Cortisol hyporesponsiveness to the low dose ACTH test is a frequent finding in a pediatric population with type 1 diabetes mellitus.

INTRODUCTION

In adults with type 1 diabetes mellitus (DM1), a 25% of risk of hypocortisolism has been found through a low dose ACTH test with negative antibodies suggesting other causes of hypothalamic-pituitary-adrenal axis dysfunction.

AIM

To evaluate adrenal function in pediatric patients with DM1 and correlate the results with the frequency of hypoglycemia and metabolic control.

METHODS

Sixty-nine patients were enrolled, age 12.3 (5.7-18.1); 50 boys and 19 girls. A 20% had additional autoimmune diseases. Mean hemoglobin A1c (HbA1c) was 8.1% and insulin dose was 1.14 U/kg/d. After an overnight fast, a low dose ACTH test (1 µg) was performed. Basal and stimulated cortisol concentrations, DHEAS, and plasma renin activity (PRA) were measured. A cortisol response post-ACTH below 18 µg/dL was considered abnormal.

RESULTS

58% of the tested patients had an abnormal response to ACTH test. These patients also had lower DHEAS concentrations, but were not different in diabetes duration, HbA1C, severe hypoglycemia, ACTH, or PRA concentrations compared to those who had a normal cortisol post-ACTH. One patient out of 59, had a positive anti-21-hydroxylase antibody (21OHA) and presented a poor response to ACTH.

CONCLUSIONS

We found a significant proportion of our patients having a subnormal cortisol response independent of the presence of anti-adrenal cell antibodies. We did not find a correlation with metabolic control, probably due to the good metabolic control of this group. The absence of 21OHA does not rule out subclinical hypocortisolism in this population. Our results suggest testing adrenal function in children with DM1.