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INTERMAP: International Population Study on Macronutrients and BP

This study is ongoing, but not recruiting participants.
Information provided by (Responsible Party):
Jeremiah Stamler, Northwestern University Identifier:
First received: May 25, 2000
Last updated: November 21, 2014
Last verified: November 2014

May 25, 2000
November 21, 2014
July 1995
August 2009   (final data collection date for primary outcome measure)
Blood pressure measurement relative to diet. [ Time Frame: 15 years ] [ Designated as safety issue: No ]
Ongoing comparisons of different nutrients, urinary sodium and blood pressure.
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Complete list of historical versions of study NCT00005271 on Archive Site
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INTERMAP: International Population Study on Macronutrients and BP
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To investigate the relationship between dietary factors, especially macronutrients, and blood pressure in an international, multicenter observational study. A particular focus is to help elucidate the role of these dietary factors in accounting for the even more adverse blood pressure patterns of less educated population strata, especially in the United States, in both less educated Blacks and whites.


Overall study findings are to be used to estimate favorable impact on blood pressure of multiple improvements in nutrition by populations. The investigators state that this should aid in making additional dietary recommendations toward the goal of primary prevention of hypertension and shifting blood pressure distributions downward to avoid excess risk associated with present levels generally above optimal.


INTERMAP's cross-sectional design is patterned after the tested INTERSALT model: a large sample size of 4,680 persons, half men and half women, ages 40-59 from 17 population samples of varied ethnicity, socioeconomic status (SES) and dietary habits in four countries (China, Japan, United Kingdom and the United States). There were eight United States INTERMAP centers. Specific aims involve elucidating influences on blood pressure of the amount and type of protein, lipids, carbohydrates, and also amino acids, calcium, magnesium, antioxidants, fiber, and caffeine. Primary hypotheses tested, with control for body mass index (BMI), intake of alcohol, age, sex, and other confounders are as follow: dietary protein is inversely related to blood pressure; inverse relations between education and blood pressure are significantly accounted for by education-related differences in dietary protein intake; there is a direct relation to blood pressure of dietary saturated fatty acids, cholesterol, Keys score, starch; there is an inverse relation of polyunsaturated fatty acids and polyunsaturated/saturated fatty acids. Randomly selected participants provide one timed 24-hr. urine collection for assessment of sodium, potassium, creatine, and urea, and complete four 24-hr. dietary recalls. Blood pressure was measured eight times at each of four clinic visits, with standardization and strict quality control of all procedures.

The study is coordinated by two Coordinating Centers--Northwestern University, Chicago and London School of Hygiene & Tropical Medicine. Urinary determinations are made at a Central Laboratory in Leuven, Belgium. Twenty-four hour dietary recalls are converted into nutrients with use of the Nutrition Data System of the University of Minnesota's Nutrition Coordinating Center. Data analyses to test hypotheses are done at the London Coordinating Center.

Recruitment and data collection began in July, 1996 through January, 1997. The main statistical analytic method is multivariate regression analysis. The study was renewed in FY 2000 and in FY 2004 to continue analysis of the data through August, 2009.

Observational Model: Cohort
Time Perspective: Cross-Sectional
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Retention:   Samples Without DNA

24 hour urine collection among all participants

Probability Sample

The INTERMAP study population includes 4,680 men and women ages 40-59 who were recruited from 17 population samples of diverse ethnicity/ SES/ eating practices in four countries (China, Japan, UK, USA).

  • Cardiovascular Diseases
  • Heart Diseases
  • Hypertension
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*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Active, not recruiting
May 2016
August 2009   (final data collection date for primary outcome measure)

Healthy individuals Men and Women Age 40-59 years old Willing to collect 24 hour urine and return to clinic for a second follow up visit

40 Years to 59 Years
Contact information is only displayed when the study is recruiting subjects
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1155, R01HL050490
Jeremiah Stamler, Northwestern University
Northwestern University
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Lawrence Appel Johns Hopkins University
Principal Investigator: Daniel Jones University of Mississippi Medical Center
Principal Investigator: Darwin Labarthe University of Texas
Principal Investigator: Beatriz Rodriguez University of Hawaii at Manoa
Principal Investigator: Jeremiah Stamler Northwestern University
Principal Investigator: Linda Van Horn Northwestern University
Northwestern University
November 2014

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP