HIGH Altitude CArdiovascular REsearch Latin America Population Study

Study Overview
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Brief Summary
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High blood pressure (BP) is one of the principal cardiovascular risk factors. While BP levels and hypertension prevalence are well characterized in many populations, information on BP and on cardiovascular risk profile in high altitude inhabitants is limited and frequently contradictory, especially in the large highland populations of South America. The information on the effects of permanent high altitude exposure on cardiovascular variables including BP may be relevant in the light of the known BP-increasing effect of acute exposure to high altitude hypoxia. This information may have practical implications for millions of people living at elevated altitudes in Asia, South America and Africa. The inconclusive epidemiological evidence on BP and cardiovascular risk in high altitude dwellers may be the result of several factors, among them: 1) confounding by genetic and socio-economic factors; 2) imperfect methods of BP evaluation, in particular lack of data on ambulatory and home BP (both methods considered superior to conventional clinic BP in the assessment of exposure to high BP). On this background, the general aim of the study is to compare blood pressure levels and cardiovascular risk profile among population-based samples of subjects residing in Peruvian communities living at different altitudes.

Official Title
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HIGH Altitude CArdiovascular REsearch Latin America Population Study

Conditions
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Hypertension, Cardiovascular Risk Factor, Altitude Hypoxia, Altitude Sickness, Erythrocytosis, Sleep

Intervention / Treatment
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* Other: Exposure to high altitude


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult (>18 years) male and female subjects; Highlanders: permanence at high (>2500 m) altitude; Lowlanders: permanence at low (<1500 m) altitude; Written informed consent to participate in the study Exclusion Criteria: Lowlanders who over 3 months preceding inclusion in the study spent considerable (> 7 consecutive days) amount of time at altitudes above 1500 m; Highlanders who over 3 months preceding inclusion in the study spent considerable (>7 consecutive days) amount of time at altitudes below 2500 m; Subjects cognitively incapable of providing informed consent or responding to a questionnaire Physical disability that would prevent study assessments from being performed Active pulmonary tuberculosis Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Lowlanders<br>People living at low (<1500 m) altitude | |
| Highlanders<br>People living at high (>2500 m) altitude | Other: Exposure to high altitude<br>* permanence at high (>2500 m) altitude; permanence is defined as being born and living at high altitude with the total time spent at lower altitudes not exceeding 2 years in the past 10 years<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in 24 h ambulatory systolic BP between lowlanders and highlanders. |  | baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in 24 h DBP, daytime and night-time systolic and diastolic BP between lowlanders and highlanders |  | baseline | 
| Difference in conventional systolic and diastolic BP between lowlanders and highlanders |  | baseline | 
| Difference in home systolic and diastolic BP between lowlanders and highlanders |  | baseline | 
| Difference in sleep quality between lowlanders and highlanders | Pittsburgh questionnaire (score) | baseline | 
| Difference in sleep duration between lowlanders and highlanders | self reported sleep duration (hours) | baseline | 
| Difference in estimated cardiovascular risk |  | baseline | 
| Difference between lowlanders and highlanders in hypertension prevalence |  | baseline | 
| Difference in a number of BP variables between highlanders living at three high altitude levels |  | baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ambulatory blood pressure monitoring, echocardiography