19 research outputs found
Dose of physical activity, physical functioning and disability risk in mobility-limited older adults: Results from the LIFE study randomized trial
<div><p>Understanding the minimal dose of physical activity required to achieve improvement in physical functioning and reductions in disability risk is necessary to inform public health recommendations. To examine the effect of physical activity dose on changes in physical functioning and the onset of major mobility disability in The Lifestyle Interventions and Independence for Elders (LIFE) Study. We conducted a multicenter single masked randomized controlled trial that enrolled participants in 2010 and 2011 and followed them for an average of 2.6 years. 1,635 sedentary men and women aged 70–89 years who had functional limitations were randomized to a structured moderate intensity walking, resistance, and flexibility physical activity program or a health education program. Physical activity dose was assessed by 7-day accelerometry and self-report at baseline and 24 months. Outcomes included the 400 m walk gait speed, the Short Physical Performance Battery (SPPB), assessed at baseline, 6, 12, and 24 months, and onset of major mobility disability (objectively defined by loss of ability to walk 400 m in 15 min). When the physical activity arm or the entire sample were stratified by change in physical activity from baseline to 24 months, there was a dose-dependent increase in the change in gait speed and SPPB from baseline at 6, 12, and 24 months. In addition, the magnitude of change in physical activity over 24 months was related to the reduction in the onset of major mobility disability (overall P < 0.001) (highest versus the lowest quartile of physical activity change HR 0.23 ((95% CI:0.10–0.52) P = 0.001) in the physical activity arm. We observed a dose-dependent effect of objectively monitored physical activity on physical functioning and onset of major mobility disability. Relatively small increases (> 48 minutes per week) in regular physical activity participation had significant and clinically meaningful effects on these outcomes.</p><p><b>Trial registration:</b> ClinicalsTrials.gov <a href="http://clinicaltrials.gov/show/NCT00116194" target="_blank">NCT00116194</a></p></div
Main characteristics of the study population.
a<p>from chi-square test or Kruskal-wallis ANOVA.</p
Odds ratios (and 95% confidence intervals) of depressed mood according to 8-iso-PGF<sub>2α</sub> concentrations.
a<p>8-iso-PGF<sub>2α.</sub> log-transformed.</p>b<p>8-iso-PGF<sub>2α</sub>. High levels (sex-specific highest quartile): >926.7 pg/mg-creatinine in men and >1,175.4 pg/mg-creatinine in women.</p><p>Abbreviations: OR, Odds Ratio; 95%CI, 95% Confidence interval.</p><p>Model 1: unadjusted.</p><p>Model 2: adjusted for age, race, education and site.</p><p>Model 3: additionally adjusted for alcohol use, smoking, Modified Mini Mental State Examination, physical activity, body mass index, cerebrovascular diseases, cardiovascular disease and diabetes.</p
Plot of (log)8-iso-PGF<sub>2α</sub> concentrations versus adjusted predicted probability of depressed mood according to sex.
<p>Predicted probability and 95% Confidence Intervals (95%CIs) are adjusted for age, race, education, site, alcohol use, smoking, 3MSE, physical activity, BMI, cerebrovascular disease, CVD and diabetes.</p
Descriptive statistics of the Lifestyle Interventions and Independence for Elders (LIFE) Study sample at baseline, by sex (n = 1130).
<p>Note: Results are presented as mean (SD) or as n (%);</p><p>*Comparison of sexes using t-tests or chi-squared tests; all accelerometry measures were adjusted for wear time; accelerometer cut points were as follows: sedentary time <100 counts/min; lower-light intensity: 100–1040 counts/min; Higher-light intensity: ≥1041 counts/min.</p><p>Descriptive statistics of the Lifestyle Interventions and Independence for Elders (LIFE) Study sample at baseline, by sex (n = 1130).</p
Hazard ratio for major mobility disability in the entire sample.
<p>Hazard ratio for major mobility disability in the entire sample.</p
Change in physical activity from baseline by randomized arm (differences between physical activity and health education P < 0.001 (calculated using the Wilcoxon rank sum test) between PA and HE at all time points.
<p>Change in physical activity from baseline by randomized arm (differences between physical activity and health education P < 0.001 (calculated using the Wilcoxon rank sum test) between PA and HE at all time points.</p
Dose of physical activity, physical functioning and disability risk in mobility-limited older adults: Results from the LIFE study randomized trial - Fig 2
<p><b>Change in 400 m walk gait speed (m/s) compared to baseline gait speed at 6, 12, and 24 months according to quartiles of change physical activity by accelerometry from baseline to 24 months, (a.) physical activity arm alone and (b.) entire group combined (least square means ± SE).</b> Overall effect P < 0.0001. Effects within each time point P < 0.0001.</p
Association with change in gait speed and SPPB in physical activity arm participants, using quartile of change from baseline to 24 months of self-reported walking plus weight training.
<p>Association with change in gait speed and SPPB in physical activity arm participants, using quartile of change from baseline to 24 months of self-reported walking plus weight training.</p