Statistical analysis

Categorical data were presented as absolute number and percentages; continuous variables were expressed as mean±sd or median (interquartile range). Comparison of continuous variables was carried out by the t-test or univariate ANOVA. For categorical parameters, Fisher's exact test or Pearson's Chi-squared test was employed. Correlation was assessed by use of Pearson's correlation coefficient. In order to describe the influence potential confounders have on lower extremity plaque presence as a binary dependent variable, a logistic regression model was employed. All statistical analyses were performed with SPSS Statistics version 23.0 (IBM, Armonk, NY, USA).