Race and sex differences in dropout from the STRRIDE trials.

Purpose: To determine if race and sex differences exist in determinants and timing of dropout among individuals enrolled in an exercise and/or caloric restriction intervention. Methods: A total of 947 adults with dyslipidemia (STRRIDE I, STRRIDE AT/RT) or prediabetes (STRRIDE-PD) were randomized to either inactive control or to 1 of 10 exercise interventions, ranging from doses of 8-23 kcal/kg/week, intensities of 50%-75% V˙O2 peak, and durations of 6-8 months. Two groups included resistance training, and one included a dietary intervention (7% weight loss goal). Dropout was defined as an individual withdrawn from the study, with the reasons for dropout aggregated into determinant categories. Timing of dropout was defined as the last session attended and aggregated into phases (i.e., "ramp" period to allow gradual adaptation to exercise prescription). Utilizing descriptive statistics, percentages were generated according to categories of determinants and timing of dropout to describe the proportion of individuals who fell within each category. Results: Black men and women were more likely to be lost to follow-up (Black men: 31.3% and Black women: 19.6%), or dropout due to work responsibilities (15.6% and 12.5%), "change of mind" (12.5% and 8.9%), transportation issues (6.3% and 3.6%), or reported lack of motivation (6.3% and 3.6%). Women in general noted lack of time more often than men as a reason for dropout (White women: 22.4% and Black women: 22.1%). Regardless of race and sex, most participants dropped out during the ramp period of the exercise intervention; with Black women (50%) and White men (37.1%) having the highest dropout rate during this period. Conclusion: These findings emphasize the importance of targeted retention strategies when aiming to address race and sex differences that exist in determinants and timing of dropout among individuals enrolled in an exercise and/or caloric restriction intervention.

Total daily energy expenditure has declined over the past three decades due to declining basal expenditure, not reduced activity expenditure.

Obesity is caused by a prolonged positive energy balance1,2. Whether reduced energy expenditure stemming from reduced activity levels contributes is debated3,4. Here we show that in both sexes, total energy expenditure (TEE) adjusted for body composition and age declined since the late 1980s, while adjusted activity energy expenditure increased over time. We use the International Atomic Energy Agency Doubly Labelled Water database on energy expenditure of adults in the United States and Europe (n = 4,799) to explore patterns in total (TEE: n = 4,799), basal (BEE: n = 1,432) and physical activity energy expenditure (n = 1,432) over time. In males, adjusted BEE decreased significantly, but in females this did not reach significance. A larger dataset of basal metabolic rate (equivalent to BEE) measurements of 9,912 adults across 163 studies spanning 100 years replicates the decline in BEE in both sexes. We conclude that increasing obesity in the United States/Europe has probably not been fuelled by reduced physical activity leading to lowered TEE. We identify here a decline in adjusted BEE as a previously unrecognized factor.

Variability in energy expenditure is much greater in males than females.

In mammals, trait variation is often reported to be greater among males than females. However, to date, mainly only morphological traits have been studied. Energy expenditure represents the metabolic costs of multiple physical, physiological, and behavioral traits. Energy expenditure could exhibit particularly high greater male variation through a cumulative effect if those traits mostly exhibit greater male variation, or a lack of greater male variation if many of them do not. Sex differences in energy expenditure variation have been little explored. We analyzed a large database on energy expenditure in adult humans (1494 males and 3108 females) to investigate whether humans have evolved sex differences in the degree of interindividual variation in energy expenditure. We found that, even when statistically comparing males and females of the same age, height, and body composition, there is much more variation in total, activity, and basal energy expenditure among males. However, with aging, variation in total energy expenditure decreases, and because this happens more rapidly in males, the magnitude of greater male variation, though still large, is attenuated in older age groups. Considerably greater male variation in both total and activity energy expenditure could be explained by greater male variation in levels of daily activity. The considerably greater male variation in basal energy expenditure is remarkable and may be explained, at least in part, by greater male variation in the size of energy-demanding organs. If energy expenditure is a trait that is of indirect interest to females when choosing a sexual partner, this would suggest that energy expenditure is under sexual selection. However, we present a novel energetics model demonstrating that it is also possible that females have been under stabilizing selection pressure for an intermediate basal energy expenditure to maximize energy available for reproduction.

Human total, basal and activity energy expenditures are independent of ambient environmental temperature.

Lower ambient temperature (Ta) requires greater energy expenditure to sustain body temperature. However, effects of Ta on human energetics may be buffered by environmental modification and behavioral compensation. We used the IAEA DLW database for adults in the USA (n = 3213) to determine the effect of Ta (-10 to +30°C) on TEE, basal (BEE) and activity energy expenditure (AEE) and physical activity level (PAL). There were no significant relationships (p > 0.05) between maximum, minimum and average Ta and TEE, BEE, AEE and PAL. After adjustment for fat-free mass, fat mass and age, statistically significant (p < 0.01) relationships between TEE, BEE and Ta emerged in females but the effect sizes were not biologically meaningful. Temperatures inside buildings are regulated at 18-25°C independent of latitude. Hence, adults in the US modify their environments to keep TEE constant across a wide range of external ambient temperatures.

Field-Based Assessments of Behavioral Patterns During Shiftwork in Police Academy Trainees Using Wearable Technology.

Circadian misalignment, as occurs in shiftwork, is associated with numerous negative health outcomes. Here, we sought to improve data labeling accuracy from wearable technology using a novel data pre-processing algorithm in 27 police trainees during shiftwork. Secondarily, we explored changes in four metabolic salivary biomarkers of circadian rhythm during shiftwork. Using a two-group observational study design, participants completed in-class training during dayshift for 6 weeks followed by either dayshift or nightshift field-training for 6 weeks. Using our novel algorithm, we imputed labels of circadian misaligned sleep episodes that occurred during daytime, which were previously were mislabeled as non-sleep by Garmin, supported by algorithm performance analysis. We next assessed changes to resting heart rate and sleep regularity index during dayshift versus nightshift field-training. We also examined changes in field-based assessments of salivary cortisol, uric acid, testosterone, and melatonin during dayshift versus nightshift. Compared to dayshift, nightshift workers experienced larger changes to resting heart rate, sleep regularity index (indicating reduced sleep regularity), and alterations in sleep/wake activity patterns accompanied by blunted salivary cortisol. Salivary uric acid and testosterone did not change. These findings show wearable technology combined with specialized data pre-processing can be used to monitor changes in behavioral patterns during shiftwork.

Total energy expenditure is repeatable in adults but not associated with short-term changes in body composition.

Low total energy expenditure (TEE, MJ/d) has been a hypothesized risk factor for weight gain, but repeatability of TEE, a critical variable in longitudinal studies of energy balance, is understudied. We examine repeated doubly labeled water (DLW) measurements of TEE in 348 adults and 47 children from the IAEA DLW Database (mean ± SD time interval: 1.9 ± 2.9 y) to assess repeatability of TEE, and to examine if TEE adjusted for age, sex, fat-free mass, and fat mass is associated with changes in weight or body composition. Here, we report that repeatability of TEE is high for adults, but not children. Bivariate Bayesian mixed models show no among or within-individual correlation between body composition (fat mass or percentage) and unadjusted TEE in adults. For adults aged 20-60 y (N = 267; time interval: 7.4 ± 12.2 weeks), increases in adjusted TEE are associated with weight gain but not with changes in body composition; results are similar for subjects with intervals >4 weeks (N = 53; 29.1 ± 12.8 weeks). This suggests low TEE is not a risk factor for, and high TEE is not protective against, weight or body fat gain over the time intervals tested.

Daily energy expenditure through the human life course.

Total daily energy expenditure ("total expenditure") reflects daily energy needs and is a critical variable in human health and physiology, but its trajectory over the life course is poorly studied. We analyzed a large, diverse database of total expenditure measured by the doubly labeled water method for males and females aged 8 days to 95 years. Total expenditure increased with fat-free mass in a power-law manner, with four distinct life stages. Fat-free mass-adjusted expenditure accelerates rapidly in neonates to ~50% above adult values at ~1 year; declines slowly to adult levels by ~20 years; remains stable in adulthood (20 to 60 years), even during pregnancy; then declines in older adults. These changes shed light on human development and aging and should help shape nutrition and health strategies across the life span.

Systolic Blood Pressure and Socioeconomic Status in a large multi-study population.

The present study used harmonized data from eight studies (N = 28,891) to examine the association between socioeconomic status (SES) and resting systolic blood pressure (SBP). The study replicates and extends our prior work on this topic by examining potential moderation of this association by race and gender. We also examined the extent to which body mass index (BMI), waist circumference (WC), and smoking might explain the association between SES and SBP. Data were available from six race/gender groups: 9200 Black women; 2337 Black men; 7248 White women; 6519 White men; 2950 Hispanic women; and 637 Hispanic men. Multivariable regression models showed that greater annual household income was associated with lower SBP in all groups except Hispanic men. The magnitude and form of this negative association differed across groups, with White women showing the strongest linear negative association. Among Black men and Hispanic women, the association was curvilinear: relatively flat among lower income levels, but then negative among higher income ranges. Education also was independently, negatively related to SBP, though evidence was weaker for race and gender differences in the strength of the association. Higher BMI and WC were associated with higher SBP, and current smoking with lower SBP. Inclusion of these risk factors resulted in only a modest change in the magnitude of the SBP and SES relation, accounting on average about 0.4 mmHg of the effect of income and 0.2 mmHg of the effect of education-effects unlikely to be clinically significant. Further understanding of mechanisms underlying the association between SBP and SES may improve risk stratification in clinical settings and potentially inform interventions aimed at reductions in social disparities in health.

Combined Inflammation and Metabolism Biomarker Indices of Robust and Impaired Physical Function in Older Adults.

OBJECTIVES: To determine whether combinations of inflammatory markers are related to physical function. DESIGN AND SUBJECTS: secondary analysis of baseline of three observational studies of community-dwelling older adults MEASUREMENTS: The baseline data from 3 cohorts of older adults with different health and disease status were employed. Twenty markers of inflammation and metabolism were individually assessed for correlation with usual gait speed and were separated into robust and impairment quartiles. For the robustness and impairment indices, individual markers were selected using step-wise regression over bootstrapping iterations, and regression coefficients were estimated for the markers individually and collectively as an additive score. RESULTS: We developed a robustness index involving 6 markers and an impairment index involving 8 markers corresponding positively and negatively with gait speed. Two markers, glycine and tumor necrosis factor receptor 1 (TNFR1), appeared only in the robustness index, and TNFR2; regulated on activation, normal T-cell expressed and secreted; the amino acid factor; and matrix metallopeptidase 3; appeared only in the impairment index. CONCLUSION: Indices of biomarkers were associated with robust and impaired physical performance but differ, in composition suggesting potential biological differences that may contribute to robustness and impairment.

Fine particulate matter and cardiovascular disease: Comparison of assessment methods for long-term exposure.

BACKGROUND: Adverse cardiovascular events have been linked with PM2.5 exposure obtained primarily from air quality monitors, which rarely co-locate with participant residences. Modeled PM2.5 predictions at finer resolution may more accurately predict residential exposure; however few studies have compared results across different exposure assessment methods. METHODS: We utilized a cohort of 5679 patients who had undergone a cardiac catheterization between 2002-2009 and resided in NC. Exposure to PM2.5 for the year prior to catheterization was estimated using data from air quality monitors (AQS), Community Multiscale Air Quality (CMAQ) fused models at the census tract and 12km spatial resolutions, and satellite-based models at 10km and 1km resolutions. Case status was either a coronary artery disease (CAD) index >23 or a recent myocardial infarction (MI). Logistic regression was used to model odds of having CAD or an MI with each 1-unit (µg/m3) increase in PM2.5, adjusting for sex, race, smoking status, socioeconomic status, and urban/rural status. RESULTS: We found that the elevated odds for CAD>23 and MI were nearly equivalent for all exposure assessment methods. One difference was that data from AQS and the census tract CMAQ showed a rural/urban difference in relative risk, which was not apparent with the satellite or 12km-CMAQ models. CONCLUSIONS: Long-term air pollution exposure was associated with coronary artery disease for both modeled and monitored data.

Body-composition changes in the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE)-2 study: a 2-y randomized controlled trial of calorie restriction in nonobese humans.

Background: Calorie restriction (CR) retards aging and increases longevity in many animal models. However, it is unclear whether CR can be implemented in humans without adverse effects on body composition.Objective: We evaluated the effect of a 2-y CR regimen on body composition including the influence of sex and body mass index (BMI; in kg/m2) among participants enrolled in CALERIE-2 (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy), a multicenter, randomized controlled trial.Design: Participants were 218 nonobese (BMI: 21.9-28.0) adults aged 21-51 y who were randomly assigned to 25% CR (CR, n = 143) or ad libitum control (AL, n = 75) in a 2:1 ratio. Measures at baseline and 12 and 24 mo included body weight, waist circumference, fat mass (FM), fat-free mass (FFM), and appendicular mass by dual-energy X-ray absorptiometry; activity-related energy expenditure (AREE) by doubly labeled water; and dietary protein intake by self-report. Values are expressed as means ± SDs.Results: The CR group achieved 11.9% ± 0.7% CR over 2-y and had significant decreases in weight (-7.6 ± 0.3 compared with 0.4 ± 0.5 kg), waist circumference (-6.2 ± 0.4 compared with 0.9 ± 0.5 cm), FM (-5.4 ± 0.3 compared with 0.5 ± 0.4 kg), and FFM (-2.0 ± 0.2 compared with -0.0 ± 0.2 kg) at 24 mo relative to the AL group (all between-group P < 0.001). Moreover, FFM as a percentage of body weight at 24 mo was higher, and percentage of FM was lower in the CR group than in the AL. AREE, but not protein intake, predicted preservation of FFM during CR (P < 0.01). Men in the CR group lost significantly more trunk fat (P = 0.03) and FFM expressed as a percentage of weight loss (P < 0.001) than women in the CR group.Conclusions: Two years of CR had broadly favorable effects on both whole-body and regional adiposity that could facilitate health span in humans. The decrements in FFM were commensurate with the reduced body mass; although men in the CR group lost more FFM than the women did, the percentage of FFM in the men in the CR group was higher than at baseline. CALERIE was registered at clinicaltrials.gov as NCT00427193.

A Guide for a Cardiovascular Genomics Biorepository: the CATHGEN Experience.

The CATHeterization GENetics (CATHGEN) biorepository was assembled in four phases. First, project start-up began in 2000. Second, between 2001 and 2010, we collected clinical data and biological samples from 9334 individuals undergoing cardiac catheterization. Samples were matched at the individual level to clinical data collected at the time of catheterization and stored in the Duke Databank for Cardiovascular Diseases (DDCD). Clinical data included the following: subject demographics (birth date, race, gender, etc.); cardiometabolic history including symptoms; coronary anatomy and cardiac function at catheterization; and fasting chemistry data. Third, as part of the DDCD regular follow-up protocol, yearly evaluations included interim information: vital status (verified via National Death Index search and supplemented by Social Security Death Index search), myocardial infarction (MI), stroke, rehospitalization, coronary revascularization procedures, medication use, and lifestyle habits including smoking. Fourth, samples were used to generate molecular data. CATHGEN offers the opportunity to discover biomarkers and explore mechanisms of cardiovascular disease.

Earbud-based sensor for the assessment of energy expenditure, HR, and VO2max.

INTRODUCTION/PURPOSE: The goal of this program was to determine the feasibility of a novel noninvasive, highly miniaturized optomechanical earbud sensor for accurately estimating total energy expenditure (TEE) and maximum oxygen consumption (VO2max). The optomechanical sensor module, small enough to fit inside commercial audio earbuds, was previously developed to provide a seamless way to measure blood flow information during daily life activities. The sensor module was configured to continuously measure physiological information via photoplethysmography and physical activity information via accelerometry. This information was digitized and sent to a microprocessor where digital signal-processing algorithms extract physiological metrics in real time. These metrics were streamed wirelessly from the earbud to a computer. METHODS: In this study, 23 subjects of multiple physical habitus were divided into a training group of 14 subjects and a validation group of 9 subjects. Each subject underwent the same exercise measurement protocol consisting of treadmill-based cardiopulmonary exercise testing to reach VO2max. Benchmark sensors included a 12-lead ECG sensor for measuring HR, a calibrated treadmill for measuring distance and speed, and a gas-exchange analysis instrument for measuring TEE and VO2max. The earbud sensor was the device under test. Benchmark and device under test data collected from the 14-person training data set study were integrated into a preconceived statistical model for correlating benchmark data with earbud sensor data. Coefficients were optimized, and the optimized model was validated in the 9-person validation data set. RESULTS: It was observed that the earbud sensor estimated TEE and VO2max with mean ± SD percent estimation errors of -0.7 ± 7.4% and -3.2 ± 7.3%, respectively. CONCLUSION: The earbud sensor can accurately estimate TEE and VO2max during cardiopulmonary exercise testing.

Use of the Corus® CAD Gene Expression Test for Assessment of Obstructive Coronary Artery Disease Likelihood in Symptomatic Non-Diabetic Patients.

The determination of the underlying etiology of symptoms suggestive of obstructive coronary artery disease (CAD, ≥50% stenosis in a major coronary artery) is a common clinical challenge in both primary care and cardiology clinics. Usual care in low to medium risk patients often involves a family history, risk factor assessment, and then stress testing with or without non-invasive imaging. If positive, this is often followed by invasive coronary angiography (ICA). Despite extensive adoption of this usual care paradigm, more than 60% of patients referred for angiography do not have obstructive CAD. In order to robustly identify those symptomatic patients without obstructive CAD, who can avoid subsequent cardiac testing and look elsewhere for the cause of their symptoms, a recently described whole blood gene expression score (GES: Corus® CAD, CardioDx, Inc., Palo Alto, CA) has been developed and validated in two multi-center trials. This paper reviews the published literature and assessments by independent parties regarding the analytical and clinical validity as well as the clinical utility of the Corus® CAD test.

In-hospital resource use and medical costs in the last year of life by mode of death (from the HF-ACTION randomized controlled trial).

Patterns of medical resource use near the end of life may differ across modes of death. The aim of this study was to characterize patterns of inpatient resource use and direct costs for patients with heart failure (HF) who died of sudden cardiac death (SCD), HF, other cardiovascular causes, or noncardiovascular causes during the last year of life. Data were from a randomized trial of exercise training in patients with HF. Mode of death was adjudicated by an end point committee. Generalized estimating equations were used to compare hospitalizations, inpatient days, and inpatient costs incurred during the final year of life in patients who died of different causes, adjusting for clinical and treatment characteristics. Of 2,331 patients enrolled in the trial, 231 died after ≥1 year of follow-up with an adjudicated mode of death, including 72 of SCD, 80 of HF, 34 of other cardiovascular causes, and 45 of noncardiovascular causes. Patients who died of SCD were younger, had less severe HF, and incurred fewer hospitalizations, fewer inpatient days, and lower inpatient costs than patients who died of other causes. After adjustment for patient characteristics, inpatient resource use varied by 2 to 4 times across modes of death, suggesting that cost-effectiveness analyses of interventions that reduce mortality from SCD compared to other causes should incorporate mode-specific end-of-life costs. In conclusion, resource use and associated medical costs in the last year of life differed markedly in patients with HF who experienced SCD and patients who died of other causes.

Metabolic deterioration of the sedentary control group in clinical trials.

Randomized clinical trials of exercise training regimens in sedentary individuals have provided a mechanistic understanding of the long-term health benefits and consequences of physical activity and inactivity. The sedentary control periods from these trials have provided evidence of the progressive metabolic deterioration that results from as little as 4-6 mo of continuing a physically inactive lifestyle. These clinical trials have also demonstrated that only a modest amount of physical activity is required to prevent this metabolic deterioration, and this amount of physical activity is consistent with current physical activity recommendations (150 min/wk of moderate intensity physical activity). These recommendations have been issued to the general population for a vast array of health benefits. While greater adherence to these recommendations should result in substantial improvements in the health of the population, these recommendations still remain inadequate for many individuals. An individual's physical activity requirements are influenced by such factors as an individual's diet, nonexercise physical activity patterns, genetic profile, and medications. Improving the understanding of how these factors influence an individual's physical activity requirements will help advance the field and help move the field toward the development of more personalized physical activity recommendations.

Development of a blood-based gene expression algorithm for assessment of obstructive coronary artery disease in non-diabetic patients.

BACKGROUND: Alterations in gene expression in peripheral blood cells have been shown to be sensitive to the presence and extent of coronary artery disease (CAD). A non-invasive blood test that could reliably assess obstructive CAD likelihood would have diagnostic utility. RESULTS: Microarray analysis of RNA samples from a 195 patient Duke CATHGEN registry case:control cohort yielded 2,438 genes with significant CAD association (p < 0.05), and identified the clinical/demographic factors with the largest effects on gene expression as age, sex, and diabetic status. RT-PCR analysis of 88 CAD classifier genes confirmed that diabetic status was the largest clinical factor affecting CAD associated gene expression changes. A second microarray cohort analysis limited to non-diabetics from the multi-center PREDICT study (198 patients; 99 case: control pairs matched for age and sex) evaluated gene expression, clinical, and cell population predictors of CAD and yielded 5,935 CAD genes (p < 0.05) with an intersection of 655 genes with the CATHGEN results. Biological pathway (gene ontology and literature) and statistical analyses (hierarchical clustering and logistic regression) were used in combination to select 113 genes for RT-PCR analysis including CAD classifiers, cell-type specific markers, and normalization genes.RT-PCR analysis of these 113 genes in a PREDICT cohort of 640 non-diabetic subject samples was used for algorithm development. Gene expression correlations identified clusters of CAD classifier genes which were reduced to meta-genes using LASSO. The final classifier for assessment of obstructive CAD was derived by Ridge Regression and contained sex-specific age functions and 6 meta-gene terms, comprising 23 genes. This algorithm showed a cross-validated estimated AUC = 0.77 (95% CI 0.73-0.81) in ROC analysis. CONCLUSIONS: We have developed a whole blood classifier based on gene expression, age and sex for the assessment of obstructive CAD in non-diabetic patients from a combination of microarray and RT-PCR data derived from studies of patients clinically indicated for invasive angiography. CLINICAL TRIAL REGISTRATION INFORMATION: PREDICT, Personalized Risk Evaluation and Diagnosis in the Coronary Tree, http://www.clinicaltrials.gov, NCT00500617.

Design and conduct of the CALERIE study: comprehensive assessment of the long-term effects of reducing intake of energy.

BACKGROUND: In a robust and consistent manner, sustained caloric restriction (CR) has been shown to retard the aging process in a variety of animal species. Nonhuman primate studies suggest that CR may have similar effects in longer-lived species. The CALERIE (Comprehensive Assessment of the Long-term Effects of Reducing Intake of Energy) research program is the first systematic investigation of CR in nonobese human beings. In the phase 2 study, it is hypothesized that 2 years of sustained CR, involving a 25% reduction of ad libitum energy intake, results in beneficial effects similar to those observed in animal studies. This article presents the design and implementation of this study. METHODS: The study is a multicenter, parallel-group, randomized controlled trial. A sample of 225 participants (22.0 ≤ body mass index [BMI] < 28.0 kg/m(2)) is being enrolled with 2:1 allocation to CR. RESULTS: An intensive dietary and behavioral intervention was developed to achieve 25% CR and sustain it over the 2 years. Adherence is monitored using a doubly labeled water technique. Primary outcomes are resting metabolic rate and core temperature, and are assessed at baseline and at 6-month intervals. Secondary outcomes address oxyradical formation, cardiovascular risk markers, insulin sensitivity and secretion, immune function, neuroendocrine function, quality of life and cognitive function. Biologic materials are stored in a central repository. CONCLUSIONS: An intricate protocol has been developed to conduct this study. Procedures have been implemented to safeguard the integrity of the data and the conclusions drawn. The results will provide insight into the detrimental changes associated with the human aging process and how CR mitigates these effects.

Quantitative assessment of cardiorespiratory fitness, skeletal muscle function, and body composition in adults with primary malignant glioma.

BACKGROUND: The study was undertaken to evaluate cardiorespiratory fitness, skeletal muscle function, and body composition of patients with newly diagnosed and untreated, postsurgical primary malignant glioma. METHODS: By using a cross-sectional design, patients with clinically stable (10 +/- 7 days postsurgery) high-grade glioma (HGG; n = 25) or low-grade glioma (LGG; n = 10) were studied. Participants performed a cardiopulmonary exercise test (CPET) with expired gas analysis to assess cardiorespiratory fitness (peak oxygen consumption, VO2peak). Other physiological outcomes included skeletal muscle cross-sectional area (CSA; magnetic resonance imaging), isokinetic muscle strength (isokinetic dynamometer), and body composition (air displacement plethysmography). Quality of life was assessed with the Functional Assessment of Cancer Therapy-Brain scale. RESULTS: CPET was a feasible and safe procedure to assess VO2peak, with no serious adverse events. VO2peak indexed to total body weight and lean body mass (LBM) for both groups was 13.0 mL x weight x min(-1) and 19 mL x LBM x min(-1), the equivalent to 59% and 38% below age- and sex-predicted normative values, respectively. Skeletal muscle strength and mid-thigh CSA were lower in HGG relative to LGG patients (83 vs 125 Nm, P = .025; 94 vs 119 cm2, P = .171, respectively). Skeletal muscle isokinetic strength, CSA, and body composition outcomes predicted VO2peak (r = -0.59 to 0.68, P < .05). CONCLUSIONS: Postsurgical glioma patients have markedly reduced cardiorespiratory fitness, isokinetic strength, and CSA. Prospective studies are now required to determine whether such abnormalities influence treatment toxicity and clinical outcome as well as to test the effect of appropriately selected interventions to prevent and/or mitigate dysfunction.

Effects of exercise training amount on physical activity energy expenditure.

INTRODUCTION: We examined the effects of three exercise training interventions on total physical activity energy expenditure (PAEE) or nonexercise PAEE in a randomized controlled trial where sedentary, overweight, and obese men and women were assigned to inactive control, low-amount/moderate-intensity, low-amount/vigorous-intensity, or high-amount/vigorous-intensity aerobic exercise. METHODS: To measure PAEE, triaxial RT3 accelerometers were worn by subjects for 7 d at the beginning and end of an 8-month exercise intervention. In total, 50 subjects (control, n = 8; two low-amount groups, n = 28; high-amount group, n = 14) had usable PAEE data collected at both time points. RESULTS: At baseline, subjects had an average age of 53.2 yr, had a body mass index of 29.7 kg x m(-2), and a relative peak VO2 of 28.7 mL x kg(-1) x min(-1). There were no significant differences between groups at baseline. After the intervention, average change in total PAEE was 8.4 +/- 20.9 kJ x h(-1) for controls, 58.6 +/- 20.9 kJ x h(-1) for the two low-amount groups, and 138.1 +/- 33.5 kJ x h(-1) for the high-amount group (means +/- SE). The high-amount group experienced a significantly greater increase in total PAEE compared with the controls (P = 0.02). As expected, total PAEE increased with increasing exercise volume. Average change in nonexercise PAEE was 8.4 +/- 20.9 kJ x h(-1) for control, 25.1 +/- 20.9 kJ x h(-1) for the low-amount groups combined, and 62.8 +/- 29.3 kJ x h(-1) for the high-amount group. There was no statistically significant difference in change of nonexercise PAEE among groups. CONCLUSIONS: We conclude that in middle-aged overweight or obese subjects participating in an extended exercise intervention, total PAEE increased, and there was no compensatory decrease in nonexercise PAEE.