B. VON SCHÜTZ and M. J. MÜLLER
M. J. MÜLLER, P. HUNZINGER, U. PASCHEN and H. J. SEITZ
G. K. STALLA, J. STALLA, M. HUBER and O. A. MÜLLER
Barbara Krautli, J. Müller, A. M. Landolt and F. von Schulthess
In 2 women with known Addison's disease, progressive hyperpigmentation reappeared years after an initial remission under conventional substitution therapy with cortisone. Excessively elevated plasma ACTH concentrations and radiological evidence of sella turcica deformation led to the diagnosis of ACTH-producing adenomas and prompted their removal by transsphenoidal microsurgery.
In one patient, a large Crooke's cell adenoma with extensive extrasellar expansion had caused severe and irreversible bilateral defects of the visual fields and unilateral optic atrophy. Surgical removal of the tumour and radiotherapy brought about a permanent disappearance of the hyperpigmentation, but eventually led to secondary hypothyroidism. In the second patient, the selective removal of a small intrasellar eosinophilic adenoma consisting of ACTH-producing cells did not alleviate the hyperpigmentation and did not lower the plasma ACTH concentration. However, hyperpigmentation regressed markedly within a year of treatment with a higher dose of cortisone.
The rarity of similar cases in the literature seems to indicate that insufficient feedback suppression of ACTH-producing cells in treated Addison's disease does not by itself induce the development of a pituitary adenoma, but might promote the growth of an independently and coincidentally occurring microadenoma, which would have caused Cushing's disease in a person with intact adrenal glands.
M. LOSA, J. ALBA-ROTH, J. MOJTO, J. SCHOPOHL, O.A. MÜLLER and K. VON WERDER
H.J. HUHNT, R. ZICK, H.J. MITZKAT, A. VON ZUR MÜHLEN and M.J. MÜLLER
B. N. Trost, M. P. Koenig, A. Zimmermann, M. Zachmann and J. Müller
In a 60 year old virilized woman the plasma testosterone concentration was markedly elevated, whereas the plasma cortisol and ACTH as well as urinary 17-ketosteroids, 17-hydroxycorticoids, pregnanetriol and dehydroepiandrosterone were normal. The plasma levels of LH and FSH were in the post-menopausal range. Dexamethasone suppressed the urinary 17-ketosteroids, 17-hydroxycorticoids and pregnanetriol normally, but had no effect upon the plasma testosterone. These findings led to the tentative diagnosis of an ovarian hilus cell tumour. However, bilateral oophorectomy revealed bilateral hyperthecosis without a tumour and did not result in any decrease of the plasma testosterone level. An attempt of adrenal vein catheterization succeeded only on the left side. The lack of a gradient in the testosterone concentration between blood from the left adrenal vein and a peripheral vein prompted a surgical exploration of the right adrenal gland, which led to the discovery and removal of an encapsulated Leydig cell type adenoma, characterized by Reinke's crystalloids. A testosterone concentration gradient between right adrenal and peripheral venous blood obtained intra-operatively, rapid normalization of the plasma testosterone concentration post-operatively, results of a tumour incubation study as well as the clinical outcome proved that this adenoma had been the source of the excessive androgen. A history of a late menarche and persistent menstrual irregularities together with elevated gonadotrophins in spite of excessive testosterone pointed to the possibility of a longstanding gonadotrophin-dependent gonadal cell population in the adrenal, which was fully activated only by the menopausal gonadotrophin rise.
M Lange, OL Svendsen, NE Skakkebaek, J Muller, A Juul, M Schmiegelow and U Feldt-Rasmussen
OBJECTIVE: The insulin-tolerance test (ITT) is currently considered to be the gold standard for evaluating adults suspected of GH deficiency (GHD). The aim of this study was to determine factors that may influence nadir blood glucose (BG) when using a mean insulin dose of 0.1 IU/kg body weight. Furthermore, we wanted to evaluate the safety and GH-related aspects of the ITT. DESIGN: ITT was performed in 277 patients, of whom 255 (129 females) were eligible for evaluation. RESULTS: Multiple regression analysis, including the whole population, showed that the major determining factors for nadir BG were basal BG and body mass index (BMI) (P<0.02). No serious adverse event was recorded. Sixty-three percent of all patients tested had severe GHD with peak GH response to hypoglycaemia below 7.8 mIU/l. The positive predictive value for IGF-I was 0.82 and the negative predictive value was 0.47, using a cut-off value corresponding to -2 s.d. GH peak response to hypoglycaemia decreased with increasing numbers of other pituitary hormone deficiencies. CONCLUSIONS: When determining the dose of insulin based on weight, factors like pre-test BG and BMI should also be considered. We propose an algorithm stating that the dose of insulin should be 0.1 IU insulin/kg body weight minus 2 IU if pre-test BG is <4.0 mmol/l and minus 2 IU if BMI is <20 kg/m(2) in order to take these factors into account. Our findings furthermore support the concept that the low-dose ITT is a safe test in adults, when performed in experienced hands. It was confirmed that IGF-I is not sufficient when diagnosing GHD in adults, and reliable stimulation tests like ITT are required in the diagnosis.
I. Maschler, J. Weidenfeld, A. Muller, S. Slavin, J. Shaefer, I. Chowers and M. Finkelstein
A 17 year old female patient with hypertension, amenorrhoea and hirsutism was found to have subnormal levels of plasma and urinary cortisol, significant plasma levels of Reichstein's compound S and 21-deoxycortisol, high urinary levels of THS and pregnanetriolone as well as elevated levels of plasma and urinary testosterone. Treatment with 0.5 mg/day of dexamethasone or 25 mg/day cortisone reduced her hypertension and restored her menstrual cycles, but also resulted in the development of moon face, body striae and a gain in weight. Lower doses of cortisone were without effect. The deficient cortisol production coupled with the presence of unusual intermediates such as Reichstein's compound S and 21-deoxycortisol can be explained by a shift in the substrate specificity of 11β-hydroxylase from C-21-hydroxylated substrates (i.e. compound S) to C-21-deoxy substrates (i.e. 17-hydroxyprogesterone).
E. Martens, R. Zick, H. J. Mitzkat, A. von zur Mühlen and M. J. Müller
Abstract. The effect of hyperglycemia on insulin-induced glucose metabolism (M) was investigated in healthy subjects using sequential clamp protocols at constant insulin + somatostatin infusions and varying plasma glucose. During euglycemia (4.8 mmol/l) M increased from 5.6 to 12.5 mg·kg−1·min−1 with increasing plasma insulin (0.34-3.00 nmol/l). At increasing glucose (6.7 mmol/l), M further increased (9.7 to 19.2 mg·kg−1·min−1) with the plasma insulin level (0.41 to 2.99 nmol/l). At a plasma glucose level of 9.8 mmol/l insulin (0.42 to 3.17 nmol/l) was still effective to increase M (13.7 to 25.2 mg·kg−1·min−1). Regression analysis showed that hyperglycemia does not only increase the maximal insulin-stimulated M, but also decreases the insulin concentration causing a half maximum effect. During prolonged clamp studies M increased by about 10% per h, independent by the plasma glucose level. We conclude that hyperglycemia increases M by increasing insulin responsiveness as well as insulin sensitivity. Data derived from euglycemic clamp studies alone are of limited value with respect to the assessment of insulin action.