Objective: To assess the association between the intake of dietary fibre and carotid intima-media thickness (IMT) in a Mediterranean population at high cardiovascular risk.
Methods: Baseline cross-sectional assessment of 457 men and women (average age 67 years) from two different Spanish centres of the PREDIMED trial. A previously validated food frequency questionnaire (137 food items) was administered by trained dieticians in a face-to-face interview. Mean common carotid IMT was measured using B-mode ultrasound imaging of the right and left carotid arteries by four certified sonographers who used a common protocol. Anthropometric and blood pressure measurements were performed and samples of fasting blood were obtained. Participants were categorized into four groups (roughly quartiles: < or =21; >21 to < or =25; >25 to < or =31 and >31 g/day) of energy-adjusted intake of dietary fibre. Multiple linear regression models were used to adjust for age, sex, centre, smoking, body mass index, diabetes, blood pressure, lipid levels and statin use.
Results: In the crude analyses, energy-adjusted fibre intake showed a significant inverse correlation with IMT (r=-0.27, P<0.001). In multivariate analyses, a modest, though statistically significant (P=0.03) inverse association between energy-adjusted fibre intake and IMT was also found. The multivariate-adjusted difference in average IMT was -0.051 mm (95% confidence interval: -0.094 to-0.009, P=0.02) for participants whose intake was >35 g/day, (n=47) when compared with those whose intake was <25 g/day (n=224).
Conclusions: Our results suggest that high fibre intake is inversely associated with carotid atherosclerosis.