Abstract
Background. There is considerable interest in the possible role of nitrate in gastric carcinogenesis, but little information on nitrate intake around the world. This is the first study to give comprehensive standardized data on nitrate excretion as a marker of intake, using 48 worldwide population samples. Methods. Urinary nitrate excretion has been shown to be a valid measure of nitrate intake in people under 50. This report presents data on 24-hour urinary nitrate excretion from urine collections obtained in the INTERSALT study, based on random samples of men and women aged 20-49 from each of 48 population samples in 30 countries. Results. There was large variation in urinary nitrate excretion both within and between samples; within-sample (individual) distributions tended to be skewed towards higher values. Median values of the samples ranged from 0.42 mmol/day (Labrador, Canada) to 3.52 (Beijing, People's Republic of China) in men and 0.44 mmol/day (Colombia) to 3.44 (Beijing) in women. Overall, median values were higher in men than women by 11% on average (higher in men in 37 of 48 population samples). Comparison by geographical region of median values for men and women combined showed relatively low values in the samples in North America and Northern Europe (range 0.46-0.88 mmol/day), slightly higher values in Western Europe and Africa (0.68-1.11), and intermediate to high values in Southern Europe, Eastern and Central Europe and India (0.86-2.47). The highest median values were found in the Far Eastern samples (up to 3.48). Median values in the Central and South American samples ranged from 0.48 mmol/day (Colombia) to 1.37 (Xingu Indians of Brazil, and Argentina). Conclusions. For the first time, these data give standardized information on urinary nitrate excretion from different geographical regions of the world, and provide a basis for the further exploration of the role of nitrate in the aetiology of disease in human populations.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 505-512 |
| Number of pages | 8 |
| Journal | International journal of epidemiology |
| Volume | 25 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jun 1996 |
Funding
ACKNOWLEDGEMENTS We are pleased to acknowledge the technical assistance in the nitrate assays of Ms Sonia Duncan and Katherine McPherson and Dr A R Cook for his helpful advice and cooperation in this work. The nitrate analyses were supported by a grant from the UK Ministry of Agriculture, Fisheries and Food (MAFF). We thank Simon Day and Jennifer Freeman (London School of Hygiene and Tropical Medicine) for assistance. INTERSALT was supported by the Council on Epidemiology and Prevention of the International Society and Federation of Cardiology; World Health Organization; International Society of Hypertension; Wellcome Trust (UK); National Heart, Lung, and Blood Institute (USA); Heart Foundations of Canada, Great Britain, Japan and The Netherlands; Chicago Health Research Foundation; Belgian National Research Foundation; Parastatal Insurance Company, Brussels; and by many national agencies supporting local studies.
Keywords
- Multi-centre study
- Urinary nitrate excretion
ASJC Scopus subject areas
- Epidemiology