Insertional Calcific Tendinopathy of the Achilles Tendon and Dysmetabolic Diseases: An Epidemiological Survey

Objective: This study reports the incidence of insertional calcific tendinopathy (ICT) of the Achilles tendon in the general population and the percentage of symptomatic patients. The secondary aim is to ascertain whether ICT is associated with diabetes mellitus, thyroid disorders, obesity, and hypercholesterolemia. We hypothesized that metabolic diseases increase the risk of ICT of the Achilles tendon. Design: Prospective observational study (level III study). Setting: Orthopedic Outpatients Clinic and Emergency Department of Tor Vergata University Hospital, Rome, Italy. Participants: Four hundred thirty-three subjects who met the inclusion criteria. Intervention Methods: We collected the plain radiographs of the foot and ankle of patients who attended the hospital. Personal data were recorded [age, sex, and body mass index (BMI)], and comorbidities investigated (diabetes mellitus, hypothyroidism, hyperthyroidism, obesity, and hypercholesterolemia). Multivariate regression analyses were performed to study the predictors of the occurrence of Achilles ICT. Results: A total of 101 patients (23.3%) showed radiographic evidence of ICT, and 3% (13 patients) were symptomatic. Age [odds ratio (OR) 1.05], diabetes (OR 2.95), hypercholesterolemia (OR 2.27), and hypothyroidism (OR 3.32) were significantly associated with the presence of ICT of the Achilles tendon. Independent predictors of ICT were age, diabetes, hypercholesterolemia, and hypothyroidism. A BMI >30 was associated with a higher incidence of calcifications, and patients with 2 or more comorbidities had more than 10 times higher risk to develop ICT. Conclusion: Insertional calcific tendinopathy of the Achilles tendon is common, but few patients are symptomatic. The incidence of ICT increases with age and is significantly higher in patients with diabetes mellitus and hypothyroidism.