Abstract P229: Cross-Sectional Investigation of the Relationship Between Fish Consumption and Its Urinary Biomarkers With Blood Pressure Across Asian and Western Populations: Results From the INTERMAP Study

Background: Evidence relating to the benefit of fish consumption on blood pressure (BP) management is inconclusive. Recent research has suggested that different patterns in fish consumption across geographic regions may modify the association between fish intake and cardiovascular outcomes. Objectives: To investigate the associations between fish intake and BP in Asian and Western population groups and to explore the associations between candidate urinary biomarkers of fish intake and BP. Methods: The International Study on Macro/Micronutrients and Blood Pressure (INTERMAP) surveyed 4680 men and women aged 40-59 years from four countries: United States of America (US), United Kingdom (UK), Peoples Republic of China (PRC) and Japan between 1996 and 1999. Standardized quality-controlled measures collected included: four 24-hour dietary recalls and two 24-hour urine collections and eight BP measurements. Proton nuclear magnetic resonance spectra of urine specimens were acquired, and partial correlation analysis adjusted for age, sex, and sample/centre were performed to identify candidate peak variables correlating to total fish and shellfish intakes. Multivariable linear regression models conducted on pooled data by geographic region (Asian: Japan and PRC; n = 1984, and Western: UK and US; n = 2696) estimated differences in BP per 2SD (33.4g/1000kcal) of total fish intake and identified urinary metabolites. Results: Japan reported the highest daily intake of fish (mean 40.3, SD 22.3 g/1000kcal) with 99% of the cohort classified as consuming fish. Mean daily fish consumption patterns were comparable between the US (9.0 SD 15.0 g/1000kcal; 53% consumers) and UK (8.5 SD, 12.4 g/1000kcal; 55% consumers). No associations were observed between total fish intake and BP in individual cohorts or by geographic region. Trimethylamine N-oxide (TMAO), taurine and homarine were identified as candidate urinary biomarkers of fish intake. Homarine showed a strong correlation with shellfish intake ( r =0.43, P β 0.32 95%CI 0.14, 0.50, P = 0.0006; fully adjusted for lifestyle and dietary intakes), this remained significant following adjustment for body mass index ( β 0.23, 95%CI 0.05, 0.41, P = 0.012). Taurine and homarine were not associated with BP. Conclusion: We observed no association between fish consumption and BP across Asian or Western populations. The differential association between urinary TMAO and DBP in Western and Asian population groups requires further investigation.