Correlation between ankle-brachial index and thermography measurements in patients with peripheral arterial disease

To correlate the ankle-brachial index and photographic thermography findings in patients with peripheral arterial disease.

Photographic thermography was performed at the foot level, and ankle-brachial index was measured in 72 lower limbs of 53 patients with peripheral arterial disease who were divided into calcified artery, patients with an ankle-brachial index greater than 1.4; and non-calcified artery classified as asymptomatic, mild, moderate, and severe on the basis of peripheral arterial disease severity. Fisher's exact test was used for categorical data, and Wilcoxon test was used for numerical data.

Spearman's correlation analysis showed a strong correlation (R = 0.7) between the ankle-brachial index and the mean plantar temperature in patients without lower limb artery calcification. Linear regression yielded the predictor equation Y = 3.296 × X + 29.75, wherein ankle-brachial index (X) can be predicted on the basis of temperature values. Spearman's correlation test showed no significance (p = 0.2174) in patients with arterial calcification. Kruskal-Wallis test with post hoc analysis using Dunn's test for multiple comparisons showed that the mean plantar temperature was lower in patients with arterial calcification.

Photographic thermography findings show a strong correlation with ankle-brachial index in patients with non-calcified arteries.