Increased interleukin 1β levels in the subacromial fluid in diabetic patients with rotator cuff lesions compared with nondiabetic patients

Background: Diabetic patients have a high prevalence of shoulder pain and stiffness. Interleukin (IL) 1β was reportedly correlated with shoulder stiffness and decreased shoulder function. We retrospectively compared the expression of IL-1β in the subacromial synovial fluid between diabetic and nondiabetic patients with rotator cuff tearing. Materials and methods: We enrolled 68 patients with rotator cuff tearing (23 diabetic patients and 45 nondiabetic patients). The preoperative sum of range-of-motion deficit (SROMD), Constant score, and visual analog scale (VAS) score were obtained. Intraoperatively, subacromial synovial fluid was collected for the IL-1β level measurement. Comparisons of IL-1β levels, Constant scores, SROMD, and VAS scores between diabetic and nondiabetic patients were analyzed with the Mann-Whitney U test. Result: Diabetic patients with rotator cuff tearing had significantly increased subacromial IL-1β levels (P=.048), SROMD (P <.001) and VAS scores (P =.022) and lower Constant scores (P <.001) than nondiabetic patients. The IL-1β levels in the subacromial fluid were significantly correlated with the Constant score (r = -0.477, P <.001), VAS score (r = 0.698, P <.001), and SROMD (r = 0.293, P=.015) in all patients. Conclusion: The elevated IL-1β levels in the subacromial fluid of patients with diabetes may explain the likelihood of pain and shoulder stiffness developing in these patients. We suggest more aggressive treatment for rotator cuff lesions in diabetic patients.