Visit-to-Visit Variability in Blood Pressure as a Predictor of Poor Cognitive Function (BPV-COG)

September 19, 2012 updated by: Hallym University Medical Center

Multicenter Retrospective Study of Visit-to-Visit Variability in Blood Pressure as a Predictor of Poor Cognitive Function

Hypertension in midlife is an independent risk factor of late life cognitive dysfunction or dementia. Chronic hypertension cause vascular damage and cerebral ischemia, which ultimately gives rise to the cognitive dysfunction or dementia.

A recent study showed that high visit-to-visit variability in clinic systolic blood pressure (BP) was a strong independent predictor of stroke. This finding suggests that high clinic systolic BP variability itself as well as chronic hypertension may cause vascular damage and cerebral ischemia. Therefore, high clinic SBP variability may be also an independent risk factor of cognitive dysfunction or dementia.

Vascular damage leads to the diminished autoregulatory capacities of cerebral arteries. The brain with the reduced autoregulatory capacity may be more vulnerable to BP fluctuation. Therefore, high BP variability may be more harmful in patients with damaged vessels (for example, in patients with cerebral small vessel disease).

Previous data about BP variability and cognition revealed very controversial. Some studies showed poor cognition in patients with high BP variability, but others did not.

The previous studies were mostly based on cross-sectional designs, and performed in small-sized heterogeneous population for primary prevention. The harmful effect of high BP variability may be clearer in the population with damaged vascular bed, such as cerebral small vessel disease. The previous studies usually used ambulatory BP monitoring (ABPM). However, recent data suggested that variability in BP on ABPM may be a weaker predictor of vascular events than be visit-to-visit variability in clinic BP.

The investigators sought to find whether high visit-to-visit variability in clinic BP is related with poor cognitive function in patients with cerebral small vessel disease.

Study Overview

Status

Unknown

Conditions

Detailed Description

This is a retrospective cohort study.

We include patients with cerebral small vessel disease, documented on MRI from Jan 2006 to Dec 2010, who have been regularly followed up.

We evaluate the patients' cognitive function after written informed consent.

We independently review patients' medical record and analyze MRI data. BP variability parameters include standard deviation(SD, primary measuring parameter), coefficient of variation, successive variation, average real variability (ARV), SD independent of mean(SDIM), SV independent of mean(SVIM), and ARV independent of mean (ARVIM). We will adjust following confounding variables: age, sex, level of education, vascular risk factors, mean SBP and DBP, NIHSS score, and white matter lesion burden on T2-weighted MRI.

Study Type

Observational

Enrollment (Anticipated)

140

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Korea, Republic of
      • Seoul, Korea, Republic of, 134-701
        • Recruiting
        • Gangdong Sacred Heart Hospital, Hallym University, College of Medicine
        • Contact:
        • Sub-Investigator:
          • Joon-Hyun Shin, MD.
      • Seoul, Korea, Republic of, 150-719
        • Recruiting
        • Hangang Sacred Heart Hospital, Hallym University, College of Medicine
        • Contact:
        • Sub-Investigator:
          • Yang-Ki Minn, MD. PhD.
      • Seoul, Korea, Republic of, 150-950
        • Recruiting
        • Gangnam Sacred Heart Hospital, Hallym University, College of Medicine
        • Contact:
    • Gangwon-do
      • Chuncheon-si, Gangwon-do, Korea, Republic of, 200-704
        • Recruiting
        • Chuncheon Sacred Heart Hospital, Hallym University, College of Medicine
        • Contact:
        • Sub-Investigator:
          • Chul-Ho Kim, MD.
    • Gyeonggi-do
      • Anyang-si, Gyeonggi-do, Korea, Republic of, 431-796
        • Recruiting
        • Hallym University Sacred Heart Hospital, Hallym University, College of Medicine
        • Contact:
        • Sub-Investigator:
          • Kyung-Ho Yu, MD. PhD.
        • Sub-Investigator:
          • Mi-Sun Oh, MD.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

60 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Outpatients of stroke clinic in secondary or tertiary hospitals

Description

Inclusion Criteria:

  • Patients with cerebral small vessel disease previously documented on MRI (definition of small vessel disease - symptomatic lacunar infarction or white matter ischemic lesion with one or more asymptomatic lacunes)

Exclusion Criteria:

  • Incomplete clinic BP data (less than 6 BP readings during recent one year)
  • History of cardiovascular or cerebrovascular events during recent one year
  • Documented cerebral infarction from large artery atherosclerosis
  • Atrial fibrillation or cardiac disease with high risk of embolism
  • Significant medical, neurological, or psychiatric disease affecting cognition
  • Known dementia treated with acetylcholine esterase inhibitor or memantine
  • Patients without informed consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Retrospective

Cohorts and Interventions

Group / Cohort
Visit-to-visit BP variability
The highest, intermediate, and the lowest visit-to-visit BP variability (Tertile grouping)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Association between raw score of K-MMSE and visit-to-visit systolic BP variability
Time Frame: Time from previous MRI documentation as small vessel disease to cognitive function evaluation; 1.5 to 7 years

Difference of mean K-MMSE raw scores between the highest and the lowest tertile group stratified by visit-to-visit systolic BP variability: Wilcoxon_Mann_Whitney test

Binary logistic regression analysis for independent association between visit-to-visit systolic BP variability and low cognition, including confounding variables with p<0.2 in univariate analysis (Low cognition, defined as the lowest tertile of K-MMSE raw score)
Time from previous MRI documentation as small vessel disease to cognitive function evaluation; 1.5 to 7 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Association between raw score of K-MMSE and visit-to-visit diastolic BP variability
Time Frame: Time from previous MRI documentation as small vessel disease to cognitive function evaluation; 1.5 to 7 years

Difference of mean K-MMSE raw scores between the highest and the lowest tertile group stratified by visit-to-visit diastolic BP variability: Wilcoxon_Mann_Whitney test

Binary logistic regression analysis for independent association between visit-to-visit diastolic BP variability and low cognition, including confounding variables with p<0.2 in univariate analysis (Low cognition, defined as the lowest tertile of K-MMSE raw score)
Time from previous MRI documentation as small vessel disease to cognitive function evaluation; 1.5 to 7 years
Association between raw scores of "K-VCI NP 30-minute protocol" sub-tests and visit-to-visit systolic BP variability
Time Frame: Time from previous MRI documentation as small vessel disease to cognitive function evaluation; 1.5 to 7 years

Difference of mean "K-VCI NP 30-minute protocol" sub-tests' raw scores between the highest and the lowest tertile group stratified by visit-to-visit systolic BP variability: Wilcoxon_Mann_Whitney test

Binary logistic regression analysis for independent association between visit-to-visit systolic BP variability and low cognition, including confounding variables with p<0.2 in univariate analysis (Low cognition, defined as the lowest tertile of each "K-VCI NP 30-minute protocol" sub-test)

"K-VCIHS NP 30-minute protocol" include Seoul Verbal Learning Test (SVLT), Semantic Fluency Test, Animal Phonemic Fluency Test, Digit Symbol-Coding (DSC), Geriatric Depression Scale (GDS), and Trail Making Test A & B.
Time from previous MRI documentation as small vessel disease to cognitive function evaluation; 1.5 to 7 years
Association between raw scores of "K-VCI NP 30-minute protocol" sub-tests and visit-to-visit diastolic BP variability
Time Frame: Time from previous MRI documentation as small vessel disease to cognitive function evaluation; 1.5 to 7 years

Difference of mean "K-VCI NP 30-minute protocol" sub-tests' raw scores between the highest and the lowest tertile group stratified by visit-to-visit diastolic BP variability: Wilcoxon_Mann_Whitney test

Binary logistic regression analysis for independent association between visit-to-visit diastolic BP variability and low cognition, including confounding variables with p<0.2 in univariate analysis (Low cognition, defined as the lowest tertile of each "K-VCI NP 30-minute protocol" sub-test)
Time from previous MRI documentation as small vessel disease to cognitive function evaluation; 1.5 to 7 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hallym University Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

May 1, 2012

Primary Completion (Anticipated)

February 1, 2013

Study Completion (Anticipated)

February 1, 2013

Study Registration Dates

First Submitted

September 16, 2012

First Submitted That Met QC Criteria

September 19, 2012

First Posted (Estimate)

September 20, 2012

Study Record Updates

Last Update Posted (Estimate)

September 20, 2012

Last Update Submitted That Met QC Criteria

September 19, 2012

Last Verified

September 1, 2012

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • BPV-Hallym

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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