and expressed as a Z score to represent nutritional status. To determine whether body mass index (BMI) was indicative of nutritional status in children undergoing BMT, BMI Z scores were compared to the reference method of BCM/HT(p) Z scores. Schofield predictive equations of basal metabolic rate (BMR) were compared to measured REE to evaluate the accuracy of the predictive equations. The mean BCM/HT(p) Z score for the subject population was -1.09+/-1.28. There was no significant relationship between BCM/HT(p) Z score and BMI Z score (r=0.34; P>0.05); however there was minimal difference between measured REE and predicted BMR (bias=-11+/-149 kcal/day). The results of this study demonstrate that children undergoing BMT may have suboptimal nutritional status and that BMI is not an accurate indication of nutritional status in this population. However, Schofield equations were found to be suitable for representing REE in children pre-BMT.

Postoperative changes in body composition after gastrectomy

Nutritional status is one of the most important clinical determinants of outcome after gastrectomy. The aim of this study was to compare changes in the body composition of patients undergoing laparoscopy-assisted gastrectomy (LAG), distal gastrectomy (DG), or total gastrectomy (TG). Total body protein and fat mass were measured by performing a multifrequency bioelectrical impedance analysis using an inBody II machine (Biospace, Tokyo, Japan) in 108 patients (72 men, 36 women) who had undergone LAG (n=24), DG (n=39), or TG (n=45). Changes between the preoperative data and results obtained on postoperative day 14 and 6 months after surgery were then evaluated. The mean preoperative body weight of the subjects was 57.6+/-10.7 kg, the mean body mass index was 22.5+/-3.4 kg/m(2), and the mean fat % was 24%+/-7%. In the immediate postoperative period (14 days), the body weight loss in the LAG group was significantly lower than in the DG and TG groups (2.5+/-0.9 kg vs. 3.5+/-1.8 kg and 4.0+/-1.9 kg, respectively; P < 0.0001). The body composition studies demonstrated a loss of total body protein rather than fat mass. Six months after surgery, body weight was not significantly different from preoperative values in the LAG and DG groups (-1.2+/-3.8 kg and -1.8+/-4.7 kg, respectively), but had decreased by 8.9+/-4.9 kg in the TG group (P=0.0003). A body composition analysis revealed a loss of fat mass in the DG and TG groups. The patients who underwent gastrectomy lost body protein mass during the early postoperative period. The type and extent of surgery has an effect on long-term body mass and composition. Bioelectric impedance analysis can be used to assess body composition and may be useful for nutritional assessment in patients who have undergone gastrectomy.

Body Water in Children During Recovery from Severe Burn Injury Using a Combined Tracer Dilution Method

Useful information about hydration and the size of the body cell mass (BCM) can be obtained by monitoring changes in the amount of total body water (TBW) and its components, extracellular water (ECW) and intracellular water (ICW). A combined tracer dilution method with deuterium to measure TBW and bromide to measure ECW was used to assess changes in ICW (as a proxy for the BCM) and in the ECW/ICW ratio (an indicator of water distribution) over the course of recovery in nine severely burned children. During the acute phase of recovery, ICW losses averaged (mean +/- SD) 2.2 +/- 2.0 liters (P = .02) or 18.5 +/- 0.4%. During the rehabilitative phase, mean ICW increased by 3.4 +/- 3.7 liters or 31.9 +/- 14%. The ECW/ICW ratio varied widely both between patients and during the course of the study. During the acute phase of recovery, the mean ECW/ICW ratio increased from 1.06 +/- 0.15 liters to 1.20 +/- 0.14 liters because the ECW compartment had expanded relative to the ICW compartment. During rehabilitation, the ECW/ICW ratio decreased from 1.20 +/- 0.14 liters to 0.86 +/- 0.20 liters, with a recoup of ICW and continued ECW losses. Tracking ICW and the ECW/ICW ratio using the combined tracer dilution method is practical for monitoring BCM and water distribution in severely burned children. Taken together, the indices provide useful information about hydration and nutritional status in individuals recovering from severe burn injury.

Adjusting body cell mass for size in women of differing nutritional status

BACKGROUND

Body cell mass (BCM) may be estimated in clinical practice to assess functional nutritional status, eg, in patients with anorexia nervosa. Interpretation of the data, especially in younger patients who are still growing, requires appropriate adjustment for size. Previous investigations of this general issue have addressed chemical rather than functional components of body composition and have not considered patients at the extremes of nutritional status, in whom the ability to make longitudinal comparisons is of particular importance.

OBJECTIVE

Our objective was to determine the power by which height should be raised to adjust BCM for height in women of differing nutritional status.

DESIGN

BCM was estimated by (40)K counting in 58 healthy women, 33 healthy female adolescents, and 75 female adolescents with anorexia nervosa. The relation between BCM and height was explored in each group by using log-log regression analysis.

RESULTS

The powers by which height should be raised to adjust BCM were 1.73, 1.73, and 2.07 in the women, healthy female adolescents, and anorexic female adolescents, respectively. A simplified version of the index, BCM/height(2), was appropriate for all 3 categories and was negligibly correlated with height.

CONCLUSIONS

In normal-weight women, the relation between height and BCM is consistent with that reported previously between height and fat-free mass. Although the consistency of the relation between BCM and fat-free mass decreases with increasing weight loss, the relation between height and BCM is not significantly different between normal-weight and underweight women. The index BCM/height(2) is easy to calculate and applicable to both healthy and underweight women. This information may be helpful in interpreting body-composition data in clinical practice.

Body Mass Index, Body Cell Mass, and 4-Year All-Cause Mortality Risk in Older Nursing Home Residents

OBJECTIVES

To investigate the relationship between body composition (assessed using body mass index (BMI) and body cell mass (BCM)) and all-cause mortality in a sample of older nursing home residents.

DESIGN

Prospective study with a median follow-up period of 3.5 years.

SETTING

Istituto di Riposo per Anziani, Padua, Italy.

PARTICIPANTS

A total of 344 participants (79.1% women) aged 65 and older at baseline.

MEASUREMENTS

Anthropometric, nutritional, and metabolic parameters were measured at baseline. BCM was measured using tetrapolar bioelectric impedance analysis. Up to 4 years of follow-up data for vital status were available. Survival analysis was conducted using Kaplan-Meier curves and multivariate Cox proportional hazards models.

RESULTS

During the follow-up period, there were 179 deaths. After adjustment for age and sex, subjects with low BMI and low BCM (lowest sex-specific tertiles) had significantly higher mortality than those with higher BMI or BCM levels. In a fully adjusted regression model, there was no association between BMI levels and risk of mortality, with subjects in the top tertile having the same likelihood of mortality as subjects in the lowest tertile (relative risk (RR)=0.94, 95% confidence interval (CI)=0.61-1.43). Conversely, there was a strong and significant inverse association between BCM levels and mortality (RR for tertile III=0.55, 95% CI=0.35-0.87; P<.01). Furthermore, participants who had high BCM had comparable survival rates in all BMI tertiles.

CONCLUSION

In this sample of older nursing home residents, BCM was a strong and independent risk factor for mortality. BCM assessment might provide more useful prognostic information for clinicians than BMI.

Energy balance in early breast cancer patients receiving adjuvant chemotherapy

Weight gain is a common problem amongst women receiving adjuvant chemotherapy for early breast cancer. We undertook a study to determine the causes of this weight gain. Prospective measurements of body mass and composition (skinfolds, bioelectrical impedance, total body potassium), energy balance (resting energy expenditure dietary intake, and physical activity), were determined in 17 women during and in the 6 months after commencing adjuvant chemotherapy. Women gained significant amounts of weight (5.0 +/- 3.8; p < 0.01) and body fat (7.1 kg +/- 4.5; p < 0.01) over the year. Waist circumference (5.1 +/- 4.5 cm; p < 0.01) and abdominal skinfold (16.2 +/- 10 mm; p < 0.01) were also increased but there was a decline in fat free mass (FFM); 1.7 +/- 2.5 kg. Women due to receive adjuvant chemotherapy had a greater resting energy expenditure (REE) compared with healthy subjects (n = 21); 100.5 +/- 8.0% Harris Benedict compared to 94.5 +/- 8.4% Harris Benedict (p = 0.05). REE declined by 3% during adjuvant chemotherapy (p < 0.05), and remained depressed until at least 3 months posttreatment. There were no significant changes in dietary intake or physical activity over the year. Failure of women to reduce their energy intake to compensate for the decreased energy requirement may account for some of the weight gain. Treatment of adjuvant chemotherapy causes gain of body fat because of reduced energy expenditure, and the failure of women to reduce their energy intake to compensate for the decline in energy requirement during and in the 6 months posttreatment. Since weight gain impacts on survival, patients should be counselled to reduce energy intake and exercise during and after adjuvant treatment.

Assessment of resting energy expenditure in mechanically ventilated patients

BACKGROUND

Usual equations for predicting resting energy expenditure (REE) are not appropriate for critically ill patients, and indirect calorimetry criteria render its routine use difficult.

OBJECTIVE

Variables that might influence the REE of mechanically ventilated patients were evaluated to establish a predictive relation between these variables and REE.

DESIGN

The REE of 70 metabolically stable, mechanically ventilated patients was prospectively measured by indirect calorimetry and calculated with the use of standard predictive models (Harris and Benedict's equations corrected for hypermetabolism factors). Patient data that might influence REE were assessed, and multivariate analysis was conducted to determine the relations between measured REE and these data. Measured and calculated REE were compared by using the Bland-Altman method.

RESULTS

Multivariate analysis retained 4 independent variables defining REE: body weight (r(2) = 0.14, P < 0.0001), height (r(2) = 0.11, P = 0.0002), minute ventilation (r(2) = 0.04, P = 0.01), and body temperature (r(2) = 0.07, P = 0.002): REE (kcal/d) = 8 x body weight + 14 x height + 32 x minute ventilation + 94 x body temperature - 4834. REE calculated with this equation was well correlated with measured REE (r(2) = 0.61, P < 0.0001). Bland-Altman plots showed a mean bias approaching zero, and the limits of agreement between measured and predicted REE were clinically acceptable.

CONCLUSION

Our results suggest that REE estimated on the basis of body weight, height, minute ventilation, and body temperature is clinically more relevant than are the usual predictive equations for metabolically stable, mechanically ventilated patients.

Is resting metabolic rate different between men and women?

A low resting metabolic rate (RMR) has been proposed as a possible cause for the increased body fat commonly seen in women compared with men. Absolute RMR is higher in men, but whether RMR adjusted for lean body mass (LBM) remains higher is unresolved. The objective of the present study was to determine whether RMR adjusted for various body composition factors differed between healthy adult men and women. Thirty men years, BMI and twenty-eight women years, BMI were included in the analyses. RMR was measured by open-circuit indirect calorimetry for 60 min. Extracellular water (ECW) was measured by corrected Br(-) space and total body water (TBW) by 2H dilution. LBM was estimated as TBW/0.732. Intracellular water (ICW) was calculated as TBW-ECW, and body cell mass (BCM) as ICW/0.732. Men were heavier and had higher BMI, LBM, BCM and ECW, but less fat mass. Absolute RMR was higher in men than women v. P<0.0001). This difference became non-significant when RMR was adjusted for LBM by ANCOVA v. P=0.2191), but remained significant when adjusted for BCM v. P=0.0249). Fat mass explained a significant amount of variation in RMR in women (r(2) 0.28, P=0.0038), but not in men (r(2) 0.03, P=0.3301). The relationships between body fat and the various subcompartments of BCM and RMR require further elucidation.

Relations of stroke volume and cardiac output to body composition: the strong heart study

BACKGROUND

Although cardiac output (CO) plays the vital role of delivering nutrients to body tissues, few data are available concerning the relations of stroke volume (SV) and CO to body composition in large population samples.

METHODS AND RESULTS

Doppler and 2D echocardiography and bioelectric impedance in 2744 Strong Heart Study participants were used to calculate SV and CO and to relate them to fat-free body mass (FFM), adipose mass, and demographic variables. Both SV and CO were higher in men than women and in overweight than normal-weight individuals, but these differences were diminished or even reversed by normalization for FFM or body surface area. In both sexes, SV and CO were more strongly related to FFM than adipose mass, other body habitus measures, arterial pressure, diabetes, or age. In multivariate analyses using the average of Doppler and left ventricular SV to minimize measurement variability, FFM was the strongest correlate of SV and CO; other independent correlates were adipose mass, systolic pressure, diabetes, age, and use of digoxin and calcium channel and beta-blockers.

CONCLUSIONS

In a population-based sample, SV and CO are more strongly related to FFM than other variables; increased FFM may be the primary determinant of increased SV and CO in obesity.

The origin of the "ideal" body weight equations

OBJECTIVE

To provide a historical perspective on the origin and similarity of the "ideal" body weight (IBW) equations, and clarify the terms ideal and lean body weight (LBW).

DATA SOURCES

Primary and review literature were identified using MEDLINE (1966-November 1999) and International Pharmaceutical Abstracts (1970-November 1999) pertaining to ideal and lean weight, height-weight tables, and obesity. In addition, textbooks and relevant reference lists were reviewed.

DATA EXTRACTION

All articles identified through the data sources were evaluated. Information deemed to be relevant to the objectives of the review were included.

DATA SYNTHESIS

Height-weight tables were generated to provide a means of comparing a population with respect to their relative weight. The weight data were found to correlate with mortality and resulted in the use of the terms desirable or ideal to describe these weights. Over the years, IBW was interpreted to represent a "fat-free" weight and thus was used as a surrogate for LBW. In addition, the pharmacokinetics of certain drugs were found to correlate with IBW and resulted in the use of IBW equations published by Devine. These equations were consistent with an old rule that was developed from height-weight tables to estimate IBW. Efforts to improve the IBW equations through regression analyses of height-weight data resulted in equations similar to those published by Devine.

CONCLUSIONS

The similarity between the IBW equations was a result of the general agreement among the various height-weight tables from which they were derived. Therefore, any one of these equations may be used to estimate IBW.

The pathophysiology of wasting in the elderly

Aging is associated with changes in body composition and energy and protein metabolism that are due both to the direct effects of aging and to the effect of age-related diseases. We have recently differentiated these changes under three categories: wasting, cachexia, and sarcopenia. We have defined wasting as unintentional loss of weight, including both fat and fat-free compartments. Experience in the HIV epidemic suggests that wasting is driven largely by inadequate dietary intake. Cachexia, on the other hand, refers to loss of fat-free mass, and especially body cell mass, but with little or no weight loss. The metabolic hallmarks of cachexia are hypermetabolism and hypercatabolism, driven by inflammatory cytokine-mediated acute phase responses. Finally, sarcopenia refers to loss of muscle mass specifically, and seems to be an intrinsic age-related condition. In the elderly, wasting as defined here is at the extreme end of the spectrum, but generally develops in the setting of pre-existing sarcopenia and cachexia. The challenges before us now are to better define these conditions, establish guidelines for their recognition, and develop better methods for intervening when appropriate.

Relationships among liver and kidney volumes, lean body mass and drug clearance

AIMS

To determine whether lean body mass (LBM), a possible surrogate of liver and kidney volumes, correlates with hepatic and renal drug clearances.

METHODS

Twenty-one disease-free patients with a history of cancer and with normal hepatic and renal function were studied. Salivary pharmacokinetics of oral antipyrine (1200 mg) and 24 h creatinine clearance were determined following the determination of LBM by dual energy X-ray absorptiometry and the determination of liver and kidney volumes by helical CT scanning.

RESULTS

Liver volume correlated with LBM (r2=0.21, P=0.04), body surface area (BSA) (r2=0.54, P<0.001), and total body weight (TBW) (r2=0.61, P<0.001). Kidney volume correlated with LBM (r2=0.49, P<0.001), BSA (r2=0.43, P=0.002) and TBW (r2=0.24, P=0.03). Stepwise multiple regression analysis, incorporating the independent variables of age, height, weight, sex, BSA, LBM, alcohol consumption, smoking status and liver volume and the dependent variable antipyrine clearance, indicated that LBM was the only independent correlate of antipyrine clearance. A stepwise multiple regression analysis with kidney volume in the independent variables, and creatinine clearance as dependent variable, showed that kidney volume and age were the only independent correlates of creatinine clearance. A nomogram using serum creatinine and LBM was comparable with the Cockcroft and Gault nomogram in calculating creatinine clearance.

CONCLUSIONS

Of the anthropometric variables tested, LBM was the only determinant of antipyrine clearance, but this was not due to a relationship between LBM and liver volume. By contrast, the relationship between creatinine clearance and LBM appeared to be due to a relationship between LBM and kidney volume.

Changes in nutritional status associated with unresectable pancreatic cancer

Weight loss is common in patients with pancreatic cancer; however, the nature and progress of their nutritional depletion are not well documented. In this study, pre-illness weight and duration of weight loss were recorded in 20 patients with histologically confirmed unresectable cancer of the pancreas. Patients then underwent nutritional analysis at monthly intervals until death. The median period of assessment was 27 weeks (interquartile range 22.5-38.0 weeks). At the time of diagnosis, all patients had lost weight [median 14.2% (10.0-20.0%) of pre-illness stable weight], and this weight loss was progressive, increasing to a median of 24.5% by the time of the last assessment (P =0.0004). Body mass index was significantly reduced from a pre-illness median value of 24.9 kg m-2 (22.4-27.4 kg m-2) to 20.7 kg m-2 (19.5-23.6 kg m-2) at the time of diagnosis and further to 17.7 kg m-2 (16.6-23.1 kg m-2) just before death (P =0.0003). Further evidence of tissue depletion was evident from the significant reductions in lean body mass [43.4 kg (36.9-53.0 kg) to 40.1 kg (33.5-50.7 kg) P =0.008] and fat mass [12.5 kg (8.9-17.8 kg) to 9.6 kg (6.3-15.1 kg) P =0.03). This study confirms that the majority of patients with unresectable pancreatic cancer have already undergone significant weight loss by the time of diagnosis and that the natural history of this process is one of inexorable progression. These results highlight the need for selective non-toxic therapeutic intervention to attenuate cachexia and indicate that such interventions should be instituted early in the course of the disease.

A review of in vivo experimental methods to determine the composition of the human body

This review of experimental methods employed in the measurement of the composition of the human body covers the developments that have occurred over the past 30 years. Early methods such as hydrodensitometry and skinfold anthropometry have been superseded by dual-energy x-ray absorptiometry and bioelectrical impedance spectroscopy. The measurement of the whole-body abundance of certain elements by isotopic dilution, neutron activation analysis and x-ray fluorescence can give important information of clinical significance, but neutron activation facilities remain available in only a few centres worldwide. The relatively simple, rapid and risk-free electrical methods such as multifrequency bioelectrical impedance analysis, which can be employed at the bedside, have been found to be more complicated in their interpretation. Electromagnetic methods may only measure the composition of the human body at its surface. X-ray computed tomography and magnetic resonance imaging have not yet been employed much in body composition measurements. Some models for the composition of the human body are reviewed.

The nutrition implications of cardiac cachexia

Weight loss is a frequent sequela in patients with congestive heart failure and is commonly referred to as cardiac cachexia. This weight loss is unlike that seen in simple starvation because it preferentially involves the depletion of lean body mass. In addition, the presence of cardiac cachexia can have profound clinical implications for patients in terms of complications, clinical outcome, and overall cost. The mechanism for the alterations in body composition is multifactorial, but a major cause may be the cytokine-mediated host response to the underlying disease. This article reviews the syndrome of cardiac cachexia in light of recent evidence regarding the role of cytokines, as well as potential therapies.

Relationship between weight loss, reduction of body cell mass and inflammatory response in patients with cancer

Reduced food intake is a major cause of continuing weight loss in patients with cancer. Previous work has suggested that an ongoing inflammatory response may also contribute to weight loss and alter the nature of body tissue loss. To examine this, body cell mass was estimated using measurements of total body potassium (TBK) in 31 patients with gastrointestinal cancer and weight loss with or without an inflammatory response (C-reactive protein level above 5 mg/l). Albumin levels, total body water and 24-h urinary creatinine clearance were also measured. When measured TBK was expressed as a percentage of predicted normal values there was a significant reduction in TBK for patients with an inflammatory response compared with that of those without (P = 0.04). However, when a different prediction equation for TBK was used this difference was not significant (P = 0.29). Therefore, it remains uncertain whether an ongoing inflammatory response in patients with cancer and weight loss contributes to loss of body cell mass.

Rheumatoid cachexia: cytokine-driven hypermetabolism accompanying reduced body cell mass in chronic inflammation

The cytokines IL-1 beta and TNF-alpha cause cachexia and hypermetabolism in animal models, but their role in human inflammation remains controversial. The relationship between in vitro cytokine production and metabolism was examined in 23 adults with RA and 23 healthy control subjects matched on age, sex, race, and weight. Body composition was measured by multicompartmental analysis of body cell mass, water, fat, and bone mass. Resting energy expenditure (REE) was measured by indirect calorimetry. Cytokine production by PBMC was measured by radioimmunoassay. Usual energy intake, physical activity, disability scores, medication use, and other confounders were also measured. Body cell mass was 13% lower (P < 0.00001), REE was 12% higher (P < 0.008), and physical activity was much lower (P < 0.001) in subjects with RA. Production of TNF-alpha was higher in RA than controls, both before and after stimulation with endotoxin (P < 0.05), while production of IL-1 beta was higher with endotoxin stimulation (P < 0.01). In multivariate analysis, cytokine production was directly associated with REE (P < 0.001) in patients but not in controls. While energy and protein intake were similar in the two groups and exceeded the Recommended Dietary Allowances, energy intake in subjects with RA was inversely associated with IL-1 beta production (P < 0.005). In this study we conclude that: loss of body cell mass is common in RA; cytokine production in RA is associated with altered energy metabolism and intake, despite a theoretically adequate diet; and TNF-alpha and IL-1 beta modulate energy metabolism and body composition in RA.

Body composition: research and clinical advances--1993 A.S.P.E.N. research workshop

The 1993 ASPEN Research Workshop examined research and clinical advances in the study of human body composition. The workshop had two themes: (1) compartments of the body and their measurement, and (2) clinical applications of body composition measurements. There were 12 speakers of varied backgrounds who gave short lectures followed by panel discussions. Speakers explored the validity and potential uses of new body composition methodologies, including dual-energy x-ray absorptiometry, multiple frequency bioimpedance analysis, computerized axial tomography, magnetic resonance imaging, nuclear magnetic resonance spectroscopy, neutron inelastic scattering, and gamma-ray resonance. The application of these methods to chronically and acutely ill hospitalized patients was described. The study of body composition is an emerging distinct research area within the broad study of human biology. This conference provided an overview of important new advances in the study of human body composition.

Anabolic therapy with growth hormone accelerates protein gain in surgical patients requiring nutritional rehabilitation

OBJECTIVE

The authors investigated the effects of exogenous growth hormone (GH) on protein accretion and the composition of weight gain in a group of stable, nutritionally compromised postoperative patients receiving standard hypercaloric nutritional therapy.

SUMMARY BACKGROUND DATA

A significant loss of body protein impairs normal physiologic functions and is associated with increased postoperative complications and prolonged hospitalization. Previous studies have demonstrated that standard methods of nutritional support enhance the deposition of fat and extracellular water but are ineffective in repleting body protein.

METHODS

Fourteen patients requiring long-term nutritional support for severe gastrointestinal dysfunction received standard nutritional therapy (STD) providing approximately 50 kcal/kg/day and 2 g of protein/kg/day during an initial 7-day equilibrium period. The patients then continued on STD (n = 4) or, in addition, received GH 0.14 mg/kg/day (n = 10). On day 7 of the equilibrium period and again after 3 weeks of treatment, the components of body weight were determined; these included body fat, mineral content, lean (nonfat and nonmineral-containing tissue) mass, total body water, extracellular water (ECW), and body protein. Daily and cumulative nutrient balance and substrate oxidation studies determined the distribution, efficiency, and utilization of calories for protein, fat, and carbohydrate deposition.

RESULTS

The GH-treated patients gained minimal body fat but had significantly more lean mass (4.311 +/- 0.6 kg vs. 1.988 +/- 0.2 kg, p < or = 0.03) and more protein (1.417 +/- 0.3 kg vs. 0.086 +/- 0.1 kg, p < or = 0.03) than did the STD-treated patients. The increase in lean mass was not associated with an inappropriate expansion of ECW. In contrast, patients receiving STD therapy tended to deposit a greater proportion of body weight as ECW and significantly more fat than did GH-treated patients (1.004 +/- 0.3 kg vs. 0.129 +/- 0.2 kg, p < 0.05). GH administration altered substrate oxidation (respiratory quotient = 0.94 +/- 0.02 GH vs. 1.17 +/- 0.05 STD, p < or = 0.0002) and the use of available energy, resulting in a 66% increase in the efficiency of protein deposition (13.37 +/- 0.8 g/1000 kcal vs. 8.04 g +/- 3.06 g/1000 kcal, p < or = 0.04).

CONCLUSIONS

GH administration accelerated protein gain in stable adult patients receiving aggressive nutritional therapy without a significant increase in body fat or a disproportionate expansion of ECW. GH therapy accelerated nutritional repletion and, therefore, may shorten the convalescence of the malnourished patient requiring a major surgical procedure.

Use of human growth hormone combined with nutritional support in a critical care unit

The administration of growth factors may potentially accelerate recovery during critical illness by reducing body protein catabolism, enhancing wound healing, and improving skeletal muscle function. The purpose of this phase 1 study was to evaluate the safety and initial efficacy of a recombinant growth factor, human growth hormone (GH), combined with nutritional support in a critical care unit. Following an initial control week, 11 individuals received GH (10 mg/day) daily for 1-6 consecutive weeks. Near constant nutrient intake was provided via parenteral and/or enteral feedings throughout the study period. Vital signs and other clinical parameters, blood values, and nutrient excretion were monitored daily. GH administration was not associated with clinically significant adverse effects. During the first 2 weeks of study, nitrogen excretion decreased from 1356 +/- 157 mmol/day (19.0 +/- 2.2 g/day) during control to 899 +/- 107 mmol/day (12.6 +/- 1.4 g/day) with growth hormone (p less than 0.002) in association with markedly reduced urea generation. Significant reductions in potassium excretion (control 100 +/- 11 mmol/day vs 69 +/- 6 with GH; p less than 0.01) and phosphorus excretion (31 +/- 5 mmol/day vs 18 +/- 3; p less than 0.025) also occurred during GH. The protein-conserving effects of GH were sustained during several weeks of treatment. Growth hormone enhanced the efficiency of administered protein and facilitated nitrogen retention without clinically significant adverse effects in this small patient group. Controlled trials are indicated to determine whether use of this anabolic hormone reduces hospitalization time and improves other clinical outcomes in severely injured patients when combined with appropriate nutritional support.

An introduction to body composition models used in nutritional studies

Chemical analysis of cadavers has led to the definition of 'reference' man but diseases may result in significant changes in body composition. By measuring body composition in patient groups the nature of disease progression can be followed and management regimens evaluated. Various techniques are available which attempt to measure body composition in vivo. Several models of body composition have evolved with the introduction of new measurement techniques. A description of these models is presented. The limitations of the models and the techniques adopted for their measurement are discussed.

Effects of artificial nutrition on the nutritional status of cancer patients

The paper critically analyzes available data on the nutritional and metabolic effects of total parenteral nutrition (TPN) and enteral nutrition (EN) in cachectic cancer patients. Only papers dealing with adult cancer patients and providing data regarding type of tumor, duration of the nutritional support, and administration rate of calories and amino acids, validated by statistical analysis of the results, are included. The main conclusions are the following: (1) No nutritional variable worsened in cancer patients receiving TPN or EN, in conditions in which progressive deterioration of the nutritional status is the rule. (2) The nutritional variables improved by TPN and EN were body weight, fat mass, and some indicators of lean body mass (nitrogen balance and whole body potassium). Thyroxin-binding prealbumin and retinol-binding protein increased only with TPN, whereas some immunologic indexes (complement factors and lymphocytes) improved only with EN. (3) The daily regimens which improved lean body mass and visceral proteins ranged from 35 to 55 kcal/kg and from 1.2 to 2.0 g of amino acids/kg for TPN; for EN it was 35 kcal/kg and 1.3 g of amino acids/kg. However, the enteral regimen capable of improving some immune responses included at least 42 kcal/kg and 2.3 g of amino acids/kg. (4) Only three randomized studies were performed to compare TPN and EN, and conflicting results were obtained. Only TPN showed some significant advantages with regard to weight gain, nitrogen balance, maintenance of serum albumin levels and some mineral balances. However, the advantage of TPN was not clear enough to recommend its indiscriminate use. The choice between TPN and EN should always consider the functionality of the GI tract, the need for hospitalization to start a TPN regimen, and the higher cost of intravenous feeding. (5) When comparing TPN to a standard oral diet, the following variables improved with the nutritional support: body weight, nitrogen balance, 3-methylhistidine, urinary excretion, and serum levels of transferrin, cholinesterase, thyroxin-binding prealbumin, and retinol-binding protein. (6) When comparing TPN with glucose vs TPN with glucose-lipids, no major difference was found with regard to most nutritional variables. In conclusion, nutritional support alone probably has a small role in managing a limited number of advanced cancer patients dying primarily because of malnutrition or mainly suffering from nutritional deterioration. It can also have a "permissive" role in those patients potentially candidate to an oncologic treatment which cannot be delivered because of a poor nutritional status.(ABSTRACT TRUNCATED AT 400 WORDS)

[Postoperative energy requirements following large abdominal surgery interventions: comparison of measuring by indirect calorimetry with estimated values]

Energy requirement after major abdominal operations, as calculated according to the formula for basic energy expenditure by Harris-Benedict, was increased by 30% in the early and by 50% in the late postoperative period. Correlation of these calculated values to measurements by indirect calorimetry was good. Even more simply a good estimation of caloric requirements can be obtained by multiplication of the body weight with a factor 30. The development of septic complications does not increase considerably postoperative energy expenditure, however, the correlation between measured and estimated values becomes poor. As supposed from isotope studies measuring gas exchange for indirect calorimetry for one hour provides sufficiently stable results.

The inhibitory effect of parenteral nutrition on recovery of neutrophil locomotory function in blunt trauma

Twenty patients were investigated to determine whether total parenteral nutrition (TPN) influences the recovery of neutrophil (PMN) locomotory dysfunction in blunt trauma. Half were given TPN consisting of amino acids, glucose, electrolytes, and trace minerals, and half were given intravenous (I.V.) fluids consisting of 5% glucose in water or saline, electrolytes, and trace minerals. PMN locomotion was assayed using micropore filters. Analysis of the data by general linear modeling showed that PMN locomotion in TPN patients was significantly slower during the first 3 to 4 days postinjury. By sequential analysis, improved PMN function in the group not given TPN (NO TPN) occurred less than 95% of the time. TPN with amino acids and glucose may worsen and delay the recovery of PMN locomotory responses in blunt trauma, but the preference ratio of NO TPN:TPN for better PMN function was less than 95:5.

Metabolic effects of recombinant human growth hormone in patients receiving parenteral nutrition

Recombinant human methionyl growth hormone (Protropin) (Genetech, Inc., San Francisco, CA) administered to normal volunteers receiving hypocaloric parenteral nutrition minimized weight loss and induced positive nitrogen balance. To evaluate whether growth hormone (GH) can promote anabolism in surgical patients, 11 stable malnourished individuals were studied. In the initial trial, subjects received a constant parenteral infusion of a hypocaloric diet that provided approximately 1100 kcal/24 hr and 1.3 g protein/kg/24 hr for at least 2 weeks. During 1 week, GH 10 mg was given subcutaneously daily, whereas the other week served as the control. Daily balance studies demonstrated that administration of GH resulted in significant retention of nitrogen (+3.4 g/24 h) and phosphorus (+218 mg/24 h), despite provision of only 60% of caloric requirements. With GH, serum blood urea nitrogen (BUN) and potassium fell, whereas glucose and insulin tended to rise, and levels of insulin-like growth factor 1 increased three to fourfold. Weight gain occurred with GH and was associated with positive mineral and water balance. Six patients received GH (10 mg subcutaneously daily) for 13-25 consecutive days after an initial control week. Significant nitrogen and phosphorus retention occurred over the entire period of GH administration, and no significant side effects were observed. In these depleted patients, GH caused significant and sustained nitrogen retention over a wide range of nutritional support. GH appears to enhance the efficacy of parenteral nutrition in stable individuals requiring repletion of body protein.