Different Methods of Ankle-Brachial Index Calculation on the Prevalence of Peripheral Arterial Disease and Arterial Calcification in Subjects with Type 2 Diabetes Mellitus from a Public Hospital in Peru

Objective: To determine the frequency of peripheral arterial disease (PAD) and arterial calcification (AC) using three methods of ankle-brachial index (ABI) in patients with type 2 diabetes mellitus. Methodology: A descriptive cross-sectional study using data from the Foot at Risk Program of the Endocrinology Department at Hospital Maria Auxiliadora from 2015 to 2020. We calculated the ABI for each lower limb using the lowest, highest, or average systolic pressure from the dorsalis pedis or posterior tibial artery in the ipsilateral leg. We defined PAD if any ABI from either leg was <0.9; AC if ABI was >1.3; and the rest were classified as normal. We calculated the prevalence of PAD and AC for each ABI method and assessed differences between ABI categories based on clinical variables using the chi-square or Fisher's exact test. Results: We included 643 subjects with a mean age of 61.4 years, 69.8% female. The prevalence of PAD was 7.8%, 15.4%, and 28.2% using the highest, average, or lowest systolic pressure as the numerator in the ABI, respectively. The highest prevalence of PAD occurred with the lowest pressure and the lowest with the highest pressure. AC was observed in 18.2%, 11%, and 16.2%, and normal values were 74%, 73.6%, and 55.7%. In all three methods, PAD was associated with older age and AC was associated with longer duration of diabetes. Conclusions: Using different ABI methods, we observed a prevalence of PAD ranging from 7.8% to 28%, and a prevalence of CA between 11% and 18% among patients with type 2 diabetes mellitus at a public hospital in Peru. Further research is necessary to verify if the new ABI calculation methods provide improved accuracy in predicting complications.