Departments of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Johns Hopkins University Center on Aging and Health, Baltimore, MD, USA.
J Alzheimers Dis. 2017;59(4):1349-1358. doi: 10.3233/JAD-170290.
Links between physical activity and dementia are based primarily on cross-sectional data or studies with unsatisfactory follow-up.
We leveraged three decades of follow-up from an established cohort to determine whether physical activity in midlife is associated with late-life cognition and dementia.
The Johns Hopkins Precursors study (n = 646) enrolled participants from 1948-1964 and administered questions about physical activity, from which we calculated metabolic equivalents (MET h/day), and exercise from 1978-present. Cognitive tests were administered in 2008. Dementia was adjudicated through 2011. To characterize associations with midlife physical activity, we used linear regression for cognitive tests and Cox proportional hazards models for dementia onset. Models adjusted for age, sex, smoking, diabetes, and hypertension.
No physical activity measure from 1978 was associated with late-life cognition or onset of dementia. Both MET h/day (β= 0.007, 95% CI: 0.002, 0.013) and regular exercise (β= 0.357, 95% CI: 0.202, 0.513) in 2006, however, were associated with better cognition in 2008.
Findings from this 30-year cohort study that physical activity measured recently, but not in mid-life, is associated with late-life cognition fits with null findings from randomized trials and other observational studies with extensive follow-up. Cross-sectional findings may be misleading due to reverse causation.
体力活动与痴呆之间的联系主要基于横断面数据或随访结果不理想的研究。
我们利用一个已建立的队列进行了长达 30 年的随访，以确定中年时期的体力活动是否与晚年认知和痴呆有关。
约翰霍普金斯大学先驱研究（n=646）招募了 1948-1964 年的参与者，并对他们的体力活动情况进行了问卷调查，从中我们计算了代谢当量（MET h/天），以及 1978 年至今的运动量。认知测试于 2008 年进行。痴呆症的诊断依据是 2011 年的结果。为了描述与中年体力活动相关的情况，我们使用线性回归分析认知测试，使用 Cox 比例风险模型分析痴呆症发病情况。模型调整了年龄、性别、吸烟、糖尿病和高血压因素。
1978 年的任何体力活动指标均与晚年认知或痴呆症发病无关。然而，2006 年的 MET h/天（β=0.007，95%CI：0.002，0.013）和规律运动（β=0.357，95%CI：0.202，0.513）与 2008 年的认知功能较好有关。
这项为期 30 年的队列研究发现，最近而非中年时期进行的体力活动与晚年认知相关，这与随机试验和其他具有广泛随访的观察性研究的阴性结果一致。横断面研究的结果可能由于反向因果关系而产生误导。
