Background: Intermittent claudication (IC) is associated with an increased cardiovascular morbidity. The goal of the present study was to assess the contribution of conventional cardiovascular risk factors (CVRFs) to this increased risk.
Method: The PRIME Study is a multicenter Prospective Cohort Study of 10 602 men recruited in 1991-1993, aged 50-59 at baseline and followed over 10 years. At baseline, a questionnaire on socio demographic data was self-administered and CVRFs were measured. Composite outcome consisted of incident MI, effort angina, unstable angina and coronary death. The standardized questionnaire of the London School of hygiene was used to identify claudicants. Data were analyzed using multivariate Cox models.
Results: Probable and possible cases of IC were reported by 1.4% (135) and 4.6% (442) of subjects, respectively. Compared to subjects with no claudication, the probable cases demonstrated higher rates of CVRFs. The incidence of CAD events was 7.23/1000 person-year. Compared to non claudicants, probable claudicants had an increased age and country adjusted risk of coronary events (HR (95% CI), 2.4 (1.5-3.7), p<0.0001). After further adjustments for school duration, family history of early myocardial infarction, tobacco consumption, alcohol consumption, BMI, systolic blood pressure, antihypertensive treatment, diabetes, total cholesterol, HDL-cholesterol, triglycerides and lipid-lowering treatment, participants with probable claudication had an increased risk of coronary events but this was no longer significant (HR (95% CI), 1.3 (0.8-2.1), p=0.23).
Conclusion: IC is associated with an increased risk of developing coronary events. This association is largely explained by the coexistence of CVRFs.