Endocrine Abstracts

Detailed information on adrenal function in autoimmune Type 1 diabetes with onset in adults is still lacking. This work aimed at gathering own data on adrenal response to low-dose (1 μg) ACTH in blood and saliva.

Twenty-three diabetics were investigated; age 44±10 yrs (mean ± S.D.), age at diagnosis 28.5±10 yr, disease duration 15±8 yr, BMI 24.5±2.7 kg/cm², HbA1c 7.2±1.2%.

The control group had 16 healthy subjects; age 27±6 yr, BMI 21.7±2.3 kg/cm². Neither group showed any clinical signs of adrenal disorders.

The study was approved by the Ethical Committee.

Adrenal reserve was tested by low dose ACTH test. Fasting blood and saliva were collected between 8–9 a.m. Blood and salivary cortisol were determined at times 0, 20, 30, 40, 60 min, ACTH and adrenal autoantibodies at 0′ only.

Maximum stimulated value in serum above 500 nmol/l was reached in 15 out of 23 patients (65.2%), normal-responders, NR. This cut off value was not reached in 8 patients (34.8%), low-reponders, LR. The results were compared with the control group (C).

NR: Basal and stimulated serum cortisol levels did not differ significantly from those in controls, while salivary cortisol in this subgroup was significantly lower at 20th min and 30th min, P<0.05.

LR: Both basal and stimulated serum cortisol, as well as salivary cortisol were significantly lower than C, P<0.001 for all times.

LR did not differ from NR in either average insulin doses, or HbA1c or basal ACTH value. Adrenal cortex autoantibodies were negative in all subjects.

In conclusion, surprisingly, in 34.8% of young adults-onset with diabetes mellitus Type 1 without signs of adrenal autoimmunity, in 1 μg ACTH test serum cortisol levels corresponding to subclinical hypocorticalism were found. Investigation of salivary cortisol brought additional information, which should be further evaluated.

The study was supported by grant IGAMZCR No.NR/9154-3.