Background: Corticosteroid injections are used to treat a variety of orthopedic conditions with the goal of decreasing
pain and inflammation. Administration of systemic or local corticosteroids risks temporarily increasing blood glucose
levels, especially diabetic patients. The purpose of this study is to quantify the effects of corticosteroid injections on
blood glucose levels in diabetic patients with shoulder pathology.
Methods: Diabetic patients who regularly monitored their blood glucose levels and were indicated for a subacromial
corticosteroid injection were included in this prospective investigation. The typical normal morning fasting glucose
and most recent hemoglobin A1c level was recorded for each patient. After injection, patients were contacted daily to
confirm their fasting morning glucose level for 10 days post-injection.
Results: Seventeen consecutive patients were enrolled. Patients with hemoglobin A1c of <7% had an average rise
in blood glucose of 38 mg/dL compared to 98 mg/dL in the poorly controlled group after injection (P<0.001). Wellcontrolled
patients’ glucose levels returned to near baseline levels around post-injection day 8, while poorly controlled
patients levels remained elevated. Similarly, insulin-dependent diabetic patients had an average increase in fasting
glucose level of 99 mg/dL versus 50 mg/dL in non-insulin-dependent diabetic patients (P<0.001).
Conclusion: After corticosteroid injection, patients with well-controlled diabetes experience smaller elevations and
faster return to baseline glucose levels than patients with poor control. Insulin dependent diabetics experienced similar
findings as patients with poor control. Future studies are needed to evaluate dosing to optimize the risks of blood
glucose elevation while maintaining therapeutic benefit.