SPP1 and peripheral arterial disease: The study showed that the level of osteoprotegerin (OPG) and osteopontin (OPN) in patients with PAD compared with the control group corresponded to (OPG) 9.89 ± 2.85 ng/mL vs. 3.47 ± 1.95 ng/mL, and (OPN) 79.99 ± 38.29 ng/mL vs. 35.21 ± 14.84 ng/mL.