School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705, USA.
Maturitas. 2009 Nov 20;64(3):182-7. doi: 10.1016/j.maturitas.2009.09.014. Epub 2009 Oct 29.
The Women's Health Initiative (WHI) study and its ancillary Memory Study (WHIMS) revealed increased rates of cardiovascular risk, cognitive decline and dementia with opposed conjugated equine estrogens (CEE). As a result, previously accepted observational data suggesting cardiovascular and cognitive benefits and reduced risk for dementia with hormone therapy (HT) were largely attributed to 'healthy-user' bias. The present observational, community-based, case-controlled study examined the 'healthy-user' bias theory by comparing cognitive task performance in two groups of postmenopausal women, who were either HT users or non-users.
Participants were 213 non-demented, postmenopausal women residing in the community and in assisted-living facilities who completed a self-report health questionnaire and underwent a 1-h cognitive test battery. To study the independent contribution of variables in the prediction of cognitive performance, we employed a series of hierarchical regression models adding terms in three stages. The first stage included only HT, the second stage added demographics, and the last stage added alcohol, depression and a cardiovascular risk factor (CVRF) composite derived from a confirmatory factor analysis. The CVRF composite consisted of: stroke, diabetes, hypertension, and hypercholesterolemia.
Although independent samples t-tests revealed no statistically significant differences in the CVRF composite and its individual components between the two groups, HT users tended to possess fewer CVRF than non-users. Conversely, HT users were younger and more educated than non-users. HT users outperformed non-users on 7/9 cognitive variables. The full regression model controlling for CVRF, demographic variables, and mood showed HT users outperformed non-users on measures of verbal memory and abstract reasoning.
While there is some evidence HT users possess fewer preexisting CVRF than non-users, the observed positive association between HT and cognition is not completely explained by this trend.
妇女健康倡议（WHI）研究及其辅助记忆研究（WHIMS）显示，与结合马雌激素（CEE）相比，雌性激素治疗（HT）增加了心血管风险、认知能力下降和痴呆的发生率。因此，先前接受的关于 HT 具有心血管和认知益处以及降低痴呆风险的观察数据在很大程度上归因于“健康使用者”偏倚。本观察性、基于社区的病例对照研究通过比较两组绝经后妇女的认知任务表现来检验“健康使用者”偏倚理论，这两组妇女分别为 HT 用户和非 HT 用户。
参与者为 213 名居住在社区和辅助生活设施中的非痴呆绝经后妇女，她们完成了一份自我报告健康问卷，并接受了 1 小时的认知测试。为了研究变量在预测认知表现中的独立贡献，我们采用了一系列层次回归模型，在三个阶段添加术语。第一阶段仅包括 HT，第二阶段添加人口统计学数据，最后阶段添加酒精、抑郁和来自验证性因子分析的心血管危险因素（CVRF）综合得分。CVRF 综合得分包括：中风、糖尿病、高血压和高胆固醇血症。
尽管独立样本 t 检验显示两组之间在 CVRF 综合得分及其各个组成部分方面没有统计学上的显著差异，但 HT 用户的 CVRF 比非 HT 用户少。相反，HT 用户比非 HT 用户年轻且受教育程度更高。HT 用户在 7/9 项认知变量上的表现优于非 HT 用户。在控制 CVRF、人口统计学变量和情绪的全回归模型中，HT 用户在言语记忆和抽象推理方面的表现优于非 HT 用户。
虽然有一些证据表明 HT 用户比非 HT 用户拥有更少的预先存在的 CVRF，但 HT 与认知之间的正相关关系并不能完全由这一趋势来解释。
