Adrenocortical insufficiency

Adrenocortical insufficiency causes difficulty in diagnosis and morbidity out of proportion to its rarity, because of the non-specific, multi-system nature of the clinical features. Most of these are due to cortisol deficiency. Prominent features are well-known ones such as weight loss and asthenia, and hypoglycaemia. Less prominent in recent accounts are those due to failure of cellular sodium export and to vasopressin excess, which are frequent and clinically significant. For this reason, the clinical features of isolated ACTH deficiency, isolated glucocorticoid deficiency and Addison's disease overlap greatly. In addition, cortisol deficiency has secondary endocrine effects, e.g. glucocorticoid-reversible hypothyroidism, hyperprolactinaemia and hypercalcaemia. Further overlap between the various steroid insufficiency syndromes occurs because of the association of various organ-specific autoimmune endocrinopathies with Addison's disease. Over 80% of Addison's disease is of the autoimmune type, though almost any systemic destructive process can cause similar steroid insufficiency. Demonstration of adrenal insufficiency requires various combinations of tetracosactrin adrenal stimulation tests, and hypoglycaemia or equivalent tests, if the cause is ACTH deficiency but the correct test can only be chosen to suit a firm clinical diagnosis. The treatment of adrenocortical insufficiency is described.     

Immunoglobulins of patients with idiopathic Addison's disease block the in vitro action of adrenocorticotropin

The presence of serum immunoglobulins (Ig) blocking ACTH-induced adrenal DNA synthesis and/or cortisol production was studied in 25 patients with idiopathic Addison's disease. For this purpose guinea pig adrenal segments kept in organ culture were exposed to ACTH and graded concentrations of patient IgG. After a 5-h culture period the cortisol present in the culture fluid was measured by RIA, and DNA synthesis in the adrenal cells was measured using Feulgen densitometry on frozen sections of the cultured adrenal segments. Addition of ACTH alone in concentrations of 0.1-10 pmol/L to the culture system stimulated in vitro cortisol secretion; the maximal stimulation was 63 +/- 35% (+/- SD; n = 5) at a concentration 0.1 pmol/L. ACTH also increased (in concentrations of 1 fmol/L to 1 pmol/L) the percentage of fasciculata cells in S-phase from 0-4% (nonstimulated) to 5-12%. IgG preparations from all but 2 of the 25 patients with idiopathic Addison's disease blocked these in vitro ACTH-induced adrenal responses in a dose-dependent fashion. IgG from 2 patients with tuberculous adrenalitis, 1 patient with secondary adrenal insufficiency, and 7 normal subjects had no blocking activity. Among 5 non-Addisonian autoimmune endocrinopathy patients who had adrenal cytoplasmic autoantibodies, 4 had no ACTH-blocking IgGs. Two of 9 patients with miscellaneous adrenal disorders (Cushing's disease, pigmented adrenal micronodular dysplasia, and adrenal nodules) had ACTH-blocking activity. These results demonstrate the existence of IgGs blocking the in vitro effects of ACTH and suggest their involvement in the pathogenesis of idiopathic Addison's disease.     

Low dose (1 microg) ACTH test in the evaluation of adrenal dysfunction in pre-clinical Addison's disease

OBJECTIVE: The presence of 21-hydroxylase autoantibodies (21OHAb) is a marker of adrenal autoimmunity and can be used to identify subjects with pre-clinical Addison's disease. The low-dose (1 microg) ACTH test (LDT) is more sensitive than the high-dose (250 microg) test (HDT) for the diagnosis of pituitary adrenal insufficiency, but no information is available on the use of a LDT in subjects with autoimmune adrenalitis and primary adrenal insufficiency. The aim of our study was to evaluate the clinical use of the LDT in the diagnosis of early adrenocortical dysfunction in patients with adrenal autoantibodies. DESIGN AND METHODS: Firstly, we evaluated the cortisol responses to both a LDT and a HDT in a group of 12 healthy volunteers. We then performed a LDT in 11 subjects positive for 21OHAb, but without clinical signs of Addison's disease identified by screening 920 patients with one or more organ-specific autoimmune diseases. In all cases, the LDT was followed by a sequential HDT which was used as a control test of the sensitivity and specificity of the LDT. RESULTS: In healthy subjects, the peak cortisol levels after the LDT were similar to those after the classical HDT. In 21OHAb-positive subjects, the LDT showed a pathological response in five out of 11 (45%) cases and the diagnostic concordance between the results of the LDT and those of the HDT was 100%. All the five cases with pathological LDT were also positive for adrenal cortex autoantibodies (ACA) and 4/5 had high levels of basal ACTH. One subject with pathological LDT developed clinical Addison's disease 4 months after the test had been performed. CONCLUSIONS: Our study demonstrates that the low dose ACTH test has a high diagnostic sensitivity and specificity for primary adrenal insufficiency and suggests that it can accurately identify subjects with pre-clinical adrenal dysfunction.     

Autoimmune polyglandular syndrome type 2 and osteoporosis in a 69 years old patient

We present a case of a 69 year old female with autoimmune polyglandular syndrome type 2 or Schmidt's syndrome. The syndrome consists of primary autoimmune adrenocortical insufficiency (Addison's disease), autoimmune hypothyroidism, and type 1 diabetes. In the presented case Addison's disease was diagnosed on the basis of clinical symptoms, low serum cortisol level: at 8 am 129,1 nmol/l (reference range 220,70-689,70), and high ACTH level: 1540,8 pg/ml (reference range 0-50). Hypothyroidism was diagnosed with serum TSH of 4,46 microU/ml (rr 0,20-3,50), aTPO antibodies titer was 117 U/ml (rr 0-60). The patient also presented insulin dependent diabetes treated with insulin and osteoporosis with a compressive vertebral fracture and a hip fracture in the past (hip T-score = -2,62). After substitutional pharmacotherapy was implemented, the patient was discharged in good health. Possible correlation between bone metabolism disorders and autoimmune polyglandular syndrome needs further investigation.     

Autoantibodies in autoimmune polyendocrine syndrome type II.

The autoimmune polyendocrine syndrome type II (APS-II) is characterized by the association of autoimmune Addison's disease with thyroid autoimmune diseases or type-1 diabetes mellitus. 21-Hydroxylase autoantibodies enable the accurate diagnosis of autoimmune Addison's disease and, in patients with other endocrine autoimmune diseases, identify subjects at high risk for clinical adrenal insufficiency. 17 alpha-Hydroxylase (17OH) and side-chain-cleavage enzyme (P450scc) are target autoantigens of steroid-cell autoantibodies, and in women with Addison's disease, 17OH autoantibodies and P450scc autoantibodies are markers of increased risk for premature ovarian failure. Thyroperoxidase autoantibodies, thyroglobulin autoantibodies, H+/K(+)-ATPase autoantibodies, and GAD65 autoantibodies are frequently detected in patients with isolated Addison's or APS-II. Screening for other organ-specific autoimmune diseases should be performed in every patient with at least one major disease component of APS-II.     

The natural history of adrenal function in autoimmune patients with adrenal autoantibodies

Adrenal autoantibodies (AA) were found in 23 of 2571 (0.9%) patients with organ-specific autoimmune diseases, in one of 632 first-degree relatives of insulin-dependent diabetic patients, and in none of 375 normal controls. In AA-positive subjects the prevalence of human leucocyte antigens (HLA)-A1, -B8 and -DR3 was significantly higher with respect to the general population. Two groups were followed (15 subjects persistently positive for AA and 51 negative subjects) for a mean period of 3.2 years. Yearly tests were made for AA and adrenal function. Of the 15 subjects persistently positive for AA, six developed Addison's disease after a period varying from 6 months to 10 years. Of the 51 subjects initially negative, two became positive during follow-up, and one of these developed Addison's disease 15 months later. In contrast, all the remaining 49 persistently negative subjects maintained normal adrenal function tests. Overall, of the 17 positive subjects, seven (41%) developed Addison's disease, three (18%) showed various degrees of subclinical adrenocortical failure and the remaining seven maintained normal glandular function. In the positive patients the yearly incidence of detriment in adrenal function was 19%. Patients who developed Addison's disease showed significant association with HLA-B8 phenotype. The development from normal adrenocortical function to overt Addison's disease seemed to progress through four distinct stages of functional impairment: increased plasma renin activity with normal/low aldosterone (stage 1), low cortisol response after i.v. administration of ACTH (stage 2), increased ACTH (stage 3), and low basal cortisol (stage 4).(ABSTRACT TRUNCATED AT 250 WORDS)     

Time course of 21-hydroxylase antibodies and long-term remission of subclinical autoimmune adrenalitis after corticosteroid therapy: case report

Subclinical Addison's disease is characterized by the presence of adrenal autoantibodies (ACA) and steroid 21-hydroxylase autoantibodies (21OHAb) with or without adrenal function failure. In our previous longitudinal study some patients with high titers of ACA and at stage 2 of subclinical adrenocortical failure showed disappearance of ACA with recovery of normal adrenocortical function after corticosteroid treatment for Graves' ophthalmopathy. To investigate whether corticosteroid-induced modification of the adrenal autoimmune markers can also involve 21OHAb and to evaluate whether the remission of subclinical adrenocortical failure can persist over a long period of time, we followed-up for 100 months the levels of 21OHAb and ACA as well as the metabolic markers of adrenal function in one patient with Graves' ophthalmopathy and at stage 2 of subclinical adrenocortical failure before and after corticosteroid therapy. A 34-yr-old woman with Graves' disease and active ophthalmopathy who was found to be positive for ACA and to have high PRA, low aldosterone levels, and normal basal ACTH and cortisol levels, but impaired cortisol response to ACTH was studied. The patient was treated with oral corticosteroid therapy for 6 months. After corticosteroid therapy, 21OHAb, initially positive, became negative in concomitance with the disappearance of ACA and the restoration of normal adrenal function. The disappearance of both 21OHAb and ACA and their prolonged absence during the follow-up suggest that corticosteroid treatment can induce long-term remission of subclinical adrenal insufficiency and prevent the onset of the clinical phase of the disease. Our pilot study may pave the way to future trials aimed at preventing the onset of the clinical signs of Addison's disease in ACA/21OHAb-positive patients.     

A case of cushing syndrome with both secondary hypothyroidism and hypercalcemia due to postoperative adrenal insufficiency

A 48-year-old woman was referred to our hospital because of secondary hypothyroidism. Upon admission a left adrenal tumor was also detected using computed tomography. Laboratory data and adrenal scintigraphy were compatible with Cushing syndrome due to the left adrenocortical adenoma, although she showed no response to the TRH stimulation test. Hypercortisolism resulting in secondary hypothyroidism was diagnosed. After a left adrenalectomy, hydrocortisone administration was begun and the dose was reduced gradually. After discharge on the 23rd postoperative day, she began to suffer from anorexia. ACTH level remained low, and serum cortisol, free thyroxine and TSH levels were within the normal range. Since her condition became worse, she was re-admitted on the 107th postoperative day at which time serum calcium level was high (15.6 mg/dl). Both ACTH response to the CRH stimulation test and TSH response to the TRH stimulation test were restored to almost normal levels, but there was no response of cortisol to CRH stimulation test. We diagnosed that the hypercalcemia was due to adrenal insufficiency. Although the serum calcium level decreased to normal after hydrocortisone was increased (35 mg/day), secondary hypothyroidism recurred. It was suggested that sufficient glucocorticoids suppressed TSH secretion mainly at the pituitary level, which resulted in secondary (corticogenic) hypothyroidism. However, both postoperative glucocorticoid deficiency and adequate amounts of thyroxine due to the elimination of inhibition of TSH secretion by glucocorticoids might cause hypercalcemia possibly through increased bone reabsorption of calcium.     

Value of the CRF test in primary and secondary adrenal insufficiency

The ACTH and cortisol responses after CRF administration were studied in 21 patients with adrenal failure and compared with those obtained in 15 control subjects. In patients with Addison's disease, cortisol and ACTH responses were respectively abolished or excessive. In patients with secondary adrenal failure, a unique bolus injection of CRF allows the differentiation between pituitary or hypothalamic secretory defect. With regard to previous reports, the usefulness of CRF test in primary and secondary adrenal failure is stressed.     

Das hypophysäre Koma

Pituitary coma is a rare case of emergency and primarily due to ACTH and TSH deficiency. Pituitary coma occurs more often in patients with well-known pituitary deficiency than in patients with intrasellar tumor. Clinical manifestations are hypotonia, bradycardia, decreased skin and nipple pigmentation, muscle weakness, vomitus, nausea, obstipation, hypothermia, and hypoventilation. A postpartal agalactia is often the first sign of Sheehan's syndrome. Unlike primary adrenal insufficiency (Addison's disease) ACTH deficiency does not cause hyperpigmentation, hyperkalemia, or salt loss. The suspicion of pituitary coma requires replacement with 100 mg hydrocortisone iv, 200 mg hydrocortisone iv/24 h, 500 micro g levothyroxine iv and fluid substitution. Since thyroxine accelerates the degradation of cortisol and can precipitate adrenal crisis in patients with limited pituitary reserve, hydrocortisone replacement should always precede levothyroxine therapy. ACTH stimulation test, CRH stimulation test and insulin tolerance test (optional) should be performed after therapeutic compensation to determine pituitary function.     

Serum dehydroepiandrosterone sulfate concentrations in secondary adrenal insufficiency

Serum dehydroepiandrosterone sulfate (DHEA-S) concentrations were studied in 84 untreated patients with secondary adrenal insufficiency. Compared to values in normal subjects of corresponding age, DHEA-S levels were decreased in 80 patients. The decrease was unrelated to the cause of the secondary adrenal insufficiency or the serum PRL level. Serum cortisol concentrations, on the other hand, were low in 71 patients and low normal in the remaining 13. Serum DHEA-S levels were decreased in 11 of these 13 patients. The frequency of decreased serum DHEA-S levels in patients with secondary adrenal insufficiency was significantly higher than that of decreased cortisol levels. These results suggest that decreased serum DHEA-S levels reflect deficient ACTH secretion in secondary adrenal insufficiency and that simultaneous determination of serum DHEA-S and cortisol levels is useful in the diagnosis of this pathological state.     

Isolated ACTH deficiency and primary hypothyroidism

A patient presented with severe primary hypothyroidism and secondary adrenal insufficiency due to the isolated deficiency of ACTH. The diagnostic evidence suggests that both are of an autoimmune aetiology. Acquired isolated or unitrophic ACTH deficiency is a rare but definite cause of adrenal insufficiency. Additional case reports and autopsy studies describing acquired isolated ACTH deficiency associated with autoimmune thyroid disease have appeared in the literature suggesting that the association is more than coincidental. Combined thyroid and adrenal failure should not always be considered to be the result of combined end organ failure. Unitrophic isolated ACTH deficiency may coexist with primary hypothyroidism.     

Adrenal-cortex autoantibodies and steroid-producing cells autoantibodies in patients with Addison's disease: comparison of immunofluorescence and immunoprecipitation assays

Autoimmune Addison's disease and premature ovarian failure are characterized by the presence of organ-specific autoantibodies. The main adrenal and gonadal autoantigens have been identified and cloned, and the relationship between the autoantibodies detected by immunofluorescence techniques and those detected by the new assays using recombinant autoantigens needed to be investigated. We studied 165 patients with Addison's disease: 143 patients had different forms of autoimmune Addison's disease (13 with idiopathic premature ovarian failure) and 22 had nonautoimmune Addison's disease. Adrenal-cortex autoantibodies and steroid-producing cell autoantibodies were measured by the immunofluorescence techniques. Autoantibodies to steroid 21-hydroxylase, 17alpha-hydroxylase, and P450 side chain cleavage enzyme were measured by immunoprecipitation assay using 35S-labeled recombinant proteins. Adrenal-cortex autoantibodies and autoantibodies to 21-hydroxylase were found in 81% of the patients with autoimmune Addison's disease. None of the patients with nonautoimmune Addison's disease had adrenal-cortex autoantibodies or autoantibodies to 21-hydroxylase. A high association between these two markers in patients with different forms of autoimmune Addison's disease and in those with short- or long-standing disease was found. Steroid-producing cells autoantibodies were found in 26% of the patients with autoimmune Addison's disease, and autoantibodies to 17alpha-hydroxylase and/or P450 side chain cleavage enzyme in 36% of the patients. Steroid-producing cells autoantibodies were found in 11/13 (85%) of patients with idiopathic premature ovarian failure associated with autoimmune Addison's disease, and autoantibodies to 17alpha-hydroxylase and/or P450 side chain cleavage were found 12/13 (92%) of patients; the only case negative for all these three markers suffered from Turner's syndrome. Provided that a high standard of immunofluorescence technique is maintained, measurement of adrenal cortex autoantibodies or steroid-producing cells autoantibodies by either immunofluorescence or immunoprecipitation assay is essentially equivalent.     

The use of theophylline as an in vivo probe of adrenocortical function

The first step in the stimulatory action of most polypeptide hormones, including ACTH, is interaction with a specific target organ plasma membrane receptor. Theophylline, a nonspecific stimulus of several endocrine processes, does so presumably by circumventing the receptor step and directly increasing cAMP by inhibiting phosphodiesterase-mediated hydrolysis. Five patients with adrenal insufficiency, documented by a lack of cortisol secretion in response to exogenous ACTH, underwent a 4-h iv infusion of theophylline. In three of the five individuals, a significant concentration of cortisol was measured in serum for the first time. The patients who responded included one patient with the syndrome of ACTH insensitivity, one with ACTH deficiency, and one with idiopathic primary adrenal failure. Two patients with autoimmune adrenalitis failed to respond to theophylline, although one was tested very early in the course of her disease. We also noted that theophylline stimulated renin secretion and, in one patient with an intact zona glomerulosa, evoked a secondary rise in aldosterone equal to that produced by diuresis and upright posture. These studies suggest that the preservation of cortisol responsiveness to theophylline, after the loss of sensitivity to ACTH, may be relate to either the duration of the adrenal insufficiency or to the etiological mechanism. Patients with autoimmune adrenalitis may undergo more rapid and complete adrenocortical destruction, therapy losing sensitivity to both ACTH and theophylline, whereas patients with insufficient or ineffective ACTH stimulation may have receptor failure before the loss of intracellular function. Thus, responsiveness to iv theophylline may serve not only as a probe of potential adrenocortical reserve, but also as an indicator of pathogenesis.     

A new less-invasive and more informative low-dose ACTH test: salivary steroids in response to intramuscular corticotrophin

OBJECTIVE: The intravenous low-dose ACTH test has been proposed as a sensitive tool to assess adrenal function through circulating steroids. The aims of this study were to: (a) find the minimal intramuscular ACTH dose that induced serum and salivary cortisol and aldosterone responses equivalent to those obtained after a pharmacological dose of ACTH; and (b) define the minimum normal salivary cortisol and aldosterone responses in healthy subjects to that dose of ACTH. We also compared the performances of the standard- and low-dose ACTH intramuscular tests to screen patients with known hypothalamo-pituitary-adrenal impairments. DESIGN: Rapid ACTH tests were performed in individuals using various intramuscular doses (12.5, 25 and 250 microg) at 2-week intervals. SUBJECTS: Twenty-one healthy volunteers and 19 patients with primary (nine cases) and secondary (10 cases) adrenal insufficiency. MEASUREMENT: Serum and salivary cortisol and aldosterone concentrations were measured at baseline and after ACTH. Serum cortisol > or = 552.0 nmol/l and aldosterone > or = 555.0 pmol/l concentrations at 30 min after 250 microg of ACTH were defined as normal responses. RESULTS: In healthy volunteers cortisol and aldosterone responded to ACTH in a dose-dependent manner. The time to peak in saliva for each steroid was delayed as the dose of ACTH increased. The minimum ACTH dose that produced equivalent steroid responses at 30 min to 250 microg of ACTH (standard-dose test; SDT) was 25 microg (low-dose test; LDT). Saliva collection 30 min after LDT and SDT showed cortisol and aldosterone concentrations of at least 20.0 nmol/l and 100.0 pmol/l, respectively. These values were defined as normal steroid responses. Blunted salivary steroid responses to LDT and SDT were found in all patients with primary adrenal insufficiency. Subnormal salivary cortisol levels in response to LDT and SDT were found in all patients with secondary adrenal insufficiency. In five patients full recovery of adrenal function was demonstrated by both tests after steroid withdrawal. In the follow-up of four patients studied during the recovery period, subnormal SAF response after LDT and normal after SDT was demonstrated. Preservation of the adrenal glomerulosa was found in all the patients with secondary adrenal insufficiency through the normal rise in salivary aldosterone after both LDT and SDT. CONCLUSIONS: Adrenal function can be accurately investigated with simultaneous measurements of salivary cortisol and aldosterone in response to 25 microg of corticotrophin injected into the deltoid muscle. Our data suggest that this may become a useful and relatively noninvasive clinical tool to detect subclinical hypoadrenal states.     

A population study of the association between thyroid autoantibodies in serum and abnormalities in thyroid function and structure

OBJECTIVE: Patients with autoimmune overt hypothyroidism may present with goitrous Hashimoto's disease or autoimmune atrophic thyroiditis. Little is known about the prevalence of subclinical autoimmune hypothyroidism. The aims of this study were to evaluate the association between thyroid autoantibodies in serum and abnormalities in thyroid function and structure, and to study the thyroid volume in subjects with subclinical autoimmune hypothyroidism. DESIGN: A population study including 4649 randomly selected subjects. MEASUREMENTS: Blood tests were used to analyse for thyroid peroxidase autoantibodies (TPO-Ab), thyroglobulin autoantibodies (Tg-Ab), TSH, fT3 and fT4. RESULTS: Thyroid volume was categorized as small (< 6.6 ml) in 4.7%, normal (6.6-14.9 ml) in 60.4% and large (> 14.9 ml) in 34.9% of participants. Thyroid nodules were found in 29.7%. Serum TSH was low (< 0.4 mIU/l) in 4.7%, normal (0.4-3.6) in 91.0% and high (> 3.6) in 4.3%. The prevalence rate of subclinical goitrous Hashimoto's disease was 0.62% and of subclinical autoimmune atrophic thyroiditis 0.24%. There was a strong association between large volume and autoantibodies, but only in subjects with elevated TSH (P < 0.001). An association between thyroid nodules and TPO-Ab in univariate analyses (P < 0.001) was due to confounding by sex and age (multivariate model, P = 0.23). CONCLUSION: We identified a subgroup of the population with subclinical goitrous Hashimoto's disease and a smaller subgroup with subclinical autoimmune atrophic thyroiditis. This relationship between small and large thyroid volume in subclinical disease is opposite to that in overt disease, which may suggest that the period between development of a small volume with circulating autoantibodies and overt hypothyroidism is relatively short.     

Primary hypothyroidism associated with secondary adrenocortical insufficiency

A 50 year old man is described in whom primary hypothyroidism and isolated ACTH deficiency leading to adrenocortical insufficiency occurred simultaneously. Low thyroid hormone levels, elevated serum TSH values and high titers of antithyroid antibodies (ATA) were consistent with primary hypothyroidism. The diagnosis of secondary adrenocortical insufficiency was based on low cortisol and ACTH morning levels, low urinary steroids, a significant increase of cortisol levels after 0.25 mg tetracosactide iv, an absence of ACTH and cortisol release after insulin-induced hypoglycemia and a similar absence of ACTH and 11-deoxycortisol increase after metyrapone administration. After one year treatment and five days withdrawal of cortisol administration, the insulin-induced hypoglycemia still failed to elicit secretory responses of ACTH and cortisol, despite the normalization of thyroid hormone levels. The etiopathogenesis of these two coexisting endocrine deficiencies is discussed.     

Estimated risk for developing autoimmune Addison's disease in patients with adrenal cortex autoantibodies

CONTEXT: Patients with adrenal cortex autoantibodies (ACA) without overt autoimmune Addison's disease (AAD) are at risk of adrenal failure. DESIGN: To assess the contribution of different clinical, immunological, genetic, and functional factors in the progression to AAD, we followed up 100 ACA-positive and 63 ACA-negative patients without AAD for a maximum of 21 yr (mean 6.0 yr, median 4.8). ACA were measured by immunofluorescence and 21-OH autoantibodies (Abs) by RIA. Adrenal function was assessed by measuring basal levels of cortisol, aldosterone, ACTH, renin activity, and cortisol response to ACTH. The risk of developing AAD was calculated using survival and multivariate analyses. RESULTS: AAD developed in 31 ACA-positive patients and one ACA-negative patient. The cumulative risk of disease in ACA-positive patients was 48.5% [95% confidence interval (CI) 40.8-56.1]. The cumulative risk was higher in children than adults (100 vs. 31.9%; P < 0.0001), males than females (68.6 vs. 42.7%; P = 0.006), patients with subclinical rather than normal adrenal function at entry (87.4 vs. 30.1%; P < 0.0001), patients with hypoparathyroidism and/or candidiasis than patients with other autoimmune or nonautoimmune diseases (100 vs. 29.7%; P < 0.0001), and patients with high rather than low-medium ACA titers (62.8 vs. 41.2%; P = 0.12). The presence of human leukocyte antigen (HLA)-DRB1 did not appear to contribute to the prediction of AAD. Adjusted hazard ratios by Cox model for the development of AAD were 3.37 for males (CI 1.38-8.24), 5.23 for hypoparathyroidism and/or candidiasis (CI 1.53-17.92), 3.33 for high antibody titers (CI 1.43-7.78), and 6.15 for impaired adrenal function at entry (CI 2.79-13.57). CONCLUSIONS: These results were used to construct a risk algorithm for estimating the probability of developing AAD from the combination of gender, age, adrenal function, antibody titer, and associated autoimmune disorders at entry. The values of estimated risk could be used to decide appropriate follow-up intervals and future immunointervention strategies.     

ACUTE CHANGES IN SERUM THYROTROPHIN IN TREATED ADDISON''S DISEASE

Serum and salivary cortisol, plasma ACTH and serum TSH, free T4, free T3, PRL, LH and FSH were measured before and hourly after the morning steroid replacement therapy of five patients with Addison's disease. In the 4 h after hydrocortisone the levels of TSH fell in all five patients, the levels (mIU/l) decreasing from 6.8 to 3.8; 0.9 to 0.6; 24.3 to 13.2; 28.1 to 7.4 and 17.2 to 11.6. No such change was seen when the procedure was repeated with the morning steroid dose withheld. In two patients, dexamethasone produced similar changes in serum TSH to those observed with hydrocortisone. Steroid therapy had no consistent effect on LH, FSH and PRL levels. Our results show that the time interval between taking medication and withdrawing blood samples should be considered when interpreting TSH levels in treated Addison's disease.     

The overnight single-dose metyrapone test is a simple and reliable index of the hypothalamic-pituitary-adrenal axis

OBJECTIVES The ACTH stimulation test examines adrenal responsiveness but may not examine the entire hypothalamic-pituitary-adrenal (HPA) axis and requires parenteral administration. The cortisol response to hypoglycaemia provides an index of activity of the entire HPA axis but is demanding for patients and medical staff. The aim of the present study was to examine the performance of the overnight single-dose metyrapone test as it provides a simple alternative test for HPA axis function. DESIGN Audit of the overnight metyrapone test performed in one centre between 1979 and 1991. PATIENTS Three hundred and ninety-eight patients underwent 576 tests. Comparisons between the responses to metyrapone and the ACTH stimulation test and of the responses to metyrapone and insulin induced hypoglycaemia test were possible in 87 and 17 patients respectively. MEASUREMENTS Following the midnight administration of metyrapone tablets, 30 mg/kg orally, blood samples were obtained between 0800 and 0930 h for radioimmunoassay of both 11-deoxycortisol and cortisol. RESULTS Five hundred and seventy-six metyrapone tests were performed on 398 patients with no serious side-effects encountered. Andrenal insufficiency was diagnosed in 105 patients. Of these, 18 had a primary adrenal disorder and 87 had a disorder of the hypothalamic-pituitary unit. One hundred per cent concordance between the metyrapone, the ACTH and the hypoglycaemia test was seen in patients with primary adrenal insufficiency. In 19 patients with secondary adrenal insufficiency, who underwent both the metyrapone and the ACTH tests, discord between these two tests was observed in 10 patients (53%). Nine of these patients demonstrated a normal response to ACTH and a subnormal response to metyrapone. In only one patient was an abnormal cortisol response to ACTH associated with a normal response to metyrapone. In contrast, in 17 patients discord between the metyrapone and the hypoglycaemia test was seen in only 1 patient who demonstrated a normal response to the metyrapone test and a subnormal response to hypoglycaemia. CONCLUSION Since the metyrapone test gives similar information about hypothalamic-pituitary axis function as does the hypoglycaemia test, we recommend the use of the overnight metyrapone test as a safe, simple and reliable index of the hypothalamic-pituitary axis integrity. The ACTH stimulation test should not be used for patients suspected of having secondary adrenal insufficiency.