Abstract P237: Relation of Egg Intake to Blood Pressure: The International Study on Macro/Micronutrients and Blood Pressure (INTERMAP)

Abstract

Background: Data regarding associations of egg intake, a major source of dietary cholesterol, with blood pressure (BP) are limited, especially from large, diverse population samples, and findings have been inconsistent. Methods: Associations between egg intake and BP were examined using data on 4680 men and women, aged 40-59 years, between 1996 and 1999, from the INTERMAP study that included 17 population samples in the United States (US), United Kingdom (UK), China and Japan. Data were collected from four 24-hour dietary recalls, 2 timed 24-hour urine collections and 8 BP measurements. Egg intake was calculated as amount consumed per day using the Nutrient Data Software for Research (University of Minnesota, USA). Multivariable linear regression models were used to estimate differences in BP per 2-SD of egg intake (50.71g/day). Country-specific regression coefficients were pooled, weighted by inverse of their variance to estimate overall association. Results: Of 4680 participants, 50% were women. Daily egg intake was highest among individuals from Japan (mean 37.74, SD 24.3g/day). With adjustment for age, sex, population sample, and average dietary energy intake/day, egg intake was significantly associated with SBP in both the pooled sample and the US sample. With each 2-SD higher egg intake, US mean SBP was significantly higher by 2mmHg (Model 1-Table). The associations remained significant with further adjustment for education level, family history of hypertension, smoking status, and use of dietary supplement (Model 2-Table). With further adjustment for urinary sodium and urinary potassium or BMI, the associations were no longer significant. No association was found for other countries, and for DBP. Conclusion: An adverse association between egg intake and SBP was observed in the US but not in other countries. Notably, this association was strongly attenuated by urinary sodium, urinary potassium and BMI. Further research is needed to better understand the relation of egg intake and BP.