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Hypertension in Blacks of West African Origin

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: May 26, 2000
Last Update Posted: July 29, 2016
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)
To continue an international collaborative study on hypertension in populations of West African origin.

Cardiovascular Diseases Heart Diseases Hypertension Obesity

Study Type: Observational

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

Study Start Date: September 1991
Study Completion Date: August 2005
Primary Completion Date: August 2005 (Final data collection date for primary outcome measure)
Detailed Description:


The increased risk of hypertension in United States Blacks remains a major unsolved public health problem. Comparisons between macro-population groups in the United States suffer from confounding by social factors and genetic admixture. The study's international comparative design provides a unique opportunity to ascertain the evolution of hypertension among populations with a common genetic background currently living in widely varied social conditions. A well-organized network of investigators currently exists in the societies of the Black diaspora and provides for the first time an opportunity to conduct cross-national research on this question.


During the first phase of the project over 12,000 adults between the ages of 25 and 74 were sampled from seven communities: West Africa (Nigeria, urban & rural; Cameroon, urban & rural), the West Indies (St. Lucia, Barbados) and Maywood (lllinois). The screening examination provided information on blood pressure (BP), height, weight, waist/hip ratio, alcohol use, education/occupation, sodium/potassium excretion and social stress. These data provided estimates of hypertension prevalence in each geographic region and the contribution of the known risk factor to higher rates among United States Blacks. In the first phase considerable effort was directed toward establishing a strong research infrastructure in each of the sites and demonstrating the feasibility of cross-national blood pressure comparisons.

In the second phase the research was continued and extended in three areas: 1) Population studies on risk factors. At the start of the study in 1991, it was not clear that adequate procedures were available to allow standardization of mean blood pressure across sites, especially since differences between some sites might be as little as 2 mmHg. Experience since that time suggested that it would be feasible to collect definitive data on this question. In-depth studies were carried out at one of the African sites to investigate the earliest stages of hypertension risk for a population. Investigators in Jamaica and the United Kingdom joined the collaborative group to examine the effect of migration from the Caribbean to the United Kingdom. 2) Prospective study of blood pressure and mortality. It was well known that hypertension accounted for much of the excess mortality among United States Blacks. It was less well recognized, however, that death rates among Blacks in the United States were higher than reported in the Caribbean or Africa. Hypertension was likely to account for that differential. A follow-up study in each region estimated the relative and attributable risk from hypertension. 3) Heredity/Genetics. The populations in this study shared a common ancestral origin in West Africa. Family studies were undertaken to determine the heritability of blood pressure/hypertension within and between sites. In addition, pilot studies on genetic distance and candidate genes for hypertension were conducted.

The study was renewed in FY 1999 to examine in further detail the role of the two most potent hypertensive risk factors, namely dietary sodium and obesity. Randomized studies will be carried out in Nigeria, Jamaica, and Chicago to determine the relative sodium sensitivity of these populations and the factors which condition the blood pressure response. The renin-angiotensin system and renal sodium handling will be compared as causal mechanisms. In addition, body composition will be studied in a large sample of each of the three populations to determine the role of body fat versus lean body mass. Insulin and leptin will be examined and physical activity will be measured by stable isotopes to assess the role of a sedentary lifestyle as a contributor to the hypertension risk experienced by the obese. Existing cohorts will be followed to determine hypertension sequelae and to examine changes in blood pressure with age.


Information from the National Library of Medicine

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Ages Eligible for Study:   up to 100 Years   (Child, Adult, Senior)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No
No eligibility criteria
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00005340

Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
OverallOfficial: Richard Cooper Loyola University
  More Information

Rotimi C, Cooper R, Cao G, Sundarum C, McGee D. Familial aggregation of cardiovascular diseases in African-American pedigrees. Genet Epidemiol. 1994;11(5):397-407.
Rotimi C, Morrison L, Cooper R, Oyejide C, Effiong E, Ladipo M, Osotemihen B, Ward R. Angiotensinogen gene in human hypertension. Lack of an association of the 235T allele among African Americans. Hypertension. 1994 Nov;24(5):591-4.
Cooper RS, Rotimi CN, Kaufman JS, Muna WF, Mensah GA. Hypertension treatment and control in sub-Saharan Africa: the epidemiological basis for policy. BMJ. 1998 Feb 21;316(7131):614-7. Review.
Luke AH, Rotimi CN, Cooper RS, Long AE, Forrester TE, Wilks R, Bennett FI, Ogunbiyi O, Compton JA, Bowsher RR. Leptin and body composition of Nigerians, Jamaicans, and US blacks. Am J Clin Nutr. 1998 Mar;67(3):391-6.
Kaufman JS, Asuzu MC, Rotimi CN, Johnson OO, Owoaje EE, Cooper RS. The absence of adult mortality data for sub-Saharan Africa: a practical solution. Bull World Health Organ. 1997;75(5):389-95.
Kaufman JS, Asuzu MC, Mufunda J, Forrester T, Wilks R, Luke A, Long AE, Cooper RS. Relationship between blood pressure and body mass index in lean populations. Hypertension. 1997 Dec;30(6):1511-6.
Kaufman JS, Durazo-Arvizu RA, Rotimi CN, McGee DL, Cooper RS. Obesity and hypertension prevalence in populations of African origin. The Investigators of the International Collaborative Study on Hypertension in Blacks. Epidemiology. 1996 Jul;7(4):398-405.
Rotimi C, Luke A, Li Z, Compton J, Bowsher R, Cooper R. Heritability of plasma leptin in a population sample of African-American families. Genet Epidemiol. 1997;14(3):255-63.
Rotimi CN, Cooper RS, Marcovina SM, McGee D, Owoaje E, Ladipo M. Serum distribution of lipoprotein(a) in African Americans and Nigerians: potential evidence for a genotype-environmental effect. Genet Epidemiol. 1997;14(2):157-68.
Forrester T, McFarlane-Anderson N, Bennett FI, Wilks R, Cooper R, Rotimi C, Morrison L, Ward R. The angiotensin converting enzyme and blood pressure in Jamaicans. Am J Hypertens. 1997 May;10(5 Pt 1):519-24.
Cooper RS, Rotimi CN, Kaufman JS, Owoaje EE, Fraser H, Forrester T, Wilks R, Riste LK, Cruickshank JK. Prevalence of NIDDM among populations of the African diaspora. Diabetes Care. 1997 Mar;20(3):343-8.
Rotimi C, Cooper R, Ogunbiyi O, Morrison L, Ladipo M, Tewksbury D, Ward R. Hypertension, serum angiotensinogen, and molecular variants of the angiotensinogen gene among Nigerians. Circulation. 1997 May 20;95(10):2348-50.
Luke A, Durazo-Arvizu R, Rotimi C, Prewitt TE, Forrester T, Wilks R, Ogunbiyi OJ, Schoeller DA, McGee D, Cooper RS. Relation between body mass index and body fat in black population samples from Nigeria, Jamaica, and the United States. Am J Epidemiol. 1997 Apr 1;145(7):620-8.
Kaufman JS, Rotimi CN, Brieger WR, Oladokum MA, Kadiri S, Osotimehin BO, Cooper RS. The mortality risk associated with hypertension: preliminary results of a prospective study in rural Nigeria. J Hum Hypertens. 1996 Jul;10(7):461-4.
Rotimi C, Cooper R. Familial resemblance for anthropometric measurements and relative fat distribution among African Americans. Int J Obes Relat Metab Disord. 1995 Dec;19(12):875-80.
Freeman V, Rotimi C, Cooper R. Hypertension prevalence, awareness, treatment, and control among African Americans in the 1990s: estimates from the Maywood Cardiovascular Survey. Am J Prev Med. 1996 May-Jun;12(3):177-85.
Freeman V, Fraser H, Forrester T, Wilks R, Cruickshank J, Rotimi C, Cooper R. A comparative study of hypertension prevalence, awareness, treatment and control rates in St Lucia, Jamaica and Barbados. J Hypertens. 1996 Apr;14(4):495-501.
Forrester T, McFarlane-Anderson N, Bennet F, Wilks R, Puras A, Cooper R, Rotimi C, Durazo R, Tewksbury D, Morrison L. Angiotensinogen and blood pressure among blacks: findings from a community survey in Jamaica. J Hypertens. 1996 Mar;14(3):315-21.
Ataman SL, Cooper R, Rotimi C, McGee D, Osotimehin B, Kadiri S, Kingue S, Muna W, Fraser H, Forrester T, Wilks R. Standardization of blood pressure measurement in an international comparative study. J Clin Epidemiol. 1996 Aug;49(8):869-77.
Kaufman JS, Owoaje EE, James SA, Rotimi CN, Cooper RS. Determinants of hypertension in West Africa: contribution of anthropometric and dietary factors to urban-rural and socioeconomic gradients. Am J Epidemiol. 1996 Jun 15;143(12):1203-18.
Rotimi C, Puras A, Cooper R, McFarlane-Anderson N, Forrester T, Ogunbiyi O, Morrison L, Ward R. Polymorphisms of renin-angiotensin genes among Nigerians, Jamaicans, and African Americans. Hypertension. 1996 Mar;27(3 Pt 2):558-63.
Cooper RS, Cheng HY, Rotimi C. Basal and stimulated platelet calcium and sodium in hypertensive versus normotensive black people. J Hum Hypertens. 1995 Sep;9(9):747-52.
Okosun IS, Forrester TE, Rotimi CN, Osotimehin BO, Muna WF, Cooper RS. Abdominal adiposity in six populations of West African descent: prevalence and population attributable fraction of hypertension. Obes Res. 1999 Sep;7(5):453-62.
Kaufman JS, Owoaje EE, Rotimi CN, Cooper RS. Blood pressure change in Africa: case study from Nigeria. Hum Biol. 1999 Aug;71(4):641-57.
Okosun IS, Cooper RS, Prewitt TE, Rotimi CN. The relation of central adiposity to components of the insulin resistance syndrome in a biracial US population sample. Ethn Dis. 1999 Spring-Summer;9(2):218-29.
Rotimi CN, Cooper RS, Okosun IS, Olatunbosun ST, Bella AF, Wilks R, Bennett F, Cruickshank JK, Forrester TE. Prevalence of diabetes and impaired glucose tolerance in Nigerians, Jamaicans and US blacks. Ethn Dis. 1999 Spring-Summer;9(2):190-200.
Long AE, Prewitt TE, Kaufman JS, Rotimi CN, Cooper RS, McGee DL. Weight-height relationships among eight populations of West African origin: the case against constant BMI standards. Int J Obes Relat Metab Disord. 1998 Sep;22(9):842-6.
Colilla S, Rotimi C, Cooper R, Goldberg J, Cox N. Genetic inheritance of body mass index in African-American and African families. Genet Epidemiol. 2000 Apr;18(4):360-76.
Kaufman JS, Tracy JA, Durazo-Arvizu RA, Cooper RS. Lifestyle, education, and prevalence of hypertension in populations of African origin. Results from the International Collaborative Study on Hypertension in Blacks. Ann Epidemiol. 1997 Jan;7(1):22-7.
Rotimi CN, Cooper RS, Ataman SL, Osotimehin B, Kadiri S, Muna W, Kingue S, Fraser H, McGee D. Distribution of anthropometric variables and the prevalence of obesity in populations of west African origin: the International Collaborative Study on Hypertension in Blacks (ICSHIB). Obes Res. 1995 Sep;3 Suppl 2:95s-105s.
Zhu X, McKenzie CA, Forrester T, Nickerson DA, Broeckel U, Schunkert H, Doering A, Jacob HJ, Cooper RS, Rieder MJ. Localization of a small genomic region associated with elevated ACE. Am J Hum Genet. 2000 Nov;67(5):1144-53. Epub 2000 Sep 19.
Cooper R, Forrester T, Ogunbiyi O, Muffinda J. Angiotensinogen levels and obesity in four black populations. ICSHIB Investigators. J Hypertens. 1998 May;16(5):571-5.
Luke A, Durazo-Arvizu RA, Rotimi CN, Iams H, Schoeller DA, Adeyemo AA, Forrester TE, Wilks R, Cooper RS. Activity energy expenditure and adiposity among black adults in Nigeria and the United States. Am J Clin Nutr. 2002 Jun;75(6):1045-50.
Collins-Schramm HE, Phillips CM, Operario DJ, Lee JS, Weber JL, Hanson RL, Knowler WC, Cooper R, Li H, Seldin MF. Ethnic-difference markers for use in mapping by admixture linkage disequilibrium. Am J Hum Genet. 2002 Mar;70(3):737-50. Epub 2002 Feb 11.
Zhu X, Bouzekri N, Southam L, Cooper RS, Adeyemo A, McKenzie CA, Luke A, Chen G, Elston RC, Ward R. Linkage and association analysis of angiotensin I-converting enzyme (ACE)-gene polymorphisms with ACE concentration and blood pressure. Am J Hum Genet. 2001 May;68(5):1139-48. Epub 2001 Mar 27.
Adeyemo AA, Prewitt TE, Luke A, Omotade OO, Rotimi CN, Brieger WR, Cooper RS. The feasibility of implementing a dietary sodium reduction intervention among free-living normotensive individuals in south west Nigeria. Ethn Dis. 2002 Spring;12(2):207-12.
Adeyemo AA, Omotade OO, Rotimi CN, Luke AH, Tayo BO, Cooper RS. Heritability of blood pressure in Nigerian families. J Hypertens. 2002 May;20(5):859-63.
Lowe Jr WL, Rotimi CN, Luke A, Guo X, Zhu X, Comuzzie AG, Schuh TS, Halbach S, Kotlar TJ, Cooper RS. The beta 3-adrenergic receptor gene and obesity in a population sample of African Americans. Int J Obes Relat Metab Disord. 2001 Jan;25(1):54-60.
Luke A, Rotimi CN, Adeyemo AA, Durazo-Arvizu RA, Prewitt TE, Moragne-Kayser L, Harders R, Cooper RS. Comparability of resting energy expenditure in Nigerians and U.S. blacks. Obes Res. 2000 Aug;8(5):351-9.
Okosun IS, Liao Y, Rotimi CN, Prewitt TE, Cooper RS. Abdominal adiposity and clustering of multiple metabolic syndrome in White, Black and Hispanic americans. Ann Epidemiol. 2000 Jul;10(5):263-70.
Schork NJ, Chakravarti A, Thiel B, Fornage M, Jacob HJ, Cai R, Rotimi CN, Cooper RS, Weder AB. Lack of association between a biallelic polymorphism in the adducin gene and blood pressure in whites and African Americans. Am J Hypertens. 2000 Jun;13(6 Pt 1):693-8.
Okosun IS, Liao Y, Rotimi CN, Dever GE, Cooper RS. Impact of birth weight on ethnic variations in subcutaneous and central adiposity in American children aged 5-11 years. A study from the Third National Health and Nutrition Examination Survey. Int J Obes Relat Metab Disord. 2000 Apr;24(4):479-84.
Okosun IS, Liao Y, Rotimi CN, Choi S, Cooper RS. Predictive values of waist circumference for dyslipidemia, type 2 diabetes and hypertension in overweight White, Black, and Hispanic American adults. J Clin Epidemiol. 2000 Apr;53(4):401-8.
Collins-Schramm HE, Kittles RA, Operario DJ, Weber JL, Criswell LA, Cooper RS, Seldin MF. Markers that discriminate between European and African ancestry show limited variation within Africa. Hum Genet. 2002 Dec;111(6):566-9. Epub 2002 Sep 14.
Cooper RS, Luke A, Zhu X, Kan D, Adeyemo A, Rotimi C, Bouzekri N, Ward R. Genome scan among Nigerians linking blood pressure to chromosomes 2, 3, and 19. Hypertension. 2002 Nov;40(5):629-33. Erratum in: Hypertension 2003 Jan;41(1):1e. Rorimi Charles [corrected to Rotimi Charles].
Cox R, Bouzekri N, Martin S, Southam L, Hugill A, Golamaully M, Cooper R, Adeyemo A, Soubrier F, Ward R, Lathrop GM, Matsuda F, Farrall M. Angiotensin-1-converting enzyme (ACE) plasma concentration is influenced by multiple ACE-linked quantitative trait nucleotides. Hum Mol Genet. 2002 Nov 1;11(23):2969-77.
Sargeant LA, Bennett FI, Forrester TE, Cooper RS, Wilks RJ. Predicting incident diabetes in Jamaica: the role of anthropometry. Obes Res. 2002 Aug;10(8):792-8.
Leman CR, Adeyemo AA, Schoeller DA, Cooper RS, Luke A. Body composition of children in south-western Nigeria: validation of bio-electrical impedance analysis. Ann Trop Paediatr. 2003 Mar;23(1):61-7.
Adeyemo A, Luke A, Cooper R, Wu X, Tayo B, Zhu X, Rotimi C, Bouzekri N, Ward R. A genome-wide scan for body mass index among Nigerian families. Obes Res. 2003 Feb;11(2):266-73.
Zhu X, Cooper RS. Linkage disequilibrium analysis of the renin-angiotensin system genes. Curr Hypertens Rep. 2003 Feb;5(1):40-6. Review.
Mendez MA, Cooper R, Wilks R, Luke A, Forrester T. Income, education, and blood pressure in adults in Jamaica, a middle-income developing country. Int J Epidemiol. 2003 Jun;32(3):400-8.
Luke A, Wu X, Zhu X, Kan D, Su Y, Cooper R. Linkage for BMI at 3q27 region confirmed in an African-American population. Diabetes. 2003 May;52(5):1284-7. Erratum in: Diabetes. 2003 Sep;52(9):2449.
Thiel BA, Chakravarti A, Cooper RS, Luke A, Lewis S, Lynn A, Tiwari H, Schork NJ, Weder AB. A genome-wide linkage analysis investigating the determinants of blood pressure in whites and African Americans. Am J Hypertens. 2003 Feb;16(2):151-3.
Cooper RS. Gene-environment interactions and the etiology of common complex disease. Ann Intern Med. 2003 Sep 2;139(5 Pt 2):437-40. Review.
Boyne MS, Sargeant LA, Bennett FI, Cooper RS, Wilks RJ, Forrester TE. Features of isolated post-challenge hyperglycaemia in Jamaican adults. West Indian Med J. 2004 Jan;53(1):7-11.
Bouzekri N, Zhu X, Jiang Y, McKenzie CA, Luke A, Forrester T, Adeyemo A, Kan D, Farrall M, Anderson S, Cooper RS, Ward R. Angiotensin I-converting enzyme polymorphisms, ACE level and blood pressure among Nigerians, Jamaicans and African-Americans. Eur J Hum Genet. 2004 Jun;12(6):460-8.
Lawoyin TO, Asuzu MC, Kaufman J, Rotimi C, Johnson L, Owoaje E, Cooper R. Using verbal autopsy to identify and proportionally assign cause of death in Ibadan, southwest Nigeria. Niger Postgrad Med J. 2004 Sep;11(3):182-6.
Sargeant LA, Boyne MS, Bennett FI, Forrester TE, Cooper RS, Wilks RJ. Impaired glucose regulation in adults in Jamaica: who should have the oral glucose tolerance test? Rev Panam Salud Publica. 2004 Jul;16(1):35-42.
Koivukoski L, Fisher SA, Kanninen T, Lewis CM, von Wowern F, Hunt S, Kardia SL, Levy D, Perola M, Rankinen T, Rao DC, Rice T, Thiel BA, Melander O. Meta-analysis of genome-wide scans for hypertension and blood pressure in Caucasians shows evidence of susceptibility regions on chromosomes 2 and 3. Hum Mol Genet. 2004 Oct 1;13(19):2325-32. Epub 2004 Aug 4.
Fejerman L, Bouzekri N, Wu X, Adeyemo A, Luke A, Zhu X, Ward R, Cooper RS. Association between evolutionary history of angiotensinogen haplotypes and plasma levels. Hum Genet. 2004 Sep;115(4):310-8.
Boyne MS, Gaskin P, Luke A, Wilks RJ, Bennett FI, Younger N, Sargeant LA, Adeyemo AA, Cooper RS, Forrester TE. Energetic determinants of glucose tolerance status in Jamaican adults. Eur J Clin Nutr. 2004 Dec;58(12):1666-8.
Mendez MA, Wynter S, Wilks R, Forrester T. Under- and overreporting of energy is related to obesity, lifestyle factors and food group intakes in Jamaican adults. Public Health Nutr. 2004 Feb;7(1):9-19.
Mendez MA, Cooper RS, Luke A, Wilks R, Bennett F, Forrester T. Higher income is more strongly associated with obesity than with obesity-related metabolic disorders in Jamaican adults. Int J Obes Relat Metab Disord. 2004 Apr;28(4):543-50.
Luke A, Adeyemo A, Kramer H, Forrester T, Cooper RS. Association between blood pressure and resting energy expenditure independent of body size. Hypertension. 2004 Mar;43(3):555-60. Epub 2004 Feb 2.
McKenzie CA, Sinsheimer JS, Adeyemo AA, Cox RD, Southam L, Hugill A, Bouzekri N, Lathrop M, Forrester TE, Cooper RS, Ward R. SNP haplotypes in the angiotensin I-converting enzyme (ACE) gene: analysis of Nigerian family data using gamete competition models. Ann Hum Genet. 2005 Mar;69(Pt 2):227-32.
Zhu X, Fejerman L, Luke A, Adeyemo A, Cooper RS. Haplotypes produced from rare variants in the promoter and coding regions of angiotensinogen contribute to variation in angiotensinogen levels. Hum Mol Genet. 2005 Mar 1;14(5):639-43. Epub 2005 Jan 13.
Cooper R, Rotimi C. Hypertension in blacks. Am J Hypertens. 1997 Jul;10(7 Pt 1):804-12. Review.

ClinicalTrials.gov Identifier: NCT00005340     History of Changes
Other Study ID Numbers: 4202
R01HL045508 ( U.S. NIH Grant/Contract )
First Submitted: May 25, 2000
First Posted: May 26, 2000
Last Update Posted: July 29, 2016
Last Verified: January 2008

Additional relevant MeSH terms:
Cardiovascular Diseases
Heart Diseases
Vascular Diseases

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