Metabolic syndrome associated to non-inflammatory Achilles enthesopathy

Enthesopathies are frequently found in rheumatic inflammatory diseases, but can be observed also in absence of systemic inflammation. Aging, overuse, and microtraumas can be responsible for enthesis-degenerative phenomena. Despite that Achilles enthesis is the more frequently affected, no systematic study on the risk factors associated to this enthesopathy has been yet performed. The aim of this paper was to assess whether the metabolic syndrome could be associated to entheseal lesions. Forty-five subjects with symptomatic non-inflammatory Achilles enthesopathy were compared to 45 asymptomatic controls. An ultrasound study of the Achilles enthesis was carried out, and the presence/absence of lesions (morphologic abnormalities, calcific deposits, enthesophytes, cortical abnormalities, and adjacent bursitis) was assessed. On the basis of history, comorbidities (osteoarthritis, diabetes, and hypertension) were recorded. In each subject, body mass index (BMI), glucose, total, and HDL cholesterol were also evaluated. All symptomatic subjects showed at ultrasound evaluation at least one structural entheseal alteration; pathologic features in asymptomatic subjects were found in 6/45 (13.3 \%) of cases. Higher values of BMI and glucose were found in subjects with symptomatic enthesopathy. At multiple logistic regression analysis, the presence of high values of BMI and glucose was related to a higher probability to detect entheseal lesions. Metabolic syndrome and overweight may have a role in the pathogenesis of Achilles enthesopathy due to their synergistic worsening effect on other pathogenetic factors of tendon degeneration, such age and overuse. Therefore, subjects with metabolic syndrome practicing sports and other activities stressing the Achilles tendon should receive advice for more frequent controls.