Background The role of social environment, i.e., the aggregate effect of social determinants of health (SDOHs), in determining dementia is unclear. Methods We developed a novel polysocial risk score for dementia based on 19 SDOH among 5,199 participants in the Health and Retirement Study, US, to measure the social environmental risk. We used a survival analysis approach to assess the association between social environment and dementia risk in 2006-2020. We further studied the interaction between social environment and lifestyles, and explored racial disparities. Results The study participants (mean age=73.4 years, SD=8.3; 58.0% female; 11.6% African American) were followed up for an average of 6.2 years, and 1,089 participants developed dementia. Every one-point increase in the polysocial risk score (ranging from 0-10) was associated with a 21.6% higher risk (aHR=1.21, 95% CI=1.15-1.26) of developing dementia, other things being equal. Among participants with high social environmental risk, regular exercise and moderate drinking were associated with a 43-60% lower risk of developing dementia (p<0.001). In addition, African Americans were 1.3 times (aHR=2.28, 95% CI=1.96-2.66) more likely to develop dementia than European Americans, other things being equal. Discussion An adverse social environment is linked to higher dementia risk, but healthy lifestyles can partially offset the increased social environmental risk. The polysocial risk score can complement the existing risk tools to identify high-risk older populations, and guide the design of targeted social environmental interventions, particularly focusing on improving the companionship of the older people, to prevent dementia.

中文翻译：

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社会环境、生活方式和遗传易感性与痴呆风险：一项针对老年人的长期纵向研究

背景 社会环境（即健康的社会决定因素（SDOH）的总体影响）在确定痴呆方面的作用尚不清楚。方法 我们根据美国健康与退休研究的 5,199 名参与者中的 19 SDOH 制定了一种新的痴呆症多社会风险评分，以衡量社会环境风险。我们使用生存分析方法来评估 2006-2020 年社会环境与痴呆风险之间的关联。我们进一步研究了社会环境和生活方式之间的相互作用，并探讨了种族差异。结果 研究参与者（平均年龄=73.4 岁，SD=8.3；58.0% 为女性；11.6% 为非裔美国人）平均随访 6.2 年，其中 1,089 名参与者出现痴呆。在其他条件相同的情况下，多社会风险评分（范围为 0-10）每增加 1 分，患痴呆症的风险就会增加 21.6%（aHR=1.21，95% CI=1.15-1.26）。在社会环境风险较高的参与者中，定期锻炼和适量饮酒可将患痴呆症的风险降低 43-60%（p<0.001）。此外，在其他条件相同的情况下，非洲裔美国人患痴呆症的可能性是欧洲裔美国人的 1.3 倍（aHR=2.28，95% CI=1.96-2.66）。讨论 不良的社会环境与较高的痴呆风险有关，但健康的生活方式可以部分抵消增加的社会环境风险。多社会风险评分可以补充现有的风险工具来识别高风险老年人群，并指导设计有针对性的社会环境干预措施，特别是注重改善老年人的陪伴，预防痴呆。