Internet intervention for increasing physical activity in persons with multiple sclerosis

Background:Physical activity has been associated with improvements in walking mobility and quality of life in persons with multiple sclerosis (MS), and yet this population is largely sedentary and inactive compared with the general population.

Objectives:We conducted a pilot, randomized controlled trial (RCT) for examining the effect of an Internet intervention based on social cognitive theory (SCT) for favorably increasing physical activity among persons with MS. We further examined variables from SCT as possible mediators of the Internet intervention.

Methods:We randomly allocated 54 persons with MS into either an Internet intervention condition or a waitlist control condition. The participants completed measures of physical activity, self-efficacy, outcome expectations, functional limitations, and goal setting before and after the 12-week period.

Results:The intervention group reported a statistically significant ( p = 0.01) and large increase in physical activity over time ( d = 0.72), whereas the control group had a small ( d = 0.04) and non-significant change in physical activity ( p = 0.71). The intervention group further reported a statistically significant ( p = 0.001) and large increase in goal setting over time ( d = 0.97), whereas the control group had a small ( d = −0.13) and non-significant change ( p = 0.17). The change in goal setting over time mediated the effect of the Internet intervention on physical activity behavior.

Conclusions:This pilot study sets the stage for a subsequent RCT that includes a larger sample of persons with MS, longer intervention period along with a follow-up, objective measure of physical activity, and secondary outcomes of walking mobility and QOL.

Symptom cluster and quality of life: preliminary evidence in multiple sclerosis

This study examined the symptom cluster of fatigue, pain, and depression as a correlate of reduced quality of life (QOL) in individuals with multiple sclerosis (MS). The sample included 291 individuals with a definite diagnosis of MS who were enrolled in a 6-month longitudinal study of physical activity and QOL. The participants completed baseline measures of fatigue, depression, and pain and follow-up measures of QOL. Cluster analysis initially identified three subgroups differing in experiences of fatigue, depression, and pain, and analysis of variance then indicated that the three subgroups differed in QOL. The subgroup with lowest scores on all three symptoms had the highest QOL, whereas the subgroup with the highest scores on the symptoms had the worst QOL. Such findings provide preliminary support for fatigue, pain, and depression as a symptom cluster that correlates with reduced QOL in persons with MS.

Validity, invariance and responsiveness of a self-report measure of functional limitations and disability in multiple sclerosis

OBJECTIVE

This study examined the structural and external aspects of score validity for the abbreviated Late Life-Function and Disability Inventory (LL-FDI) as well as its longitudinal measurement invariance and responsiveness in individuals with multiple sclerosis (MS).

METHODS

The sample included 292 individuals with MS who completed a battery of questionnaires on two occasions separated by 6 months. The battery included the abbreviated LL-FDI along with measures of mobility disability; neurological impairments; symptoms of fatigue, anxiety, depression and pain; health status; and quality of life. The data were analysed using Analysis of Moment Structures (AMOS) and Statistical Package for the Social Sciences (SPSS), versions 16.0.

RESULTS

Confirmatory factor analysis supported the structural validity and longitudinal measurement invariance of the disability and functional limitations components of the abbreviated LL-FDI. MANOVA and bivariate correlations supported the external aspects of score validity based on differences in mean scores as a function of clinical MS course (relapsing vs. progressive) and level of mobility disability (mild vs. moderate mobility disability) and associations with measures of neurological impairments, symptoms, health status and QOL, respectively. ANOVA established the responsiveness (i.e., sensitivity for reflecting clinically important differences in health status across time) of the functional limitations and disability components of the abbreviated LL-FDI for detecting changes in mobility disability across 6-months.

CONCLUSION

Such findings provide a new option for the measurement of functional limitations and disability using the abbreviated LL-FDI in persons with MS.

Plasticity of brain networks in a randomized intervention trial of exercise training in older adults

Research has shown the human brain is organized into separable functional networks during rest and varied states of cognition, and that aging is associated with specific network dysfunctions. The present study used functional magnetic resonance imaging (fMRI) to examine low-frequency (0.008 < f < 0.08 Hz) coherence of cognitively relevant and sensory brain networks in older adults who participated in a 1-year intervention trial, comparing the effects of aerobic and non-aerobic fitness training on brain function and cognition. Results showed that aerobic training improved the aging brain's resting functional efficiency in higher-level cognitive networks. One year of walking increased functional connectivity between aspects of the frontal, posterior, and temporal cortices within the Default Mode Network and a Frontal Executive Network, two brain networks central to brain dysfunction in aging. Length of training was also an important factor. Effects in favor of the walking group were observed only after 12 months of training, compared to non-significant trends after 6 months. A non-aerobic stretching and toning group also showed increased functional connectivity in the DMN after 6 months and in a Frontal Parietal Network after 12 months, possibly reflecting experience-dependent plasticity. Finally, we found that changes in functional connectivity were behaviorally relevant. Increased functional connectivity was associated with greater improvement in executive function. Therefore the study provides the first evidence for exercise-induced functional plasticity in large-scale brain systems in the aging brain, using functional connectivity techniques, and offers new insight into the role of aerobic fitness in attenuating age-related brain dysfunction.

Individual, social environmental and physical environmental barriers to achieving 10 000 steps per day among older women

This study examined the determinants of attaining/not attaining 10 000 steps per day among older women.

METHODS

Daily step counts over 7 days were measured using accelerometry. Self-reported environmental characteristics, self-efficacy, social support and functional limitations were assessed in 128 older women. The presence of areas for activity within 1 km of each participant's residence was assessed using Geographic Information Systems. Multivariate analysis of variances were used to examine the degree to which these groups differed on measured constructs, and discriminant analysis was used to determine the profiles that discriminate among those who did not attain 10 000 steps per day and those who did.

RESULTS

Participants who did not attain 10 000 steps per day reported lower self-efficacy (P < 0.05), greater functional limitations (P < 0.05), had significantly fewer walking paths (P < 0.05) within 1 km of their home and reported significantly less street connectivity (P < 0.05) and safety from traffic (P < 0.05) than those who achieved 10 000 steps per day.

CONCLUSION

Lack of perceived and actual environmental supports for walking, more functional limitations and lower self-efficacy are barriers to achieving 10 000 steps per day. The absence of these individual and environmental characteristics inhibits walking behavior in older women and should be considered in campaigns to promote a physically active lifestyle.

Cardiovascular exercise training extends influenza vaccine seroprotection in sedentary older adults: the immune function intervention trial

OBJECTIVES

To determine whether cardiovascular exercise training resulted in improved antibody responses to influenza vaccination in sedentary elderly people who exhibited poor vaccine responses.

DESIGN

Single-site randomized parallel-arm 10-month controlled trial.

SETTING

University of Illinois at Urbana-Champaign.

PARTICIPANTS

One hundred forty-four sedentary, healthy older (69.9 +/- 0.4) adults.

INTERVENTIONS

Moderate (60-70% maximal oxygen uptake) cardiovascular exercise was compared with flexibility and balance training.

MEASUREMENTS

The primary outcome was influenza vaccine response, as measured according to hemagglutination inhibition (HI) anti-influenza antibody titer and seroprotective responses (HI titer > or =40). Secondary measures included cardiovascular fitness and body composition.

RESULTS

Of the 160 participants enrolled, 144 (90%) completed the 10-month intervention with excellent compliance ( approximately 83%). Cardiovascular, but not flexibility, exercise intervention resulted in improvements in indices of cardiovascular fitness, including maximal oxygen uptake. Although not affecting peak (e.g., 3 and 6 weeks) postvaccine anti-influenza HI titers, cardiovascular exercise resulted in a significant increase in seroprotection 24 weeks after vaccination (30-100% dependent on vaccine variant), whereas flexibility training did not.

CONCLUSION

Participants randomized to cardiovascular exercise experienced improvements in influenza seroprotection throughout the entire influenza season, whereas those in the balance and flexibility intervention did not. Although there were no differences in reported respiratory tract infections, the exercise group exhibited reduced overall illness severity and sleep disturbance. These data support the hypothesis that regular endurance exercise improves influenza vaccine responses.

Pathways between physical activity and quality of life in adults with multiple sclerosis

OBJECTIVE

This prospective study examined symptoms of depression, fatigue, pain, self-efficacy, and social support as possible intermediaries in the pathway between changes in physical activity and quality of life (QOL) across a 6-month period in persons with multiple sclerosis (MS).

DESIGN AND MAIN OUTCOME MEASURES

Adults with a definite diagnosis of MS wore an accelerometer for 7 days and then completed a battery of questionnaires at baseline (n = 292) and 6-months follow-up (n = 276). The data were analyzed using panel analysis and covariance modeling in Mplus 3.0.

RESULTS

The initial analysis indicated that change in physical activity was associated with a statistically significant and small residual change in QOL (beta = .07). The subsequent analysis indicated that change in physical activity was associated with residual changes in fatigue (gamma = -.17), pain (gamma = -.13), social support (gamma = .07), and self-efficacy (gamma = .11), and, in turn, changes in fatigue (beta = -.13), pain (beta = -.09), social support (beta = .18), and self-efficacy (beta = .10) were associated with a residual change in QOL.

CONCLUSION

The observed pattern of relationships supports the possibility that physical activity is indirectly associated with improved QOL through pathways that include fatigue, pain, social support, and self-efficacy in individuals with MS.

Validation of the multidimensional outcome expectations for exercise scale in ambulatory, symptom-free persons with multiple sclerosis

McAuley E, Motl RW, White SM, Wójcicki TR. Validation of the Multidimensional Outcome Expectations for Exercise Scale in ambulatory, symptom-free persons with multiple sclerosis.

OBJECTIVE

To determine the psychometric properties of the 3-factor Multidimensional Outcome Expectations for Exercise Scale in a sample of ambulatory, symptom-free persons with multiple sclerosis (MS).

DESIGN

Cross-sectional validation study.

SETTING

Midwestern university.

PARTICIPANTS

Community-dwelling adults (N=242) with an established definite diagnosis of MS, as corroborated by the participant's neurologist, who were relapse free for the last 30 days and ambulatory with minimal assistance.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Multidimensional Outcome Expectations for Exercise Scale, physical activity, self-efficacy, and physical health status. Confirmatory factor analyses using covariance modeling and correlational analyses were used to establish factorial and construct validity.

RESULTS

Analyses showed excellent factorial validity for the hypothesized factor structure reflecting physical, social, and self-evaluative outcome expectations. All 3 subscales were internally consistent. Theoretically, relevant correlations between outcome expectations and self-efficacy, physical activity, and physical health status were all supported.

CONCLUSIONS

The Multidimensional Outcome Expectations for Exercise Scale appears to be a reliable and valid measure of outcome expectations for exercise in this limited sample of community-dwelling adults with MS. Further validation in clinical samples is warranted.

Construct validation of a non-exercise measure of cardiorespiratory fitness in older adults

Background

Cardiorespiratory fitness (CRF) is associated with a decreased risk of all-cause mortality but is rarely assessed in medical settings due to burdens of time, cost, risk, and resources. The purpose of this study was to test the construct validity of a regression equation developed by Jurca and colleagues (2005) to estimate CRF without exercise testing in community dwelling older adults.

Methods

Participants (n = 172) aged 60 to 80 years with no contraindications to submaximal or maximal exercise testing completed a maximal graded exercise test (GXT) and the submaximal Rockport 1-mile walk test on separate occasions. Data included in the regression equation (age, sex, body mass index, resting heart rate, and physical activity) were obtained via measurement or self-report. Participants also reported presence of cardiovascular conditions.

Results

The multiple R for the regression equation was .72, p < .001 and CRF estimated from this equation was significantly correlated with the MET value from the GXT (r = 0.66) and with CRF estimated from submaximal field testing (r = 0.67). All three CRF indices were significantly and inversely associated with reporting more cardiovascular conditions.

Conclusions

This research provides preliminary evidence that a non-exercise estimate of CRF is at least as valid as field test estimates of CRF and represents a low-risk, low-cost, and expedient method for estimating fitness in older adults.

Functional connectivity: a source of variance in the association between cardiorespiratory fitness and cognition?

Over the next 20 years the number of Americans diagnosed with dementia is expected to more than double (CDC, 2007). It is, therefore, an important public health initiative to understand what factors contribute to the longevity of a healthy mind. Both default mode network (DMN) function and increased aerobic fitness have been associated with better cognitive performance and reduced incidence of Alzheimer's disease among older adults. Here we examine the association between aerobic fitness, functional connectivity in the DMN, and cognitive performance. Results showed significant age-related deficits in functional connectivity in both local and distributed DMN pathways. However, in a group of healthy elderly adults, almost half of the age-related disconnections showed increased functional connectivity as a function of aerobic fitness level. Finally, we examine the hypothesis that functional connectivity in the DMN is one source of variance in the relationship between aerobic fitness and cognition. Results demonstrate instances of both specific and global DMN connectivity mediating the relationship between fitness and cognition. We provide the first evidence for functional connectivity as a source of variance in the association between aerobic fitness and cognition, and discuss results in the context of neurobiological theories of cognitive aging and disease.

Accelerometry in persons with multiple sclerosis: measurement of physical activity or walking mobility?

OBJECTIVE

Motion sensors such as accelerometers have been recognized as an ideal measure of physical activity in persons with MS. This study examined the hypothesis that accelerometer movement counts represent a measure of both physical activity and walking mobility in individuals with MS.

METHODS

The sample included 269 individuals with a definite diagnosis of relapsing-remitting MS who completed the Godin Leisure-Time Exercise Questionnaire (GLTEQ), International Physical Activity Questionnaire (IPAQ), Multiple Sclerosis Walking Scale-12 (MSWS-12), Patient Determined Disease Steps (PDDS), and then wore an ActiGraph accelerometer for 7days. The data were analyzed using bivariate correlation and confirmatory factor analysis.

RESULTS

The results indicated that (a) the GLTEQ and IPAQ scores were strongly correlated and loaded significantly on a physical activity latent variable, (b) the MSWS-12 and PDDS scores strongly correlated and loaded significantly on a walking mobility latent variable, and (c) the accelerometer movement counts correlated similarly with the scores from the four self-report questionnaires and cross-loaded on both physical activity and walking mobility latent variables.

CONCLUSION

Our data suggest that accelerometers are measuring both physical activity and walking mobility in persons with MS, whereas self-report instruments are measuring either physical activity or walking mobility in this population.

Abstract B5: Psychosocial mechanisms for explaining the relationship between physical activity and fatigue in breast cancer survivors

Fatigue is one of the most commonly reported and enduring symptoms experienced as a result of breast cancer treatment. One important behavior that has been identified as having the potential to reduce breast cancer related fatigue is physical activity. However, few attempts have been made to fully understand this relationship and it is not known whether physical activity directly influences fatigue or operates through other factors. The purpose of this study was to examine the role of psychosocial mechanisms, self-efficacy and depression, as potential pathways from physical activity to fatigue in a cross-sectional sample of breast cancer survivors (N=192). Participants completed measures of health status, physical activity, depression, fatigue, and self-efficacy. Data were analyzed using path analysis within a covariance modeling framework. This model proposed that that physical activity's influence on fatigue is indirect through its direct effect on self-efficacy which, in turn, has both a direct effect on fatigue and an indirect effect through depression. The hypothesized path model provided an excellent fit to the data (Ξ2 = 1.48, df = 2, p =.48; SRMR = 0.02, CFI = 1.00). All of the proposed path coefficients of the hypothesized model were significant. Overall, the model accounted for 45.2% of the variation in fatigue. As a result of the robust relationship between fatigue and depression (β =.51), the analysis was re-run using a depression score which excluded items assessing “somatic and retarded activity” symptoms. The fit of the model was almost identical to the previously described model (Ξ2 = 1.48, df = 2, p =.45; SRMR = 0.03, CFI = 1.00). A final analysis was conducted on the original model to test effects of for demographics (i.e., age, education, employment, income), time since diagnosis, breast cancer stage, current treatment, menopausal status, body mass index, and comorbidities on model fit and path coefficients, as well as the model components themselves. This model also was an excellent fit to the data (Ξ2 = 2.10, df = 2, p =.35; SRMR = 0.01, CFI = 1.00). In general, the magnitude and direction of the hypothesized relationships were unaffected by the inclusion of the covariates in the model. Our findings suggest support for one set of psychosocial pathways from physical activity to fatigue, an important concern in breast cancer survivors. Subsequent work might replicate such associations in other survivor populations and attempt to determine whether model relations change with physical activity interventions, and the extent to which other known correlates of fatigue such as impaired sleep and inflammation can be incorporated into this model.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B5.

Exercise preference patterns, resources, and environment among rural breast cancer survivors

CONTEXT

Rural breast cancer survivors may be at increased risk for inadequate exercise participation.

PURPOSE

To determine for rural breast cancer survivors: (1) exercise preference "patterns," (2) exercise resources and associated factors, and (3) exercise environment.

METHODS

A mail survey was sent to rural breast cancer survivors identified through a state cancer registry, and 483 (30%) responded.

FINDINGS

The majority (96%) were white, with mean education of 13 (+/-2.5) years and mean 39.0 (+/-21.5) months since diagnosis. Most participants (67%) preferred face-to-face counseling from an exercise specialist (27%) or other individual (40%). A third (31%) preferred home-based exercise with non face-to-face counseling from someone other than an exercise specialist. Participants preferring face-to-face counseling were more apt to prefer supervised exercise (38% vs 9%, P < 0.001) at a health club (32% vs 8%, P < 0.001). Home exercise equipment was reported by 63%, with 97% reporting home telephone and 67% reporting Internet access. Age, education, self-efficacy, treatment status, and exercise behavior were associated with exercise resources. The physical environment was often not conducive to exercise but a low crime rate and high trust in neighbors was reported.

CONCLUSIONS

Rural health education programs encouraging exercise should offer multiple programming options while considering the physical environment and capitalizing on available resources and beneficial social environmental characteristics.

Aerobic fitness is associated with hippocampal volume in elderly humans

Deterioration of the hippocampus occurs in elderly individuals with and without dementia, yet individual variation exists in the degree and rate of hippocampal decay. Determining the factors that influence individual variation in the magnitude and rate of hippocampal decay may help promote lifestyle changes that prevent such deterioration from taking place. Aerobic fitness and exercise are effective at preventing cortical decay and cognitive impairment in older adults and epidemiological studies suggest that physical activity can reduce the risk for developing dementia. However, the relationship between aerobic fitness and hippocampal volume in elderly humans is unknown. In this study, we investigated whether individuals with higher levels of aerobic fitness displayed greater volume of the hippocampus and better spatial memory performance than individuals with lower fitness levels. Furthermore, in exploratory analyses, we assessed whether hippocampal volume mediated the relationship between fitness and spatial memory. Using a region-of-interest analysis on magnetic resonance images in 165 nondemented older adults, we found a triple association such that higher fitness levels were associated with larger left and right hippocampi after controlling for age, sex, and years of education, and larger hippocampi and higher fitness levels were correlated with better spatial memory performance. Furthermore, we demonstrated that hippocampal volume partially mediated the relationship between higher fitness levels and enhanced spatial memory. Our results clearly indicate that higher levels of aerobic fitness are associated with increased hippocampal volume in older humans, which translates to better memory function.

Assessing calcium intake in postmenopausal women

INTRODUCTION

Because foods fortified with calcium are increasingly available, the calcium content of calcium-fortified foods may not be adequately captured in traditional assessments of dietary intake, such as dietary records analyzed with commercially available software. The primary objective of our study was to design and test a calcium-focused food frequency questionnaire (CFFFQ) including foods naturally rich in calcium and calcium-fortified foods. Secondary objectives were to review calcium sources and adequacy of intake in black and in white postmenopausal women.

METHODS

We studied a convenience sample of 46 black and 139 white postmenopausal women (mean [SD] age 69.4 [5.8] years). Participants completed a multiple-pass interview for 24-hour recall of foods eaten and the 46-item CFFFQ.

RESULTS

The correlation between measures for total daily calcium intake was moderately strong (r = 0.53, P < .001). The CFFFQ estimated greater total daily calcium intake than did the 24-hour recall (mean [SD], 1,021 [624] mg/d vs 800 [433] mg/d, P < .001). As daily calcium intake increased, the 24-hour recall increasingly underreported calcium (r = 0.41, P < .001) compared with the CFFFQ. Cross-tabulation and Chi2 analyses found that the CFFFQ had greater specificity for lower calcium intakes. For calcium classified by food groups, there was moderate correlation for dairy (r = 0.56, P < .001) and fruits (r = 0.43, P < .001). The CFFFQ overestimated mean total calcium compared with the 24-hour recall by 221 mg/d (P < .001), including within racial groups (195 mg/d for black women, P = .04, and 229 mg/d for white women, P < .001). Dairy was the primary calcium source for both groups (55% of intake for black women and 57% of intake for white women).

CONCLUSION

The CFFFQ can be used to identify postmenopausal women with inadequate calcium intakes (<800 mg/d) and to identify key sources of dietary calcium. Older black women consume less daily calcium than do older white women.

Trajectory of declines in physical activity in community-dwelling older women: social cognitive influences

Studies examining physical activity behavior suggest that activity levels decline with age. Such declines are particularly problematic among older adults in light of the research suggesting a protective effect of physical activity on numerous physical health outcomes associated with independent living. Despite a growing recognition of the importance of a physically active lifestyle, little is known about the role of demographic and psychosocial variables on this trajectory of change. In this study, the roles played by outcome expectations, self-efficacy, and functional limitations on changes in physical activity levels over a 2-year period in older women were assessed using latent growth curve modeling. Data were obtained from 249 community-dwelling older women (M age = 68.12, n = 81 Black, and n = 168 White). Demographic, health status, and psychosocial data were collected via self-report upon entry into the study. Self-reported physical activity was assessed at baseline and again at 12 and 24 months. As expected, physical activity declined over the 2-year period. Self-efficacy demonstrated an indirect association with the trajectory of decline in physical activity through functional limitations. Importantly, the pattern of relationships appears independent of demographic factors and chronic health conditions.

Symptom cluster as a predictor of physical activity in multiple sclerosis: preliminary evidence

The present study examined the symptom cluster of fatigue, pain, and depression, and its direct and indirect prediction of physical activity behavior in a sample of individuals with multiple sclerosis (MS) using a prospective research design and the Theory of Unpleasant Symptoms. The sample included 292 individuals with a definite diagnosis of MS. The participants completed self-report measures of fatigue, depression, pain, self-efficacy, and functional limitations at baseline and six months later, wore an accelerometer for seven days and completed a self-report measure of physical activity behavior. The data analysis indicated that: 1) fatigue, depression, and pain represented a symptom cluster; 2) the symptom cluster had a strong and negative predictive relationship with physical activity behavior; and 3) functional limitations, but not self-efficacy, accounted for the predictive relationship between the symptom cluster and physical activity behavior. Such findings provide preliminary support to the importance of considering symptom clusters as a meaningful correlate of physical activity behavior in persons with MS.

Longitudinal analysis of physical activity and symptoms as predictors of change in functional limitations and disability in multiple sclerosis

OBJECTIVE

This longitudinal, observational study examined changes in physical activity and symptoms as correlates of changes in functional limitations and disability across a 6-month period among individuals with multiple sclerosis (MS).

METHOD

Individuals with MS wore an accelerometer for a 7-day period and completed a battery of measures including the Godin Leisure-Time Exercise Questionnaire (Godin & Shephard, 1985), Symptom Inventory (Schwartz, Vollmer, & Lee, 1999), MS-Related Symptom Checklist (Gulick, 1989), and abbreviated Late-Life Function and Disability Inventory (McAuley, Konopack, Motl, Rosengren, & Morris, 2005) at baseline (n = 292) and 6-month follow-up (n = 276). The data were analyzed using panel analysis with latent variables in AMOS 16.0.

RESULTS

The standardized coefficients indicated that (a) change in physical activity was associated with residual change in function (beta = .22), (b) change in symptoms was associated with residual changes in both function (beta = -.29) and disability (gamma = -.15), and (c) change in function was associated with residual change in disability (beta = .20).

CONCLUSION

Our findings indicate that change in physical activity is associated with change in disability through a pathway that is consistent with Nagi's (1976) Disablement Model and its extension in individuals with MS.

Sex differences in the relationship between obesity, C-reactive protein, physical activity, depression, sleep quality and fatigue in older adults

Fatigue is a serious health concern in the elderly. Sex differences exist in adiposity, systemic inflammation, physical activity/fitness and fatigue; however, the relations among these variables remain inadequately characterized impeding the development of fatigue prevention strategies. Measures of adiposity, C-reactive protein, physical activity, aerobic fitness, fatigue, sleep quality and depression were obtained from 127 community-dwelling older adults. Although similar in age (70 y) and BMI (28.0kg/m(2)) women (n=80) reported 63% greater fatigue than men (p=0.04). Adiposity (r=0.44), CRP (r=0.29), physical activity (r=-0.26) and fitness (r=-0.41) were related to fatigue in women (all p<0.05), but not in men. Depression was also related to fatigue in women (r=0.37), and was the only variable related to fatigue in men (r=0.42). In women, fatigue was independently explained (all p<0.05) by CRP (6.6%), depression (6.3%), physical activity (5.8%), and adiposity (3.9%); however, in men, only depression explained variance in fatigue (12.0%). CRP was 40% higher and adiposity 12% higher in women reporting fatigue compared to those with no fatigue; no such differences existed in men. Obese women perceived a greater degree of fatigue than non-obese women, but this was not the case in men. Women report more fatigue than men which was independently associated with inflammation, depression, physical activity and adiposity, whereas in men the only independent predictor was depression. Strategies to prevent fatigue may differ in older women and men, especially with regard to inflammation, physical activity and adiposity.

Reduction in trunk fat predicts cardiovascular exercise training-related reductions in C-reactive protein

C-reactive protein (CRP) is an independent risk factor for cardiovascular disease. We sought to determine (1) if 10 months of cardiovascular exercise training (Cardio) reduces CRP in a group of older adults, (2) if such a reduction is related to improvements in trunk fat, fitness, and/or psychosocial variables, and (3) if the effect of Cardio on CRP differs between men and women. Community-dwelling residents (n=127; 60-83 yrs) were randomized to a Flex group (n=61) where they participated in 2-75 min supervised sessions per wk during which they performed non-cardiovascular flexibility and balance exercises or a Cardio group (n=66) where they participated in three supervised sessions per wk during which they performed cardiovascular exercises for approximately 45-60 min at 60-70% maximal oxygen uptake. The main outcome measures were serum CRP, cardiovascular fitness, total and central adiposity, and self-reported psychosocial function. Cardio experienced a reduction in CRP (-0.5mg/L), as well as improvements in fitness (+7%) and total (-1.5%) and central (i.e., trunk) (-2.5%) adiposity. These relationships were not modified by sex. Regression analyses indicated that only the reduction in trunk fat was significantly related to the reduction in CRP. Ten months of cardiovascular exercise training reduced CRP in previously sedentary older adults and this effect was partially mediated by a reduction in trunk fat.

Translating physical activity interventions for breast cancer survivors into practice: an evaluation of randomized controlled trials

BACKGROUND

Although physical activity (PA) interventions have been effective for improving health outcomes in breast cancer survivors, little is known relative to their potential for translation into practice.

PURPOSE

This review was designed to provide a quantitative estimate of the reporting of both internal and external validity in recent studies of PA in breast cancer survivors (BCS).

METHODS

The Reach, Efficacy/Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework was utilized to assess the reporting of internal and external validity in 25 randomized controlled trials (RCTs) of PA and BCS published between 1998 and 2008. Each trial was evaluated relative to the degree it met criteria for each of the above dimensions.

RESULTS

The majority of studies in this review reported dimensions reflecting internal validity. The overall level of detail relative to external validity of PA interventions was rarely reported, limiting the generalizability of study findings.

CONCLUSIONS

As with many RCTs of health behavior change, detail relative to contextual elements of published PA interventions in BCS is limited. It is recommended that future physical activity interventions in BCS be designed to facilitate scalable and sustainable interventions for improving health outcomes in this population.

Physical activity and quality of life in community dwelling older adults

BACKGROUND

Physical activity has been consistently associated with enhanced quality of life (QOL) in older adults. However, the nature of this relationship is not fully understood. In this study of community dwelling older adults, we examined the proposition that physical activity influences global QOL through self-efficacy and health-status.

METHODS

Participants (N = 321, M age = 63.8) completed measures of physical activity, self-efficacy, global QOL, physical self worth, and disability limitations. Data were analyzed using covariance modeling to test the fit of the hypothesized model.

RESULTS

Analyses indicated direct effects of a latent physical activity variable on self-efficacy but not disability limitations or physical self-worth; direct effects of self-efficacy on disability limitations and physical self worth but not QOL; and direct effects of disability limitations and physical self-worth on QOL.

CONCLUSION

Our findings support the role of self-efficacy in the relationship between physical activity and QOL as well as an expanded QOL model including both health status indicators and global QOL. These findings further suggest future PA promotion programs should include strategies to enhance self-efficacy, a modifiable factor for improving QOL in this population.

Assessing outcome expectations in older adults: the multidimensional outcome expectations for exercise scale

Outcome expectations, an important element of social cognitive theory, have been associated with physical activity in older adults. Yet, the measurement of this construct has often adopted a unidimensional approach. We examined the validity of a theoretically consistent three-factor (physical, social, and self-evaluative) outcome expectations exercise scale in middle-aged and older adults (N = 320; M age = 63.8). Participants completed questionnaires assessing outcome expectations, physical activity, self-efficacy, and health status. Comparisons of the hypothesized factor structure with competing models indicated that a three-factor model provided the best fit for the data. Construct validity was further demonstrated by significant association with physical activity and self-efficacy and differential associations with age and health status. Further evidence of validity and application to social cognitive models of physical activity is warranted.

Personality, Menopausal Symptoms, and Physical Activity Outcomes in Middle-Aged Women

The menopausal transition is characterized by increased reporting of various symptoms, however, little is known about what underlies individual differences in their reporting. The present study examined the contribution of personality factors to the reporting of menopausal symptoms in the context of a 4-month randomized controlled exercise trial. Symptomatic middle-aged women (N = 164 M age = 49.9, SD = 3.6) completed measures of menopausal symptoms, personality, physical activity, fitness and body composition assessment at the beginning and end of a 4-month randomized controlled trial involving walking and yoga. After controlling for baseline values, psychological symptoms at the end of the trial were associated with trait anxiety (beta = .47, p < .001) and changes in fitness (beta = -.20, p < .01); vasomotor symptoms with optimism (beta = -.18, p < .05) and changes in fitness (beta = -.15, p = .053); and sexual symptoms were associated with changes in fitness (beta = -.16, p < .05). Personality characteristics partially explain symptom reports during menopause however improvements in physical parameters such as fitness may reduce reported symptomatology.

Physical activity and quality of life in multiple sclerosis: intermediary roles of disability, fatigue, mood, pain, self-efficacy and social support

Physical activity has been associated with a small improvement in quality of life (QOL) among those with multiple sclerosis (MS). This relationship may be indirect and operate through factors such as disability, fatigue, mood, pain, self-efficacy and social support. The present study examined variables that might account for the relationship between physical activity and QOL in a sample (N = 292) of individuals with a definite diagnosis of MS. The participants wore an accelerometer for 7 days and then completed self-report measures of physical activity, QOL, disability, fatigue, mood, pain, self-efficacy and social support. The data were analysed using covariance modelling in Mplus 3.0. The model provided an excellent fit for the data (chi(2) = 51.33, df = 18, p < 0.001, standardised root mean squared residual = 0.03, comparative fit index = 0.98). Those who were more physically active reported lower levels of disability (gamma = -0.50), depression (gamma = -0.31), fatigue (gamma = -0.46) and pain (gamma = -0.19) and higher levels of social support (gamma = 0.20), self-efficacy for managing MS (gamma = 0.41), and self-efficacy for regular physical activity (gamma = 0.49). In turn, those who reported lower levels of depression (beta = -0.37), anxiety (beta = -0.15), fatigue (beta = -0.16) and pain (beta = -0.08) and higher levels of social support (beta = 0.26) and self-efficacy for controlling MS (beta = 0.17) reported higher levels of QOL. The observed pattern of relationships supports the possibility that physical activity is indirectly associated with improved QOL in individuals with MS via depression, fatigue, pain, social support and self-efficacy for managing MS.

Change in body mass index is a stronger predictor of change in fat mass than lean mass in elderly black and white women

The aim of this study was to determine the relation between change in body mass index (BMI) and changes in fat mass (FM), lean soft tissue (LST), and percentage body fat (%Fat) in elderly (67.6 +/- 6.0 years) women varying in race (53 black, 144 white) who underwent measurements of BMI, FM, LST, and %Fat at baseline and after 2 years. The group did not markedly change body composition over 2 years (BMI = -0.1 +/- 1.5 kg/m(2), P = 0.53; FM = 0.0 +/- 2.8 kg, P = 0.95; LST = -0.4 +/- 1.7 kg, P < 0.001; %Fat = 0.3 +/- 2.0%, P = 0.06). Change in BMI predicted change in FM (r = 0.90, SEE = 1.19 kg FM, P < 0.001) but was less predictive of change in %Fat (r = 0.64, SEE = 1.54%Fat, P < 0.001). Change in BMI was curvilinearly related to change in LST adjusted for change in height (R = 0.76, SEE = 1.10 kg LST, P < 0.001). Change in BMI more strongly predicts change in FM than LST and could be used to monitor change in FM in community-dwelling women.

Dedifferentiation in the visual cortex: an fMRI investigation of individual differences in older adults

Dedifferentiation, or decreased processing specificity, has been suggested to represent a ubiquitous characteristic of cognitive aging. In this study, we examined both age-related differences and intra-group differences in neural specificity in the ventral visual cortex for color, words, faces and places. Our results demonstrated that neural dedifferentiation was not ubiquitous across stimulus categories. Neural dedifferentiation was also relatively stable, across age, in a group of older adults. Older adults with more overall gray matter showed less neural dedifferentiation in the visual cortex. However, regional gray matter volume was not associated with neural dedifferentiation. We illustrate these effects using a discriminability metric, a signal detection theory measure, for neural dedifferentiation that takes into account both magnitude and variance of brain activation. The dedifferentiation measure provides a quantitative means to examine activation patterns and individual difference factors associated with neural dedifferentiation, and to test theories of behavioral dedifferentiation in cognitive aging literature.

Cardiovascular exercise intervention improves the primary antibody response to keyhole limpet hemocyanin (KLH) in previously sedentary older adults

Based upon a prior cross-sectional study, we hypothesized that an aerobic exercise intervention in sedentary older adults would improve a primary T cell-dependent immune response. Participants were a subset of older subjects from a large, ongoing exercise intervention study who were randomly assigned to either an aerobic exercise (Cardio, n=30, 68.9+0.8 years) or flexibility/balance (Flex, n=20, 69.9+1.2 years) intervention. The intervention consisted of either three aerobic sessions for 30-60 min at 55-70% VO(2 max) or two 60 min flexibility/balance sessions weekly for 10 months. Eight months into the intervention, samples were collected before intramuscular administration of KLH (125 microg), followed by sampling at 2, 3, and 6 weeks post-KLH. Serum anti-KLH IgM, IgG1, and IgG2 was measured by ELISA. Physiological and psychosocial measures were also assessed pre- and post-intervention. While there was no difference in the anti-KLH IgG2 response between groups, Cardio displayed significantly (p<0.05) higher anti-KLH IgG1 (at weeks 2, 3, and 6 post) and IgM responses when compared to Flex. Despite cardiovascular intervention-induced improvement in physical fitness (approximately 11% vs. 1% change in VO(2 peak) in Cardio vs. Flex, respectively), we found no relationship between improved fitness and enhanced anti-KLH antibody responses. Optimism, perceived stress, and affect were all associated with enhanced immune response. We have shown for the first time that cardiovascular training in previously sedentary elderly results in significantly higher primary IgG1 and IgM antibody responses, while having no effect on IgG2 production.

Self-efficacy and environmental correlates of physical activity among older women and women with multiple sclerosis

Physical inactivity is a major health problem in the United States, particularly in elderly and disabled populations. Little research exists examining the relationships between aspects of the built environment and physical activity in older adults and individuals with multiple sclerosis (MS). We adopted a social cognitive perspective to examine the independent roles of perceptions of the environmental, self-efficacy and functional limitations in understanding physical activity levels among elderly women and women with MS. Older women (n=136) and women diagnosed with MS (n=173) were recruited to participate in separate cross-sectional studies. Individuals completed a battery of questionnaires and wore an activity monitor for 7 days. All measures were issued and collected through the mail with the use of self-addressed, pre-paid envelopes. Initial correlational analyses indicated that self-efficacy, functional limitations and environmental perceptions were significantly related to physical activity. Among older women, self-efficacy, functional limitations and street connectivity demonstrated independent contributions to physical activity behavior. Only self-efficacy and functional limitations demonstrated significant associations among women with MS. The prospective contributions of the environment and individual factors to changes in physical activity need to be determined.

Correlates of leisure-time physical activity in Korean immigrant women

This study describes the physical activity behavior of Korean immigrant women and examines the relationships among leisure-time physical activity (LTPA) behavior, background, and intrapersonal correlates of behavior in Korean immigrant women in the United States using a cross-sectional survey design. A convenience sample of Midwestern Korean immigrant women completed the long form of the International Physical Activity Questionnaire in Korean. Among the participants, 78% were physically active, meeting the Healthy People 2010 goal for physical activity when all physical activity behaviors were considered, whereas 23% met the goal when only LTPA was considered. Women who were older, did not have a child younger than 5, used environmental resources for physical activity, had lower depressive symptoms, and had higher confidence for overcoming exercise barriers were spent more time in LTPA. Accommodating those with young children, enhancing environmental resource use, and improving exercise self-efficacy are important considerations for interventions aimed at increasing LTPA in Korean immigrant women.

Neighborhood satisfaction, functional limitations, and self-efficacy influences on physical activity in older women

BACKGROUND

Perceptions of one's environment and functional status have been linked to physical activity in older adults. However, little is known about these associations over time, and even less about the possible mediators of this relationship. We examined the roles played by neighborhood satisfaction, functional limitations, self-efficacy, and physical activity in a sample of older women over a 6-month period.

METHODS

Participants (N = 137, M age = 69.6 years) completed measures of neighborhood satisfaction, functional limitations, self-efficacy, and physical activity at baseline and again 6 months later.

RESULTS

Analyses indicated that changes in neighborhood satisfaction and functional limitations had direct effects on residual changes in self-efficacy, and changes in self-efficacy were associated with changes in physical activity at 6 months.

CONCLUSION

Our findings support a social cognitive model of physical activity in which neighborhood satisfaction and functional status effects on physical activity are in part mediated by intermediate individual outcomes such as self-efficacy. Additionally, these findings lend support to the position that individual perceptions of both the environment and functional status can have prospective effects on self-efficacy cognitions and ultimately, physical activity behavior.

Greater intake of vitamins B6 and B12 spares gray matter in healthy elderly: a voxel-based morphometry study

Previous studies have reported that high concentrations of homocysteine and lower concentrations of vitamins B6, B12, and folate increase the risk for cognitive decline and pathology in aging populations. In this cross-sectional study, high resolution magnetic resonance imaging (MRI) scans and a 3-day food diary were collected on 32 community-dwelling adults between the ages of 59 and 79. We examined the relation between vitamins B6, B12, and folate intake on cortical volume using an optimized voxel-based morphometry (VBM) method and global gray and white matter volume after correcting for age, sex, body mass index, calorie intake, and education. All participants met or surpassed the recommended daily intake for these vitamins. In the VBM analysis, we found that adults with greater vitamin B6 intake had greater gray matter volume along the medial wall, anterior cingulate cortex, medial parietal cortex, middle temporal gyrus, and superior frontal gyrus, whereas people with greater B12 intake had greater volume in the left and right superior parietal sulcus. These effects were driven by vitamin supplementation and were negated when only examining vitamin intake from diet. Folate had no effect on brain volume. Furthermore, there was no relationship between vitamins B6, B12, or folate intake on global brain volume measures, indicating that VBM methods are more sensitive for detecting localized differences in gray matter volume than global measures. These results are discussed in relation to a growing literature on vitamin intake on age-related neurocognitive deterioration.

Influence of self-efficacy on the functional relationship between ratings of perceived exertion and exercise intensity

PURPOSE

Rating of perceived exertion (RPE) has been consistently used as a subjective index of exercise intensity for both exercise testing and prescription. Little empirical efforts have been made to determine how psychological factors influence changes in RPE. This study examined the influence of self-efficacy expectations on changes in RPE as a function of exercise intensity.

METHODS

Participants were 193 sedentary older adults (mean age = 66.7 years) who completed an assessment of exercise self-efficacy and aerobic capacity.

RESULTS

Analyses indicated that RPE during exercise changed in both a linear and a quadratic manner as intensity increased and that self-efficacy was a predictor of both patterns of change. Those high in self-efficacy maintained a constant rate of change in RPE as exercise intensity increased, whereas less efficacious participants exhibited a slower rate of change in RPE as a function of exercise intensity, with an initial gradual curve at lower intensity and a more dramatic trajectory at higher intensity.

CONCLUSIONS

Results have important implications for using RPE for exercise prescription in older adults and suggest that exercise self-efficacy is implicated in patterns of RPE change.