Relationship of dietary cholesterol to blood pressure: The INTERMAP study

Objective: A direct relationship of dietary cholesterol to blood pressure of men has been reported in a few observational studies from the USA. It is not clear whether this association prevails consistently, for example, in populations with varied dietary habits, across ethnic groups, and sexes. Cross-sectional data from the International Study of Macro/Micro-nutrients and Blood Pressure (INTERMAP) were used to assess relations of dietary cholesterol intake to blood pressure in men and women from four countries. Methods: Data include 83 nutrients from four multipass 24-h dietary recalls and two-timed 24-h urine collections; eight blood pressure readings, and questionnaire data, for 4680 participants ages 40-59 years from 17 population samples in Japan, People's Republic of China, UK, and USA. Results: With sequential models to control for multiple possible confounders (dietary, other), linear regression analyses showed that dietary cholesterol was directly related to SBP for all participants and for nonhypertensive individuals, but not to DBP. With adjustment for 12 variables, estimated SBP differences with 2SD for higher cholesterol intake (131.0 mg/1000 kcal) were 0.9 mmHg (P < 0.05) for all participants and 1.1 mmHg (P < 0.01) for nonhypertensive individuals, findings attenuated with addition of height and weight to the model. Conclusion: INTERMAP found a low-order, positive relationship of dietary cholesterol intake to SBP with control for multiple possible confounders. Reduction of dietary cholesterol intake may contribute to prevention and control of adverse blood pressure levels in general populations.