Effect of repeated transforaminal epidural low-dose dexamethasone injections on glucose profiles of diabetic and non-diabetic patients with low back pain.

Abstract

We aimed to investigate the effect of repeated transforaminal epidural low-dose dexamethasone injections on glucose profiles and pituitary-adrenal axis functions of diabetic and non-diabetic patients with low back pain. A total of 28 patients (ten diabetic [DM group] and 18 non-diabetic patients [non-DM group]) with low back pain were followed-up. Transforaminal epidural low-dose dexamethasone (1.65mg) injections were repeated every 7-14days for 8weeks. Fasting blood sugar (FBS), hemoglobin A1c (HbA1c), morning plasma adrenocorticotropin (ACTH), and cortisol levels were measured at baseline and during the 8-week follow-up period. There were no significant changes in FBS and HbA1c levels between baseline and 8-week follow-up period in both DM and non-DM groups (difference in FBS [95% confidence Interval, CI]: -0.6mg/dL [-6.4, 5.1], p = 0.83 in the non-DM group, -0.2mg/dL [-26.2, 25.8], p = 0.99 in the DM group; difference in HbA1c [95% CI] -0.02% [-0.1, 0.1], p = 0.69 in the non-DM group, 0.04% [-0.3, 0.4], p = 0.79 in the DM group). There were no significant longitudinal changes in ACTH and cortisol levels (ACTH, p = 0.38 [baseline vs. 8week], p = 0.58 [non-DM vs. DM]; cortisol, p = 0.52 [baseline vs. 8week], p = 0.90 [non-DM vs. DM]). Repeated transforaminal epidural low-dose dexamethasone injections provided no significant elevations in blood glucose or suppression of the pituitary-adrenal axis for two months from the first injection in both diabetic and non-diabetic patients. Our results indicate the intermediate-term safety of repeated transforaminal epidural low-dose dexamethasone injections with regard to the effect on glucose profile and pituitary-adrenal axis functions.