Cerebral Tissue Oxygenation in Highlanders/Lowlanders

Cerebral Tissue Oxygenation in Highlanders With Pulmonary Hypertension Compared to Highlanders Without Pulmonary Hypertension and Lowlanders

The purpose of the current study is to evaluate the cerebral tissue oxygenation of Kyrgyz highlanders with high altitude pulmonary hypertension (HAPH) by performing a longitudinal cohort study. To this end, the investigators will invite the same highlanders who participated in the study in 2012 to undergo follow-up examinations in 2017, in order to allow comparisons of current results with baseline data from 2012.

Study Overview

• Status: Completed
• Conditions: High Altitude Pulmonary Hypertension

• Study Type: Observational
• Enrollment (Actual): 79

Contacts and Locations

Study Locations

• Kyrgyzstan
  • Bishkek, Kyrgyzstan, 720040
    • National Center for Cardiology and Internal Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Highlanders with high altitude pumonary hypertension living at an altitude of 2500-4000 m; healthy highlanders living at an altitude of 2500-4000 m; healthy lowlanders living at an altitude of <1000 m.

Description

Inclusion Criteria:

• high altitude pulmonary hypertension confirmed by clinical presentation and mean pulmonary artery pressure >30 mmHg measured by echocardiography at altitude of residence.
• healthy subjects (high altitude controls)
• Both genders
• Age >16 y
• Kyrgyz ethnicity
• born, raised and currently living at >2500 m
• healthy subjects currently living at <1000 m (low altitude controls)

Exclusion Criteria:

• Pulmonary hypertension from other causes, in particular from left ventricular failure as judged clinically and by echocardiography
• Excessive erythrocytosis
• Other coexistent disorders that may interfere with the cardio-respiratory system and sleep
• Regular use of medication that affects control of breathing
• Heavy smoking

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort
High altitude pulmonary hypertension; Highlanders with high altitude pulmonary hypertension living above 2500 m.
High altitude control; Healthy highlanders living above 2500 m.
Low altitude control; Healthy lowlanders living below 1000 m.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in cerebral tissue oxygenation	Difference in the change in cerebral tissue oxygenation (CTO, measured by near infrared spectroscopy) 2012 to 2017 in highlanders with high altitude pulmonary hypertension, healthy highlanders and healthy lowlander	Year 2012 to 2017

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in cerebrovascular response to hyperoxia	Difference in the change in cerebrovascular response (total hemoglobin concentration, a surrogate to blood volume, measured by near infrared spectroscopy) to hyperoxia 2012 to 2017 in highlanders with high altitude pulmonary hypertension, healthy highlanders and healthy lowlander	Year 2012 to 2017
Changes in cerebrovascular response to hypocapnia	Difference in the change in cerebrovascular response (total hemoglobin concentration, a surrogate to blood volume, measured by near infrared spectroscopy) to hypocapnia 2012 to 2017 in highlanders with high altitude pulmonary hypertension, healthy highlanders and healthy lowlander	Year 2012 to 2017
Arterial oxygen saturation	Difference in the change in the arterial oxygen saturation 2012 to 2017 in highlanders with high altitude pulmonary hypertension, healthy highlanders and healthy lowlander	Year 2012 to 2017

Collaborators and Investigators

• Sponsor: University of Zurich
• Collaborators: National Center of Cardiology and Internal Medicine named after academician M.Mirrakhimov
• Investigators: Study Chair: Talant M Sooronbaev, MD, NCCIM

Study record dates

Study Major Dates

• Study Start (Actual): May 24, 2017
• Primary Completion (Actual): August 16, 2017
• Study Completion (Actual): August 16, 2017

Study Registration Dates

• First Submitted: May 23, 2017
• First Submitted That Met QC Criteria: May 29, 2017
• First Posted (Actual): June 1, 2017

Study Record Updates

• Last Update Posted (Actual): August 16, 2019
• Last Update Submitted That Met QC Criteria: August 15, 2019
• Last Verified: August 1, 2019

More Information

Terms related to this study

• Keywords: pulmonary hypertension; hypoxia; disease progression; cerebral tissue oxygenation
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Respiratory Tract Diseases; Lung Diseases; Hypertension; Hypertension, Pulmonary
• Other Study ID Numbers: 01-8/433C

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No