Direct and indirect effects of adiposity on markers of autonomic nervous system activity in older adults.

Several cardiovascular disease (CVD) risk factors (e.g., hypertension, poor glycemic control) can affect and be affected by autonomic nervous system (ANS) activity. Since excess adiposity can influence CVD development through its effect on hypertension and diabetes mellitus, it is important to determine how adiposity and altered ANS activity are related. The present study employed structural equation modeling to investigate the relation between adiposity and ANS activity both directly and indirectly through biological variables typically associated with glycemic impairment and cardiac stress in older adults. Utilizing the Atherosclerosis Risk in Communities (ARIC) dataset, 1,145 non-smoking adults (74±4.8 yrs, 62.8% female) free from known CVD, hypertension, and diabetes and not currently taking beta-blockers were evaluated for fasting blood glucose (FBG), insulin, and HbA1c concentrations, waist circumference (WC), blood pressure (BP), and markers of ANS activity. WC was recorded just above the iliac crest and was used to reflect central adiposity. Resting 2-minute electrocardiograph recordings, pulse wave velocity, and ankle-brachial index data were used to assess the root mean square of successive differences in RR intervals (RMSSD) and the pre-ejection period (PEP), markers of parasympathetic and sympathetic activity, respectively. FBG, insulin, and HbA1c inferred a latent variable termed glycemic impairment (GI), whereas heart rate and diastolic BP inferred a latent variable termed cardiac stress (CS). The structural equation model fit was acceptable [root mean square error of approximation = 0.050 (90% CI = .036, .066), comparative fit index = .970, Tucker Lewis Index = 0.929], with adiposity having both significant direct (ß = 0.208, p = 0.018) and indirect (ß = -.217, p = .041) effects on PEP through GI. Adiposity displayed no significant direct effect on RMSSD. CS displayed a significant pathway (ß = -0.524, p = 0.035) on RMSSD, but the indirect effect of WC on RMSSD through CS did not reach statistical significance (ß = -0.094, p = 0.137). These results suggest that adiposity's relation to ANS activity is multifaceted, as increased central adiposity had opposing direct and indirect effects on markers of sympathetic activity in this population of older adults.

A randomized controlled trial comparing changes in fitness with or without supervised exercise in patients initiated on enzalutamide and androgen deprivation therapy for non-metastatic castration-sensitive prostate cancer (EXTEND).

BACKGROUND: Androgen deprivation therapy (ADT) and androgen receptor signaling inhibitors (ARSI) are associated with deleterious physical effects, which exercise may mitigate; however, exercise has never been studied in patients initiating treatment with ADT and an ARSI. Our objective was to determine whether supervised exercise prior to and during initial therapy could mitigate adverse effects of ADT plus enzalutamide. METHODS: We conducted a single center trial in patients with recurrent prostate cancer treated with ADT and enzalutamide. We randomized 26 patients to 16 weeks of supervised exercise (aerobic and resistance), starting 4 weeks before initiation of ADT and enzalutamide, or usual care. The primary endpoint was change in peak oxygen uptake (VO2peak) as a measure of cardiorespiratory fitness (CRF). Secondary endpoints were functional capacity, maximal strength, body composition, patient-reported outcomes, safety, and feasibility. Analysis of covariance was used to compare outcomes for groups at Week 17 adjusted for baseline values. RESULTS: The usual care group (N = 13) showed declines from baseline to week 17 in both absolute CRF (-0.31 L/min, -10.9%; p < 0.01) and relative CRF (-3.2 mL/kg/min, -8.9%; p = 0.04); worse fatigue (p = 0.01); and worse quality of life (p = 0.01). At week 17, the exercise group (N = 13) demonstrated improved absolute CRF (between-group change +0.20 L/min, p = 0.05), leg strength (+48.6 kg, p < 0.01) and functional capacity (+21.0 m, p = 0.01) at week 17. CONCLUSIONS: This is the first randomized controlled trial demonstrating a clinically significant decline in CRF in patients initiating ADT and enzalutamide. We show the effectiveness of short-term supervised exercise to mitigate declines in absolute CRF, and improve maximal leg strength and functional capacity. GOV IDENTIFIER: NCT02256111.

Intrapersonal and Interpersonal Factors Influencing Physical Activity in Arab Americans.

BACKGROUND: Many Arab Americans do not meet the physical activity (PA) guidelines despite evidence to support health benefits. AIMS: We aimed to investigate the relationships between PA and sample characteristics, intrapersonal factors, and interpersonal factors and examine to what extent these factors influence PA in Arab Americans. A cross-sectional, descriptive-correlational design using a self-administered questionnaire with 140 Arab Americans was used. Spearman ρ correlation was used to assess the associations between PA and sample characteristics, intrapersonal factors, and interpersonal factors. Three simultaneous gamma regression models were used to assess to what extent these factors jointly influenced PA. RESULTS: Most participants (58.6%) reported a high level of PA. Significant positive associations were found between PA and health status, religiosity, and PA self-efficacy (rs = 0.21, P = .019; rs = 0.19, P = .029; and rs = 0.28, P = .003, respectively). Multiple regression models revealed that being employed (model 1: Exp[b] = 1.87, P = .030; Model 3: Exp[b] = 1.77, P = .043) and having chronic conditions (model 1: Exp[b] = 1.88, P = .031; model 2: Exp[b] = 1.96, P = .034; model 3: Exp[b] = 1.91, P = .047) were associated with greater PA, when accounting for other sample characteristics, intrapersonal factors, and interpersonal factors. CONCLUSION: Presence of chronic health conditions and employment status should be considered when promoting PA in Arab Americans. Future research is needed to explore the relationship between religiosity, PA self-efficacy, and PA in this population.

Aerobic, Resistance, and Combination Training on Health-Related Quality of Life: The STRRIDE-AT/RT Randomized Trial.

Purpose: The main purpose of this study was to determine the differential effects of aerobic training (AT), resistance training (RT), and a combination of aerobic and resistance training (AT/RT) on changes in self-rated HrQoL measures, including the Short-Form 36 (SF-36) survey and Satisfaction with Physical Function and Appearance survey. We also sought to determine if combination training (AT/RT) has a more or less additive effect compared to AT or RT alone on self-rated HrQoL measures. Materials and Methods: Participants (n = 137) completed one of three 8-month exercise interventions: (1) AT: 14 kcal exercise expenditure per kg of body weight per week (KKW; equivalent to roughly 12 miles/week) at 65-80% of peak oxygen consumption; (2) RT: 3 days per week, 8 exercises, 3 sets per exercise, 8-12 repetitions per set; (3) AT/RT: full combination of the AT and RT interventions. The SF-36 survey, Satisfaction with Physical Function and Appearance survey, physical fitness, and anthropometrics were assessed at baseline and post-intervention. Paired t-tests determined significant pre- vs. post-intervention scores within groups (p < 0.05). Analyses of covariance determined differences in change scores among groups (p < 0.05). Results: On average, participants were 49.0 ± 10.6 years old, obese (BMI: 30.6 ± 3.2 kg/m2), female (57.7%), and Caucasian (84.7%). Following the 8-month intervention, exercise groups improved peak VO2 (all groups), strength (RT and AT/RT), and anthropometric measures (AT and AT/RT). For the SF-36, RT (p = 0.03) and AT/RT (p < 0.001) significantly improved their physical component score; only AT/RT (p < 0.001) significantly improved their mental component score. Notably, all groups significantly improved both their satisfaction with physical function and appearance scores (All Groups: p < 0.001 for both outcomes). Conclusions: We found that aerobic, resistance, or combination exercise training improves several components of self-rated HrQoL, including physical function, appearance, and mental well-being. Clinical Trial Registration: No. NCT00275145.

Go with the FLOW: Implementation of a psychological skills intervention in an exercise program for post-bariatric surgery patients.

Bariatric surgery is an effective obesity treatment; however, most individuals regain weight following surgery. Following a Lifestyle of Wellness (FLOW) is a psychological skills intervention with strategies designed to increase self-efficacy and promote living a healthy lifestyle including regular physical activity. Eleven participants completed FLOW. Results indicated participants enjoyed the program and intended to continue this lifestyle upon program completion. Interviews indicated FLOW was effective for improving self-perceptions, and exercise motivation. The most effective sessions were goal setting, future planning, and stress management. Suggestions for program improvement were provided. This information can be used to improve the FLOW program and for implementation into other settings.

High-Intensity Exercise and Carbohydrate Supplementation do not Alter Plasma Visfatin.

The purpose of the study was to examine the effect of high-intensity exercise and carbohydrate supplementation (CHO) on plasma visfatin. On 2 separate days, 10 sprint-trained males (age = 26.4 ± 5.3 yr; Ht = 1.77 ± 0.03 m; Wt = 78.78 ± 9.10 kg; BF% = 13.96 ± 7.28%) completed 4, 3-min bouts of cycling at 50% mean anaerobic power, with 6 min of rest between bouts. On CHO day, subjects ingested 50g of CHO 30 min before exercise. On control day, subjects ingested a sugar-free drink (CON) 30 min before exercise. Blood was drawn before supplementation, 15 min before exercise, before and after each exercise bout, and 15 and 30 min post exercise. Visfatin, glucose, and insulin were determined. Truncal fat was assessed by dual energy x-ray. Visfatin was not significantly different between treatments (CHO vs CON) at any time point (p = 0.163), and was not significantly altered by exercise (p = 0.692). Insulin [25.65 vs 8.35 mU/l, CHO vs CON, respectively] and glucose [138.57 vs 98.10 mg/dl, CHO vs CON, respectively] were significantly elevated after CHO ingestion and remained elevated throughout the first half of exercise. Baseline visfatin was significantly correlated with truncal fat (r2 = 0.7782, p < 0.05). Visfatin was correlated to truncal fat in sprint-trained males, but was not altered by exercise or CHO supplementation.

Comparison of Estimations Versus Measured Oxygen Consumption at Rest in Patients With Heart Failure and Reduced Ejection Fraction Who Underwent Right-Sided Heart Catheterization.

Cardiac output during right-sided heart catheterization is an important variable for patient selection of advanced therapies (cardiac transplantation and left ventricular assist device implantation). The Fick method to determine cardiac output is commonly used and typically uses estimated oxygen consumption (VO2) from 1 of 3 published empirical formulas. However, these estimation equations have not been validated in patients with heart failure and reduced ejection fraction (HFrEF). The objectives of the present study were to determine the accuracy of 3 equations for estimating VO2 compared with direct measurement of VO2 and determine the extent clinically significant error occurred in calculating cardiac output of patients with HFrEF. Breath-by-breath measurements of VO2 from 44 patients who underwent cardiac catheterization (66% men; age, 65 ± 11 years, left ventricular ejection fraction, 22 ± 6%) were compared with the derived estimations of LaFarge and Miettinen, Dehmer et al, and Bergstra et al. Single-sample t tests found only the mean difference between the estimation of LaFarge and Miettinen and the measured VO2 to be nonsignificant (-10.3 ml/min ± 6.2 SE, p = 0.053). Bland-Altman plots demonstrated unacceptably large limits of agreement for all equations. The rate of ≥25% error in the equations by LaFarge and Miettinen, Dehmer et al, and Bergstra et al occurred in 11%, 23%, and 45% of patients, respectively. Misclassification of cardiac index derived from each equation for 2 clinically important classifications: cardiogenic shock-21%, 23%, and 32% and hypoperfusion-16%, 16%, and 25%; respectively. In conclusion, these findings do not support the use of these empiric formulas to estimate the VO2 at rest in patients with HFrEF who underwent right-sided heart catheterization.

Effects of exercise accumulation on plasma lipids and lipoproteins.

Debate exists as to whether improvements in some cardiometabolic risk factors following exercise training result more from the last session of, or from an accumulation of, exercise sessions. This study was designed to compare the effect of a single exercise session with 3 consecutive days of exercise on triglyceride (TG), high-density lipoprotein-cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C). Twelve young adult (aged 22.5±2.5 years), overweight (body mass index=29.7±4 kg·m(-2)), sedentary, black (n=5) and white (n=7) men (n=6) and women (n=6) completed, in random order, a single treadmill exercise session at 60% maximal oxygen uptake for 90 min (1EX), accumulated exercise sessions (same as for 1EX) for 3 consecutive days (3EX), and a control protocol (no exercise for 6 days). Plasma samples were collected from baseline through 24, 48, and 72 h postexercise. Significant treatment-by-time interactions (p<0.05) existed in HDL-C and LDL-C. Postexercise responses of HDL-C differed at 48 h (1EX: -3.6, 3EX: +3.7 mg·dL(-1)) and 72 h (1EX: -1.7, 3EX: +3.2 mg·dL(-1)). LDL-C responses differed at 48 h (1EX: -16, 3EX: +6 mg·dL(-1)). Although not statistically significant, TG concentrations decreased by 29% at 24 h after 3EX, compared with -7% after 1EX. An inverse relationship between baseline and postexercise reduction in TG was present with 3EX (r=-0.655; p<0.05). In conclusion, 3EX increased HDL-C and decreased TG more than 1EX, while the decrease in LDL-C after 1EX was suppressed. Blood lipid panel changes may be due to more accumulated effects over time rather than just a result of the most recent exercise session.

The obesity paradox in chronic heart failure: what does it mean?

Heart failure (HF) is a growing health problem, at least in part due to the concurrent obesity epidemic plaguing developed countries. However, once a patient develops HF, an elevated BMI appears to confer a survival benefit--a phenomenon termed the "obesity paradox." The exact explanation for this paradox has been difficult to ascertain. Numerous plausible mechanisms have been asserted, including the fact that obese patients tend to be younger and more symptomatic, leading them to seek medical attention earlier in the course of their HF. Obese patients may also have larger energy reserves that help to offset the catabolic changes seen with HF. Other hypotheses highlight the limitations of BMI as an obesity classifier. The purpose of this review is to examine the various theories for the obesity paradox in HF and discuss the implications for the clinical management of obese patients with HF.

A hybrid online intervention for reducing sedentary behavior in obese women.

Sedentary behavior (SB) has emerged as an independent risk factor for cardiovascular disease and type 2 diabetes. While exercise is known to reduce these risks, reducing SB through increases in non-structured PA and breaks from sitting may appeal to obese women who have lower self-efficacy for PA. This study examined effects of a combined face-to-face and online intervention to reduce SB in overweight and obese women. A two-group quasi-experimental study was used with measures taken pre and post. Female volunteers (M age = 58.5, SD = 12.5 years) were enrolled in the intervention (n = 40) or waitlisted (n = 24). The intervention, based on the Social Cognitive Theory, combined group sessions with email messages over 6 weeks. Individualized feedback to support mastery and peer models of active behaviors were included in the emails. Participants self-monitored PA with a pedometer. Baseline and post measures of PA and SB were assessed by accelerometer and self-report. Standard measures of height, weight, and waist circumference were conducted. Repeated measures ANOVA was used for analyses. Self-reported SB and light PA in the intervention group (I) changed significantly over time [SB, F(1, 2) = 3.81, p = 0.03, light PA, F(1, 2) = 3.39, p = 0.04]. Significant Group × Time interactions were found for light PA, F(1, 63) = 5.22, p = 0.03, moderate PA, F(1, 63) = 3.90, p = 0.05, and for waist circumference, F(1, 63) = 16.0, p = 0.001. The intervention group decreased significantly while the comparison group was unchanged. Hybrid computer interventions to reduce SB may provide a non-exercise alternative for increasing daily PA and potentially reduce waist circumference, a risk factor for type 2 diabetes. Consumer-grade accelerometers may aide improvements to PA and SB and should be tested as part of future interventions.

Effects of respiratory exchange ratio on the prognostic value of peak oxygen consumption and ventilatory efficiency in patients with systolic heart failure.

OBJECTIVES: The purpose of this analysis was to evaluate the prognostic characteristics of peak oxygen consumption (Vo2) and the minute ventilation/carbon dioxide (VE/Vco2) slope of different peak respiratory exchange ratios (RERs) obtained from cardiopulmonary exercise testing in patients with heart failure (HF). BACKGROUND: For patients with HF, peak Vo2 and the VE/Vco2 slope are used for assessing prognosis. Peak Vo2 is assessed in association with peak RER ≥1.10, indicating maximal effort and prognostic sensitivity. Conversely, the VE/Vco2 slope provides effort-independent prognostic discrimination. METHODS: Patients with HF scheduled to undergo cardiopulmonary exercise testing were enrolled. Patients were subclassified by peak RER (RER <1.00, RER 1.00 to 1.04, RER 1.05 to 1.09, RER ≥1.10) and followed for up to 3 years for major cardiac-related events (death, left ventricular assist device implantation, or cardiac transplantation). RESULTS: Included were 1,728 patients with HF (75% males; 40% ischemic etiology; age: 55 ± 14 years; left ventricular ejection fraction: 28 ± 10%). Two hundred seventy major events occurred, with no proportional differences across the RER subgroups. Multivariate Cox regression analysis indicated that the VE/Vco2 slope and peak Vo2 remained prognostic within each subgroup; the VE/Vco2 slope remained the strongest predictor. Receiver-operating characteristic analysis demonstrated equitable prognostic cutoffs for the VE/Vco2 slope (range: 34.9 to 35.7; area under the curve [AUC] range: 0.69 to 0.75) and peak Vo2 (range: 13.8 to 14.0 ml·kg(-1)·min(-1); AUC range: 0.68 to 0.75). CONCLUSIONS: Peak Vo2 provided a sensitive assessment of prognosis in patients with HF in all RER subgroups. The VE/Vco2 slope provided greater prognostic discrimination in all RER subgroups. Clinical consideration may be warranted for patients with low RER, low peak Vo2, and an elevated VE/Vco2 slope.

A university system-wide qualitative investigation into student physical activity promotion conducted on college campuses.

PURPOSE: This study aimed to examine college student physical activity promotion. DESIGN: A cross-sectional approach to qualitative research was used. SETTING: Southeastern state university system. PARTICIPANTS: Fourteen of 15 (93%) universities recruited were included in this study; 22 university employees participated in a semistructured interview. METHOD: Nonprobabilistic purposive and snowball sampling strategies were used to recruit individuals who were likely to be engaged in physical activity promotion efforts on their respective campuses. Thematic analyses lead to the identification of emerging themes that were coded and analyzed using NVivo software. RESULTS: Themes informed three main areas: key personnel responsible for promoting physical activity to students, actual physical activity promotion efforts implemented, and factors that influence student physical activity promotion. Results suggest that ecological approaches to promote physical activity on college campuses are underused, the targeting of mediators of physical activity in college students is limited, and values held by university administration influence campus physical activity promotion. CONCLUSION: Findings support recommendations for future research and practice. Practitioners should attempt to implement social ecological approaches that target scientifically established mediators of physical activity in college students. Replication of this study is needed to compare these findings with other types of universities, and to investigate the relationship between promotion activities (type and exposure) and physical activity behaviors of college students.

Effects of Tai Chi Chuan on insulin and cytokine levels in a randomized controlled pilot study on breast cancer survivors.

BACKGROUND: Tai Chi Chuan (TCC) is an integrative medicine mind-body practice with a physical activity component that has positive effects on aerobic capacity, muscular strength, and quality of life among cancer survivors, similar to the effects elicited by other modes of moderate-intensity exercise. Inflammatory cytokines and insulin and insulin-related signaling molecules may contribute to weight gain and affect cancer recurrence rates and survival; exercise can curb cancer- and treatment-related weight gain, increase survival, and reduce levels of insulin and inflammatory cytokines. Despite knowing the beneficial effects of conventional exercise interventions on these mediators, little is known about the physiologic effects of TCC on these pathways in breast cancer survivors. METHODS: We assessed the effects of a 12-week, moderately intense, TCC intervention (n = 9) compared with a non-physical activity control (n = 10) consisting of psychosocial support therapy (PST), on levels of insulin, insulin-like growth factor (IGF)-1, insulin growth factor-like binding protein (IGFBP)-1, IGFBP-3, and cytokines interleukin (IL)-6, IL-2, and interferon (IFN)-γ in breast cancer survivors. RESULTS: Levels of insulin are significantly different in TCC and PST groups; levels remained stable in the TCC group but increased in the PST control group (P = .099). Bivariate analysis revealed novel and significant correlations (all r > 0.45, all P ≤ .05) of both decreased fat mass and increased fat-free mass with increased IL-6 and decreased IL-2 levels. CONCLUSIONS: This pilot study shows that TCC may be associated with maintenance of insulin levels and changes in cytokine levels that may be important for maintenance of lean body mass in breast cancer survivors.

Axillary lymph node dissection for malignant melanoma.

BACKGROUND: Malignant melanoma is a common and life-threatening malignancy that often metastasizes to lymph nodes, necessitating lymph node dissections. Dissections aim for regional disease control. Dissections often result in significant morbidity and are associated with local recurrences (LRs) in the surgical field. This study aims to ascertain the LR rate and complication rate in axillary lymph node dissections (ALND) for malignant melanoma. It also aims to identify risk factors for both LR and complications. METHODS: This retrospective clinical study involved the analysis of 74 patients who were identified by the Victorian Melanoma Service database as having ALND between 1999 and 2008. Three patients underwent bilateral ALND and three patients underwent reoperative procedures following initial incomplete dissections. Patient demographics and information on the primary tumour was collected using a prospectively kept database and histopathological reports. Operative and post-operative information was obtained through a retrospective review of clinical notes and histopathological reports. RESULTS: Twelve (16%) patients developed LR at a median follow-up time of 9.5 months, and 32 (46%) patients had a post-operative complication. Kaplan­Meier estimates revealed an overall risk of LR to be 24.96% (95% CI: 13.8%­45.1%). Cox regression analysis revealed that having a primary melanoma upon the abdomen statistically significantly increased the risk of LR in the dissected field. (Hazard ratio 3.84; 95% CI: 1.0­15.0; P = 0.048). Twenty-eight (38%) patients died from disseminated disease. CONCLUSIONS: ALND is associated with a significant risk of post-operative complications. It can achieve regional disease control, but a significant risk of LR exists. If LR occurs the prognosis is very poor.

The hypertriglyceridemic waist phenotype among women.

BACKGROUND: Elevated plasma triglycerides (TG) and waist girth (hypertriglyceridemic waist (HTGW)) has been associated with elevated insulin, small dense low-density lipoprotein (sLDL) particles, and Apo B in men. The HTGW has not been reported for women and the effect of cardiorespiratory fitness ("fitness") on associations between HTGW and coronary risk factors is unknown. PURPOSE: To determine the prevalence of HTGW and the influence of fitness on the relationship between HTGW and coronary risk among 137 healthy women (54+/-9 year; body mass index (BMI)=28+/-6 kg/m(2)). METHODS: HTGW was defined as waist girth >88 cm and TG >150 mg/dl. The metabolic triad was defined as insulin >31 pmol/l, Apo B >69 mg/dl and LDL-C >84 mg/dl. Fitness was assessed with a maximal treadmill exercise test. RESULTS: The sample prevalence of HTGW (n=15) was 11% (95% CI=5.7-16.0%). Apo B (P=0.04) and insulin (P=0.0001) increased across quintiles of waist girth, and LDL-C (P=0.004) increased across quintiles of TG. Metabolic triad prevalence was highest (67%, n=10) among HTGW women and lowest (22%, n=26) among non-HTGW women. A trend for higher coronary heart disease CHD risk factors was observed among HTGW compared with non-HTGW women. Among the HTGW group, a trend for lower CHD risk factors was observed among fit (>or=6.5 METs, n=7) versus unfit women (<6.5 METs, n=8). Sample size limitations prohibited meaningful tests of significant differences in CHD risk factors when stratified simultaneously on HTGW and fitness status. CONCLUSIONS: HTGW is associated with increased coronary risk factors similarly among women as reported for men. Higher fitness may improve the CHD risk profile among women with HTGW.