Endocrine Abstracts

Introduction: Maintenance immunosuppressive regimens after renal transplantation (RTx) most often include prednisolone which may induce secondary adrenal insufficiency. Adrenal insufficiency is a potentially life-threatening side effect to glucocorticoid treatment due to the risk of acute adrenal crisis. We aimed to investigate the prevalence of prednisolone-induced adrenal insufficiency in RTx patients receiving long-term low-dose prednisolone treatment.

Material and methods: In a case-control study, 30 RTx patients (17 males, mean age 50.4 S.D. 13.1) treated with prednisolone and 30 dialysis patients (19 males, mean age 59 S.D. 13.1) not treated with prednisolone underwent testing for adrenal insufficiency by a 250 μg Synacthen test. RTx patients were transplanted at least one year before enrollment and receiving continuous treatment with either 5 or 7.5 mg prednisolone/day for at least 6 months before the study. Fifteen peritoneal dialysis (CAPD) patients and 15 haemodialysis patients comprised the control group. The Synacthen test was performed fasting in the morning. Transplanted patients paused prednisolone for 48 hours before the test and all patients (n=7) paused locally applied glucocorticoids for as long as possible. Normal adrenal function was defined as P-cortisol ≥420 nmol/l 30 min after Synacthen injection, as validated for the local Roche Elecsys^® Cortisol II assay.

Results: Of the RTx patients, 13 (43%; CI: 27–61%) had an insufficient response to the Synacthen test compared to one patient in the control group (3%; CI: 0.6–17%) (P=0.0004). Insufficient response in RTx patients was seen in 9/25 and 4/5 patients treated with 5 and 7.5 mg prednisolone/day respectively. For the RTx group both baseline P-cortisol and 30 min P-cortisol was generally lower compared to dialysis patients with a mean of 265 nmol/l (S.D. 100) vs 350 nmol/l (S.D. 69) for baseline P-cortisol and mean of 411 nmol/l (S.D. 153) vs 623 nmol/l (S.D. 99) nmol/l for 30 min P-cortisol (P <0.0001). No correlation was found between duration of treatment and 30 min P-cortisol (P=0.68, r=0.08). Of the seven patients treated with local glucocorticoids, 3/4 were insufficient in the transplant group and 1/3 in the control group.

Conclusion: We found a high prevalence of adrenal insufficiency among RTx patients receiving low-dose prednisolone treatment. We therefore advocate for an increased clinical alertness and a discussion of how to manage the risk of adrenal insufficiency in patients with a kidney graft.