Whereas the systemic effects of glucocorticoid therapy have been extensively reported, little is known about those of local glucocorticoid injections. The objective of this study was to look for systemic effects of local glucocorticoid injections at two sites in diabetic and non-diabetic patients.

We studied 29 patients (18 women and 11 men with an age range of 18-86years). The injection site was the epidural space in 18 patients (4 with and 14 without diabetes) with disk-related sciatica and the shoulder in 11 patients (8 with and 3 without diabetes) with frozen shoulder. Each patient was given three injections of 1.5ml cortivazol (5.625mg of cortivazol or about 85mg prednisone-equivalent per injection and about 250mg prednisone-equivalent in all), at 3-day intervals. Of the 12 patients with diabetes, 2 were on insulin therapy. At baseline and at the post-treatment visits 1, 7, and 21days after the third injection, the following tests were done: plasma cortisol and ACTH at 8 am, urinary free cortisol excretion in 24hours, fasting and postprandial blood glucose, serum cholesterol and triglycerides, and serum sodium and potassium. Blood pressure was measured at each visit.

Mean systolic blood pressure increased significantly between baseline (123±10mmHg) and the first two post-treatment visits (day 1, 127±9mmHg; and day 7, 128±10mmHg) but returned to baseline values by the third post-treatment visit (day 21). Mean postprandial blood glucose was significantly higher at the day 1 post-treatment visit (10.1±5.4mmol/l) than at baseline (7.5±2.9mmol/l). At the day 7 post-treatment visit, blood glucose remained significantly elevated compared to baseline in the 12 diabetic patients (13.9±4.8mmol/l versus 9.4±3.3mmol/l at baseline). In both the overall population and the various subgroups, plasma cortisol and ACTH and urinary free cortisol were markedly reduced at the day 1 and day 7 post-treatment visits, compared to baseline. At the day 21 visit, these variables were diminished in the group given epidural injections, whereas plasma cortisol and ACTH were normal in the group treated intra-articularly. No significant variations were noted for fasting blood glucose or for serum levels of cholesterol, triglycerides, sodium, and potassium.

The administration of three local cortivazol injections was followed by suppression of the corticotropic axis that persisted beyond 21days after epidural injection and recovered more rapidly after intra-articular injection. Systolic blood pressure increased transiently. Elevations in postprandial glucose levels lasted longer in diabetic than non-diabetic patients.