Karlamangla Arun S, Lachman Margie E, Han WeiJuan, Huang MeiHua, Greendale Gail A
Divison of Geriatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America.
Department of Psychology, Brandeis University, Waltham, Massachusetts, United States of America.
PLoS One. 2017 Jan 3;12(1):e0169008. doi: 10.1371/journal.pone.0169008. eCollection 2017.
Although cross-sectional studies suggest that cognitive aging starts in midlife, few longitudinal studies have documented within-individual declines in cognitive performance before the seventh decade. Learning from repeat testing, or practice effects, can mask the decline in younger cohorts. In women, the menopause transition also affects test performance and can confound estimates of underlying decline. We designed this study to determine if, after controlling for practice effects, the menopause transition, and the symptoms associated with it, there is evidence of cognitive aging in midlife women. We used data from a longitudinal observational study in 2,124 participants from the Study of Women's Health Across the Nation. Outcomes examined were scores on annual tests of processing speed, verbal episodic memory (immediate and delayed), and working memory. To reduce the impact of practice effects and of the menopause transition, we used the third cognition testing visit as the baseline. Average age at this baseline was 54 years, and the majority of the women were postmenopausal; half the cohort was 2 or more years beyond the final menstrual period. There were 7,185 cognition assessments with median follow-up time of 6.5 years. In mixed effects regression, adjusted for practice effects, retention, menopause symtoms (depressive, anxiety, vasomotor, and sleep disturbance), and covariates, scores on 2 of 4 cognition tests declined. Mean decline in cognitive speed was 0.28 per year (95% confidence interval [CI] 0.20 to 0.36) or 4.9% in 10 years, and mean decline in verbal episodic memory (delayed testing) was 0.02 per year (95% CI: 0.00 to 0.03) or 2% in 10 years. Our results provide strong, longitudinal evidence of cognitive aging in midlife women, with substantial within-woman declines in processing speed and memory. Further research is needed to identify factors that influence decline rates and to develop interventions that slow cognitive aging.
尽管横断面研究表明认知衰老始于中年，但很少有纵向研究记录到在七十岁之前个体认知能力的下降。重复测试带来的学习效应，即练习效应，可能掩盖年轻队列中的认知能力下降。在女性中，绝经过渡也会影响测试表现，并可能混淆对潜在认知能力下降的估计。我们开展这项研究是为了确定，在控制了练习效应、绝经过渡及其相关症状之后，中年女性是否存在认知衰老的迹象。我们使用了来自全国女性健康研究中2124名参与者的纵向观察性研究数据。所检测的结果是每年处理速度、言语情景记忆（即时和延迟）以及工作记忆测试的分数。为了减少练习效应和绝经过渡的影响，我们将第三次认知测试访视作为基线。该基线时的平均年龄为54岁，大多数女性已绝经；一半的队列在最后一次月经后已过2年或更长时间。共有7185次认知评估，中位随访时间为6.5年。在混合效应回归中，经练习效应、留存率、绝经症状（抑郁、焦虑、血管舒缩和睡眠障碍）及协变量校正后，4项认知测试中的2项分数下降。认知速度的平均年下降率为0.28（95%置信区间[CI]0.20至0.36），即10年下降4.9%；言语情景记忆（延迟测试）的平均年下降率为0.02（95%CI：0.00至0.03），即10年下降2%。我们的结果提供了中年女性认知衰老的有力纵向证据，表明女性个体的处理速度和记忆力有显著下降。需要进一步研究以确定影响下降速率的因素，并制定减缓认知衰老的干预措施。
