Differences in the ankle-brachial index in the general population after 4 years of follow-up

Background: Variation in the ankle-brachial index (ABI) is related to the progression of atherosclerosis in the lower extremities and is associated with mid-term cardiovascular morbidity and mortality. The aim of this study was to investigate the changes in ABI after four years of follow-up of individuals in the general population, and the factors associated with relevant variations observed. Patients and methods: The study was performed in 750 volunteers (mean age 69.9 years) men without any evidence of peripheral artery disease, who attended a primary care centre. A complete physical examination, together with standard blood tests and ABI were performed. Four years later a new clinical evaluation was done. Variations in ABI values were considered relevant if > 10 %. Results: Mean ABI in the second visit was 1.07 +/- 0.15, which represented 0.02 +/- 0.12 points lower than in the first visit (P < 0.001). Of these subjects, 157 (21.6%) had an ABI decrease > 10 %. Multivariate analysis showed that the change was associated with male gender, cardiovascular history, no intake of blockers of the renin-angiotensin system, and the presence of atherogenic dyslipidaemia. A relevant increase in ABI was observed in 117 subjects (16.1 %), but was not associated with any of the studied factors. Conclusions: ABI values tend to decrease in the general population, although one sixth of the studied subjects had a relevant increase in this parameter.