Orthostatic hypotension and orthostatic hypertension are both associated with lower cognitive function: The S.AGES cohort

Hypotension with neurovascular changes and cognitive dysfunction: An epidemiological, pathobiological, and treatment review

ABSTRACT

Hypotension is a leading cause of age-related cognitive impairment. The available literature evidences that vascular factors are associated with dementia and that hypotension alters cerebral perfusion flow and can aggravate the neurodegeneration of Alzheimer's disease (AD). Despite the discovery of biomarkers and the recent progress made in neurovascular biology, epidemiology, and brain imaging, some key issues remain largely unresolved: the potential mechanisms underlying the neural deterioration observed in AD, the effect of cerebrovascular alterations on cognitive deficits, and the positive effects of hypotension treatment on cognition. Therefore, further well-designed studies are needed to unravel the potential association between hypotension and cognitive dysfunction and reveal the potential benefits of hypotension treatment for AD patients. Here, we review the current epidemiological, pathobiological, and treatment-related literature on neurovascular changes and hypotension-related cognitive dysfunction and highlight the unsettled but imminent issues that warrant future research endeavors.

Orthostatic blood pressure changes do not influence cognitive outcomes following intensive blood pressure control

BACKGROUND

Effects of intensive blood pressure (BP) control on cognitive outcomes in patients with excess orthostatic BP changes are unclear. We aimed to evaluate whether orthostatic BP changes modified the effects of BP intervention on cognitive impairment.

METHODS

We analyzed 8547 participants from the Systolic Blood Pressure Intervention Trial Memory and cognition IN Decreased Hypertension. Associations between orthostatic BP changes and incident cognitive outcomes were evaluated by restricted cubic spline curves based on Cox models. The interactions between orthostatic BP changes and intensive BP intervention were assessed.

RESULTS

The U-shaped associations were observed between baseline orthostatic systolic BP changes and cognitive outcomes. However, there were insignificant interactions between either change in orthostatic systolic BP (P for interaction = 0.81) or diastolic BP (P for interaction = 0.32) and intensive BP intervention for the composite outcome of probable dementia or mild cognitive impairment (MCI). The hazard ratio of intensive versus standard target for the composite cognitive outcome was 0.82 (95% CI 0.50-1.35) in those with an orthostatic systolic BP reduction of >20 mmHg and 0.41 (95% CI 0.21-0.80) in those with an orthostatic systolic BP increase of >20 mmHg. Results were similar for probable dementia and MCI. The annual changes in global cerebral blood flow (P for interaction = 0.86) consistently favored intensive BP treatment across orthostatic systolic BP changes.

CONCLUSION

Intensive BP control did not have a deteriorating effect on cognitive outcomes among hypertensive patients experiencing significant postural BP changes.

Orthostatic Hypotension and Cognitive Function in Individuals 85 Years of Age: A Longitudinal Cohort Study in Sweden

Orthostatic hypotension (OH) is more common in the elderly and associated with increased mortality. However, its implications for 85-year-olds are not known. In the prospective observational cohort study Elderly in Linköping Screening Assessment (ELSA 85), 496 individuals in Linköping, Sweden, were followed from age 85 years with cognitive assessments. Blood pressure (BP) was measured supine and after 1, 3, 5, and 10 minutes of standing. Participants with a BP fall of ≥20 mmHg systolic or ≥10 mmHg diastolic after 1 or 3 minutes were classified as classical continuous or classical transient OH depending on whether the BP fall was sustained or not, at subsequent measurements. Those with a BP fall of the same magnitude, but only after 5 or 10 minutes were classified as delayed OH. Of participants, 329 took part in BP measurements and were included. Of these, 156 (47.4%) had classical OH (113 [34.3%] continuous classical, 38 [11.6%] transient classical), and 15 (4.6%) had delayed OH. Cognitive assessments were not markedly different between groups. After 8.6 years, 195 (59.3%) of the participants had died, and delayed vs no OH was associated with twice the risk of all-cause mortality, HR 2.15 (95% CI 1.12-4.12). Transient classical OH was associated with reduced mortality, HR 0.58 (95% CI 0.33-0.99), but not after multiple adjustments, and continuous classical OH was not associated with mortality. OH may have different implications for morbidity and mortality in 85-year-olds compared with younger populations.