A 2-year physical activity program for sedentary older adults does not improve cognitive functioning more than a health education program [commentary]

摘要

Summary of: Sink KM, Espeland MA, Castro CM, Church T, Cohen R, Dodson JA, et al. Effect of a 24-month physical activity intervention vs health education on cognitive outcomes in sedentary older adults: the LIFE randomized trial. JAMA. 2015;314:781-790. Question: Does a physical activity program result in better cognitive function than a health education program in sedentary older adults living in the community? Design: Randomised, controlled trial with concealed allocation and blinded assessment. Setting: Eight community centres in the United States of America. Participants: The study included sedentary men and women, aged 70 to 89 years, who were at risk of mobility disability but were able to walk 400 m. The key exclusion criterion was having a diagnosis of dementia or significant cognitive impairment based on the Modified Mini-Mental State Examination score. Randomisation of 1635 parti- cipants allocated 818 to the physical activity group and 817 to the health education group. Interventions: The physical activity group participated in a 24-month program of twice-weekly, centre-based sessions of up to 30 minutes of moderate intensity walking, 10 minutes of lower limb resistance training, and 10 minutes of balance and flexibility exercises. In addition, the physical activity group were prescribed home exercises 3 to 4 times per week. The health education group attended weekly sessions for 26 weeks and monthly sessions thereafter. Sessions consisted of presentations, demonstrations or field trips. Outcome measures: The primary outcomes for this report were cognitive outcomes assessed at baseline and 24 months. Cognitive outcomes included the Digital Symbol Coding task (scored from 0 to 133 points) and the Hopkins Verbal Learning Test (scored from 0 to 12 words). Secondary1836-9553/ 2016 Australian Physiotherapy Association. Published by Elsevier B creativecommons.org/licenses/by-nc-nd/4.0/).outcome measures included executive function (measured with three tasks to assess speed of processing and executive function on a laptop computer), a composite global function score, and the incidence of mild cognitive impairment or dementia at 24 months. Results: A total of 1476 participants (90%) completed the study. Median attendance at physical activity sessions was 71%. At 24 months, there were no between-group differences for the Digital Symbol Coding Task (MD C0.01 points, 95% CI C0.80 to 0.77) or the Hopkins Verbal Learning Test for delayed word recall (MD C0.03 words, 95% CI C0.29 to 0.24) or immediate word recall (MD C0.14 words, 95% CI C0.58 to 0.29). There were no between-group differences for global and executive function measures, although sub-group analyses indicated benefits in executive function associated with physical activity for those aged at least 80 years and for those scoring<8 on the Short Physical Performance Battery. There was no difference in the incidence of mild cognitive impairment or dementia between the physical activity group (13.2%) and the health education group (12.1%) (OR 1.08, 95% CI 0.80 to 1.46). Conclusion: A 24-month physical activity program for older sedentary adults did not improve cognitive functioning compared with a health education program. Provenance: Invited. Not peer reviewed. Nicholas Taylor Associate Editor, Journal of Physiotherapy http://dx.doi.org/10.1016/j.jphys.2015.12.008.