Prognostic Factors (Diabetes)
Moderate evidence suggests that patients with diabetes will have higher re-tear rates and poorer quality of life and patient reported outcome scores after rotator cuff repair.

Rationale
One high quality study (Kim 2018) demonstrated higher rotator cuff repair re-tears in patients with diabetes.  One high quality study (Chung 2012) demonstrated poorer patient reported outcome scores using the HRQOL physical health-related quality of life in patients with diabetes.

There are no undue risks or harms when performing rotator cuff repair on patient who have diabetes, other than perioperative complications related to having diabetes (e.g. adhesive capsulitis).  Patients should be counseled that patient reported outcomes are poorer compared to patients without diabetes.

Future Research
Future research should determine if adequate control of diabetes will improve patient reported outcomes and improve healing after rotator cuff repair.