Investigate Body Composition Research Articles

Physical activity and body composition in patients with ankylosing spondylitis

Patients with ankylosing spondylitis (AS) are at risk for accelerated muscle loss and reduced physical activity. Accurate data are needed on body composition and physical activity in this patient group. The purpose of this study was to investigate body composition and objectively assessed physical activity in patients with AS. Twenty-five AS patients (15 men, mean ± SD age 48 ± 11 years) were compared with 25 healthy adults matched for age, sex, and body mass index. Body composition was measured using a 3-compartment model based on air-displacement plethysmography to assess body volume and deuterium dilution to assess total body water. The fat-free mass index (FFMI; fat-free mass divided by height squared) and the percent fat mass (%FM) were calculated. Daily physical activity was assessed for 7 days using a triaxial accelerometer and physical fitness with an incremental test until exertion on a bicycle ergometer. Blood samples were taken to determine C-reactive protein (CRP) level and tumor necrosis factor α. Accelerometer output (kilocounts/day) showed the same physical activity level for patients and controls (mean ± SD 319 ± 105 versus 326 ± 66). There was no difference in the FFMI or %FM between the patients and controls. Physical activity was positively related to the FFMI (partial R = 0.38, P = 0.01) and inversely related to CRP level (R = -0.39, P < 0.01), independent of group. CRP level was inversely related to the FFMI, but the effect was less strong than with physical activity (partial R = -0.31, P = 0.03). Daily physical activity may help preserve fat-free mass in patients with AS.

Pharmacological interventions for geriatric cachexia: a narrative review of the literature.

The objective of this review was to investigate the range of pharmacological interventions that have been studied for treatment of geriatric cachexia, and to evaluate their effect on selected clinical outcomes in this population. Databases including Medline and Cochrane Central Register of Controlled Trials were searched up to March 2010 with search terms including "cache*", "intervention", "megestrol acetate" and "cytokine inhibitors". Studies investigating subjects with mean age <60y or disease-related cachexia were excluded. Outcomes assessed were weight or BMI, body composition, appetite and laboratory parameters indicative of cachexia. Fifteen publications met the selection criteria, reporting on ten studies. Seven studies investigated use of megestrol acetate (MA): two randomised controlled trials, one case control study, two pre-test/post-test studies and two retrospective chart reviews. Weight/BMI was common amongst outcomes and these studies showed an improvement in weight compared with baseline. MA studies which investigated body composition, appetite and/or laboratory parameters provided some evidence for improvement in these outcomes. Three randomised controlled trials investigated the use of other interventions: ghrelin, growth hormone and vitamin supplementations. All demonstrated a significant increase in lean body mass. The only other outcome of interest in these three trials was weight in one study with a significant increase demonstrated. Little investigation has been conducted in this population and the diagnosis of cachexia is problematic however these trials provide preliminary evidence for beneficial outcomes in older adults likely to have cachexia. Further high quality adequately powered prospective studies are necessary to provide effective treatment for geriatric cachexia.

Postnatal early overfeeding induces hypothalamic higher SOCS3 expression and lower STAT3 activity in adult rats

Postnatal early overnutrition (EO) is a risk factor for future obesity and metabolic disorders. Rats raised in small litters (SLs) develop overweight, hyperphagia, hyperleptinemia, hyperinsulinemia and hypertension when adults. As obesity is related to hyperleptinemia, leptin resistance and metabolic syndrome, we aimed to investigate body composition, plasma hormone levels, glucose tolerance and the leptin signaling pathway in hypothalamus from early overfed animals at weaning and adulthood. To induce postnatal EO, we reduced litter size to three pups/litter (SL), and the groups with normal litter size (10 pups/litter) were used as control. Rats had free access to standard diet and water postweaning. Body weight and food intake were monitored daily, and offspring were killed at 21 (weaning) and 180 days old (adulthood). Postnatal EO group had higher body weight and total and visceral fat mass at both periods. Lean mass and serum high-density lipoprotein cholesterol (HDL-C) were higher at 21 days and lower at 180 days. Small litter rats presented higher levels of globulins at both periods, while albumin levels were higher at weaning and lower at adulthood. There was higher leptin, insulin and glucose serum concentrations at 21 days old, while no glucose intolerance was observed in adulthood. Leptin signaling pathway was unaffected at weaning. However, postnatal EO induced lower JAK2 and p-STAT3, and higher SOCS3 expression in adult animals, indicating central leptin resistance in adulthood. In conclusion, postnatal EO induces obesity, higher total and visceral fat mass, lower HDL-C and central leptin resistance in adult life.

The Grey Mouse Lemur Uses Season-Dependent Fat or Protein Sparing Strategies to Face Chronic Food Restriction

During moderate calorie restriction (CR) the heterotherm Microcebus murinus is able to maintain a stable energy balance whatever the season, even if only wintering animals enter into torpor. To understand its energy saving strategies to respond to food shortages, we assessed protein and energy metabolisms associated with wintering torpor expression or summering torpor avoidance. We investigated body composition, whole body protein turnover, and daily energy expenditure (DEE), during a graded (40 and 80%) 35-day CR in short-days (winter; SD40 and SD80, respectively) and long-days (summer; LD40 and LD80, respectively) acclimated animals. LD40 animals showed no change in fat mass (FM) but a 12% fat free mass (FFM) reduction. Protein balance being positive after CR, the FFM loss was early and rapid. The 25% DEE reduction, in LD40 group was mainly explained by FFM changes. LD80 animals showed a steady body mass loss and were excluded from the CR trial at day 22, reaching a survival-threatened body mass. No data were available for this group. SD40 animals significantly decreased their FM level by 21%, but maintained FFM. Protein sparing was achieved through a 35 and 39% decrease in protein synthesis and catabolism (protein turnover), respectively, overall maintaining nitrogen balance. The 21% reduction in energy requirement was explained by the 30% nitrogen flux drop but also by torpor as DEE FFM-adjusted remained 13% lower compared to ad-libitum. SD80 animals were unable to maintain energy and nitrogen balances, losing both FM and FFM. Thus summering mouse lemurs equilibrate energy balance by a rapid loss of active metabolic mass without using torpor, whereas wintering animals spare protein and energy through increased torpor expression. Both strategies have direct fitness implication: 1) to maintain activities at a lower body size during the mating season and 2) to preserve an optimal wintering muscle mass and function.

Body composition at high altitude: a randomized placebo-controlled trial of dietary carbohydrate supplementation

BackgroundBody mass loss is inevitable with chronic hypoxic exposure. However, the exact body-composition changes, their causes, and possible treatments remain unknown. ObjectiveThe objective was to investigate body composition during a high-altitude expedition by using non–empirically derived methods, experimentally manipulating energy intake, and investigating the influence of initial body composition. DesignForty-one participants completed a 21-d expedition in the Himalayas. Energy intake was manipulated with a double-blind, placebo-controlled, randomized trial of carbohydrate energy supplementation. Body composition was assessed before and after the expedition by using a 4-component model including fat mass, total body water, bone mineral mass, and residual mass (principally protein and glycogen). Data were analyzed by repeated-measures analysis of variance. ResultsParticipants allocated to receive carbohydrate were given an additional 15,058 ± 6211 kcal over the 21-d expedition (>6 kcal · kg−1 · d−1). Nevertheless, the functionally important residual mass decreased in both groups by 6% (main effect of time: P = 0.021), with no effect of allocation (interaction effect: P = 0.116). Similar decreases were observed for fat mass (11%) and total body water (3%), which were also unabated by allocation. Furthermore, high initial fat mass (by median split) did not preserve residual mass (high-fat compared with low-fat participants: residual loss = 5% compared with 8%; P = 0.990). ConclusionsHigh-altitude exposure decreased body mass, including the functionally important residual component. These losses were not abated by increasing energy intake or an initially high fat mass. Factors other than negative energy balance must contribute to body-composition changes with chronic hypoxia. This trial was registered at clinicaltrials.gov as NCT00731510.

BMI, fat and muscle differences in urban women of five ethnicities from two countries

To investigate body composition differences, especially the relationship between body mass index (BMI) and percent body fat (%BF), among five ethnic groups. Cross-sectional. Seven hundred and twenty-one apparently healthy women aged 18-60 years (BMI: 17.4-54.0 kg/m(2)) from South Africa (SA, 201 black, 94 European) and New Zealand (NZ, 173 European, 76 Maori, 84 Pacific, 93 Asian Indian). Anthropometry, including waist circumference, and total, central and peripheral body fat, bone mineral content and total appendicular skeletal muscle mass (ASMM) derived from dual X-ray absorptiometry. Regression analysis determined that at a BMI of 30 kg/m(2), SA European women had a %BF of 39%, which corresponded to a BMI of 29 for SA black women. For a BMI of 30 kg/m(2) in NZ Europeans, equivalent to 43% body fat, the corresponding BMIs for NZ Maori, Pacific and Asian Indian women were 34, 36 and 26 kg/m(2), respectively. Central fat mass was lower in black SA than in European SA women (P<0.001). In NZ, Pacific women had the lowest central fat mass and highest ASMM, whereas Asian Indian women had the highest central fat mass, but lowest ASMM and bone mineral content. The relationship between %BF and BMI varies with ethnicity and may be due, in part, to differences in central fatness and muscularity. Use of universal BMI or waist cut-points may not be appropriate for comparison of obesity prevalence among differing ethnic groups, as they do not provide a consistent reflection of adiposity and fat distribution across ethnic groups.

Relationship between Body Composition and Functional Outcomes in Males with Subacute Stroke

The purpose of this study was to investigate body composition focusing on motor functional capacity and to correlate body composition with functional outcomes with subacute stroke patients. The subjects of this study were 34 inpatients with hemiparetic stroke who could walk. Motor functional capacity of patients was assessed on the basis of the Brunnstrom recovery stage (BRS), and functional status was measured using the Functional Independence Measure (FIM) instrument scores and gait velocity. Body composition was assessed by bioelectrical impedance analysis. Significant correlations were observed between FIM scores and the BRS of the lower extremity or lean body mass. The correlations for body water in affected and unaffected legs with the FIM subscores were statistically significant (p<0.05). The correlations for the FIM scores with BRS and body water were higher in the lower extremity than in the upper extremity. Differences in body composition were calculated between the affected and unaffected sides. There was no significant difference in body water between the affected leg and the unaffected leg, but body water in the affected arm was lower than that in the unaffected arm (p<0.01). These results suggest that motor function capacity and body composition are generally related with functional status rather than the lower extremity or upper extremity.

Cadaver studies and their impact on the understanding of human adiposity

The skinfold thickness is a much-used measurement for monitoring adiposity in a wide range of medical, health, occupational and sport science disciplines. Misconceptions abound, however, in its use, particularly that of purportedly predicting body ‘fat’ as opposed to ‘adipose tissue’. To obtain data to investigate body composition and the extent to which anthropometry can be justifiably used to predict whole-body adiposity, an extensive dissection study was undertaken on 34 cadavers. In addition, to pre-empt questions on the applicability of cadaver data to living subjects, 40 elderly in vivo subjects of the same age range were compared with the cadaver population. No significant macro-morphological differences were found between males or females in the morbid and in vivo groups. Significant findings affect our previous understanding of the predictability of whole-body ‘fat’. Skinfold compressibility was by no means constant; skin thickness varied with location in both sexes, females having thinner skin than males; there were significant sex differences in adipose tissue patterning. An identical thickness of adipose tissue did not necessarily contain the same concentrations of fat. Despite this variability, a relationship was demonstrated between aggregate skinfold measures and subcutaneous adipose tissue mass (as opposed to subcutaneous fat), this relationship being more evident in men. A strong relationship was found between subcutaneous adiposity and whole-body adiposity, and between direct skinfold depth measures and whole-body adiposity. The amount of visceral adipose tissue was the same in men and women, but in the men this represented a greater proportion of their total body adiposity. Further, the use of waist-to-hip girth ratio (WHR) was identified as an important predictor of health risk. These findings demonstrate that it is not sustainable to introduce a non-quantifiable error by transforming anthropometric values (skinfolds) into predictions of percentage body fat. If subcutaneous adiposity can be predicted, then an excellent indication of overall adiposity could be obtained. Currently, skinfold measurement can yield a reasonable indication of comparative subcutaneous adiposity (better in men than in women). In neither gender is this prediction completely reliable due to both inter- and intra-individual differences in the skinfold measurement procedure.

Sarcopenia and increased adipose tissue infiltration of muscle in elderly African American women

Aging is associated with metabolic, physiologic, and functional impairments, in part through age-related changes in body composition. During the later adult years, skeletal muscle mass decreases and body fat becomes centralized. The goal of the study was to investigate body composition over time ( +/- SD: 2.04 +/- 0.6 y) in healthy, ambulatory, elderly African American women. The hypothesis that a reduction in total-body skeletal muscle (SM) and increases in visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) are ongoing in healthy, weight-stable elderly was tested. The study was a longitudinal evaluation of 26 women (age at baseline: 75.5 +/- 5.1 y) with a body mass index (in kg/m(2)) of 27.0 +/- 4.0. Body composition was measured by using whole-body magnetic resonance imaging for the quantification of SM, total adipose tissue (TAT), VAT, SAT, and IMAT. SM (P < 0.001) and bone (P < 0.05) masses decreased, and regional analyses showed a decrease in dual-energy X-ray absorptiometry-derived leg SM (P < 0.05). VAT (P = 0.011) and IMAT (P < 0.001) increased. No changes occurred in TAT (P = 0.45), SAT (P = 0.96), physical function, or food intake. These data show an age-related remodeling of body composition with reductions in SM and corresponding increases in VAT and IMAT. Changes in the previously unstudied depot of IMAT may be involved in the deterioration of metabolic values frequently observed during aging.

Growth hormone secretion and leptin in morbid obesity before and after biliopancreatic diversion: relationships with insulin and body composition.

Obesity is characterized by increased leptin levels and insulin resistance, whereas blunted GH secretion is paired with normal, low, or high plasma IGF-I levels. To investigate body composition in human obesity and the interactions among the GH-IGF-I axis, leptin, and insulin resistance [measured with the homeostasis model assessment (HOMA) score], we studied 15 obese females, aged 23-54 yr (mean age, 42.7 +/- 2.6), with a body mass index (BMI) of 44.02 +/- 1.45 kg/m(2), who underwent treatment by biliopancreatic diversion (BPD), before and after surgery (16-24 months; BMI, 28.29 +/- 0.89 kg/m(2)). Our controls were 15 normal females, aged 28-54 yr (mean age, 40.8 +/- 2.3 yr), with a BMI of 27.52 +/- 0.53 kg/m(2). Insulin and leptin levels and HOMA scores were higher pre-BPD than in the controls. The GH response to GHRH was blunted, with a GH peak and GH area under the curve (AUC) significantly lower than those in controls. IGF-I and IGF-binding protein-3 (IGFBP-3) were also lower than control values. After surgery, BMI, fat mass, lean body mass, HOMA, insulin, and leptin significantly decreased. Furthermore, the GH response to GHRH severely increased; IGF-I and IGFBP-3 levels did not significantly vary. Considering all subjects, correlation analysis showed a strong positive correlation between insulin and leptin, and a negative correlation between insulin and GH peak and between insulin and GH AUC. Regression analysis performed grouping pre- and post-BPD indicated that leptin and GH peak or AUC could best be predicted from insulin levels. The surgical treatment of severe obesity after stabilization of body weight decreases BMI and fat mass while preserving normal lean body mass as well as positively influencing insulin sensitivity and thus aiding the normalization of leptin levels. The insulin reduction may be mainly involved in the increase in the GH response to GHRH through various possible central and peripheral mechanisms while decreasing the peripheral sensitivity to GH itself, as shown by the stable nature of the IGF-I and IGFBP-3 values. Our findings suggest that the changes in insulin levels are the starting point for changes in both leptin levels and the somatotrope axis after BPD.

Effects of growth hormone secretion on body composition in patients with Crohn's disease.

Crohn's disease is a multisystem disorder characterized by chronic intestinal inflammation. Accumulation of mesenteric fat occurs in patients with Crohn's disease, although the mechanisms underlying site-specific changes in adipose deposition are unclear. To investigate whether there are alterations in site-specific adipose deposition in patients with Crohn's disease and to determine hormonal influences that may underlie such changes, we investigated body composition and serum hormone levels in 20 men with Crohn's disease (mean age, 45 +/- 2 yr) and 20 age-, gender-, and body mass index-matched normal controls (mean age, 43 +/- 3 yr). None of the Crohn's patients was receiving glucocorticoid therapy. Subjects underwent hourly GH sampling for 12 h beginning at 2000 h and fasting serum IGF-I and testosterone measurements. Body composition was assessed by quantitative computed tomography of the abdomen and bioelectrical impedance analysis. In the Crohn's disease and control subjects, mean serum GH levels were 1.07 +/- 0.2 and 1.7 +/- 0.2 ng/ml (P = 0.06), serum IGF-I levels were 162.7 +/- 10.5 and 194.8 +/- 15.7 ng/ml (P = 0.1), and serum testosterone levels were 489 +/- 33 and 514 +/- 38 ng/ml (P = NS), respectively. Percentage body fat was significantly higher in the Crohn's patients (21 +/- 0.8% vs. 17.7 +/- 0.9%, respectively; P = 0.013). Intraabdominal fat (IAF) was significantly higher in the Crohn's subjects vs. controls (115 +/- 11 vs. 69 +/- 7 cm(2), respectively; P = 0.001). The ratio of intraabdominal to total body fat was higher in the Crohn's subjects than in the controls (0.4 +/- 0.1 vs. 0.3 +/- 0.1, respectively; P = 0.025). Subcutaneous fat area was similar in the two groups. IAF was higher in Crohn's patients even when controlling for testosterone and mean serum GH. Mean serum GH contributed independently to the differences in IAF (P = 0.001). The ratio of IAF to total body fat remained higher in the Crohn's subjects when controlling for serum testosterone, but was no longer significant in a model that also included IGF-I and mean serum GH. GH levels contributed independently to the differences in the intraabdominal to total body fat ratio (P = 0.02). In the Crohn's patients, serum GH correlated negatively with intraabdominal and total body fat and the ratio of intraabdominal to total body fat. Crohn's disease is associated with an increase in central fat accumulation, with more IAF and a higher ratio of intraabdominal to total body fat compared with controls. Although serum GH levels were similar in the two groups, GH contributed significantly to the abdominal fat measurements. These data show that GH has an important role in modulating visceral fat distribution in patients with Crohn's disease.

Body composition assessed by anthropometry and bioelectric impedance analysis in older persons recovering from cerebrovascular accident.

We investigated body composition in older patients who had experienced a cerebrovascular accident (CVA) and were participating in a recovery program that included physical exercise. We studied 61 persons in two groups. One group consisted of 13 men and 12 women (mean age, 68 years) who were receiving day center care to recover from a CVA that had occurred from six months to one year previously. The second group (control) consisted of 20 men and 16 women (mean age, 68 years) in good health, residing in a retirement home. Most subjects in both groups were able to perform normal activities of daily living without help and showed a high degree of independence (> 60 on the Barthel scale). Bioelectric impedance and anthropometric methods were used to measure the magnitude of changes in fat-free mass and fat mass. Percentage total body fat measured with bioelectric impedance was higher in both groups than when measured anthropometrically. The anthropometric values and bioelectric impedance results in patients who participated in a physical exercise program were similar to the findings in control subjects. The anticipated loss in muscle mass and gain in body fat as a result of inactivity associated with illness was not seen, possibly because of the personalized program of continuous physical exercise. Our comparison of older people recovering from CVA and apparently healthy older people illustrates the benefits of physical exercise in compensating for changes in body composition as a result of immobility during convalescence.

MUSCLE MASS, BONE MINERAL CONTENT AND FAT MASS IN HEMIPLEGIC STROKE PATIENTS

PURPOSE: The aim of this study was to investigate body composition changes that occur due to immobilization on the affected side in hemiplegic stroke patients. Patients with hemiplegia experience decreases in muscle mass, bone demineralization and increases in fat mass. METHODS: 23 hospitalized elderly men with a mean age 72.1 ± 8.2 years. All the patients were post stroke with hemiparesis or muscle weakness on one side. Muscle mass, bone mineral content (BMC) and fat mass were assessed with Dual X-ray Absorptiometry (DEXA) Lunar DPX-L model for both affected and unaffected side. RESULTS: A t-test was used to examine significant differences between the affected and unaffected sides. The affected side had 5% (p = .001) higher fat mass than the unaffected side. No difference was found between the sides in muscle mass and BMC (p = .920; p = .122 respectively). However, the affected side showed a 4.5% decrease in BMC compared to the unaffected side. CONCLUSIONS: The study failed to show significant difference between affected and unaffected sides in muscle mass and BMC. However there is a trend of lower BMC in the affected side. The lack of statistical significance in muscle and bone mass between the two sides might be attributed to the fact that these patients were very deconditioned at the time of the study and that loss of muscle and bone mass was generalized throughout the body because of extended periods of inactivity. If activity is reinitiated, lean muscle mass may be regained; in contrast, extended inactivity generalizes deficits found in these compartments. However, loss of BMC and fat accumulation appears difficult to prevent, regardless of lean muscle mass effect. FUNDING ACKNOWLEDGEMENTS: Funded by National VA merit #2117, Retirement Research Foundation; the NIH National Center for Research Resources GCRC Grant #MO1 RR02719; the NIH NIA Gerontology Research Center; John Hopkins University School of Medicine Institutional Research Grants; the Houston VAMC Center for Healthy Aging with Disabilities; the Cheasapeake Physicians' Professional Association Research and Education Fund; and the Levindale Care for the Aged Research Fund.

Physical limitations of the TOBEC method: Accuracy and long-term stability

While measurement of electrical conductivity provides one way of estimating body composition in live animals, the accuracy of methods based on this principle requires further study. In this work, we evaluate the effect of the ambient conditions and sample geometry on the response given by an SA-2 model (EM-SCAN) apparatus as well as the reproducibility of the measurements over time. A 2 °C variation of the sample temperature (a normal range for living animals) can result in a 6–10% variation in the response. When the conductive mass of a sample is increased in length, the response of the apparatus does not increase once the sample length reaches half the length of the measurement chamber. Samples having the same conductive mass but different shapes can show up to a 17-fold variation in signal. The geometry of the sample itself appears to be of prime importance for determining the strength of the response. We find that the reference phantom provided by the manufacturer is inadequate for calibration and is unable to detect the 10% variation over time of the signal of the apparatus. Until these problems are resolved, the usefulness of the EM-SCAN SA-2 to investigate body composition accurately is questionable.

Tumor Necrosis Factor, Interleukin-6,and Epinephrine Are Associated with Hypermet abolism in AIDS Patients with Acute Opportunistic Infections

During a 9-day period we investigated body composition, resting energy expenditure (REE), IL-6, TNF, and sTNFR-55 and sTNFR-75 plasma concentrations during infectious complications in 12 patients with HIV disease. At study entry, IL-6 was detectable in 5 and TNF in 10 patients. TNF was closely correlated with sTNFR-75 concentration (r = 0.84, p < 0.001) whereas sTNFR/sTNFR-55 ratio increased throughout the study. TNF concentrations were significantly correlated with the 24-hour excretion of epinephrine and norepinephrine (r = 0.64 and 0.69; each p < 0.01). Compared to expected values REE was increased by 34%. Body cell mass was the single best predictor of REE and explained 72% of its variance. In contrast, the deviation of measured from predicted REE was correlated with TNF and IL-6 concentrations (r = 0.9). We conclude that increased plasma concentrations of cytokines in complicated HIV disease display little biologic variability and relate to hypermetabolism in these patients.

Changes in body composition during breast cancer chemotherapy with the CMF-regimen.

Weight gain is a reported problem associated with adjuvant chemotherapy for breast cancer and often generates psychosocial stress in women [1]. It also may affect prognosis and survival. Changes in body composition and weight during chemotherapy, particularly adjuvant treatment of breast carcinoma, have been previously reported [1-3]. Multiple reasons for this weight gain have been suggested though few theories have been scientifically validated [4]. The aim of this study was to investigate body composition and its relationship to weight change associated with the CMF-based breast cancer chemotherapy protocols. Total body nitrogen (TBN), body fat, total body water (TBW), and anthropometric measurements were conducted on 25 female out-patients (median age 47, range 26-70 years) receiving adjuvant CMF-based chemotherapy for breast cancer. Total body nitrogen was measured using the In Vivo Neutron Capture Analysis (IVNCA) technique (on day 1 of cycles 2-6) and TBP was calculated by multiplying TBN by 6.25 [5]. Nitrogen Index (NI) was calculated by expressing TBN as a percentage of normal. There was a significant increase in mean body weight during chemotherapy of 2.35 kg (p < 0.0001). Serial measurements showed no significant change in mean TBN, NI, or percentage body fat. Break down of body weight showed a significant increase in mean TBW of 0.79 kg (p = 0.003) and mean fat mass of 1.49 kg (p = 0.008). We conclude that weight gain observed during adjuvant chemotherapy for breast carcinoma is primarily due to an increase in fat and TBW.

Long-term administration of GHB does not affect muscular mass in alcoholics

Gamma-hydroxybutyric acid (GHB) is a drug recently utilized for alcoholism management. It has been shown that GHB has anabolic effects since it can increase growth hormone (GH) release in healthy subjects. At present, there are no studies investigating body composition in alcoholics during long-term GHB treatment. In this study body composition and GH secretion in alcohol dependent subjects was evaluated during addiction and at different time of GHB administration and alcohol abstinence. A total of 45 male alcohol dependent patients (mean age 39.7 ± 9.8 yrs, mean height: 171 ± 6.8 cm, body mass index -BMI- 22.1 ± 1.6 kg/m 2) were consecutively enrolled. Body composition was assessed by anthropometry, bioimpedance analysis and tritiated water method. A 7-day food diary was collected. Plasma GH levels were determined by radioimmunoassay. A 6-month total abstinence was obtained in 22 patients, by means of psychological support counseling and self-help groups in 9 subjects and also by 50 mg/kg/day of GHB in 13 subjects. At 1, 2, 3 and 6 months of abstinence, the biochemical assessment and metabolic variables were re-examined. Fat-free mass (FFM) and basal GH secretion were similar at the different times of follow-up in both groups of patients. GHB treated patients and those receiving psychological support alone showed similar values in FFM and GH. Both groups of patients did not differ in FFM and plasma GH level from healthy controls at any of the times evaluated. Waist-to-hip ratio did not differ between patient groups, while higher values were shown in alcoholics with respect to control subjects. The present study shows that long-term administration of GHB did not affect muscular mass and did not determine an increase of GH release in chronic alcoholics. This findings could be due to an impairment of the hypothalamic-limbic system and of GABAergic neurotransmission in alcoholics' brain.

Malnutrition in tuberculosis

Tuberculosis has a dramatic effect on nutritional state and this has been borne out in all the studies that have investigated body composition in affected patients. I have included some of the key studies in this review; those I have not cited generally reach the same conclusions. Such malnutrition undoubtedly contributes to the morbidity of the disease and may also contribute to mortality, particularly in resource-poor settings where nutritional state, even in the "healthy," may be parlous. The extent to which such malnutrition also contributes to pathology remains unclear. Certainly, in other models, nutritional depletion has a major impact on immune function (Chandra, 1997) and depression of lymphocyte function cannot be a desirable commodity in an individual fighting invasive mycobacterial infection. Considering the reverse relationship, there is good evidence, both at the population level and at the clinical level, for the effect of primary malnutrition on tuberculosis, both to increase frequency of occurrence and to exacerbate clinical manifestations. It has not been possible to explore this relationship within the context of this paper but it is clearly an important aspect of the bi-directional relationship between tuberculosis and malnutrition. There is still more to be understood about the pathophysiology of the wasting seen in chronic infections such as tuberculosis but it is clear that, in addition to good anti-tuberculous therapy, such patients need a good supply of nutrition during the treatment/recovery phase. In the developed world, this may include medical measures to achieve nutritional support whereas in resource-poor settings, nutritional intake may have more to do with equitable resource distribution and community involvement in health care.

The usefulness of a new TOBEC instrument (ACAN) for investigating body composition in small mammals

Estimates of water mass, lean body mass (LBM) and fat content based on total body electrical conductivity (TOBEC) measured with ACAN-2 were compared with direct measurements of carcass composition in two species of rodents: the laboratory mouse (n=20) and the bank vole (n=14). There was a strong linear relation relation between ACAN readings and lean mass or water mass. Body temperature did not affected the results, but the readings were dependent on the species and sex of the individuals. That could be due to differences in the body shape. The accuracy of predicting an average LBM or water mass was very high (1.5%), but the errors for predicting individual values were larger (8.5%). The predicted fat content values have identical confidence intervals as that for LBM. However, the relative error for prediction of the amount of fat was higher, becouse the mass of fat was much smaller than LBM.

Body composition, body fat distribution, and resting metabolic rate in healthy centenarians

Our study investigated body composition and body fat distribution in healthy centenarians. Body composition, body fat distribution, and resting metabolic rate (RMR) were studied in 40 adult subjects aged < 50 y, 35 aged subjects > 75 y, and 15 healthy centenarians aged > 100 y. Body composition was determined by bioimpedance analysis, body fat distribution was calculated as waist-hip ratio (WHR), and RMR was calculated by using the Arciero-Poehlman formula. Healthy centenarians had a cognitive impairment and degree of disability greater than aged subjects. Despite such differences, fat-free mass (FFM) and RMR were not different in centenarians compared with aged subjects but were lower than in adult subjects. In contrast, healthy centenarians had a WHR lower than that of aged subjects but not different from that of the adult subjects. After the level of physical activity and degree of disability were adjusted for, FFM (44 +/- 2.7 and 40 +/- 1.1 kg; P < 0.05) and RMR (6757 +/- 761 and 5891 +/- 723 kJ/24 h; P < 0.05) were significantly higher in healthy centenarians than in aged subjects, respectively. Independent of age, sex, body weight, degree of disability, level of physical activity, and fasting plasma triiodothyronine, there was a strong correlation between RMR and FFM (r = 0.50, P < 0.05) in healthy centenarians. In conclusion, healthy centenarians had a lower FFM and higher body fat content than aged subjects. Level of physical activity and degree of disability seem to be the major determinants for explaining such differences.