INTERMAP

Investigators
Paul Elliott, PI INTERMAP Study
Jeremy Nicholson, PI INTERMAP Metabonomics Study
Elaine Holmes, co-PI INTERMAP Metabonomics Study
Tim Ebbels, co-PI INTERMAP Metabonomics Study
Maria de Iorio, co-PI INTERMAP Metabonomics Study
Queenie Chan, Project Manager, London Coordinating Centre
Ioanna Tzoulaki, Lecturer (epidemiology)
Ian Brown, Research Associate (epidemiology)
Magda Bictash, Research Associate (metabonomics)
Ivan Yap, Research Associate (metabonomics)

Project Summary
INTERMAP (INTERnational collaborative study of MAcronutrients, micronutrients and blood Pressure) is a multi-centre cross-sectional epidemiologic investigation designed to help clarify unanswered questions regarding the role of dietary factors in the development of unfavourable blood pressure (BP) levels in adults. 

Between 1996 and 1999, BP, dietary, urinary, anthropometric and questionnaire data were collected from 4,680 men and women (40-59 years) recruited from 17 populations across four countries (Japan, China, UK, USA). Participants were selected randomly, and each completed four 24-hour dietary recalls; two timed 24-hour urine collections (for assessment of sodium, potassium, creatinine and urea); and 8 BP measurements. Laboratory analyses were conducted at the Central Laboratory in Leuven, Belgium. 

The INTERMAP database is a valuable resource for investigating associations of nutritional factors and the BP levels of individuals. The original aims of the study – now addressed in published papers – included investigating potential associations of protein (amount and type), lipids, carbohydrate, and minerals with BP. Additional funding has been obtained for amino acid analysis and metabonomic analysis of INTERMAP urine specimens. These data – available for the first time for a large number of individuals from diverse free-living populations – offer unique potential to provide novel biomarkers for nutrient intake, shed light on metabolic pathways involved in diet-BP associations, and identify therapeutic targets for BP control. 

Work is underway to enhance the INTERMAP nutrient database in order to investigate the role of novel nutrients (e.g., lycopene, isoflavones), glycaemic index, foods, food groups, and eating patterns in blood pressure regulation.

This department is the coordinating and data analysis centre for the study, and works closely with the Metabonomics Laboratory in the Department of Biomolecular Medicine, Imperial College London; colleagues at Northwestern University, Chicago; and collaborators in Japan, China, the UK and the USA. INTERMAP (main grant, urinary amino acids study, and metabonomics study) is funded primarily by the US National Heart, Lung, and Blood Institute.  

Key Publications
Brown IJ, Elliott P, Robertson CE, Chan Q, Daviglus ML, Dyer AR, Huang CC, Rodriguez BL, Sakata K, Ueshima H, Van Horn L, Zhao L, Stamler J. Dietary starch intakes of individuals and their blood pressure: the International Study of Macronutrients and Micronutrients and Blood Pressure. J Hypertens 2009; 27:231-236. PubMed, doi:10.1097/HJH.0b013e32831a7294

Holmes E, Loo RL, Stamler J, Bictash M, Yap IKS, Chan Q, Ebbels T, de Iorio M, Brown IJ, Veselkov KA, Daviglus ML, Kesteloot H, Ueshima H, Zhao L, Nicholson JK, Elliott P. Human metabolic phenotype diversity and its association with blood pressure. Nature 2008; 453:396-400. PubMed, doi:10.1038/nature06882

Tzoulaki I, Brown IJ, Chan Q, Van Horn L, Ueshima H, Zhao L, Stamler J, Elliott P. Relation of iron and red meat intake to blood pressure: cross sectional epidemiological study. Brit Med J 2008; 337:a258. PubMed, doi:10.1136/bmj.a258

Elliott P, Kesteloot H, Appel L, Dyer A, Ueshima H, Chan Q, Brown IJ, Zhao L, Stamler J. Dietary phosphorus and blood pressure: International Study of Macro- and Micro-Nutrients and Blood Pressure. Hypertension 2008; 51:669-675. PubMed, doi:10.1161/hypertensionaha.107.103747

Elliott P, Stamler J, Dyer AR, Appel L, Dennis B, Kesteloot H, Ueshima H, Okayama A, Chan Q, Garside DB. Association between protein intake and blood pressure. The INTERMAP Study. Arch Intern Med 2006; 166:79-87. PubMed