Division of Epidemiology, Department of Health Informatics and Public Health, Tohoku University School of Public Health, Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
J Neurol. 2019 May;266(5):1222-1229. doi: 10.1007/s00415-019-09252-w. Epub 2019 Mar 2.
This cohort study estimated the population attributable fraction (PAF) of seven combined major risk factors for incident dementia.
We conducted a cohort study of 8563 community-dwelling individuals aged ≥ 65 years. In a baseline survey (2006), we collected data on major seven risk factors: diabetes mellitus, hypertension, obesity, physical inactivity, severe psychological distress, smoking, and low educational attainment. The total number of risk factors was applied as an exposure variable. Subjects were categorized into four groups according to the total number of risk factors they possessed (0, 1, 2, ≥ 3 risk factors). Data on incident dementia were retrieved from the public Long-term Care Insurance database. Hazard ratios (HRs) and 95% confidence interval (95% CI) were estimated using the Cox proportional regression model. We also calculated the PAF using HRs and the prevalences in our cohort data.
The number of cases of incident dementia was 577 (6.7%). A dose-response relationship between the total number of risk factors and incident dementia was observed; in comparison with no risk factors (reference), the age- and sex-adjusted HRs (95% CIs) were 1.25 (0.92-1.70) for one risk factor, 1.59 (1.18-2.15) for two, and 2.21 (1.62-3.01) for three or more (P trend < 0.001). If subjects had adhered to none of the risk factors, the PAF would have been 32.2%. If subjects had improved toward one better category, the PAF would have been 23.0%.
Our findings suggest that reducing the combined number of risk factors would contribute significantly to reducing the incidence of dementia.
本队列研究估计了七种联合主要痴呆风险因素对发病的人群归因分数（PAF）。
我们对 8563 名年龄≥65 岁的社区居民进行了队列研究。在基线调查（2006 年）中，我们收集了关于七种主要风险因素的数据：糖尿病、高血压、肥胖、身体活动不足、严重心理困扰、吸烟和低教育程度。总风险因素数量被用作暴露变量。根据所拥有的总风险因素数量，将受试者分为四组（0、1、2、≥3 个风险因素）。从公共长期护理保险数据库中检索到痴呆发病数据。使用 Cox 比例回归模型估计风险比（HR）和 95%置信区间（95%CI）。我们还使用 HR 和队列数据中的患病率计算了 PAF。
发病痴呆的病例数为 577 例（6.7%）。总风险因素数量与发病痴呆之间存在剂量-反应关系；与无风险因素（参照）相比，年龄和性别调整后的 HR（95%CI）为 1.25（0.92-1.70）、1 个风险因素，1.59（1.18-2.15）、2 个风险因素，2.21（1.62-3.01）、3 个或更多风险因素（P趋势<0.001）。如果受试者没有遵守任何风险因素，PAF 将为 32.2%。如果受试者向一个更好的类别改善，PAF 将为 23.0%。
我们的研究结果表明，减少联合风险因素的数量将显著有助于降低痴呆的发病率。
