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Hypertension in Families of African Origin

This study has been completed.
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI) Identifier:
First received: May 25, 2000
Last updated: February 17, 2016
Last verified: July 2004
To investigate familial patterns of hypertension and related cardiovascular (CV) risk factors in the United States and Nigeria.

Cardiovascular Diseases Heart Diseases Hypertension

Study Type: Observational

Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Study Start Date: August 1995
Study Completion Date: July 2001
Detailed Description:


It has been known for many years that African Americans experience twofold higher rates of hypertension than do whites. The underlying biological mechanisms which lead to this differential are still not understood, however. Despite widespread speculation that persons of African descent are genetically susceptible to hypertension, few direct studies have been carried out. Rates of hypertension remain low in West Africa, and this study will provide a contrast between populations of similar genetic background in a low versus high risk environmental setting


A total of 240 families were identified from completed community surveys in Maywood, Illinois and Ibadan, Nigeria. Probands were ages 45-55 and equally divided between males and females. A minimum of five first-degree relatives were examined in each family to obtain information on the following variables: blood pressure (BP), obesity, urinary sodium and potassium, socioeconomic status and physical activity. In addition, plasma and DNA were collected and stored for future studies of relevant physiologic intermediate phenotypes and candidate genes for hypertension in the two contrasting populations. These data provided the basis for examining familial aggregation of blood pressure/hypertension and related CV risk factors. Three primary goals were addressed: 1) to determine whether the familial aggregation of blood pressure in Black populations was influenced by the overall distribution of environmental factors at the population level, by contrasting the distribution of familial correlations of blood pressure and the familial aggregation of hypertension, in Nigeria and the United States; to determine the significance of measured environmental correlates of blood pressure by comparing the magnitude of variance components for probands and relatives in each setting; and 3) to use path analysis to obtain estimates of genetic and cultural heritability of blood pressure, controlling for clustering environmental factors at the household level. Plasma and DNA samples collected in this study provided additional valuable resources for future molecular research.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.


Ages Eligible for Study:   up to 100 Years   (Child, Adult, Senior)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No
No eligibility criteria
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Please refer to this study by its identifier: NCT00005444

Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
OverallOfficial: Charles Rotimi Howard University
  More Information

Publications: Identifier: NCT00005444     History of Changes
Other Study ID Numbers: 4373
R29HL052075 ( U.S. NIH Grant/Contract )
Study First Received: May 25, 2000
Last Updated: February 17, 2016

Additional relevant MeSH terms:
Cardiovascular Diseases
Heart Diseases
Vascular Diseases processed this record on September 21, 2017