Adrenal dysfunction in asymptomatic patients with adrenocortical autoantibodies.

Autoantibodies to the adrenal cortex (AA) were sought by indirect immunofluorescence using unfixed human adrenal tissue in 1675 patients with insulin-dependent diabetes (IDD), 2032 relatives of patients with IDD, and 2543 normal subjects. The frequencies of AA were significantly greater in patients with IDD (1.8%) and their relatives (1.4%) than in normal subjects (0.6%; P less than 0.013). Women more frequently had AA than men (P less than 0.011). There were no differences in the frequencies of AA between caucasoid and black individuals in all three patient groups. Patients with AA had higher frequencies of thyroid microsomal and gastric parietal cell autoantibodies than age-, sex-, and race-matched normal subjects (P less than 0.01). Adrenal function was studied in 30 asymptomatic patients (13 with AA, including 5 with IDD, and 17 subjects with no AA, including 8 with IDD). The mean plasma levels of ACTH at 0600 and 2000 h were significantly higher in those with AA than in matched subjects with no AA (P less than 0.01). The mean PRA levels (both recumbent and upright) were also significantly higher in those with AA than in subjects without AA (P less than 0.01). However, serum cortisol and aldosterone concentrations or 24-h urinary cortisol and aldosterone excretion were no different between the groups. These patients, therefore, appear to have compensated adrenal hypofunction, with the compensation maintained by increased ACTH and renin secretion. Whether these patients will remain in this compensated state of adrenal dysfunction or whether they will develop overt adrenal insufficiency requires longer follow-up.