Comparison of 1-micro g and 250-micro g corticotropin stimulation tests for the evaluation of adrenal function in patients with acquired immunodeficiency syndrome.

Many patients with acquired immunodeficiency syndrome (AIDS) have symptoms suggestive of adrenal insufficiency, but a normal 250- micro g corticotropin (ACTH) stimulation test. We compared the results of 1- micro g and standard 250- micro g ACTH stimulation tests in patients with AIDS. Each patient was studied on 2 separate days. On day 1, 1 micro g ACTH was given intravenously at 8 am after an overnight fast and serum cortisol levels were measured at baseline, and 30 and 60 minutes after ACTH infusion. On day 2, the procedure was repeated with 250- micro g ACTH. An absolute peak cortisol value of > 18 micro g/dL and an increment of 7 micro g/dL or more from baseline constituted a normal response. Among 31 patients, 16 (52%) had discrepant results: 14 (45%) had subnormal responses to 1 micro g ACTH but normal responses to 250 micro g ACTH (group 1); 2 (6%) had normal responses to 1 micro g but subnormal responses to 250 micro g (group 2) ACTH; 6 patients (19%) had concordant abnormal responses (group 3); and 9 (30%) had concordant normal responses (group 4). Eight patients of group 1 underwent a confirmatory insulin tolerance test (ITT); 4 of these patients had abnormal responses to ITT. Kappa statistic and McNemar's test were used to evaluate the data. A kappa statistic value of 0.095 and a P value less than.003 for the McNemar test indicate only random level of agreement and significant differences in the probability of positive result between the 2 ACTH tests. We conclude that discrepancies between the 1- micro g and the 250- micro g ACTH stimulation tests are common in patients with AIDS, with the likelihood of agreement with the "gold standard" ITT of only 50% for each test in our sample of patients. Larger studies are needed to further evaluate the use of these tests in patients with AIDS.

Twenty-four-hour urinary free cortisol in patients with acquired immunodeficiency syndrome.

Many patients with acquired immune deficiency syndrome (AIDS) have symptoms consistent with adrenal insufficiency, but only a small subset of these patients meet criteria for adrenal insufficiency during a short corticotropin (ACTH) stimulation test. We hypothesized that patients with AIDS and symptoms of adrenal insufficiency who produce normal amounts of cortisol in response to administration of 0.25 mg cosyntropin may nevertheless produce lower amounts of cortisol in a course of 24 hours than comparably sick AIDS patients without symptoms of adrenal insufficiency or comparably sick patients without AIDS. We studied four groups of male patients: AIDS patients with symptoms suggestive of adrenal insufficiency but with a normal response to cosyntropin (group I), AIDS patients without symptoms suggestive of adrenal insufficiency (group II), human immunodeficiency virus (HIV)-negative patients with serious acute or chronic illness (group III), and healthy subjects (group IV). The following variables were examined: age, CD4 cell count, Acute Physiologic and Chronic Health Evaluation (APACHE) score, serum cortisol and plasma ACTH at baseline; serum cortisol at 30 and 60 minutes after intravenous administration of 0.25 mg cosyntropin; and 24-hour urinary free cortisol. The four groups had a similar mean age and baseline plasma ACTH and serum cortisol levels. However, a change in cortisol from baseline to 30 and 60 minutes after administration of cosyntropin was significantly smaller in both groups of AIDS patients than in the sick patients without AIDS and normal subjects. There were also differences noted between the two groups of AIDS patients: both baseline and stimulated levels of cortisol tended to correlate directly with ACTH levels in patients without symptoms of adrenal insufficiency, while this relationship appeared to be inverse in patients with symptoms suggestive of adrenal insufficiency (r = -.57 to -.7, P < .05 to .14). The 24-hour urinary free cortisol levels were similar among all groups, but correlated strongly with baseline and stimulated serum cortisol levels only in patients with AIDS and symptoms of adrenal insufficiency (r = .8 to .9, P < .002 to .015). We conclude that (1) AIDS patients with and without symptoms of adrenal insufficiency may have either normal adrenal function or somewhat suboptimal adrenal reserve as demonstrated by a blunted cortisol response during the short ACTH stimulation test in comparison to HIV-negative comparably sick patients or healthy subjects; and (2) 24-hour urinary free cortisol is not a useful test for detection of subtle abnormalities of adrenal function in patients with AIDS.