Introduction: FMD has been proposed as a tool in cardiovascular (CV) risk stratification. However, this has only been studied in relatively small, high risk populations.

Objective: We investigated whether FMD was related to CV risk factors and intima media thickness (IMT) in a low risk population, the Nijmegen Biomedical Study (NBS).

Method: FMD and IMT were measured non-invasively in the brachial and the common carotid artery, respectively, using ultrasound. The NBS is a low risk population based cohort, aged 50–70 years. Interim analysis of FMD and IMT were performed in 337 subjects (mean age 60.3 year, % male 57.5). All traditional clinical and biochemical CV risk factors were determined.

Results: Mean IMT was 0.83 ± 0.11 mm. Mean FMD was 1.45 ± 2.45%. After correction for age and gender, all CV risk factors were significantly correlated to IMT (Pearson’s R 0.11–0.33), explaing 42% of the variance in IMT. However, for FMD no significant correlations with any of the CV risk factors were found (Pearson’s R 0.007 –0.13), except for TC and apoB . All CV risk factors explained only 9,5% of the variance in FMD whereas 6% of the variation in FMD was explained by IMT.

Conclusion: In our low risk population based cohort, aged 50–70 years old, FMD was not related to most of the CV risk factors whereas IMT contributed significantly to the variation in FMD. Our results question the additive value of FMD compared to IMT in terms of CV risk assessment, in older low risk populations.