Etiologic factors associated with symptomatic Achilles tendinopathy

Background: The purpose of this study was to determine if a statistical association exists between Achilles tendinopathy (also referred to as tendinosis) and obesity, diabetes mellitus, hypertension, the supplemental use of estrogen, and exposure to local or systemic steroids. Methods: From July, 1997, to February, 2003, 82 patients with a diagnosis of Achilles tendinopathy were identified. The diagnosis of Achilles tendinopathy was confirmed by a review of medical records, radiographs, and MRI. There were 44 women and 38 men with an average age of 50 (range 27 to 77) years. For the parameters of obesity, hypertension, diabetes, steroid exposure, and the use of estrogen compounds, all patients were analyzed both cumulatively and stratified into subgroups by gender and age. Chi-square 2 x 2 tables were used to compare the observed prevalence of the parameters in patients with Achilles tendinopathy to the expected prevalence of these disorders and exposures in the population at large. Results: Cumulatively, 98% percent (43 of 44 women; 29 of 38 men) had hypertension, diabetes, obesity, and steroid or estrogen exposure. Seventy-six percent of men (29) had hypertension, diabetes, and obesity, or steroid exposure. Sixty-eight percent of women (15 of 22) had a history of hormone replacement therapy and 44% (8 of 15) had a positive history for use of oral contraceptives. When compared with published national data using Chi-square analysis, the association between tendinopathy and hormone replacement therapy and oral contraceptives was found to be statistically significant with p-values of 0.01 and 0.001, respectively. For both women and men, obesity was statistically associated with Achilles tendinopathy with p-values of 0.025 and. 001, respectively. Hypertension was statistically associated with Achilles tendinopathy only for women. Diabetes mellitus and Achilles tendinopathy were found to have a statistical association only for men younger than 44 years old Conclusions: Obesity, hypertension, and steroids have as their end-organ effect a diminution of local microvascularity. The significant correlation of these factors with Achilles tendinopathy suggests the importance of their effect on microvascularity in the development of Achilles tendinopathy.