We plan to enroll 150 patients. Patients will be grouped into patients with PAD and patients without PAD. We then compare them in the following parameters: clinical data, laboratory data, survival and other outcome data. Two-sample student's t-tests will be used for the comparisons of continuous variables. Chi-square test will be used to detect the difference between categorical variables. The difference is considered statistically significant if P < 0.05. All statistics works were analyzed using the SPSS 17.0 software (Chicago, IL, USA), R software (Gimc packages).