Time spent being sedentary is associated with poorer cognitive function and risk of developing Alzheimer’s disease (AD). The present study aimed to compare patterns of sitting in a free-living environment among older adults with and without early stage AD who were similar in physical limitations, body mass, and cardiorespiratory capacity. We also compared estimates of sitting patterns between two different monitors (postural and non-postural) with different body placements (thigh-worn vs. hip-worn). Comparing older adults without cognitive impairment to those with early AD, we found that although there was no difference in the total amount of daily sitting time (p = .52), the AD group tended to have longer durations of sitting than those without AD. Inclinometry data from the hip-worn ActiGraph GT3X+ consistently underestimated time spent sitting compared to the thigh worn monitor activPAL™ (hours per day, proportion of waking hours, number of sitting bouts greater than 30 minutes, and duration of sitting bouts). Our results have implications for prevention strategies to reduce sedentary time, which is predominantly sitting, in persons with cognitive impairment and highlight the importance of monitor selection and placement for the accurate assessment of sitting patterns in this population.
Amber Watts, Mauricio Garnier-Villarreal, and Paul Gardiner
Natasha Reid, Justin W. Keogh, Paul Swinton, Paul A. Gardiner, and Timothy R. Henwood
This study investigated the association of sitting time with sarcopenia and physical performance in residential aged care residents at baseline and 18-month follow-up. Measures included the International Physical Activity Questionnaire (sitting time), European Working Group definition of sarcopenia, and the short physical performance battery (physical performance). Logistic regression and linear regression analyses were used to investigate associations. For each hour of sitting, the unadjusted odds ratio of sarcopenia was 1.16 (95% confidence interval [0.98, 1.37]). Linear regression showed that each hour of sitting was significantly associated with a 0.2-unit lower score for performance. Associations of baseline sitting with follow-up sarcopenia status and performance were nonsignificant. Cross-sectionally, increased sitting time in residential aged care may be detrimentally associated with sarcopenia and physical performance. Based on current reablement models of care, future studies should investigate if reducing sedentary time improves performance among adults in end of life care.
Sharon Hetherington, Paul Swinton, Tim Henwood, Justin Keogh, Paul Gardiner, Anthony Tuckett, Kevin Rouse, and Tracy Comans
In this article, the authors assessed the cost-effectiveness of center-based exercise training for older Australians. The participants were recipients of in-home care services, and they completed 24 weeks of progressive resistance plus balance training. Transport was offered to all participants. A stepped-wedge randomized control trial produced pre-, post-, and follow-up outcomes and cost data, which were used to calculate incremental cost-effectiveness ratios per quality-adjusted life year gained. Analyses were conducted from a health provider perspective and from a government perspective. From a health-service provider perspective, the direct cost of program provision was $303 per person, with transport adding an additional $1,920 per person. The incremental cost–utility ratio of the program relative to usual care was $70,540 per quality-adjusted life year over 6 months, decreasing to $37,816 per quality-adjusted life year over 12 months. The findings suggest that Muscling Up Against Disability offers good value for the money within commonly accepted threshold values.
Brigid M. Lynch, Suzanne C. Dixon-Suen, Andrea Ramirez Varela, Yi Yang, Dallas R. English, Ding Ding, Paul A. Gardiner, and Terry Boyle
Background: It is not always clear whether physical activity is causally related to health outcomes, or whether the associations are induced through confounding or other biases. Randomized controlled trials of physical activity are not feasible when outcomes of interest are rare or develop over many years. Thus, we need methods to improve causal inference in observational physical activity studies. Methods: We outline a range of approaches that can improve causal inference in observational physical activity research, and also discuss the impact of measurement error on results and methods to minimize this. Results: Key concepts and methods described include directed acyclic graphs, quantitative bias analysis, Mendelian randomization, and potential outcomes approaches which include propensity scores, g methods, and causal mediation. Conclusions: We provide a brief overview of some contemporary epidemiological methods that are beginning to be used in physical activity research. Adoption of these methods will help build a stronger body of evidence for the health benefits of physical activity.
Samantha M. Gray, Peggy Chen, Lena Fleig, Paul A. Gardiner, Megan M. McAllister, Joseph H. Puyat, Joanie Sims-Gould, Heather A. McKay, Meghan Winters, and Maureen C. Ashe
Background: Physical activity confers many health benefits to older adults, and adopting activity into daily life routines may lead to better uptake. The purpose of this study was to test the effect of a lifestyle intervention to increase daily physical activity in older women through utilitarian walking and use of public transportation. Methods: In total, 25 inactive women with mean age (SD) of 64.1 (4.6) years participated in this pilot randomized controlled trial [intervention (n = 13) and control (n = 12)]. Seven-day travel diaries (trips per week) and the International Physical Activity Questionnaire (minutes per week) were collected at baseline, 3, and 6 months. Results: At 3 months, intervention participants reported 9 walking trips per week and 643.5 minutes per week of active transportation, whereas control participants reported 4 walking trips per week and 49.5 minutes per week of active transportation. Adjusting for baseline values, there were significant group differences favoring Everyday Activity Supports You for walking trips per week [4.6 (0.5 to 9.4); P = .04] and active transportation minutes per week [692.2 (36.1 to 1323.5); P = .05]. At 6 months, significant group differences were observed in walking trips per week [6.1 (1.9 to 11.4); P = .03] favoring the intervention (9 vs 2 trips per week). Conclusion: Given these promising findings, the next step is to test Everyday Activity Supports You model’s effectiveness to promote physical activity in older women within a larger study.
Dori E. Rosenberg, Melissa L. Anderson, Anne Renz, Theresa E. Matson, Amy K. Lee, Mikael Anne Greenwood-Hickman, David E. Arterburn, Paul A. Gardiner, Jacqueline Kerr, and Jennifer B. McClure
Background: The authors tested the efficacy of the “I-STAND” intervention for reducing sitting time, a novel and potentially health-promoting approach, in older adults with obesity. Methods: The authors recruited 60 people (mean age = 68 ± 4.9 years, 68% female, 86% White; mean body mass index = 35.4). The participants were randomized to receive the I-STAND sitting reduction intervention (n = 29) or healthy living control group (n = 31) for 12 weeks. At baseline and at 12 weeks, the participants wore activPAL devices to assess sitting time (primary outcome). Secondary outcomes included fasting glucose, blood pressure, and weight. Linear regression models assessed between-group differences in the outcomes. Results: The I-STAND participants significantly reduced their sitting time compared with the controls (–58 min per day; 95% confidence interval [–100.3, –15.6]; p = .007). There were no statistically significant changes in the secondary outcomes. Conclusion: I-STAND was efficacious in reducing sitting time, but not in changing health outcomes in older adults with obesity.