Assessment of hypothalamic-pituitary-adrenal axis function after corticosteroid therapy in inflammatory bowel disease

In patients with inflammatory bowel disease (IBD), little is known about the effect of long term corticosteroid therapy (CT) on the hypothalamic-pituitary-adrenal (HPA) axis function. Our aim was to assess HPA axis function in IBD, before the end of CT, during the tapering phase.

HPA axis function was assessed with cortisol (ng/ml) measurement before (T0) (normal > 100) and 60 min (normal > 210) after 0.25 mg tetracosactide (Synacthen immédiat) injection (T60) in 55 consecutive cases of IBD attacks. Abnormal response was defined as a T60 <210. The attacks were separated into two groups according to the result of the Synacthen test (ST).

In all, 36 of 55 ST were abnormal. The time for recovery normal HPA axis function was 7.2+/-1.3 months. Duration of disease since onset, past history of surgical or immunosuppressive treatment, severity and extension of the attack, need for surgical or immunosuppressive treatment, total cumulative and mean daily corticosteroid dose, total duration of CT, and steroid dose at the time of ST were not significantly different in the two groups. In multivariate analysis a past history of CT was predictive of abnormal ST (OR = 8.4, 95% CI = 2.2-31.5, p = 0.0009). Among patients with a past history of CT, the time (months) elapsed between the last course of CT was significantly longer in those with normal ST than in those with abnormal ST (45.5+/-13.5 vs 15.4+/-6.0; p = 0.02), and in multivariate analysis a duration free of CT < 15 months was predictive of abnormal ST (OR = 15.00, CI = 1.23-183.00, p = 0.03).

In all, 65% of the ST were abnormal. These results suggest that ST should be performed before corticosteroid withdrawal, especially in patients with recent past history of CT.