INTERMAP: International Population Study on Macronutrients and BP

Hypertension Clinical Trial

Official title:

INTERMAP: International Population Study on Macronutrients and BP

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00005271
• Other study ID #: 1155
• Secondary ID: R01HL050490
• Status: Completed
• Phase: N/A
• First received: May 25, 2000
• Last updated: January 11, 2016
• Start date: July 1995
• Est. completion date: May 2015

Study information

• Verified date: January 2016
• Source: Northwestern University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Federal Government
• Study type: Observational

Clinical Trial Summary

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.

Description:

BACKGROUND:

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.

DESIGN NARRATIVE:

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 4680
• Est. completion date: May 2015
• Est. primary completion date: August 2009
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 40 Years to 59 Years

Eligibility

Inclusion Criteria:

• Healthy individuals

• Men and women

• Age 40-59 years

• Willing to collect 24 hour urine and return to clinic for second follow-up visit

Exclusion Criteria:

• Existing disease

• Unwilling to provide 24 hour urine collections

• Unable to attend follow-up visits

• Unable to recall dietary intake

Study Design

Observational Model: Cohort, Time Perspective: Cross-Sectional

Related Conditions & MeSH terms

• Cardiovascular Diseases
• Heart Diseases
• Hypertension

Locations

Country	Name	City	State
n/a

Sponsors (2)

Lead Sponsor	Collaborator
Northwestern University	National Heart, Lung, and Blood Institute (NHLBI)

References & Publications (12)

Beevers DG, Stamler J. Background to the INTERMAP study of nutrients and blood pressure. J Hum Hypertens. 2003 Sep;17(9):589-90. — View Citation

Conway R, Robertson C, Dennis B, Stamler J, Elliott P; INTERMAP Research Group. Standardised coding of diet records: experiences from INTERMAP UK. Br J Nutr. 2004 May;91(5):765-71. — View Citation

Daviglus ML, Greenland P, Stamler J, Elliott P, Appel LJ, Carnethon MR, Chan Q, Claeys G, Kesteloot H, Miura K, Nakagawa H, Pirzada A, Steffen L, Yan LL, Zhou B, Dyer AR. Relation of nutrient intake to microalbuminuria in nondiabetic middle-aged men and women: International Population Study on Macronutrients and Blood Pressure (INTERMAP). Am J Kidney Dis. 2005 Feb;45(2):256-66. — View Citation

Dennis B, Stamler J, Buzzard M, Conway R, Elliott P, Moag-Stahlberg A, Okayama A, Okuda N, Robertson C, Robinson F, Schakel S, Stevens M, Van Heel N, Zhao L, Zhou BF; INTERMAP Research Group. INTERMAP: the dietary data--process and quality control. J Hum Hypertens. 2003 Sep;17(9):609-22. — View Citation

Dyer AR, Elliott P, Stamler J, Chan Q, Ueshima H, Zhou BF; INTERMAP Research Group. Dietary intake in male and female smokers, ex-smokers, and never smokers: the INTERMAP study. J Hum Hypertens. 2003 Sep;17(9):641-54. — View Citation

Dyer AR, Greenland P, Elliott P, Daviglus ML, Claeys G, Kesteloot H, Chan Q, Ueshima H, Stamler J; INTERMAP Research Group. Estimating laboratory precision of urinary albumin excretion and other urinary measures in the International Study on Macronutrients and Blood Pressure. Am J Epidemiol. 2004 Aug 1;160(3):287-94. — View Citation

Dyer AR, Greenland P, Elliott P, Daviglus ML, Claeys G, Kesteloot H, Ueshima H, Stamler J; INTERMAP Research Group. Evaluation of measures of urinary albumin excretion in epidemiologic studies. Am J Epidemiol. 2004 Dec 1;160(11):1122-31. — View Citation

Elliott P, Stamler J, Dyer AR, Appel L, Dennis B, Kesteloot H, Ueshima H, Okayama A, Chan Q, Garside DB, Zhou B. Association between protein intake and blood pressure: the INTERMAP Study. Arch Intern Med. 2006 Jan 9;166(1):79-87. — View Citation

Stamler J, Elliott P, Appel L, Chan Q, Buzzard M, Dennis B, Dyer AR, Elmer P, Greenland P, Jones D, Kesteloot H, Kuller L, Labarthe D, Liu K, Moag-Stahlberg A, Nichaman M, Okayama A, Okuda N, Robertson C, Rodriguez B, Stevens M, Ueshima H, Horn LV, Zhou B. Higher blood pressure in middle-aged American adults with less education-role of multiple dietary factors: the INTERMAP study. J Hum Hypertens. 2003 Sep;17(9):655-775. — View Citation

Stamler J, Elliott P, Dennis B, Dyer AR, Kesteloot H, Liu K, Ueshima H, Zhou BF; INTERMAP Research Group. INTERMAP: background, aims, design, methods, and descriptive statistics (nondietary). J Hum Hypertens. 2003 Sep;17(9):591-608. Review. — View Citation

Zhao L, Stamler J, Yan LL, Zhou B, Wu Y, Liu K, Daviglus ML, Dennis BH, Elliott P, Ueshima H, Yang J, Zhu L, Guo D; INTERMAP Research Group. Blood pressure differences between northern and southern Chinese: role of dietary factors: the International Study on Macronutrients and Blood Pressure. Hypertension. 2004 Jun;43(6):1332-7. Epub 2004 Apr 26. — View Citation

Zhou BF, Stamler J, Dennis B, Moag-Stahlberg A, Okuda N, Robertson C, Zhao L, Chan Q, Elliott P; INTERMAP Research Group. Nutrient intakes of middle-aged men and women in China, Japan, United Kingdom, and United States in the late 1990s: the INTERMAP study. J Hum Hypertens. 2003 Sep;17(9):623-30. — View Citation

* Note: There are 12 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Blood pressure measurement relative to diet.	Ongoing comparisons of different nutrients, urinary sodium and blood pressure.	15 years	No