Relationship Between Urinary Nitrate Excretion and Blood Pressure in the InChianti Cohort
American Journal of Hypertension
Oxford University Press (OUP)
Reason for embargo
BACKGROUND: Inorganic nitrate from the oxidation of endogenously synthesized nitric oxide (NO) or consumed in the diet can be reduced to NO via a complex enterosalivary circulation pathway. The relationship between total nitrate exposure by measured urinary nitrate excretion and blood pressure in a large population sample has not been assessed previously. METHODS: For this cross-sectional study, 24-hour urinary nitrate excretion was measured by spectrophotometry in the 919 participants from the InChianti cohort at baseline and blood pressure measured with a mercury sphygmomanometer. RESULTS: After adjusting for age and sex only, diastolic blood pressure was 1.9 mm Hg lower in subjects with ≥2 mmol urinary nitrate excretion compared with those excreting <1 mmol nitrate in 24 hours: systolic blood pressure was 3.4 mm Hg (95% confidence interval (CI): -3.5 to -0.4) lower in subjects for the same comparison. Effect sizes in fully adjusted models (for age, sex, potassium intake, use of antihypertensive medications, diabetes, HS-CRP, or current smoking status) were marginally larger: systolic blood pressure in the ≥2 mmol urinary nitrate excretion group was 3.9 (CI: -7.1 to -0.7) mm Hg lower than in the comparison <1 mmol excretion group. CONCLUSIONS: Modest differences in total nitrate exposure are associated with lower blood pressure. These differences are at least equivalent to those seen from substantial (100 mmol) reductions in sodium intake.
This project was funded by an NHS small grant awarded by the Royal Devon and Exeter Hospital Research and Development department. PGW, ACS, and MG are supported by the NIHR Exeter Clinical Research Facility. MG, NB and PGW received financial support from James White Drinks Ltd for the development of a nitrate-depleted form of beetroot juice.
This is the author accepted manuscript. The final version is available from OUP via the DOI in this record.
Published online 19 April 2017
Place of publication