Tenocytes do not just lie in a vacuum: the role of lipids, glycemic metabolism and thyroid hormones in tendinopathy and tendon rupture. A narrative review

Abstract

Purpose: Tendinopathies and tendon ruptures are a common cause of pain and disabilities. The pathogenesis is considered multifactorial, and currently described as the failed healing response. Traditionally, tendon injuries have been mostly referred to age, overuse or mechanical factors. Recently, some authors have focused their attention on the influence of metabolic diseases and hormones on tendon homeostasis, opening new perspectives. There are even more studies which show how systemic condition and pathologies are able to influence the proliferation of tenocytes, the synthesis of extracellular matrix proteins, and the organization and properties of the extra cellular matrix of the tendons. Methods: In this article, we reviewed the current knowledge about the influence of lipids, glucose and thyroid hormones on the pathogenesis of tendinopathy. Results: Beside the traditional extrinsic and mechanical risk factors, this article showed the importance of metabolism and hormones of tendon health, reinforcing the idea of their great influence on the pathogenesis of tendinopathy. Current literature indicates that hypercholesterolemia, obesity, diabetes mellitus and hypothyroidism are all risk factors for tendinopathies and tendon ruptures. Conclusions: The precise role of each predisposing factor remains incompletely understood, and further epidemiology and laboratory studies should be performed to establish the strength of the association with tendon pathologies and their pathogenetic mechanism. Keywords: inertial measurement unit; acceleration; max speed; metrics; team sports.