ESPE Abstracts

Background: Primary adrenocortical insufficiency (Addison’s disease) is reported to be five more times frequent in adult patients with type 1 diabetes mellitus (T1DM) than in the general population with a multifactorial aetiology involving autoimmune, inflammatory and metabolic mediators. Recent data indicate that more than half of children with T1DM show subnormal cortisol response. Subnormal cortisol response may impair the metabolic control of patients with T1DM as they are more susceptible to recurrent hypoglycemia.

Objective: To evaluate adrenal function in pediatric patients with T1DM and correlate these results with demographic and anthropometric data as well as metabolic control, presence of severe or recurrent hypoglycemia, other autoimmune diseases and the presence of autoantibodies against adrenal cells.

Methods: Patients with T1DM, aged >6 years, with no history of use of corticosteroids or immunosuppressive drugs were assessed with a low-dose Synacthen test (500 ng per 1.73 m² of body surface). The test was performed three hours after the insertion of a vein catheter and blood samples for serum cortisol measurements were collected at time intervals 0, 5, 10, 15, 20, 25, 30, 35, 40 and 45 min after Synacthen administration. A cortisol response below 18.125 μg/dl or an elevation below 7.25 μg/dl from baseline value was considered abnormal.

Results: Thirty-five patients (19 boys and 16 girls) with T1DM and a mean age of 13.26±4.10 years (range: 6–19 years) were finally analyzed. In 30 of them a history of recurrent hypoglycemia was recorded. Mean glycosylated hemoglobin (HbA1C) was 7.60±1.19 and duration of diabetes was 5.46±3.58 years widely ranging from 1 to 15 years. In 10 patients (28.57%) a subnormal cortisol response was recorded with predominance in male patients (9 out of 10, P=0.01). No statistical significant difference was observed between patients with normal and sub-normal cortisol response regarding HbA1c levels, age, z-scores of anthropometric parameters (weight, height, BMI), or the presence of other autoimmune disease. Years since diagnosis were lower in patients with normal compared to those with subnormal response to Synacthen test with a difference that was approaching significance (4.76±3.31 vs 7.20±3.82, P=0.07). No patient in our study showed positivity to adrenal autoantibodies.

Conclusions: Approximately one-third of pediatric patients with T1DM showed subnormal response in low-dose Synacthen test despite the absence of autoantibodies against adrenals and this should be taken into consideration especially when evaluating T1DM patients with recurrent hypoglycemia.