Influence of Hypertension on Neurocognitive Domains in Nondemented Parkinson’s Disease Patients

Abstract

Objective. Health comorbidities, particularly cardiovascular risk factors, are well known to pose risks for cognitive decline in older adults. To date, little attention has focused on the impact of these comorbidities on Parkinson's disease (PD). This study examined the prevalence and contribution of comorbidities on cognitive status in PD patients, above and beyond the effects of disease severity. Methods. A cross sectional design was used, including neuropsychological data on 341 PD patients without severe cognitive decline. Comorbidity data were collected via medical chart review. Data were analyzed using a series of multiple hierarchical regressions, controlling for PD-related disease variables. Results. Overall sample characteristics are 69% male, disease duration 9.7 years, Unified Parkinson's Disease Rating Scale 26.4, and age 64.7 years. Hypercholesterolemia (41.6%), hypertension (38.1%), and hypotension (30.2%) were the most reported comorbidities. The presence of hypertension significantly contributed to domains of executive function and verbal memory. The cooccurrence of orthostatic hypotension moderated the relationship between hypertension and executive function. Conclusions. This study on a large cohort of PD patients provides evidence for a detrimental influence of health comorbidities, particularly hypertension, on cognitive domains that have traditionally been conceptualized as being frontally and/or temporally mediated.

The Cardiovascular and Cerebrovascular Effects on Cognition in Persons with Parkinson’s Disease: A Systematic Review of the Literature

“…This finding shows that altered cerebral perfusion secondary to HTN or OH is correlated with decreased cognitive function. Jones et al [24] found that HTN has an influence on executive function and memory recall that goes beyond the deficits produced by the typical PD disease process. They hypothesized that while these deficits are small, they may become more conspicuous and profound as the disease progresses [24].…”

“…Through single photon emission computed tomography (SPECT), a direct correlation was revealed between hypoperfusion of the posterior association, limbic, posterior cingulate and parietal precuneus cortices (combined score-p = 0.000) in the less affected hemisphere (ipsilateral hemisphere to side of body with prevalence of motor symptoms) and executive function in persons with PD [26]. This adds support to the presence of a "PD Cognitive Pattern (PDCP)" of hypoperfusion described in previous literature and thought to be correlated with a variety of measures of executive function [26] [34]) when compared to those with a diagnosis of PD and "health comorbidities in general" (health comorbidities defined as comorbidities that affected at least 10% of the study population: cholesterol, HTN, hypotension, neurologic, cardiac, arthritis, gastroesophageal reflux disease, cancer, prostate, Roberts syndrome, respiratory, diabetes) (PD + "health comorbidities"-p = 0.146) [24]. The same study also reported the presence of comorbid HTN in persons with PD resulted in decreased scores on tests of executive function (tests of executive function combined score PD + HTN-p = 0.041) compared to persons with PD + OH, PD + OH + HTN, or PD with no other vascular comorbidity [24].…”

“…This adds support to the presence of a "PD Cognitive Pattern (PDCP)" of hypoperfusion described in previous literature and thought to be correlated with a variety of measures of executive function [26] [34]) when compared to those with a diagnosis of PD and "health comorbidities in general" (health comorbidities defined as comorbidities that affected at least 10% of the study population: cholesterol, HTN, hypotension, neurologic, cardiac, arthritis, gastroesophageal reflux disease, cancer, prostate, Roberts syndrome, respiratory, diabetes) (PD + "health comorbidities"-p = 0.146) [24]. The same study also reported the presence of comorbid HTN in persons with PD resulted in decreased scores on tests of executive function (tests of executive function combined score PD + HTN-p = 0.041) compared to persons with PD + OH, PD + OH + HTN, or PD with no other vascular comorbidity [24]. The latter result is supported by Kim et al [25] who found a negative correlation between executive function scores (COWAT-grocery, p < 0.05; COWAT-phonemic, p < 0.05; Stroop Word Test, p < 0.05) and the standard deviation of systolic blood pressure (SBP) (normal cognition group = 13.0 ± 3.5, mild cognitive impairment group = 12.8 ± 2.9, dementia group = 18.8 ± 11.1).…”

“…Four studies examined the cerebrovascular and/or cardiovascular effects on verbal memory or word fluency in persons with PD [24] [26]- [28]. Using SPECT, a significant correlation was found between cerebral hypoperfusion in the temporoparietal association areas (combined score-p = 0.017) of the cortex in the less affected hemisphere with decreased scores on tests of verbal memory [26].…”

“…These results are similar to a previous study of persons with Alzheimer's Disease, a neurodegenerative disease that mimics regional cerebral perfusion maps seen in persons with PDD, which found bilateral temporal perfusion scores were closely correlated to performance of word list learning [26] [41] [42]. Persons with PD and an existing diagnosis of HTN (Hopkins Verbal Learning Test-R [43], form (HVLT-R) and Logical Memory Stories II (WMS-II) [44]; combined score PD + HTN-p = 0.021) [24] or OH (Rey Auditory Verbal Learning Test (RAVLT) [45], PD + OHp = 0.02] [28]) were also found to have decreased delayed verbal memory recall scores. Decreases in verbal memory recall scores in persons with PD and OH were maintained when persons with MMSE < 24 were excluded from statistical analysis (RAVLT, p = 0.03) [28].…”