Longitudinal Association Between Orthostatic Hypotension at 30 Seconds Post-Standing and Late-Life Depression

Abstract

There is an established cross-sectional association between orthostatic hypotension (OH) and late-life depression. The aim of this observational study was to clarify the longitudinal association between baseline symptomatic OH (sOH-30) and incident depression in a sample of >3000 older people without baseline depression (mean age: 62 years at baseline). This study was embedded within the Irish Longitudinal Study on Ageing using data from waves 1 to 3, collected between 2009 and 2014. At 2- and 4-year follow-up, a score ≥9 on the 8-item Center for Epidemiological Studies Depression Scale was used to define incident depression. sOH-30 was defined as a drop in systolic blood pressure ≥20 mm Hg or diastolic blood pressure ≥10 mm Hg at 30 seconds post-standing in conjunction with orthostatic symptoms, such as dizziness, using beat-to-beat measurements. Almost one fifth (proportion, 18%; 95% confidence interval [CI], 16-20) of the study sample had sOH-30. One tenth (proportion, 10%; 95% CI, 9-12) had incident depression. Participants with incident depression were twice as likely to have sOH-30 at baseline compared with those without incident depression (linear regression, 13% [95% CI, 8-19] versus 7% [95% CI, 6-8]). Weighted logistic regression models demonstrated that sOH-30 predicted incident depression with an odds ratio of 1.90 (95% CI, 1.15-3.15) after controlling for covariates, including subthreshold depression, hypotension, cognitive impairment, and antidepressant use. Asymptomatic OH at 30 seconds and initial OH did not predict depression. This study demonstrates that sOH-30 predicts incident depression in a population-representative sample of older people and may, therefore, represent a potentially modifiable risk factor for late-life depression.

The association between frontal lobe perfusion and depressive symptoms in later life

“…These findings are supported by prior neuroimaging studies showing a similar association between late-life depression and both global and frontal cerebral perfusion 11 , 12 . Smaller studies utilising NIRS have also demonstrated similar disparities between depressed and non-depressed participants when undertaking cognitive tasks 28 , 29 .…”

“…These findings are supported by prior neuroimaging studies showing a similar association between late-life depression and both global and frontal cerebral perfusion. 11,12 Smaller studies utilising NIRS have also demonstrated similar disparities between depressed and non-depressed participants when undertaking cognitive tasks. 28,29 However, our findings are cross-sectional and the direction of the relationship between frontal lobe cerebral perfusion and depressive symptoms remains uncertain, with limited longitudinal analyses to date.…”

“…33 Additionally, conditions causing global cerebral hypoperfusion, such as orthostatic hypotension or chronically low blood pressure, have been shown to increase the risk of incident depression in older people. 11,12 Understanding the nature of the link between incident depression and cerebral perfusion is important because cerebral blood flow is potentially modifiable. Factors such as alcohol intake, blood pressure and cognitive training may influence cerebral blood flow.…”

“…The frontal lobe is particularly susceptible to damage by cerebral hypoperfusion 10 and conditions affecting cerebral blood flow, such as systemic hypotension and orthostatic hypotension, have been shown to increase the risk of incident depression in older people. 11,12 A hypothesised mechanism for this is via reduction in blood flow to the frontal lobe resulting in frontal WMHs and altered frontal lobe function. 1 Cross-sectional single-photon emission computed tomography and magnetic resonance imaging (MRI) studies have shown frontal lobe perfusion deficits in older depressed participants when compared with controls 13,14 and prospectively, reduced global cerebral perfusion measured by transcranial Doppler ultrasound is a predictor of greater depressive symptomology in older people with heart failure at 1-year follow-up.…”

“…Depressed older people have demonstrated poorer scores on formal frontal lobe–related cognitive tests compared with controls, 1 and late-life depression is also closely associated with other clinical syndromes where frontostriatal connectivity has been implicated, including gait disorders, dementia and urinary incontinence. The frontal lobe is particularly susceptible to damage by cerebral hypoperfusion 10 and conditions affecting cerebral blood flow, such as systemic hypotension and orthostatic hypotension, have been shown to increase the risk of incident depression in older people 11 , 12 . A hypothesised mechanism for this is via reduction in blood flow to the frontal lobe resulting in frontal WMHs and altered frontal lobe function 1 .…”