The syndrome of apparent mineralocorticoid excess (AME) is an inherited form of human hypertension thought to result from a deficiency of 11 beta-hydroxysteroid dehydrogenase (11 beta HSD). This enzyme normally converts cortisol to inactive cortisone and is postulated to thus confer specificity for aldosterone upon the mineralocorticoid receptor. We have analysed the gene encoding the kidney isozyme of 11 beta HSD and found mutations on both alleles in nine of 11 AME patients (eight of nine kindreds). These mutations markedly affect enzymatic activity. They thus permit cortisol to occupy the renal mineralocorticoid receptor and thereby cause sodium retention and hypertension.
Whereas aldosterone is normally a much stronger mineralocorticoid than cortisol in vivo, mineralocorticoid receptors have identical in vitro affinities for these hormones. The in vivo specificity of the receptors is, at least in part, the result of activity of 11-HSD, an enzyme located in most mineralocorticoid target tissues that converts cortisol to cortisone. Cortisone is not a ligand for the receptor, whereas aldosterone is not a substrate of the enzyme. The syndrome of AME is a rare form of juvenile hypertension in which 11-HSD is defective. This deficiency allows mineralocorticoid receptors to be occupied by cortisol, leading to hypertension, because plasma concentrations of cortisol are much higher than those of aldosterone. Licorice, which contains 11-HSD inhibitors, causes a similar syndrome. There are two known isozymes of 11-HSD. The liver or type I isozyme is expressed at high levels in the liver, has a relatively low affinity for steroids (micromolar Km), catalyzes both dehydrogenation and the reverse reductase reaction, and utilizes NADP+ or NADPH as cofactors. The kidney or type 2 isozyme is expressed at high levels in the kidney and placenta, has a high affinity (nanomolar Km) for steroids, catalyzes only dehydrogenation, and utilizes NAD+ as a cofactor. Mutations in the HSD11B2 (HSD11K) gene encoding the kidney isozyme of 11-HSD have been detected in all kindreds with AME studied thus far. This gene represents a candidate locus for the common, "essential" form of hypertension.
Abstract. This clinical practice guideline of the diagnosis and treatment of adrenal insufficiency (AI) including adrenal crisis was produced on behalf of the Japan Endocrine Society. This evidence-based guideline was developed by a committee including all authors, and was reviewed by a subcommittee of the Japan Endocrine Society. The Japanese version has already been published, and the essential points have been summarized in this English language version. We recommend diagnostic tests, including measurement of basal cortisol and ACTH levels in combination with a rapid ACTH (250 µg corticotropin) test, the CRH test, and for particular situations the insulin tolerance test. Cut-off values in basal and peak cortisol levels after the rapid ACTH or CRH tests are proposed based on the assumption that a peak cortisol level ≥18 µg/ dL in the insulin tolerance test indicates normal adrenal function. In adult AI patients, 15-25 mg hydrocortisone (HC) in 2-3 daily doses, depending on adrenal reserve and body weight, is a basic replacement regime for AI. In special situations such as sickness, operations, pregnancy and drug interactions, cautious HC dosing or the correct choice of glucocorticoids is necessary. From long-term treatment, optimal diurnal rhythm and concentration of serum cortisol are important for the prevention of cardiovascular disease and osteoporosis. In maintenance therapy during the growth period of patients with 21-hydroxylase deficiency, proper doses of HC should be used, and long-acting glucocorticoids should not be used. Education and carrying an emergency card are essential for the prevention and rapid treatment of adrenal crisis.Key words: Adrenal insufficiency, Adrenal crisis, Cortisol, Hydrocortisone, Congenital adrenal hyperplasia
Summary of Recommendations
I. Chronic adrenal insufficiency (AI) I-1.0 SymptomsWe recommend suspecting AI in patients who have the following symptoms.
These results suggest that the sensitivity of secretion to physiological doses of ACTH in descending order is aldosterone > DHEA = cortisol. When peak and incremental values are used, sufficient doses of ACTH are 0.1 microgram for plasma aldosterone and 0.5 microgram for plasma cortisol and DHEA in the rapid ACTH test.
Aims/Introduction
Non‐alcoholic fatty liver disease (NAFLD) is often observed in individuals with type 2 diabetes mellitus, and it is known that the presence of type 2 diabetes mellitus leads to the aggravation of NAFLD. The aim of this study was to compare the possible effects of three kinds of oral hypoglycemic agents on NAFLD in individuals with type 2 diabetes mellitus.
Materials and Methods
We carried out a prospective clinical trial (a randomized and open‐label study) in patients with type 2 diabetes mellitus and NAFLD. A total of 98 patients were randomly allocated either to the dapagliflozin (
n
= 32), pioglitazone (
n
= 33) or glimepiride (
n
= 33) group, and the patients took these drugs for 28 weeks. The primary end‐point was the change of the liver‐to‐spleen ratio on abdominal computed tomography.
Results
There was no difference in baseline clinical characteristics among the three groups. Dapagliflozin, pioglitazone and glimepiride ameliorated hyperglycemia similarly. Bodyweight and visceral fat area were significantly decreased only in the dapagliflozin group. Serum adiponectin levels were markedly increased in the pioglitazone group compared with the other two groups. Dapagliflozin and pioglitazone, but not glimepiride, significantly increased the liver‐to‐spleen ratio, and the effects of dapagliflozin and pioglitazone on the liver‐to‐spleen ratio were comparable.
Conclusions
The present study showed that the decrease of visceral fat area and the increase of adiponectin level contributed to the improvement of NAFLD in patients with type 2 diabetes mellitus. Furthermore, dapagliflozin and pioglitazone exerted equivalent beneficial effects on NAFLD in patients with type 2 diabetes mellitus, although it seemed that these two drugs had different mechanisms of action.
We have examined the effect of adrenal androgen, dehydroepiandrosterone (DHEA), on glucose uptake, phosphatidylinositol (PI) 3-kinase, and protein kinase C (PKC) activity in rat adipocytes. DHEA (1 μM) provoked a twofold increase in 2-[3H]deoxyglucose (DG) uptake for 30 min. Pretreatment with DHEA increased insulin-induced 2-[3H]DG uptake without alterations of insulin specific binding and autophosphorylation of insulin receptor. DHEA also stimulated PI 3-kinase activity. [3H]DHEA bound to purified PKC containing PKC-α, -β, and -γ. DHEA provoked the translocation of PKC-β and -ζ from the cytosol to the membrane in rat adipocytes. These results suggest that DHEA stimulates both PI 3-kinase and PKCs and subsequently stimulates glucose uptake. Moreover, to clarify the in vivo effect of DHEA on Goto-Kakizaki (GK) and Otsuka Long-Evans fatty (OLETF) rats, animal models of non-insulin-dependent diabetes mellitus (NIDDM) were treated with 0.4% DHEA for 2 wk. Insulin- and 12- O-tetradecanoyl phorbol-13-acetate-induced 2-[3H]DG uptakes of adipocytes were significantly increased, but there was no significant increase in the soleus muscles in DHEA-treated GK/Wistar or OLETF/Long-Evans Tokushima (LETO) rats when compared with untreated GK/Wistar or OLETF/LETO rats. These results indicate that in vivo DHEA treatment can result in increased insulin-induced glucose uptake in two different NIDDM rat models.
Luseogliflozin exerts more protective effects in an early stage of diabetes compared to an advanced stage, and longer-term use of luseogliflozin exerts more beneficial effects on pancreatic β-cells compared to short-term use.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.