Impairments in Hemodynamic Responses to Orthostasis Associated with Frailty: Results from The Irish Longitudinal Study on Ageing (TILDA).

To characterize the relationships between orthostatic blood pressure (BP) and heart rate recovery and frailty in an older population. Cross-sectional study. Two health centers in the Republic of Ireland. The Irish Longitudinal Study on Ageing participants aged 50 and older (N=4,334). Continuous noninvasive BP responses during active standing were captured using digital photoplethysmography. Frailty was assessed using the Cardiovascular Health Study criteria. Linear mixed models (random intercept) with piecewise splines were used to model differences in rate of BP and heart rate recovery. Ninety-three (2.2%) participants were frail, and 1,366 (31.5%) were prefrail. Adjusting for age and sex, frailty was associated with a slower rate of systolic BP recovery 10 to 20 seconds after standing (frailty by time = -4.12, 95% confidence interval=-5.53 to -2.72) and with subsequent deficits in BP 20 to 50 seconds after standing. Similar results were seen for diastolic BP and heart rate. Further adjustment for health behaviors, morbidities, and medications reduced, but did not attenuate, these associations. Of the 5 frailty criteria, only slow gait speed was consistently related to impaired BP and heart rate responses in the full model. Frailty, particularly slow gait speed, was associated with slower rate of BP and heart rate recovery after active standing. Impaired BP recovery may be a marker of physiological frailty.

O'Connell MD ，Savva GM ，Finucane C ，Romero-Ortuno R ，Fan CW ，Kenny RA ... -  《-》

What Is the Relationship Between Orthostatic Blood Pressure and Spatiotemporal Gait in Later Life?

Little work to date has examined the relationship between gait performance and blood pressure (BP) recovery after standing in later life. The aim of this study is to clarify the association of orthostatic BP with spatiotemporal gait parameters in a large cohort of older people. Cross-sectional study using multilevel linear regression to ascertain the difference in orthostatic BP patterns across tertiles of gait speed, and linear regression to analyze the association of orthostatic hypotension 30 seconds after standing (OH-30) with specific gait characteristics. The Irish Longitudinal Study on Ageing. A total of 4311 community-dwelling adults, aged 50 years or older (mean age = 62.2 years; 54% female), one fifth (n = 791) of whom had OH-30. Continuous orthostatic BP was measured during active stand. OH-30 was defined as a drop in systolic BP of 20 mm Hg or more or drop in diastolic BP of 10 mm Hg or more at 30 seconds. Spatiotemporal gait was assessed using the GAITRite system, reporting gait speed, step length, step width, and double support time in both single and dual (cognitive task) conditions. OH-30 was associated with slower gait speed (β = -3.01; 95% confidence interval [CI] = -4.46 to -1.56) and shorter step length (β = -.73; 95% CI = -1.29 to -.16) in fully adjusted models during single task walking. Similar findings were observed in dual task conditions, in addition to increased double support phase (β = .45; 95% CI = .02-.88). Multilevel models demonstrated that participants in the slowest tertile for gait speed had a significantly larger drop in systolic BP poststanding compared to those with faster gait speeds in single and dual task conditions. This study demonstrates that slower recovery of BP after standing is independently associated with poorer gait performance in community-dwelling older adults. Given the adverse outcomes independently associated with OH and gait problems in later life, increasing awareness that they commonly coexist is important, particularly as both are potentially modifiable. J Am Geriatr Soc 68:1286-1292, 2020.

Briggs R ，Donoghue OA ，Carey D ，O'Connell MDL ，Newman L ，Kenny RA ... -  《-》

Orthostatic hypotension, orthostatic intolerance and frailty: The Irish Longitudinal Study on Aging-TILDA.

Because frailty may represent impaired response to physiological stress we explored the associations between frailty and orthostatic hypotension (OH), and orthostatic intolerance (OI). This study was based on a cross-sectional analysis of 5692 community dwelling adults aged 50 years and older included in wave 1 of the Irish Longitudinal Study on Aging. Frailty was assessed using both the phenotypic (FP) and frailty index (FI) models. OH was defined as a drop of ≥20 mmHg in systolic blood pressure or a drop of ≥10 mmHg diastolic pressure on standing from a seated position. OI was defined as reporting feeling dizzy, light headed or unsteady during this test. 346 (6.1%) participants had OH and 381 (6.7%) participants had OI. The prevalence OH in frail participants was 8.9%, compared to 5% in robust. Similarly the prevalence of OI was 14.3% in frail and 5.7% in robust participants. After adjustment for age and gender, OH was not significantly related to the FP (OR=1.10 95% CI=0.67, 1.81). Conversely OI was (OR=1.80 95% CI=1.13, 2.87), even after adjustment for age, gender, cardiovascular factors and mental health. In fully adjusted models OI remained related to slowness and low muscle strength and to higher FI scores. These data suggest OI symptoms in older adults may reflect various important underlying health deficits, indicative of increasing levels of frailty. Further assessment of frailty in patients experiencing OI is a potential opportunity for early intervention to delay functional decline.

O'Connell MD ，Savva GM ，Fan CW ，Kenny RA ... -  《-》

Age-related normative changes in phasic orthostatic blood pressure in a large population study: findings from The Irish Longitudinal Study on Ageing (TILDA).

In this report, we provide the first normative reference data and prevalence estimates of impaired orthostatic blood pressure (BP) stabilization, initial orthostatic hypotension, and orthostatic hypotension based on beat-to-beat blood pressure methods in a population-representative sample. Participants were recruited from a nationally representative cohort study (≥50 years). Beat-to-beat systolic BP, diastolic BP, and heart rate records were analyzed among those who underwent an active stand test (n=4475). Normograms were estimated by use of generalized additive models for location, shape, and scale with Box-Cox power exponential distribution. Prevalence estimates of impaired BP stabilization, initial orthostatic hypotension, and orthostatic hypotension are reported. Orthostatic BP responses in adults aged 50 to 59 years stabilized within 30 seconds of standing, with older groups taking 30 seconds or longer. The total prevalence of impaired BP stabilization was 15.6% (95% confidence interval [CI], 14.1%-17.1%), increasing with age to 41.2% (95% CI, 30.0%-52.4%) in people ≥80 years old. Initial orthostatic hypotension occurred in 32.9% (95% CI, 31.2%-34.6%) of the population aged ≥50 years, with no age gradient evident. The prevalence of orthostatic hypotension was 6.9% (95% CI, 5.9%-7.8%) in the total population, increasing to 18.5% (95% CI, 9.0%-28.0%) in those aged ≥80 years old. Significant age-related differences exist in the time course of postural BP responses, with abnormal responses taking longer than 30 seconds to stabilize. Impaired BP stabilization is more common as we age, affecting more than two-fifths of the population aged ≥80 years, and may play a future role in the management of falls and syncope.

Finucane C ，O'Connell MD ，Fan CW ，Savva GM ，Soraghan CJ ，Nolan H ，Cronin H ，Kenny RA ... -  《-》

One-Dimensional Statistical Parametric Mapping Identifies Impaired Orthostatic Cerebrovascular and Cardiovascular Response in Frailty Index.

Orthostasis is a potent physiological stressor which adapts with age. The age-related accumulation of health deficits in multiple physiological systems may impair the physiological response to orthostasis and lead to negative health outcomes such as falls, depression, and cognitive decline. Research to date has focused on changes with orthostasis at prespecified intervals of time, without consideration for whole signal approaches. One-dimensional statistical parametric mapping identified regions in time of significant association between variables of interest using a general linear model. Frailty index operationalized accumulated health and social deficits using 32-items from a computer-assisted interview. This study examined the association of frailty index on blood pressure, heart rate, and cerebral oxygenation during an orthostatic test in a sample of 2742 adults aged 50 or older from The Irish Longitudinal Study on Ageing. Frailty index was seen to be negatively associated with cerebral oxygenation changes from baseline over a period of 7 seconds (p = .036). Heart rate and systolic blood pressure were positively and negatively associated with frailty index over periods of 17 seconds (p = .001) and 10 seconds (p = .015), respectively. Statistical parametric mapping demonstrated these significant regions of cerebral oxygenation during orthostasis provide indirect evidence of impaired autoregulation associated with frailty. Statistical parametric mapping also replicated prior relationships in heart rate and systolic blood pressure associated with a higher frailty index. These findings highlight the utility of 1-dimensional statistical parametric modeling in identifying significant regions of interest in physiological recordings.

Maguire F ，Romero-Ortuno R ，O'Connor JD ，Reilly RB ，Knight SP ，Kenny RA ... -  《-》