Posture and the circulation: The age effect

Smith, James J.; Porth, Carol M.

doi:10.1016/0531-5565(91)90007-9

Cited by 19 publications

(15 citation statements)

References 41 publications

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“…These fluctuations are thought to arise from internal and external sources including changes in neurohormonal activity [25], circulating volume [26], changes in sympathetic and parasympathetic activity [8], and environmental effects [11]. Furthermore the active stand response is under the influence of a number of additional factors including self-selected speed of standing, muscle pump activation [27], movement artefact [16], time of day [28] and other experiment effects (e.g.…”

Section: Discussionmentioning

confidence: 99%

Reliability of orthostatic beat-to-beat blood pressure tests: implications for population and clinical studies

Finucane

Kenny

2017

Clin Auton Res

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ObjectiveTo assess the test-retest reliability of orthostatic beat-to-beat blood pressure responses to active standing and related clinical definitions of orthostatic hypotension. MethodsA random sample of community dwelling older adults from the pan-European Survey of Health, Ageing and Retirement in Europe, Ireland underwent a health assessment which mimicked that of the Irish Longitudinal Study on Ageing. An active stand test was performed using continuous blood pressure measurements. Participants attended a repeat assessment 4-12 weeks after the initial measurement. A mixed-effects regression model estimated the reliability and minimum detectable change while controlling for fixed observer and time of day effects. ResultsA total of 125 individuals underwent repeat assessment (mean age 66.2±7.5;55.6% women).Mean time between visits was 84.3±23.3 days. There was no significant mean difference in heart rate or blood pressure recovery variables between the first and repeat assessments.Minimum detectable change was noted for changes from resting values in systolic blood pressure(26.4mmHg) and diastolic blood pressure(13.7mmHg) at 110 seconds and for changes in heart rate(10.9bpm) from resting values at 30 seconds after standing. Intra-class correlation values ranged from 0.47 for nadir values to 0.80 for heart rate and systolic blood pressure values measured 110 seconds after standing. ConclusionContinuous orthostatic beat-to-beat blood pressure and related clinical definitions show moderate reliability and substantial natural variation over a 4-12 week period.Understanding variation in measures is essential for study design or estimating the effects of orthostatic hypotension, while clinically it can be used when evaluating longer term treatment effects.

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Section: Discussionmentioning

confidence: 99%

Reliability of orthostatic beat-to-beat blood pressure tests: implications for population and clinical studies

Finucane

Kenny

2017

Clin Auton Res

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“…The differences in total peripheral resistance indicate that vascular response, not cardiac regulation, matters most. The underlying mechanisms, in turn, might be altered vascular reflexes among men, a reduction in the performance of the skeletal muscle mass, different receptor density or sensitivity in peripheral arterioles, or enhanced stiffness due to arteriosclerosis, as suggested by others [27][28][29][30][31]. This could be the focus of further studies.…”

Section: Vascular Responsementioning

confidence: 97%

“…Due to the relatively high proportion of participants with low ortostatic tolerance during ordinary tilt, we also used a low-grade tilt, 30°, which is often used in experimental settings, challenging the cardiovascular system [30], but with less discomfort.…”

Section: Strengths and Limitationsmentioning

confidence: 99%

Gender differences in orthostatic tolerance in the elderly

Mellingsæter

Wyller

et al. 2013

Aging Clin Exp Res

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“…Studies have shown that there is a lesser increase in heart rate upon standing in older compared with younger individuals (Smith and Porth, 1991). This may be attributed to a decrease in baroreceptor reflexes in the elderly.…”

Section: Figurementioning

confidence: 98%

The Postural Autonomic Regulation of Pulpal Blood Flow

et al. 2012

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Evidence suggests that postural changes in systemic blood pressure may significantly affect blood flow in the dental pulp. This in vivo study examined the responses of pulpal perfusion, systemic blood pressure, and heart rate to postural changes in humans. The experiments were done on 21 premolars in 16 participants aged 20-31 yrs. Pulpal blood flow recordings were measured by means of a laser Doppler Flowmeter. A blood pressure monitor was used to record blood pressure and heart rate. All measurements were simultaneously recorded for 1 min, 5 min after participants made postural changes. Changing from supine to standing caused a significant reduction in pulpal perfusion, while heart rate and diastolic blood pressure increased significantly. A significant non-linear relationship was found between percentage changes in pulpal perfusion and heart rate resulting from standing up. We speculate that when patients arise from the supine position, the shift in venous blood to the legs transiently (2-10 sec) lowers venous return and cardiac output, causing less inhibition of the vasomotor center, which, in turn, results in increased heart rate and blood pressure, but a decrease in pulpal blood flow. These results suggest that pulpal blood flow is affected by postural change, presumably via the autonomic nervous system.

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Posture and the circulation: The age effect

Cited by 19 publications

References 41 publications

Reliability of orthostatic beat-to-beat blood pressure tests: implications for population and clinical studies

Reliability of orthostatic beat-to-beat blood pressure tests: implications for population and clinical studies

Gender differences in orthostatic tolerance in the elderly

The Postural Autonomic Regulation of Pulpal Blood Flow

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