Evaluating Muscle Mass in Survivors of Acute Respiratory Distress Syndrome: A 1-Year Multicenter Longitudinal Study.
ABSTRACT: OBJECTIVES:Rapid muscle wasting occurs during acute respiratory failure, resulting in muscle weakness and functional impairments. This study examines survivors' body composition in the year after acute respiratory distress syndrome and tests associations of patient characteristics, hospital exposures, and survivors' strength and physical functioning with whole body percent lean mass. DESIGN:Prospective cohort study with 6- and 12-month follow-up. SETTING:National study enrolling patients from five study centers. PATIENTS:Acute respiratory distress syndrome survivors (n = 120). INTERVENTIONS:None. MEASUREMENTS AND MAIN RESULTS:Lean and fat mass from dual energy x-ray absorptiometry. On average, survivors gained whole body total mass (+1.4?kg; 0.1-2.7) and fat mass (+1.2?kg; 0.2-2.2) and maintained lean mass (+0.2?kg; -0.4 to 0.8) between 6 and 12 months. Proportionally, percent fat mass increased and percent lean mass decreased for the whole body, trunk, and legs (p < 0.05). Greater whole body percent lean mass was associated with younger age, male sex, and lower baseline body mass index, but not other patient characteristics or ICU/hospital exposures. Greater percent lean mass was also significantly associated with gait speed and 6-minute walk distance, but not volitional strength or self-reported functional status. CONCLUSIONS:In the first year after acute respiratory distress syndrome, patients gained fat mass and maintained lean mass. We found no association of whole body percent lean mass with commonly hypothesized hospital risk factors. Direct measurement of body composition and performance-based functional measures may be helpful for understanding functional recovery in ICU survivors.
Project description:Survivors of acute respiratory distress syndrome (ARDS) experience severe muscle wasting. Upper arm anthropometrics can provide a quick, non-invasive estimate of muscle status, but its accuracy is unknown. This study examines the accuracy of upper arm percent muscle area (UAMA) with reference measures of lean mass from dual energy X-ray absorptiometry (DXA). Data are from 120 ARDS survivors participating in a multicenter national study. Receiver operating characteristic (ROC) curves, by patient sex, demonstrated that UAMA did no better than chance in discriminating low appendicular skeletal muscle mass identified using DXA findings (c-statistics, 6 months: 0.50-0.59, 12 months: 0.54-0.57). Modest correlations of UAMA with DXA measures (whole-body: r?=?0.46-0.49, arm-specific: r?=?0.50-0.51, p?<?0.001) and Bland-Altman plots indicate poor precision. UAMA is not an appropriate screening measure for estimating muscle mass when compared to a DXA reference standard. Alternate screening measures should be evaluated in ARDS survivors.
Project description:This study examined the effect of 12 months of aerobic and resistance exercise versus usual care on changes in body composition in postmenopausal breast cancer survivors taking aromatase inhibitors (AIs).The Hormones and Physical Exercise study enrolled 121 breast cancer survivors and randomized them to either supervised twice-weekly resistance exercise training and 150 min/wk of aerobic exercise (N = 61) or a usual care (N = 60) group. Dual-energy X-ray absorptiometry scans were conducted at baseline, 6 months, and 12 months to assess changes in body mass index, percent body fat, lean body mass, and bone mineral density.At 12 months, the exercise group relative to the usual care group had a significant increase in lean body mass (0.32 vs. -0.88 kg, P = 0.03), a decrease in percent body fat (-1.4% vs. 0.48%, P = 0.03), and a decrease in body mass index (-0.73 vs. 0.17 kg/m2 , P = 0.03). Change in bone mineral density was not significantly different between groups at 12 months (0.001 vs. -0.006 g/cm2 , P = 0.37).A combined resistance and aerobic exercise intervention improved body composition in breast cancer survivors taking AIs. Exercise interventions may help to mitigate the negative side effects of AIs and improve health outcomes in breast cancer survivors.
Project description:OBJECTIVES:To determine whether weight extremes impact clinical outcomes in pediatric acute respiratory distress syndrome. DESIGN:Post hoc analysis of a cohort created by combining five multicenter pediatric acute respiratory distress syndrome studies. SETTING:Forty-three academic PICUs worldwide. PATIENTS:A total of 711 subjects prospectively diagnosed with pediatric acute respiratory distress syndrome. INTERVENTION:Subjects more than 2 years were included and categorized by Center for Disease Control and Prevention body mass index z score criteria: underweight (< -1.89), normal weight (-1.89 to +1.04), overweight (+1.05 to +1.64), and obese (? +1.65). Subjects were stratified by direct versus indirect lung injury leading to pediatric acute respiratory distress syndrome. The primary outcome was in-hospital mortality. In survivors, secondary analyses included duration of mechanical ventilation and ICU length of stay. MEASUREMENTS AND MAIN RESULTS:A total of 331 patients met inclusion criteria; 12% were underweight, 50% normal weight, 11% overweight, and 27% obese. Overall mortality was 20%. By multivariate analysis, body mass index category was independently associated with mortality (p = 0.004). When stratified by lung injury type, there was no mortality difference between body mass index groups with direct lung injury; however, in the indirect lung injury group, the odds of mortality in the obese were significantly lower than normal weight subjects (odds ratio, 0.11; 95% CI, 0.02-0.84). Survivors with direct lung injury had no difference in the duration of mechanical ventilation or ICU length of stay; however, those with indirect lung injury, the overweight required longer duration of mechanical ventilation than other groups (p < 0.001). CONCLUSIONS:These data support the obesity paradox in pediatric acute respiratory distress syndrome. Obese children with indirect lung injury pediatric acute respiratory distress syndrome have a lower risk of mortality. Importantly, among survivors, the overweight with indirect lung injury requires longer duration of mechanical ventilation. Our data require prospective validation to further elucidate the pathobiology of this phenomenon.
Project description:Purpose: Adiposity is one of the important determinants of blood pressure. The aim of this study is to evaluate the association between blood pressure and body composition indices throughout the whole lifespan of healthy adults. Patients and Methods: This study was from an ongoing cross-sectional survey of the Chinese health wherein data included basic physiological parameters. Partial Pearson correlation analysis was used to assess the correlation between blood pressure and body composition indices. Multiple linear regression analysis was used to assess the association of body mass index, lean mass percent, and visceral fat rating against blood pressure in each age group. Results: In the whole population stratified by gender, while body mass index had the highest r-value of correlation with systolic blood pressure in both males (r = 0.296, p < 0.001) and females(r = 0.237, p < 0.001), and fat mass percent had the highest r-value of correlation with diastolic blood pressure in males (r = 0.351, p < 0.001) and females(r = 0.277, p < 0.001), the strength of association with blood pressure were similar across most of the body composition indices. In multiple linear regression analysis, both body mass index and visceral fat rating were positively while lean mass percent was negatively associated with blood pressure in all age groups in both genders, whereas all the association was weaker in the elderly compared to the younger. Conclusion: Maintain the total body fat in a favorable range and appropriately increase the body muscle mass is a strategy to reduce the occurrence of cardiovascular event by decreasing the risk of hypertension through the whole adult life.
Project description:To identify biomarkers of body mass index, body fat, trunk fat, and appendicular lean mass, nontargeted metabolomics was performed in plasma from 319 black men in the Health, Aging and Body Composition study (median age 72 years, median body mass index 26.8 kg/m2). Body mass index was calculated from measured height and weight; percent fat, percent trunk fat, and appendicular lean mass were measured with dual-energy x-ray absorptiometry. Pearson partial correlations between body composition measures and metabolites were adjusted for age, study site, and smoking. Out of 350 metabolites, body mass index, percent fat, percent trunk fat, and appendicular lean mass were significantly correlated with 92, 48, 96, and 43 metabolites at p less than .0014. Metabolites most strongly correlated with body composition included carnitine, a marker of fatty acid oxidation (positively correlated), triacylglycerols (positively correlated), and amino acids including branched-chain amino acids (positively correlated except for acetylglycine and serine). Gaussian Graphical Models of metabolites found that 25 lipid metabolites clustered into a single network. Groups of five amino acids, three plasmalogens, and two carnitines were also observed. Findings confirm prior reports of associations between amino acids, lean mass, and fat mass in addition to associations not previously reported. Future studies should consider whether these metabolites are relevant for metabolic disease processes.
Project description:BACKGROUND:Maintenance of lean muscle mass and related strength is associated with lower risk for numerous chronic diseases of aging in women. OBJECTIVE:Our aim was to evaluate whether the association between dietary protein and lean mass differs by physical activity level, amino acid composition, and body mass index categories. DESIGN:We performed a cross-sectional analysis of a prospective cohort. PARTICIPANTS/SETTING:Participants were postmenopausal women from the Women's Health Initiative with body composition measurements by dual-energy x-ray absorptiometry (n=8,298). MAIN OUTCOME MEASURES:Our study measured percent lean mass, percent fat mass, and lean body mass index. STATISTICAL ANALYSES PERFORMED:Linear regression models adjusted for scanner serial number, age, calibrated energy intake, race/ethnicity, neighborhood socioeconomic status, and recreational physical activity were used to determine the relationship between protein intake and body composition measures. Likelihood ratio tests and stratified analysis were used to investigate physical activity and body mass index as potential effect modifiers. RESULTS:Biomarker-calibrated protein intake was positively associated with percent lean mass; women in the highest protein quintile had 6.3 percentage points higher lean mass than the lowest quintile (P<0.001). This difference rose to 8.5 percentage points for physically active women in the highest protein quintile (Pinteraction=0.023). Percent fat mass and lean body mass index were both inversely related to protein intake (both P<0.001). Physical activity further reduced percent fat mass (Pinteraction=0.022) and lean body mass index (Pinteraction=0.011). Leucine intake was associated with lean mass, as were branched chain amino acids combined (both P<0.001), but not independent of total protein. All associations were observed for normal-weight, overweight, and obese women. CONCLUSIONS:Protein consumption up to 2.02 g/kg body weight daily is positively associated with lean mass in postmenopausal women. Importantly, those that also engage in physical activity have the highest lean mass across body mass index categories.
Project description:In adults, obesity has been associated with several health outcomes including increased bone density. Our objective was to evaluate the association between percent body fat and fat mass with bone mineral density (BMD) in a nationally representative population of children and adolescents.A total of 8,348 participants 8-18 years of age from the National Health and Nutrition Examination Survey (NHANES) 1999-2006 had whole body DXA scans performed. We conducted linear regressions to examine the relationship between percent body fat and fat mass with outcome variables of total body, pelvic and lumbar spine areal BMD (aBMD), controlling for lean body mass and assessing for gender and race/ethnicity interactions.We found evidence of gender and race/ethnicity interactions with percent body fat and total fat mass for the different BMD areas. Generally, there were decreases in total body aBMD (p<0.001) and lumbar spine aBMD (p<0.001) with increasing percent body fat and total fat mass, with less consistent patterns for pelvic aBMD.Our findings of regional differences in the relationship of adiposity to aBMD in children and adolescents with significant interactions by gender and race/ethnicity emphasizes the need for further investigations to understand the impact of adiposity on bone health outcomes.
Project description:Success in the treatment of young people with cancer, as measured conventionally by survival rates, is mitigated by late effects of therapy that impose a burden of morbidity and limit life expectancy. Among these adverse sequelae are altered body composition, especially obesity, and compromised bone health in the form of osteoporosis and increased fragility. These outcomes are potentially reversible and even preventable. This study will examine measures of body composition and bone health in long-term survivors of acute lymphoblastic leukaemia (ALL) in childhood and adolescence. These measures will be complemented by measures of physical activity and health-related quality of life (HRQL).Survivors of ALL who are at least 10 years from diagnosis, following treatment on uniform protocols, will undergo measurements of body mass index; triceps skin fold thickness and mid-upper arm circumference; fat mass, lean body mass, skeletal muscle mass and bone mineral density by dual energy X-ray absorptiometry; trabecular and cortical bone indices and muscle density by peripheral quantitative CT; physical activity by the Habitual Activity Estimation Scale; and HRQL by Health Utilities Index instruments. Descriptive measures will be used for continuous variables and number (percent) for categorical variables. Associations between variables will be assessed using Fisher's exact t test and the χ(2) test; correlations will be tested by the Pearson correlation coefficient.The study is approved by the institutional research ethics board and is supported by a competitive funding award. Dissemination of the results will occur by presentations to scientific meetings and publications in peer-reviewed journals, and by posting summaries of the results on websites accessed by adolescent and young adult survivors of cancer.
Project description:BACKGROUND:Young male cancer survivors have lower testosterone levels, higher fat mass, and worse quality of life (QoL) than age-matched healthy controls. Low testosterone in cancer survivors can be due to orchidectomy or effects of chemotherapy and radiotherapy. We have undertaken a double-blind, placebo-controlled, 6-month trial of testosterone replacement in young male cancer survivors with borderline low testosterone (7-12 nmol/l). METHODS AND FINDINGS:This was a multicentre United Kingdom study conducted in secondary care hospital outpatients. Male survivors of testicular cancer, lymphoma, and leukaemia aged 25-50 years with morning total serum testosterone 7-12 nmol/l were recruited. A total of 136 men were randomised between July 2012 and February 2015 (42.6% aged 25-37 years, 57.4% 38-50 years, 88% testicular cancer, 10% lymphoma, matched for body mass index [BMI]). Participants were randomised 1:1 to receive testosterone (Tostran 2% gel) or placebo for 26 weeks. A dose titration was performed after 2 weeks. The coprimary end points were trunk fat mass and SF36 Physical Functioning score (SF36-PF) at 26 weeks by intention to treat. At 26 weeks, testosterone treatment compared with placebo was associated with decreased trunk fat mass (-0.9 kg, 95% CI -1.6 to -0.3, p = 0.0073), decreased whole-body fat mass (-1.8 kg, 95% CI -2.9 to -0.7, p = 0.0016), and increased lean body mass (1.5 kg, 95% CI 0.9-2.1, p < 0.001). Decrease in fat mass was greatest in those with a high truncal fat mass at baseline. There was no treatment effect on SF36-PF or any other QoL scores. Testosterone treatment was well tolerated. The limitations of our study were as follows: a relatively short duration of treatment, only three cancer groups included, and no hard end point data such as cardiovascular events. CONCLUSIONS:In young male cancer survivors with low-normal morning total serum testosterone, replacement with testosterone is associated with an improvement in body composition. TRIAL REGISTRATION:ISRCTN: 70274195, EudraCT: 2011-000677-31.
Project description:OBJECTIVE:To investigate the association of predicted lean body mass, fat mass, and body mass index (BMI) with all cause and cause specific mortality in men. DESIGN:Prospective cohort study. SETTING:Health professionals in the United States PARTICIPANTS: 38?006 men (aged 40-75 years) from the Health Professionals Follow-up Study, followed up for death (1987-2012). MAIN OUTCOME MEASURES:All cause and cause specific mortality. RESULTS:Using validated anthropometric prediction equations previously developed from the National Health and Nutrition Examination Survey, lean body mass and fat mass were estimated for all participants. During a mean of 21.4 years of follow-up, 12?356 deaths were identified. A J shaped association was consistently observed between BMI and all cause mortality. Multivariable adjusted Cox models including predicted fat mass and lean body mass showed a strong positive monotonic association between predicted fat mass and all cause mortality. Compared with those in the lowest fifth of predicted fat mass, men in the highest fifth had a hazard ratio of 1.35 (95% confidence interval 1.26 to 1.46) for mortality from all causes. In contrast, a U shaped association was found between predicted lean body mass and all cause mortality. Compared with those in the lowest fifth of predicted lean body mass, men in the second to fourth fifths had 8-10% lower risk of mortality from all causes. In the restricted cubic spline models, the risk of all cause mortality was relatively flat until 21 kg of predicted fat mass and increased rapidly afterwards, with a hazard ratio of 1.22 (1.18 to 1.26) per standard deviation. For predicted lean body mass, a large reduction of the risk was seen within the lower range until 56 kg, with a hazard ratio of 0.87 (0.82 to 0.92) per standard deviation, which increased thereafter (P for non-linearity <0.001). For cause specific mortality, men in the highest fifth of predicted fat mass had hazard ratios of 1.67 (1.47 to 1.89) for cardiovascular disease, 1.24 (1.09 to 1.43) for cancer, and 1.26 (0.97 to 1.64) for respiratory disease. On the other hand, a U shaped association was found between predicted lean body mass and mortality from cardiovascular disease and cancer. However, a strong inverse association existed between predicted lean body mass and mortality from respiratory disease (P for trend <0.001). CONCLUSIONS:The shape of the association between BMI and mortality was determined by the relation between two body components (lean body mass and fat mass) and mortality. This finding suggests that the "obesity paradox" controversy may be largely explained by low lean body mass, rather than low fat mass, in the lower range of BMI.