Relationship between self-reported and objectively measured physical activity and subjective memory impairment in breast cancer survivors: role of self-efficacy, fatigue and distress.

PURPOSE: Many breast cancer survivors report cancer and cancer treatment-associated cognitive change. However, very little is known about the relationship between physical activity and subjective memory impairment (SMI) in this population. The purpose of this study is to examine the relationship between physical activity and SMI and longitudinally test a model examining the role of self-efficacy, fatigue and distress as potential mediators. METHODS: Post-treatment breast cancer survivors (N = 1477) completed measures of physical activity, self-efficacy, distress (depression, concerns about recurrence, perceived stress, anxiety), fatigue and SMI at baseline and 6-month follow-up. A subsample (n = 362) was randomly selected to wear an accelerometer. It was hypothesized that physical activity indirectly influences SMI via exercise self-efficacy, distress and fatigue. Relationships were examined using panel analysis within a covariance modeling framework. RESULTS: The hypothesized model provided a good fit in the full sample (χ2 = 1462.5, df = 469, p = <0.001; CFI = 0.96; SRMR = 0.04) and the accelerometer subsample (χ2 = 961.8, df = 535, p = <0.001, CFI = 0.94, SRMR = 0.05) indicating increased physical activity is indirectly associated with reduction in SMI across time, via increased exercise self-efficacy and reduced distress and fatigue. CONCLUSIONS: Higher levels of physical activity, lower levels of fatigue and distress and higher exercise self-efficacy may play an important role in understanding SMI in breast cancer survivors across time. Future research is warranted to replicate and explore these relationships further. Copyright © 2016 John Wiley & Sons, Ltd.

Physical activity, self-efficacy and self-esteem in breast cancer survivors: a panel model.

PURPOSE: Physical activity (PA) has been consistently associated with improved self-esteem in breast cancer survivors. However, this relationship is poorly understood. The purpose of this study was to examine whether changes in PA and self-efficacy influenced changes in self-esteem in breast cancer survivors across 6 months. Increases in PA were hypothesized to result in increases in self-efficacy, which were hypothesized to influence increases in physical self-worth (PSW) and global self-esteem. METHODS: Breast cancer survivors (n = 370; Mage = 56.04) wore accelerometers to measure PA and completed measures of self-efficacy (e.g., exercise and barriers self-efficacy), PSW, and global self-esteem at baseline and 6 months. RESULTS: The hypothesized model provided a good fit to the data (χ2 = 67.56, df = 26, p < 0.001; comparative fit index (CFI) = 0.98; standardized root mean residual = 0.05). Women with higher activity at baseline reported significantly higher levels of barrier (ß = 0.29) and exercise (ß = 0.23) self-efficacy. In turn, more efficacious women reported significantly higher PSW (ß = 0.26, 0.16). Finally, higher PSW was significantly associated with greater global self-esteem (ß = 0.47). Relationships were similar among changes in model constructs over 6 months. After controlling for covariates, the hypothesized model provided an excellent fit to the data (χ2 = 59.93, df = 33, p = 0.003; comparative fit index = 0.99; standardized root mean residual = 0.03). CONCLUSION: Our findings provide support for the role played by PA and self-efficacy in positive self-esteem, a key component of well-being. Highlighting successful PA mastery experiences is likely to enhance self-efficacy and improve self-esteem in this population. Copyright © 2016 John Wiley & Sons, Ltd.

Correlates of objectively measured sedentary behavior in breast cancer survivors.

BACKGROUND: Emerging evidence indicates increased sedentary behavior is associated with poorer health outcomes and quality of life among cancer survivors. However, very little is known about which factors are associated with increased sedentary behavior. The purpose of the present study was to examine potential correlates of sedentary behavior among breast cancer survivors. METHODS: We used hierarchical general linear modeling to examine the associations between demographic, disease-specific, and psychosocial factors at baseline and accelerometer-estimated daily proportion of time spent sedentary at 6 months in breast cancer survivors [n = 342; M age = 56.7 (SD = 9.4)]. All models adjusted for objectively measured moderate and vigorous intensity physical activity and sedentary behavior at baseline. RESULTS: The final model including all baseline potential predictor variables and physical activity and sedentary behavior explained 49.8 % of the variance in the proportion of daily time spent sedentary at 6 months. The following factors were significantly (p < 0.05) associated with increased sedentary behavior among breast cancer survivors: higher number of comorbidities, more advanced disease stage, and increased fatigue severity. Additionally, being treated with surgery and chemotherapy was significantly related to a lower proportion of time spent sedentary compared to women who had received surgery alone. CONCLUSIONS: This study provides preliminary insight into factors associated with sedentary behavior in breast cancer survivors. Future research is warranted to understand the potential demographic, disease-specific, psychosocial correlates of sedentary behavior to determine which correlates are potential mechanisms of behavior change and intervention targets.

Objectively measured physical activity and sedentary behavior and quality of life indicators in survivors of breast cancer.

BACKGROUND: The primary purpose of the current study was to determine prospective associations of accelerometer-assessed physical activity intensity and sedentary time with health-related quality of life (HRQOL) indicators among survivors of breast cancer. METHODS: A total of 358 survivors of breast cancer wore an accelerometer for 7 days at baseline to assess different activity intensities (light, lifestyle, and moderate to vigorous) and sedentary behavior. Six months later, survivors completed online questionnaires that assessed HRQOL indicators (disease-specific HRQOL, fatigue, depression, and anxiety) and relevant covariates. Relationships between activity and sedentary behavior quartiles and HRQOL indicator scores were examined using generalized liner models with Bonferroni multiple comparison adjustment. RESULTS: After adjustment for covariates and sedentary time, each increasing lifestyle activity quartile was associated with reduced fatigue duration (P for trend, .03). Each increasing baseline moderate-to-vigorous physical activity (MVPA) quartile was found to be significantly associated with higher Physical Well-Being, Functional Assessment of Cancer Therapy-Breast (FACT-B) total, and trial outcome index scores; fewer breast cancer-specific concerns; and lower fatigue interference, and these differences were statistically and clinically significant between survivors in quartile 1 and quartile 4. After controlling for covariates and MVPA, relationships between sedentary time and HRQOL were mostly null with the exception of lower fatigue duration. CONCLUSIONS: Objectively measured MVPA was found to be positively associated with many HRQOL indicators. Lifestyle activity was found to be only inversely associated with fatigue duration whereas sedentary time was found to be positively associated with fatigue duration. Future research is warranted to explore these relationships further.

Differential exercise effects on quality of life and health-related quality of life in older adults: a randomized controlled trial.

PURPOSE: Maintaining quality of life (QOL) and physical and mental health status are important outcomes throughout the aging process. Although cross-sectional studies suggest a relationship between global QOL and physical activity, it is unclear whether such a relationship exists as a function of exercise training. METHODS: We examined the effects of two exercise intervention arms on health-related quality of life (HRQOL) and global QOL. Low-active, older adults (n = 179) were randomly assigned to either a 12-month aerobic walking group or a strengthening and flexibility group. HRQOL and QOL were measured at baseline, 6, and 12 months. RESULTS: There was a significant group by time effect on QOL [F(2,176) = 3.11, p = 0.047, η (2) = 0.03]. There was also a significant overall group by time effect for HRQOL [F(4,174) = 2.46, p = 0.047, η (2) = 0.05], which was explained by the significant group by time interaction for mental health status (p = 0.041, η (2) = 0.02) favoring the walking condition. Further analyses using latent class analysis revealed three classes of individuals with differential patterns of change in QOL and HRQOL across time. These classes reflected no change, declines, and improvements in these constructs across time. CONCLUSIONS: Walking appears to enhance the mental aspect of HRQOL and global QOL when compared to a non-aerobic intervention. Additionally, the patterns of change in QOL and HRQOL were not linear over time. Our findings are in contrast to previous reports that these outcomes change a little or not at all in randomized trials.

Effects of a randomized exercise trial on physical activity, psychological distress and quality of life in older adults.

OBJECTIVE: Evidence suggests improvements in positive psychological health indices (e.g., self-esteem) may explain the relationship between physical activity and quality of life (QoL) in older adults. Less is known about the role of reductions in negative psychological health indices (e.g., depression). The present study examined the effects of changes in moderate-to-vigorous physical activity (MVPA) and psychological distress on change in QoL in older adults enrolled in an exercise program. METHODS: Older adults (N=247, Mage=65.68±4.59) participated in a six-month randomized exercise trial. Participants wore accelerometers and completed questionnaires to measure MVPA, psychological health, and QoL at baseline and post-intervention. Psychological distress was modeled as a latent factor comprised of anxiety, depression, sleep dysfunction, and stress. Structural models were used to examine the effects of changes in MVPA and distress on change in QoL. RESULTS: Increases in MVPA predicted reductions in distress from baseline to post-intervention (B=-0.10, p=0.05). In turn, reductions in distress predicted increases in QoL (B=-0.51, p=0.001). The indirect effect of MVPA on QoL through distress was also significant (p=0.05; 90% CI=0.005, 0.125). CONCLUSIONS: Findings extend previous research on the mediators of the MVPA-QoL relationship in older adults, suggesting reductions in negative psychological health outcomes may also mediate this pathway.

Effects of Gait Self-Efficacy and Lower-Extremity Physical Function on Dual-Task Performance in Older Adults.

Objectives. Despite evidence of self-efficacy and physical function's influences on functional limitations in older adults, few studies have examined relationships in the context of complex, real-world tasks. The present study tested the roles of self-efficacy and physical function in predicting older adults' street-crossing performance in single- and dual-task simulations. Methods. Lower-extremity physical function, gait self-efficacy, and street-crossing success ratio were assessed in 195 older adults (60-79 years old) at baseline of a randomized exercise trial. During the street-crossing task, participants walked on a self-propelled treadmill in a virtual reality environment. Participants crossed the street without distraction (single-task trials) and conversed on a cell phone (dual-task trials). Structural equation modeling was used to test hypothesized associations independent of demographic and clinical covariates. Results. Street-crossing performance was better on single-task trials when compared with dual-task trials. Direct effects of self-efficacy and physical function on success ratio were observed in dual-task trials only. The total effect of self-efficacy was significant in both conditions. The indirect path through physical function was evident in the dual-task condition only. Conclusion. Physical function can predict older adults' performance on high fidelity simulations of complex, real-world tasks. Perceptions of function (i.e., self-efficacy) may play an even greater role. The trial is registered with United States National Institutes of Health ClinicalTrials.gov (ID: NCT01472744; Fit & Active Seniors Trial).

Regional Brain Volumes Moderate, but Do Not Mediate, the Effects of Group-Based Exercise Training on Reductions in Loneliness in Older Adults.

Introduction: Despite the prevalence of and negative health consequences associated with perceived loneliness in older adults, few studies have examined interactions among behavioral, psychosocial, and neural mechanisms. Research suggests that physical activity and improvements in perceived social support and stress are related to reductions in loneliness. Yet, the influence of brain structure on these changes is unknown. The present study examined whether change in regional brain volume mediated the effects of changes in social support and stress on change in perceived loneliness after an exercise intervention. We also examined the extent to which baseline brain volumes moderated the relationship between changes in social support, stress, and loneliness. Methods: Participants were 247 older adults (65.4 ± 4.6 years-old) enrolled in a 6-month randomized controlled trial comprised of four exercise conditions: Dance (n = 69), Strength/Stretching/Stability (n = 70), Walk (n = 54), and Walk Plus (n = 54). All groups met for 1 h, three times weekly. Participants completed questionnaires assessing perceived social support, stress, and loneliness at baseline and post-intervention. Regional brain volumes (amygdala, prefrontal cortex [PFC], hippocampus) before and after intervention were measured with automatic segmentation of each participant's T1-weighted structural MRI. Data were analyzed in a latent modeling framework. Results: Perceived social support increased (p = 0.003), while stress (p < 0.001), and loneliness (p = 0.001) decreased over the intervention. Increased social support directly (-0.63, p < 0.01) and indirectly, through decreased stress (-0.10, p = 0.02), predicted decreased loneliness. Changes in amygdala, PFC, and hippocampus volumes were unrelated to change in psychosocial variables (all p ≥ 0.44). However, individuals with larger baseline amygdalae experienced greater decreases in loneliness due to greater reductions in stress (0.35, p = 0.02). Further, individuals with larger baseline PFC volumes experienced greater reductions in stress due to greater increases in social support (-0.47, p = 0.02). No group differences in these pathways were observed. Conclusions: The social support environment and resulting reductions in stress, as opposed to exercise mode, may represent important features of exercise programs for improving older adults' perceived loneliness. As amygdala volume has been linked to anxiety, depression and impaired cognitive control processes in the PFC, moderation findings suggest further investigation in this area is warranted. Trial Registration: ClinicalTrials.gov identifier NCT01472744 (https://clinicaltrials.gov/ct2/show/NCT01472744?term=NCT01472744&rank=1).

White Matter Integrity Declined Over 6-Months, but Dance Intervention Improved Integrity of the Fornix of Older Adults.

Degeneration of cerebral white matter (WM), or structural disconnection, is one of the major neural mechanisms driving age-related decline in cognitive functions, such as processing speed. Past cross-sectional studies have demonstrated beneficial effects of greater cardiorespiratory fitness, physical activity, cognitive training, social engagement, and nutrition on cognitive functioning and brain health in aging. Here, we collected diffusion magnetic resonance (MRI) imaging data from 174 older (age 60-79) adults to study the effects of 6-months lifestyle interventions on WM integrity. Healthy but low-active participants were randomized into Dance, Walking, Walking + Nutrition, and Active Control (stretching and toning) intervention groups (NCT01472744 on ClinicalTrials.gov). Only in the fornix there was a time × intervention group interaction of change in WM integrity: integrity declined over 6 months in all groups but increased in the Dance group. Integrity in the fornix at baseline was associated with better processing speed, however, change in fornix integrity did not correlate with change in processing speed. Next, we observed a decline in WM integrity across the majority of brain regions in all participants, regardless of the intervention group. This suggests that the aging of the brain is detectable on the scale of 6-months, which highlights the urgency of finding effective interventions to slow down this process. Magnitude of WM decline increased with age and decline in prefrontal WM was of lesser magnitude in older adults spending less time sedentary and more engaging in moderate-to-vigorous physical activity. In addition, our findings support the anterior-to-posterior gradient of greater-to-lesser decline, but only in the in the corpus callosum. Together, our findings suggest that combining physical, cognitive, and social engagement (dance) may help maintain or improve WM health and more physically active lifestyle is associated with slower WM decline. This study emphasizes the importance of a physically active and socially engaging lifestyle among aging adults.

Contamination by an Active Control Condition in a Randomized Exercise Trial.

Contamination is commonly overlooked in randomized trials. The present study examined contamination (minutes of aerobic activity outside of exercise sessions) within an active control condition in a 6-month randomized exercise trial for older adults. We hypothesized that outside aerobic activity would be greater in the control condition compared to the intervention conditions. Participants (mean age = 65.06 years, 66.2% female) were randomly assigned to: Dance (n = 50), Walking, (n = 108), or Strength/Stretching/Stability (SSS; n = 48). Dance and Walking represented the experimental conditions and SSS the control condition. Participants attended exercise sessions three times weekly for 24 weeks. Participants recorded their physical activity outside of class on a weekly home log. Group assignment and covariates (age, gender, body mass index, exercise session intensity and enjoyment, and program adherence) were examined as predictors of weekly aerobic activity outside of exercise sessions. Participants who returned zero home logs were removed from the dataset (final N = 195). Out-of-class aerobic activity was lowest in the Walking group. Significant effects of gender, group, enjoyment, and intensity on out-of-class weekly aerobic activity were observed, all p<0.003. Higher perceived enjoyment of exercise sessions was associated with more out-of-class aerobic activity, while higher perceived intensity was associated with less out-of-class aerobic activity. A group x intensity interaction, p = 0.002, indicated that group differences in out-of-class aerobic activity were evident only among those with lower intensity perceptions. Walkers may have perceived exercise sessions as sufficient weekly exercise, while the Dance and SSS groups may have perceived the sessions as necessary, but insufficient. The lower aerobic intensity Dancers attributed to exercise sessions and non-aerobic nature of SSS may partially explain contamination observed in this study. Further examination of contamination in randomized controlled exercise trials is critically needed. TRIAL REGISTRATION: ClinicalTrials.gov NCT01472744.

Effects of a DVD-Delivered Exercise Intervention on Maintenance of Physical Activity in Older Adults.

BACKGROUND: Previous research supports the efficacy of a 6-month DVD-delivered program for enhancing physical activity (PA) in older adults. In the current study, we examined the degree to which intervention-related increases in PA were maintained after a 6-month, no-contact follow-up. METHODS: Follow-up assessments of PA via accelerometry and the Godin Leisure-Time Exercise Questionnaire (GLTEQ) were collected in a sample of older adults (N = 238). Repeated measures analyses of variance were conducted to examine changes in PA over the course of the follow-up period. RESULTS: For accelerometer measured PA, there was a significant time × treatment × age group interaction, F1,203 =11.319, P = .001, η2 = .053, such that younger (≤70 years) intervention participants maintained high levels of PA across the follow-up period, while PA in older intervention and young control participants declined significantly. Rates of PA in older control participants remained low over the course of the follow-up period. Analyses of GLTEQ scores revealed similar, though less significant patterns. CONCLUSIONS: DVD-based exercise programs may be effective for maintaining PA in younger members of the older adult population; however, there remains a need to develop better strategies for promoting PA maintenance in older individuals when using home-based designs.

Exercise Mode Moderates the Relationship Between Mobility and Basal Ganglia Volume in Healthy Older Adults.

OBJECTIVES: To examine whether 12 months of aerobic training (AT) moderated the relationship between change in mobility and change in basal ganglia volume than balance and toning (BAT) exercises in older adults. DESIGN: Secondary analysis of a randomized controlled trial. SETTING: Champaign-Urbana, Illinois. PARTICIPANTS: Community-dwelling older adults (N=101; mean age 66.4). INTERVENTION: Twelve-month exercise trial with two groups: AT and BAT. MEASUREMENTS: Mobility was assessed using the Timed Up and Go test. Basal ganglia (putamen, caudate nucleus, pallidum) was segmented from T1-weighted magnetic resonance images using the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain Software Library Integrated Registration and Segmentation Tool. Measurements were obtained at baseline and trial completion. Hierarchical multiple regression was conducted to examine whether exercise mode moderates the relationship between change in mobility and change in basal ganglia volume over 12 months. Age, sex, and education were included as covariates. RESULTS: Exercise significantly moderated the relationship between change in mobility and change in left putamen volume. Specifically, for the AT group, volume of the left putamen did not change, regardless of change in mobility. Similarly, in the BAT group, those who improved their mobility most over 12 months had no change in left putamen volume, although left putamen volume of those who declined in mobility levels decreased significantly. CONCLUSION: The primary finding that older adults who engaged in 12 months of BAT training and improved mobility exhibited maintenance of brain volume in an important region responsible for motor control provides compelling evidence that such exercises can contribute to the promotion of functional independence and healthy aging.

Associations Between Physical Fitness Indices and Working Memory in Breast Cancer Survivors and Age-Matched Controls.

BACKGROUND: This study examined the effects of cardiorespiratory fitness, heart rate recovery, and physical activity on working memory in breast cancer survivors and age-matched controls. METHOD: Using a case-control design, 32 women who had received a breast cancer diagnosis and completed primary treatment within the past 36-months (11 radiation only; 21 chemotherapy) and 30 age-matched women with no previous cancer diagnosis completed a n-back continuous performance task commonly used as an assessment of working memory. In addition, cardiorespiratory fitness and heart rate recovery were measured during a submaximal graded exercise test and physical activity was measured using 7-days of accelerometer monitoring. RESULTS: Breast cancer survivors who had received chemotherapy had poorer heart rate recovery (p = .010) and engaged in less physical activity than women who had received radiation only (p = .004) or non-cancer controls (p = .029). Cancer treatment (radiation; chemotherapy) predicted differences in reaction times on the 1-back working memory task (p = .029). However, more rapid heart rate recovery predicted shorter reaction times on the 1-back task in the age-matched control group (p = .002). All participants with greater cardiorespiratory fitness displayed greater accuracy independent of disease status on the 1-back task (p = .017). No significant group differences in reaction times were observed for 2-back target trials between breast cancer survivors and controls. However, greater total physical activity predicted shorter reaction times in breast cancer survivors (radiation, chemotherapy) on the 2-back task (p = .014). In addition, all participants who exhibited more rapid heart rate recovery demonstrated better greater accuracy regardless of disease status (p = .013). CONCLUSION: These findings support differences in physical activty participation, heart rate recovery, and 1- and 2-back working memory reaction times between breast cancer survivors and age-matched controls. Greater cardiorespiratory fitness, heart rate recovery, and physical activity were positively associated with better working memory performance across conditions.

Moderate Physical Activity Mediates the Association between White Matter Lesion Volume and Memory Recall in Breast Cancer Survivors.

Increased survival rates among breast cancer patients have drawn significant attention to consequences of both the presence of cancer, and the subsequent treatment-related impact on the brain. The incidence of breast cancer and the effects of treatment often result in alterations in the microstructure of white matter and impaired cognitive functioning. However, physical activity is proving to be a successful modifiable lifestyle factor in many studies that could prove beneficial to breast cancer survivors. This study investigates the link between white matter lesion volume, moderate physical activity, and cognition in breast cancer survivors following treatment compared to non-cancer age-matched controls. Results revealed that brain structure significantly predicted cognitive function via mediation of physical activity in breast cancer survivors. Overall, the study provided preliminary evidence suggesting moderate physical activity may help reduce the treatment related risks associated with breast cancer, including changes to WM integrity and cognitive impairment.

Maintenance Effects of a DVD-Delivered Exercise Intervention on Physical Function in Older Adults.

BACKGROUND: Exercise training has been demonstrated to enhance physical function and to have a protective effect against functional limitations and disability in older adults. PURPOSE: The objective of this study was to determine whether the effects of a home-based, DVD-delivered exercise intervention on functional performance and limitations were maintained 6-month postintervention termination. METHODS: Follow-up assessments of functional performance and limitations were conducted in a sample of community-dwelling older adults (N = 237) who participated in a 6-month randomized controlled exercise trial. Participants were initially randomized to a DVD-delivered exercise intervention or an attentional control condition. The Short Physical Performance Battery, measures of flexibility and strength, and functional limitations were assessed immediately before and after the intervention and then again 6 months later. Analyses of covariance were conducted to examine changes in physical function between the two conditions at the end of the intervention to 6-month follow-up. RESULTS: There were statistically significant adjusted group differences in the Short Physical Performance Battery (η(2) = 0.03, p = .01), upper-body strength (η(2) = 0.03, p = .005), and lower-body flexibility (η(2) = 0.02, p = .05), indicating that gains brought about by the intervention were maintained 6 months later. CONCLUSIONS: A DVD-delivered exercise program specifically designed to target elements of functional fitness in older adults can produce clinically meaningful gains in physical function that are maintained beyond intervention cessation.

Differential trajectories of well-being in older adult women: the role of optimism.

BACKGROUND: Well-being is important to healthy aging. The present study examined the trajectories and determinants of well-being in older women (n = 248) over a 39-month period. METHODS: Participants completed measures of optimism, pessimism, functional limitations, physical activity, and self-efficacy. Well-being, operationalised as life satisfaction, was assessed at baseline, 12, 24, and 39 months. Latent growth and class analyses examined trajectories of well-being and antecedents of change. RESULTS: The overall model testing a linear growth pattern fit the data well [χ(2) (df = 5) = 7.77, p = .17, CFI = .98, RMSEA = .05], revealing an overall significant, but modest decline in well-being. Three latent classes were further revealed; one class (n = 34, 13.3%) began with moderate levels of well-being (Mi = 25.4, p < .001), which decreased across time (Ms = -3.12, p < .001). A second class (n = 54, 21.8%) began with lower well-being (Mi = 17.1, p < .001) that remained low (Ms = .702, p = .378). The third class (n = 161, 64.9%) started with high levels of well-being (Mi = 28.4, p < .001) which were maintained (Ms = -.027, p = .841). Higher optimism and lower pessimism differentiated between declining well-being and maintaining well-being across time. CONCLUSIONS: Optimism and pessimism appear to differentiate patterns of well-being in community-dwelling older women. Promoting optimism-inducing strategies may be useful for maintaining well-being in older adulthood.