11beta-hydroxysteroid dehydrogenase activity in acromegalic patients with normal or impaired carbohydrate metabolism

Presence of aberrant adrenocorticotropic hormone precursors in two cases of McCune-Albright syndrome

McCune-Albright syndrome (MAS) is a rare disorder. MAS is classically defined by the occurrence of fibrous dysplasia, café-au-lait skin macules, and precocious puberty. In addition to precocious puberty, other hyperfunctioning endocrinopathies may occur. We evaluated hypothalamic-pituitary-adrenal function in two cases of typical MAS associated with fibrous dysplasia and growth hormone excess. Pituitary adenoma or hyperplasia was not detected by magnetic resonance imaging. Hormonal data showed normal or low cortisol levels, despite high ACTH levels in the blood. A high ratio of circulating ACTH to cortisol was found in the two cases. Insulin tolerance and CRH tests showed hyper-responses of ACTH and an insufficient increase in cortisol levels. No involvement of 11β-HSD1 by GH excess was suggested because basal levels of ACTH and cortisol showed no changes, even after therapy for acromegaly by somatostatin analogues. Patients with Cushing's disease cases of pituitary macroadenoma can have high circulating ACTH precursor levels, and elevated ACTH precursors have been observed in ectopic ACTH syndrome. Autonomous cortisol excess was excluded by the level of midnight cortisol and the level of cortisol after a low-dose dexamethasone suppression test in the two cases. Finally, the gel filtration profiles of immunoreactive ACTH contents showed the presence of aberrant ACTH precursors. To the best of our knowledge, there have been no reports of MAS associated with aberrant ACTH precursors. Our findings in these cases emphasize that attention should be to secretion of inactive ACTH precursors in MAS.

Cortisol metabolism in pregnancies with small for gestational age neonates

Small for gestational age (SGA) newborns are often born from hypertensive pregnancies. This study aimed to compare the systemic metabolism of cortisol (F) in pregnancies with SGA and appropriate for gestational age (AGA) infants, considering both the normotensive (NT) and hypertensive patients. We hypothesized that the disturbances in systemic metabolism of F in pre-eclampsia (PE) might be attributed not to hypertension only, but to SGA. The study included 117 pregnants in the third trimester, divided into groups: NT pregnancy and SGA neonate (SGA-NT); NT pregnancy and AGA neonate (AGA-NT; controls), and respective groups with PE: SGA-PE and AGA-PE. We assessed the glucocorticoid balance with the function of enzymes involved in systemic metabolism of F: 11β-hydroxysteroid dehydrogenase type 1 and 2 (11β-HSD1 and 11β-HSD2), 5α- and 5β-reductase. The enzymes' functions were estimated with the levels of F, cortisone (E), and their metabolites in plasma or urine, which we measured with HPLC-FLD and HPLC-MS/MS. The plasma F/E and urinary free F/E (UFF/UFE) ratios correlated significantly only in patients with the normal function of 5α- and 5β-reductase. The increased function of 11β-HSD2 was noted in all pre-eclamptic pregnancies. Increased function of 5α- and 5β-reductase was specific only for SGA-PE pregnancies, and the function of 5α-reductase was dependent on fetal sex. The SGA-NT pregnancies with male fetuses trended towards the higher function of renal 11β-HSD2 and 5β-reductase; SGA-NT pregnancies with female fetuses lacked any systemic glucocorticoid imbalance. In conclusion, systemic metabolism of F is the most intensive in pre-eclamptic pregnancies complicated by SGA with female fetuses. Our study supports the hypothesis about the different origins of PE and idiopathic intrauterine growth restriction and suggests the sex-specific mechanisms responsible for fetal growth restriction.

Increased cortisol metabolism in women with pregnancy-related hypertension

PURPOSE

The diminished function of 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) was found in placentae from preeclamptic pregnancies. Here, we examine the overall maternal glucocorticoid balance in pregnancy-related hypertension. We aim to answer the question if the functions of primary enzymes involved in cortisol metabolism: 11β-HSD1 and 11β-HSD2 and 5-reductases (both 5α- and 5β) are altered in the course of hypertensive pregnancy.

METHODS

We determined plasma and urinary cortisol and cortisone as well as their urinary tetrahydro- and allo-tetrahydrometabolites, both in free and conjugated forms in samples obtained from 181 Polish women in the third trimester of pregnancy. We compared steroid profiles in women with preeclampsia (PE), gestational hypertension (GH), chronic hypertension (CH) and in normotensives (controls).

RESULTS

We found significant differences in glucocorticoid balance in pregnancy-related hypertension. Plasma cortisol to cortisone was significantly lower in PE than in controls (3.00 vs. 4.79; p < 0.001). Increased function of renal 11β-HSD2 in PE and GH was manifested by significantly lower urinary free cortisol to cortisone ratio (0.169 and 0.206 vs. 0.277 in controls; p < 0.005). Markedly enhanced metabolism of cortisol was observed in pregnancy-related hypertension, with no significant alterations in CH, and the changes were more clearly expressed in PE than in GH.

CONCLUSIONS

The glucocorticoid balance in PE and GH is shifted towards decreasing cortisol concentration either due to intensified conversion to cortisone or enhanced production of tetrahydro and allo-tetrahydrometabolites.