Alterations of tendons in patients with diabetes mellitus: a systematic review

Aims To perform a systematic review of observational studies which analyse tendon alterations in patients with diabetes mellitus compared with healthy individuals. Methods Data collection was performed, with no language restriction, using the databases of PubMed/Medline, BIREME, CINAHL, LILACS and Cochrane, as well as the references found in these studies. Three reviewers performed independent extractions of articles. Subsequently, these reviewers analysed the articles, focusing on their methodological quality, using the appropriate scale to evaluate observational studies from the Agency for Healthcare Research and Quality. Results Six articles were included in the analysis. Of these, four had used ultrasonographic diagnostics, one computed tomography and one magnetic resonance imaging. The patient pool comprised 396 individuals. All the articles evaluated tendon thickness and presented heterogeneous results. Two articles stated thickening or increased volume of the tendons in diabetic people, one article did not report any alteration, the fourth failed to determine any alterations and the fifth showed thinning of the tendons. The arrangement of collagen fibrils and the presence of calcification were analysed in only one article (n = 80), showing that 88.10% (n = 68) of individuals with diabetes presented disorientation of collagen fibril arrangement, while only 10% (n = 1) of healthy individuals presented this condition. Regarding tendon calcification, the article showed diabetic individuals with higher values than healthy individuals. Conclusions All the articles indicated some relation between diabetes mellitus and tendon alterations in human beings, but due to methodological drawbacks, this association could not be sustained.