Metabolic and endocrinal effects of epidural glucocorticoid injections

Epidural steroid injections are an integral part of nonsurgical management of radicular pain from lumbar spine disorders. We studied the effect of dexamethasone 8 mg epidural injections on the hypothalamic-pituitary-adrenal axis and serum glucose control of Asian patients.

18 patients were recruited: six diabetics and 12 non-diabetics. Each patient received a total of dexamethasone 8 mg mixed with a local anaesthetic solution of lignocaine or bupivacaine, delivered into the epidural space. Levels of plasma cortisol, adrenocorticotropic hormone (ACTH), serum glucose after an overnight fast and two-hour postprandial glucose, as well as weight, body mass index, blood pressure and heart rate were measured within one week prior to the procedure (baseline) and at one, seven and 21 days after the procedure.

Median fasting blood glucose levels were significantly higher on post-procedure Day 1 than at baseline. However, there was no significant change in median two-hour postprandial blood glucose from baseline levels. At seven and 21 days, there was no significant difference in fasting or two-hour postprandial glucose levels. Both ACTH and serum cortisol were significantly reduced on Day 1 compared to baseline in all patients. There was no significant difference in ACTH and serum cortisol levels from baseline at Days 7 and 21.

Our study shows that epidural steroid injections with dexamethasone have a real, albeit limited, side effect on glucose and cortisol homeostasis in an Asian population presenting with lower back pain or sciatica.