An investigation of antihypertensive class, dementia, and cognitive decline

Objective High blood pressure is one of the main modifiable risk factors
for dementia. However, there is conflicting evidence regarding the best
antihypertensive class for optimising cognition. Our objective was to
determine whether any particular class of antihypertensive was associated
with a reduced risk of cognitive decline or dementia using comprehensive
meta-analysis including reanalysis of original participant data. Methods
To identify suitable studies MEDLINE, Embase and PsycINFO® and
pre-existing study consortia were searched from inception to December
2017. Authors of prospective longitudinal human studies or trials of
antihypertensives were contacted for data-sharing and collaboration.
Outcome measures were incident dementia or incident cognitive decline
(classified using the reliable change index method). Data were separated
into mid and late-life (>65 years) and each antihypertensive class
was compared to no treatment and to treatment with other
antihypertensives. Meta-analysis was used to synthesize data. Results Over
50,000 participants from 27 studies were included. Among those aged
>65 years, with the exception of diuretics, we found no
relationship by class with incident cognitive decline or dementia.
Diuretic use was suggestive of benefit in some analyses but results were
not consistent across follow-up time, comparator group and outcome.
Limited data precluded meaningful analyses in those ≤65 years. Conclusions
Our findings, drawn from the current evidence base, support clinical
freedom in the selection of antihypertensive regimens to achieve blood
pressure goals.

研究目的：高血压是痴呆可改变的主要危险因素之一。然而，针对优化认知功能的最佳降压药物类别，现有研究证据尚存分歧。本研究旨在通过全面的荟萃分析（meta-analysis），包括对原始受试者数据的再分析，明确某一特定类别的降压药物是否与认知下降或痴呆风险降低相关。

研究方法：为筛选符合要求的研究，我们检索了MEDLINE、Embase及PsycINFO®数据库，以及已有的研究联盟，检索时限为各数据库建库至2017年12月。我们联系了前瞻性纵向人体研究或降压药物临床试验的作者，以获取数据共享与合作机会。本研究的结局指标为新发痴呆或新发认知下降（采用可靠变化指数法进行分类）。我们将数据按中年及晚年（年龄>65岁）进行分层，并将各类降压药物分别与未治疗组及其他降压药物治疗组进行比较，采用荟萃分析对研究数据进行综合整合。

研究结果：本研究共纳入27项研究的5万余名受试者。在年龄>65岁的人群中，除利尿剂外，未发现各类降压药物类别与新发认知下降或痴呆存在显著关联。使用利尿剂在部分分析中显示出获益趋势，但该结果在随访时长、对照组别及结局指标方面并不一致。对于年龄≤65岁的人群，因可用数据有限，无法开展有意义的分析。

研究结论：基于当前现有证据得出的本研究结果，支持临床医生在选择降压治疗方案以达成血压控制目标时拥有自主选择权。