Saedon Nor Izzati, Frith James, Wan Ahmad Wan Azman, Tan Maw Pin
Faculty of Medicine, Department of Medicine, Ageing and Age-Associated Disorders Research Group, Division of Geriatric Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
Consultant of Geriatric Medicine, Falls and Syncope Service, Older People's Medicine, The Campus of Ageing and Vitality, Newcastle upon Tyne, UK.
Clin Auton Res. 2025 Sep 8. doi: 10.1007/s10286-025-01152-6.
Orthostatic hypotension (OH) is prevalent in older adults and is often associated with falls. However, the presence or absence of symptoms in OH may be mediated by cerebral autoregulation, which helps maintain cerebral perfusion during blood pressure fluctuations.
We recruited 40 older adults (aged ≥ 55 years) from the Malaysian Elders Longitudinal Research (MELoR) cohort. Participants underwent cerebral blood flow velocity monitoring using transcranial Doppler ultrasonography and beat-to-beat blood pressure recording. Three protocols were used: active stand, mental arithmetic, and Valsalva manoeuvre. Participants were categorized, based on OH (≥ 30 mmHg systolic drop) and fall history, into four groups. Cerebrovascular resistance (CVR) was derived and analysed.
Participants with OH but no history of falls demonstrated preserved autoregulatory responses, as reflected by adaptive reductions in CVR. In contrast, fallers-regardless of OH status-had impaired CVR modulation. Significant group differences were found during the active stand test at 165 s and 180 s (p < 0.05).
Preserved cerebral autoregulation may protect older adults with OH from symptomatic manifestations such as falls. Targeting cerebral autoregulation could offer novel approaches for preventing falls in this population.
直立性低血压（OH）在老年人中很常见，且常与跌倒有关。然而，OH中症状的出现与否可能由脑自动调节介导，脑自动调节有助于在血压波动期间维持脑灌注。
我们从马来西亚老年人纵向研究（MELoR）队列中招募了40名老年人（年龄≥55岁）。参与者接受了经颅多普勒超声脑血流速度监测和逐搏血压记录。使用了三种方案：主动站立、心算和瓦尔萨尔瓦动作。根据OH（收缩压下降≥30mmHg）和跌倒史，将参与者分为四组。计算并分析脑血管阻力（CVR）。
有OH但无跌倒史的参与者表现出保留的自动调节反应，表现为CVR适应性降低。相比之下，无论OH状态如何，跌倒者的CVR调节均受损。在主动站立测试的165秒和180秒时发现了显著的组间差异（p<0.05）。
保留的脑自动调节可能保护患有OH的老年人免受跌倒等症状表现的影响。针对脑自动调节可能为预防该人群跌倒提供新方法。
