School of Public Health, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Int J Geriatr Psychiatry. 2013 Aug;28(8):841-9. doi: 10.1002/gps.3890. Epub 2012 Sep 25.
We sought to examine the longitudinal relationship between cognitive function and all-cause mortality among Japanese community-dwelling older adults, using an 8-year prospective cohort study design with mortality surveillance.
A total of 454 men and 386 women, aged 70 years and older, participated in the study. The Mini Mental State Examination (MMSE) was administered to assess global cognition. The total MMSE score and subscale scores were used as independent variables, and age, gender, education level, chronic disease, sensory deficit, depressive symptoms, and instrumental activities of daily living were used as covariates.
During the follow-up period, 191 subjects (139 men and 52 women) died, and 64 subjects (31 men and 33 women) moved to a different region of Japan and were lost to follow-up. Use of the multivariate Cox proportional hazards model, adjusted for potential confounders, showed that global cognition was significantly and independently associated with mortality (hazard ratio [HR] = 1.59, 95% confidence interval [CI]: 1.14-2.23 and HR = 2.81, 95% CI: 1.77-4.36 for the middle [24-27 points] and lowest [0-23 points] categories, respectively). Among the MMSE subscales, place orientation (HR = 1.57, 95% CI: 1.09-2.25), calculation (HR = 1.67, 95% CI: 1.18-2.35), and delayed recall (HR = 1.42, 95% CI: 1.03-1.96), were also significantly and independently associated with mortality.
Our study suggests that among older individuals, those with lower levels of cognitive function are more likely to have a shorter lifespan compared with those with higher cognitive functioning.
我们旨在通过一项为期 8 年的前瞻性队列研究设计，对认知功能与日本社区居住的老年人群全因死亡率之间的纵向关系进行研究，同时进行死亡率监测。
共有 454 名男性和 386 名女性（年龄均在 70 岁及以上）参与了本研究。使用简易精神状态检查（MMSE）评估总体认知能力。将 MMSE 的总评分和各分量表评分作为自变量，年龄、性别、教育程度、慢性疾病、感觉缺失、抑郁症状和日常生活活动的工具作为协变量。
在随访期间，共有 191 名受试者（139 名男性和 52 名女性）死亡，64 名受试者（31 名男性和 33 名女性）搬至日本不同地区而失联。使用多变量 Cox 比例风险模型，对潜在混杂因素进行调整后，结果表明总体认知能力与死亡率显著相关（中值[24-27 分]和最低值[0-23 分]分别为危险比[HR] = 1.59，95%置信区间[CI]：1.14-2.23 和 HR = 2.81，95% CI：1.77-4.36）。在 MMSE 各分量表中，定向力（HR = 1.57，95% CI：1.09-2.25）、计算力（HR = 1.67，95% CI：1.18-2.35）和延迟回忆（HR = 1.42，95% CI：1.03-1.96）也与死亡率显著相关。
我们的研究表明，在老年人中，认知功能较低的人群与认知功能较高的人群相比，寿命更短的可能性更大。
