Cardiovascular responses to orthostasis and their association with falls in older adults

Abstract

Background: Orthostatic hypotension (OH) refers to a marked decline in blood pressure when upright. OH has a high incidence and prevalence in older adults and represents a potential intrinsic risk factor for falls in these individuals. Previous studies have not included more recent definitions for blood pressure responses to orthostasis, including initial, delayed, and recovery blood pressure responses. Furthermore, there is little research examining the relationships between cerebrovascular functioning and falling risk. Therefore, we aimed to: (i) test the association between different blood pressure responses to orthostatic stress and retrospective falling history and; (ii) test the association between cerebrovascular responses to orthostatic stress and falling history.

Methods: We tested 59 elderly residents in long term care facilities who underwent a passive seated orthostatic stress test. Beat-to-beat blood pressure and cerebral blood flow velocity (CBFV) responses were assessed throughout testing. Risk factors for falls and falling history were collected from facility records. Cardiovascular responses to orthostasis were compared between retrospective fallers (≥1 fall in the previous year) and non-fallers.

Results: Retrospective fallers had larger delayed declines in systolic arterial pressure (SAP) compared to non-fallers (p = 0.015). Fallers also showed poorer early (2 min) and late (15 min) recovery of SAP. Fallers had a greater decline in systolic CBFV.

Conclusions: Older adults with a positive falling history have impaired orthostatic control of blood pressure and CBFV. With better identification and understanding of orthostatic blood pressure impairments earlier intervention and management can be implemented, potentially reducing the associated risk of morbidity and mortality. Future studies should utilize the updated OH definitions using beat-to-beat technology, rather than conventional methods that may offer less accurate detection.

Fig. 1

Cardiovascular Responses to the Passive Seated Orthostatic Stress Test in Fallers (Black) and Non-fallers (White). Data are shown at each time point of interest, expressed as the mean percentage change relative to supine values ± standard error of the mean. Abbreviations: systolic arterial pressure (SAP); diastolic arterial pressure (DAP); heart rate (HR); stroke volume (SV); cardiac output (CO); and total peripheral resistance (TPR). Significant differences between groups (Student’s t-test or Mann–Whitney U test) are denoted by * (p < 0.05)

Fig. 2

Cerebrovascular Responses to the Passive Seated Orthostatic Stress Test in Fallers (Black) and Non-fallers (White). a. Average seated percentage change in systolic (sCBFV) and diastolic (dCBFV) cerebral blood flow velocity in response to the passive seated orthostatic stress. The sCBFV decrease was significantly larger in fallers (-10.4 ± 4.3 cm.sec⁻¹) than in non-fallers (+2.0 ± 3.0 cm.sec⁻¹, p = 0.03). The dCBFV decrease was not significantly different between groups (fallers: −6.0 ± 3.3 cm.sec⁻¹; non-fallers: −1.2 ± 1.3 cm.sec⁻¹: p = 0.67). The solid horizontal line denotes the median; dashed horizontal line denotes the mean. b. Individual responses showing sCBFV in supine and seated positions in fallers (Black) and non-fallers (White). Group mean data with error bars (standard error of the mean) are shown with diamond symbols. In fallers, seated sCBFV were significantly lower than the supine values