**17. Lower extremity peripheral artery diseases and cholesterol**

A common cause of lower extremity peripheral artery disease is atherosclerosis. It is common in men who have cigarette use at a young age. Diabetes and smoking are the most common causes of amputation in peripheral artery diseases. In the atherosclerotic process, progressive narrowing of the vessel wall occurs. Clinical signs are observed in the later stages of the disease. Clinical disease severity is determined by Fontaine and Rutherford classifications. There are studies that argue that the ankle brachial index (ABI) used in lower extremity diseases should be used as a risk factor for coronary artery disease. When ABI is above 0.9, it is considered normal but below 0.40 is considered as serious disease.

The 2017 ESC guidelines for peripheral arterial disease recommended LDL cholesterol lowering to 70 mg/dL or 50% reduction in LDL levels in patients with an initial LDL level of 70–135 mg/dL. Studies in lower extremity arterial disease patients have shown that statin therapy decreases all-cause mortality and cardiovascular mortality.
