Tendon pathology is a general term used to describe a group of musculoskeletal conditions related to tendons and surrounding structures. There is only limited evidence available regarding the exact aetiology and natural history of tendon pathology. In hypercholesterolaemia environments, lipids could accumulate within the extracellular matrix of the tendon and thus affect the mechanical properties of the tendon. Current evidence suggested that hypercholesterolaemia was an important risk factor in the development and progression of tendon pathology. The severity of hypercholesterolaemia was correlated with the severity of tendon pathology. The translational potential of this article: Hypercholesterolaemia lead to the structural, inflammatory and mechanical changes in tendons, which predispose hypercholesterolaemia patients to a greater risk of tendon pathology. Measurements of serum cholesterol are suggested to be performed in patients presenting with tendon pathology. The strict control of hypercholesterolaemia would mitigate the development and progression of tendon pathology.

Background

Tendon pathology is a general term used to describe a group of musculoskeletal conditions related to tendons and surrounding structures [1]. Tendon pathology could be broadly classified into traumatic, degenerative and overuse-related tendinopathy. Rotator cuff tears, Achilles tendinopathy, Achilles tendon rupture, and tennis elbow are common examples of these conditions. Tendon xanthoma is a special type of tendon pathology. There is only limited evidence available regarding the exact aetiology and natural history of tendon pathology [2]. Possible etiologic factors may include aging, overuse, trauma, biomechanical abnormalities, glucocorticoids use, quinolone antibiotics use, microcirculation, and metabolic disorders [3]. Because the pathogenesis of tendon pathology is so complex and involves a variety of biological phenomena, there is no consistently effective treatment available for tendon pathology. Clinically available treatment options may include nonsteroid antiinflammatory drug, corticosteroid injection, platelet-rich plasma injection, low-energy laser stimulation, extracorporeal shock wave therapy, and surgical interventions [3]. Although these approaches may relieve the symptoms in the short term, there is presently limited scientific evidence supporting these therapies and their efficacy. Hypercholesterolaemia is a systemic metabolic disease characterised by abnormally high levels of cholesterol in the blood. Hypercholesterolaemia is defined as elevated amounts of total cholesterol (
۲۴۰ mg/dL) in the blood. Hypercholesterolaemia has well-known impact on vascular systems and internal organs [4]. Recently, the influence of hypercholesterolaemia on musculoskeletal system has attracted much attention. In hypercholesterolaemia environments, lipids could accumulate within the extracellular matrix of the tendon and thus affect the mechanical properties of the tendon [5,6]. Several studies have explored the relationship between hypercholesterolaemia and tendon pathology. Animal studies indicated that high levels of cholesterol would lead to poorer mechanical properties and adversely affect tendon healing after surgical repair [7e9], while clinical studies showed inconsistent results on the association between hypercholesterolaemia and tendon pathology [10,11]. Better understanding of the relationship between hypercholesterolaemia and tendon pathology, the impact of hypercholesterolaemia on tendon structure and healing as well as the mechanisms of hypercholesterolaemia in the development and progression of tendon pathology would aid the development of an effective treatment strategy. The purpose of this review was (1) to summarise the association between hypercholesterolaemia and tendon pathology, (2) to discuss the pathogenic mechanisms in causing and exacerbating tendon pathology and (3) to explore the potential treatment strategies for tendon pathology in hypercholesterolaemia patients.