Effectiveness of Propionyl-L-Carnitine Supplementation on Exercise Performance in Intermittent Claudication: A Systematic Review

Lower extremity peripheral artery disease (PAD) affects 8.5 million people in the United States and more than 200 million worldwide. The most significant risk factors for PAD are hyperlipidemia, hypertension, diabetes mellitus, chronic kidney disease, and smoking. Intermittent claudication (IC) is the predominant symptom of PAD, but only about 10% of patients with PAD experience IC and are associated with reduced exercise capacity. The pathophysiology of IC is characterized by different degrees of stenosis and obstruction, with a progressive reduction in distal perfusion pressure and blood flow. Supervised exercise therapy is recommended as the initial therapy for IC, but the recommendations for medical treatment of IC vary significantly. Propionyl L-carnitine is an acyl derivative of levocarnitine (L-carnitine) and is indicated for patients with the peripheral arterial occlusive disease. It corrects secondary muscle carnitine deficiency in patients with PAD, significantly improving the walking capacity; its levels increase in serum and muscle. Thus, it is suggested to enhance blood flow and oxygen supply to the muscle tissue via improved endothelial function, thereby reducing hypoxia-induced cellular and biochemical disruptions.