Department of Psychiatry, China Medical University Hsinchu Hospital, China Medical University, Hsinchu.
Department of Public Health and Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei.
Aust N Z J Psychiatry. 2022 Jan;56(1):16-27. doi: 10.1177/0004867420976853. Epub 2020 Dec 8.
Heart rate variability, a quantitative measure of mainly parasympathetic activity, has been applied in evaluating many types of psychiatric and neurological disorders, including dementia (or neurocognitive disorders). However, although dementia patients often showed significantly lower heart rate variability (various indices) than healthy controls, and different types of dementia had distinct heart rate variability features, the results were not identical across studies. We designed a systematic review and meta-analysis for incorporating data from different studies.
We gathered studies comparing heart rate variability in patients with dementia and in healthy controls. Heart rate variability was analysed in several ways: parasympathetic function in hierarchical order (main analysis), total variability, comparison of heart rate variability between different subtypes of dementia, specific indices of heart rate variability and heart rate variability reactivity.
In the initial search, we found 3425 relevant articles, from which 24 studies with a total of 1107 dementia patients and 1017 control participants finally entered the main meta-analysis. The dementia patients had a significantly lower resting heart rate variability for parasympathetic function (Hedges' = -0.3596, = 0.0002) and total variability (Hedges' = -0.3059, = 0.0002) than the controls. For diagnostic subgroup analysis relative to the controls, heart rate variability was significantly lower in patients with mild cognitive impairment (Hedges' = -0.3060) and in patients with dementia with Lewy bodies (Hedges' = -1.4154, < 0.0001). Relative to patients with Alzheimer's disease, heart rate variability in patients with dementia with Lewy bodies was significantly lower (Hedges' = -1.5465, = 0.0381). Meta-regression revealed that gender proportion was significantly associated with effect size.
Our results show that dementia patients (especially those with dementia with Lewy bodies and mild cognitive impairment) have lower parasympathetic activity than healthy people. The influence of gender on the results should be carefully interpreted.
心率变异性是一种主要反映副交感活动的定量测量方法，已被应用于评估多种精神和神经疾病，包括痴呆症（或神经认知障碍）。然而，尽管痴呆症患者的心率变异性（各种指标）通常明显低于健康对照组，且不同类型的痴呆症具有不同的心率变异性特征，但不同研究的结果并不完全一致。我们设计了一项系统评价和荟萃分析，以整合来自不同研究的数据。
我们收集了比较痴呆症患者和健康对照组心率变异性的研究。心率变异性通过以下几种方式进行分析：按层次顺序分析副交感功能（主要分析）、总变异性、不同类型痴呆症之间的心率变异性比较、心率变异性的特定指标以及心率变异性反应性。
在最初的搜索中，我们发现了 3425 篇相关文章，其中 24 项研究共纳入了 1107 例痴呆症患者和 1017 例对照组参与者，最终进入了主要的荟萃分析。痴呆症患者的静息心率变异性的副交感功能（Hedges' = -0.3596， = 0.0002）和总变异性（Hedges' = -0.3059， = 0.0002）明显低于对照组。相对于对照组的诊断亚组分析，轻度认知障碍患者（Hedges' = -0.3060）和路易体痴呆患者（Hedges' = -1.4154， < 0.0001）的心率变异性明显降低。与阿尔茨海默病患者相比，路易体痴呆患者的心率变异性明显降低（Hedges' = -1.5465， = 0.0381）。元回归显示，性别比例与效应大小显著相关。
我们的结果表明，痴呆症患者（尤其是路易体痴呆和轻度认知障碍患者）的副交感活动低于健康人。性别对结果的影响应谨慎解释。
