Modifiable factors related to life-space mobility in community-dwelling older adults: results from the Canadian Longitudinal Study on Aging.

BACKGROUND: The most common methods for measuring mobility in older adulthood include performance-based tests, such as the Timed-Up-and-Go and gait speed. While these measures have strong predictive validity for adverse outcomes, they are limited to assessing what older adults do in standardized settings, rather than what they do in their daily life. Life-space mobility, which is the ability to move within environments that expand from one's home to the greater community, has been proposed as a more comprehensive measure of mobility. The aim of this study was to determine the association between modifiable factors and life-space mobility in older adults enrolled in the Canadian Longitudinal Study on Aging (CLSA). METHODS: Life-space mobility was measured using the Life Space Index (LSI). Explanatory factors included physical, psychosocial and cognitive determinants, as well as pain, fatigue, driving status, nutrition, body mass index, smoking status, and vision. To estimate the association between the LSI and explanatory variables, univariate and multivariable ordinary least squares regression analyses were performed. RESULTS: All adults 65 years and older (n = 12,646) were included in the analysis. Fifty percent were women and the mean age was 73.0 (SD5.7). The mean LSI score was 80.5, indicating that, on average, the sample was able to move outside of their neighborhood independently. All explanatory variables were significantly associated with the LSI except for balance and memory. The top 3 variables that explained the most variation in the LSI were driving, social support and walking speed. CONCLUSION: To our knowledge, this was the first study to examine the association between life-space mobility and a comprehensive set of modifiable factors that were selected based on a theoretical framework and existing research evidence. This study had two important messages. First, driving, social support and walking speed emerged as the most significant correlates of life-space mobility in older adults. Second, life-space mobility is multifactorial and interventions that are pragmatic in their design and testing are needed that consider the complexity involved. A multi-disciplinary approach to examining life-space mobility in older adults is needed to optimize opportunities for healthy aging and develop strategies that support mobility in older adulthood.

Effect of aerobic exercise on cancer-associated cognitive impairment: A proof-of-concept RCT.

BACKGROUND: Change in cognitive ability is a commonly reported adverse effect by breast cancer survivors. The underlying etiology of cognitive complaints is unclear and to date, there is limited evidence for effective intervention strategies. Exercise has been shown to improve cognitive function in older adults and animal models treated with chemotherapy. This proof-of-concept randomized controlled trial tested the effect of aerobic exercise versus usual lifestyle on cognitive function in postmenopausal breast cancer survivors. METHODS: Women, aged 40 to 65 years, postmenopausal, stages I to IIIA breast cancer, and who self-reported cognitive dysfunction following chemotherapy treatment, were recruited and randomized to a 24-week aerobic exercise intervention (EX; n = 10) or usual lifestyle control (CON; n = 9). Participants completed self-report measures of the impact of cognitive issues on quality of life (Functional Assessment of Cancer Therapy-Cognitive version 3), objective neuropsychological testing, and functional magnetic resonance imaging at baseline and 24 weeks. RESULTS: Compared to CON, EX had a reduced time to complete a processing speed test (trail making test-A) (-14.2 seconds, P < .01; effect size 0.35). Compared to CON, there was no improvement in self-reported cognitive function and effect sizes were small. Interestingly, lack of between-group differences in Stroop behavioral performance was accompanied by functional changes in several brain regions of interest in EX compared to CON at 24 weeks. CONCLUSION: These findings provide preliminary proof-of-concept results for the potential of aerobic exercise to improve cancer-related cognitive impairment and will serve to inform the development of future trials.

Does obesity modify the relationship between physical activity and breast cancer risk?

PURPOSE: With only 5-10% of breast cancer cases attributed to genetic inheritance, prevention efforts have focused on modifiable risk factors. Physical activity plays a role in reducing breast cancer risk; however, the interaction between physical activity and other modifiable risk factors, such as obesity, has received little attention. METHODS: A systematic review and meta-analysis was conducted of studies examining the relationship between physical activity and breast cancer and how it may be modified by body mass index (BMI). RESULTS: A total of 29 papers were included: 18 were cohort and 11 were case-control studies. Overall, a significant reduction in the relative risk of breast cancer was found in postmenopausal women with high versus low levels of physical activity for women with a BMI <25 kg/m2 (RR 0.85, 95% CI 0.79, 0.92) and ≥25 kg/m2 (RR 0.87, 95% CI 0.81, 0.93) but not ≥30 kg/m2 (RR: 0.93, 95% CI 0.76, 1.13). Physical activity was not associated with a significant reduction in risk of breast cancer in premenopausal women in any BMI group. CONCLUSION: The results of this meta-analysis suggest that physical activity is associated with a larger breast cancer risk reduction among women who are normal weight or overweight than among women who are obese. Since the included studies used diverse methods for assessment of physical activity and categories of BMI, results should be interpreted with caution and additional work is needed.

Fee-for-service cancer rehabilitation programs improve health-related quality of life.

BACKGROUND: Rigorously applied exercise interventions undertaken in a research setting result in improved health-related quality of life (hrqol) in cancer survivors, but research to demonstrate effective translation of that research to practice is needed. The objective of the present study was to determine the effect of fee-for-service cancer rehabilitation programs in the community on hrqol and on self-reported physical activity and its correlates. METHODS: After enrolment and 17 ± 4 weeks later, new clients (n = 48) to two fee-for-service cancer rehabilitation programs completed the 36-Item Short Form Health Survey (rand-36: rand Corporation, Santa Monica, CA, U.S.A.), the Godin Leisure-Time Exercise Questionnaire, and questions about physical activity correlates. Normal fee-for-service operations were maintained, including a fitness assessment and individualized exercise programs supervised in a group or one-on-one setting, with no minimum attendance required. Fees were associated with the assessment and with each exercise session. RESULTS: Of the 48 participants, 36 (75%) completed both questionnaires. Improvements in the physical functioning, role physical, pain, and energy/fatigue scales on the rand-36 exceeded minimally important differences and were of a magnitude similar to improvements reported in structured, rigorously applied, and free research interventions. Self-reported levels of vigorous-intensity (p = 0.021), but not moderate-intensity (p = 0.831) physical activity increased. The number of perceived barriers to exercise (p = 0.035) and the prevalence of fatigue as a barrier (p = 0.003) decreased. Exercise self-efficacy improved only in participants who attended 11 or more sessions (p = 0.002). Exercise enjoyment did not change (p = 0.629). CONCLUSIONS: Enrolment in fee-for-service cancer rehabilitation programs results in meaningful improvements in hrqol comparable to those reported by research interventions, among other benefits. The fee-for-service model could be an effective model for delivery of exercise to more cancer survivors.

Age-dependent increased odds of cardiovascular risk factors in cancer survivors: Canadian Longitudinal Study on Aging cohort.

Background: This study compared the odds of self-reported and objectively measured cardiovascular (cv) risk factors in a sample of Canadian cancer survivors and individuals without cancer. Methods: A nationally representative sample of 45- to 85-year-old cancer survivors (n = 6288) in the Canadian Longitudinal Study on Aging were compared with individuals without cancer (n = 44,051). Results: The most prevalent risk factors in cancer survivors were all self-reported or easily measured in clinic: overweight or obesity (68.0%), former smoking (62.9%), fewer than 5 daily servings of fruits and vegetables (59.8%), hypertension (43.7%), and high waist circumference (47.0%). After adjustment for sex and education, the odds ratios of several cv risk factors varied by age in cancer survivors and the non-cancer controls. At ages 50 and 60, cancer survivors have increased odds of overweight or obesity, former smoking, hypertension, high waist circumference and truncal fat, diabetes, lung disease, and heart rate greater than 80 bpm compared with non-cancer controls. At age 70, odds did not differ for many risk factors; at age 80, no differences were evident. Without modification by age, low physical activity was more prevalent in cancer survivors (odds ratio: 1.27; 95% confidence interval: 1.17 to 1.39). There were no differences in the odds of cv risk factors measured by specialized equipment, including electrocardiography, carotid ultrasonography, spirometry, and dual-energy X-ray absorptiometry. Conclusions: The odds of several easy-to-assess cv disease risk factors are higher among middle-aged, but not older, cancer survivors relative to the general Canadian population. Initial assessment of cv risk for middle-aged adults in the survivorship setting could be quickly and inexpensively performed using self-reported and easily measured metrics.