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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 63-year-old man with bilateral adrenal tumors was treated for hypertension and diabetes mellitus. Endocrinologic examination during follow-up revealed the production of cortisol to be independent of the regulation of the hypothalamo-pituitary-adrenal axis. Therefore, he was diagnosed as having subclinical Cushing syndrome, and these tumors were removed. Adrenocorticotropic hormone-independent macronodular adrenal hyperplasia (AIMAH) was endocrinologically and histopathologically diagnosed. This is the first report demonstrating that endocrinologic changes of AIMAH can be observed during long-term follow-up.
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PMID:Subclinical Cushing syndrome due to adrenocorticotropic hormone-independent macronodular adrenocortical hyperplasia: changes in plasma cortisol levels during long-term follow-up. 1075 62

Unilateral adrenal hyperplasia (UAH) is a rare, surgically correctable subset of primary aldosteronism (PA), which shows similar endocrine features to aldosterone-producing adenoma (APA). We report here two Japanese patients with UAH. Case 1 was a 62-year-old man with a four-year history of hypertension. Hypokalemia and suppressed plasma renin activity (PRA) with elevated plasma aldosterone concentration (PAC) were observed, while no adrenal nodules were identified by abdominal computed tomographic (CT) scan. Adrenal scintigraphy did not reveal definite localization. The selective adrenal-vein sampling for determinations of PAC showed an over-functioning left adrenal gland, and a left adrenalectomy was performed. Diffuse micronodular adrenocortical hyperplasia was observed. Case 2 was a 61-year-old man with a six-year history of hypertension. At the first visit to our hospital, hypokalemia and suppressed PRA with elevated PAC were observed. An abdominal CT scan showed a left adrenal mass 1.5 cm in diameter, while adrenal scintigraphy did not reveal definite laterality. A left adrenalectomy was performed, and three macronodules and diffuse micronodular adrenocortical hyperplasia were observed. Hypokalemia, hypertension and endocrine data became normal, and both patients have been well with no signs of recurrence for eight years (case 1) and seven months (case 2) after surgery. Clinical characteristics and endocrine features of UAH are also reviewed.
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PMID:Primary aldosteronism due to unilateral adrenal hyperplasia: report of two cases and review of the literature. 1107 25

The glucocorticoid metabolising enzymes, 11beta-hydroxysteroid dehydrogenases (11beta-HSD), play a critical role in determining the availability of glucocorticoids to activate their receptors and hence modulate target gene transcription. There are two isozymes, 11beta-HSD-1 and -2, which act in opposing directions. 11beta-HSD-2 acts as a dehydrogenase, converting active corticosterone (cortisol in humans) to its inactive 11-keto derivative (11-dehydrocorticosterone in rodents and cortisone in humans), whereas 11beta-HSD-1 acts as a reductase, regenerating active glucocorticoids in a tissue-specific manner. Owing to the lack of specific inhibitors of these enzymes, it has been difficult to confirm the roles and determine the importance of these enzymes in vivo. Hence, to address this, we produced transgenic mice with null-mutations in the genes encoding the 11beta-HSD-1 or 11beta-HSD-2 enzymes. 11beta-HSD-2 -/- mice show signs of hypertension, hypotonic polyuria, hypokalemia and hypochloremia. These symptoms arise from illicit activation of mineralocorticoid receptors by glucocorticoids, in the absence of the protective action of 11beta-HSD-2. The phenotype is directly comparable to the Syndrome of Apparent Mineralocorticoid Excess, seen in humans with mutations in the 11beta-HSD-2 gene. Mice lacking 11beta-HSD-1, however, show a more subtle phenotype with reduced activation of glucocorticoid-induced processes. They were unable to convert 11-dehydrocorticosterone to corticosterone in vivo, confirming 11beta-HSD-1 as the sole 11-reductase in the mouse. They have elevated circulating levels of plasma corticosterone levels and adrenal hyperplasia, but they also have attenuated glucocorticoid-induced activation of gluconeogenic enzymes in response to fasting, and lower glucose levels in response to obesity or stress. Overall, these transgenic models have proved very useful for elucidating the roles of 11beta-HSDs in vivo and will be a unique resource for investigating the importance of each enzyme in the diverse actions of glucocorticoids.
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PMID:Phenotypic analysis of mice bearing targeted deletions of 11beta-hydroxysteroid dehydrogenases 1 and 2 genes. 1116 6

Low-renin hypertension is common and usually implies increased retention of sodium (Na(+)). In every case of known etiology, there is a mineralocorticoid-induced increase in number of epithelial Na(+) channels (ENaCs) in the collecting duct of the kidney, leading to a state of "hyperENaCactivity." In primary aldosteronism, a result of either an adrenal adenoma or bilateral adrenal hyperplasia, aldosterone itself mediates the increase in ENaC function. A severe form of low-renin hypertension in which a molecular mutation in ENaC prevents removal of the channel from the cell surface, known as Liddle's syndrome, results in increased net ENaC activity but, in this case, independently of an increase in aldosterone. Glucocorticoid remedial aldosteronism, an autosomal dominant form of primary aldosteronism, results from a "new" or chimeric gene for aldosterone synthase. Adrenocorticotropic hormone stimulates its expression as well as secretion of aldosterone. Apparent mineralocorticoid excess results from a molecular mutation that allows cortisol to bind to the mineralocorticoid receptor. Both glucocorticoid remedial aldosteronism and apparent mineralocorticoid excess result in an increase in the number of ENaCs. The question remains whether low-renin essential hypertension is related to an increase in ENaC activity. Low-renin hypertension is most common in black patients, who tend to have lower levels of aldosterone as well as renin, which are features that resemble those found in Liddle's syndrome. Preliminary findings suggest that black patients with low-renin hypertension who are resistant to standard antihypertensive therapy respond favorably to the addition of spironolactone, a mineralocorticoid receptor antagonist that reduces ENaC activity.
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PMID:Low-renin hypertension: more common than we think? 1117 96

Hypokalaemic hypertension or resistant hypertension justify investigation for primary hyperaldosteronism. The first step of this investigation is to exclude the ingestion of liquorice, alkalis and diuretics. The second is to make sure that the treatment is compatible with the hormonal tests and that the natriuresis and kaliuresis are normal. The diagnosis then depends on an increased plasma or urinary concentration of aldosterone with a low plasma renin activity. The adenoma of Conn is present in 2/3 of cases and surgically curable, and should be distinguished from adrenal hyperplasia which is treatable with distal diuretics. This is a diagnosis which requires computerised tomography or, when inconclusive, demonstration of unilateral secretion of aldosterone. Adrenalectomy, usually by coelioscopy, is indicated in Conn's adenoma when the patient is young and the hypertension severe or recent. Surgical abstention is strongly advised in cases of adrenal hyperplasia.
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PMID:[Hypertension and primary hyperaldosteronism]. 1119 Feb 97

The traditional workup for primary aldosteronism is cumbersome and requires discontinuing antihypertensive medications, which is inconvenient and potentially dangerous. A simple and accurate screening test that can be used without modifying medications is needed. The plasma aldosterone-renin ratio (ARR) is a valid screening assay for primary aldosteronism, but antihypertensives are usually discontinued before obtaining this ratio, limiting its utility. The present prospective study is designed to examine the validity of the ARR as a screening test for primary aldosteronism if the ratio is measured randomly while patients continue antihypertensive therapy. During the 18-month study period, 90 patients were referred to the hypertension clinic with poorly controlled hypertension. ARR was measured in random blood samples in all 90 patients while maintaining their prescribed antihypertensive medications. Those with elevated ARRs (>100 ng/dL / ng/mL/h) underwent further diagnostic workup, including adrenal computed tomography and/or magnetic resonance imaging and adrenal iodine 131 norcholesterol uptake scan. Fifteen patients (17%) had elevated ARRs greater than 100:1. Ten of 15 patients were found to have adrenal adenoma on diagnostic workup, and adenoma was later confirmed by histological examination after surgical removal in these 10 patients. Five patients were found to have adrenal hyperplasia; all 5 patients responded to antialdosterone treatment. Thus, all 15 patients had good control of blood pressure after surgery and/or antialdosterone medications. No patient showed a falsely elevated ARR. Data suggest that the ARR is a valid screening assay for primary aldosteronism in patients with poorly controlled blood pressure, and discontinuation of antihypertensive medications is not needed for this test.
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PMID:Screening for primary aldosteronism without discontinuing hypertensive medications: plasma aldosterone-renin ratio. 1127 68

Wider application of the aldosterone/plasma renin activity ratio among hypertensives has facilitated the detection of primary aldosteronism at earlier stages of evolution (with most patients normokalemic), and found prevalence rates far greater than those previously reported. Reliable detection of patients with PAL requires that 1) the diagnosis is considered in all hypertensives; 2) blood samples are collected under standardized conditions of diet, posture, and time of day; 3) medications known to alter the ratio are avoided or their effects taken into account; 4) aldosterone and plasma renin activity are measured using consistently accurate assay techniques; and 5) reliable methods (such as fludrocortisone suppression testing) are used to confirm primary aldosteronism. Adrenal venous sampling is the only dependable way to differentiate aldosterone-producing adenoma from bilateral adrenal hyperplasia. As has occurred in familial hyperaldosteronism type I, the elucidation of genetic mutations causing other forms of primary aldosteronism should further facilitate detection of this potentially curable or specifically treatable variety of hypertension.
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PMID:Primary aldosteronism: rare bird or common cause of secondary hypertension? 1135 74

Cushing's syndrome is an uncommon but important disease. Twenty-one confirmed cases of spontaneous Cushing's syndrome were documented at the University Hospital of the West Indies over a 21-year period. They were predominantly young females (F:M ratio of 17:4; mean age 25 years and 3 months). The commonest presenting symptoms were amenorrhoea (41%) and obesity (19%). Common clinical features were cushingnoid features (95%), hypertension (76%) and hirsutism (82%). Twenty-nine per cent had frank hyperglycaemia. Cushing's syndrome was due to Cushing's disease in 10 cases, adrenal adenoma in 3 and adrenal carcinoma in 2 cases. In 4 cases with presumed adrenal hyperplasia, the histology was either unavailable or was not consistent with the diagnosis. Two cases appear now to have had the ectopic ACTH Syndrome. Adrenalectomy was the commonest treatment offered. There were no intra-operative or post-operative deaths but recurrence was common after subtotal adrenalectomy in Cushing's disease. Twenty-seven per cent of the patients developed Nelson's syndrome, which was fatal in 50%. Long-term hormone replacement therapy was unnecessary after surgery for adrenal adenomas. Treatment of Cushing's syndrome was well tolerated by the patients.
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PMID:A clinico-pathological study of Cushing's syndrome at the University Hospital of the West Indies and a review of the literature. 1139 90

This is a case report of a 23 year old female. She had earlier been diagnosed to have Cushing's syndrome due to macronodular adrenal hyperplasia, for which bilateral adrenalectomy was performed three years before. The initial full recovery was sustained for about one and a half years, following which there was progressive recurrence of obesity, hypertension and hypercalcaemia. Plasma cortisol concentrations were markedly elevated and a diagnosis of recurrent Cushing's syndrome was made. Pre-operative localisation of the source of hypercortisolism through intravenous urogram, abdominal ultrasonogram and computerised tomogram was unfruitful, thus an exploratory laparatomy was undertaken. At surgery, extensive and dense adhesions were seen which caused difficult dissection and accidental injury to the patient's liver and kidney, necessitating massive intra-operative blood transfusions. The patient died within two hours of recovery from anaesthesia of acute massive pulmonary embolism. We postulate that the recurrent Cushing's syndrome in this patient could have been due autografting of remnants of adrenal tissue within the abdominal cavity. A pre-operative localisation with radio-labelled cholesterol scanning may have made reoperation of the patient easier.
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PMID:A follow up report: recurrent Cushing's syndrome after bilateral adrenalectomy. 1150 90

With increasing case reports, it has been indicated that some cases with adrenocorticotropic hormone (ACTH)-independent macronodular adrenal hyperplasia (AIMAH) show abnormal responses in cortisol to various stimulation tests. Here we report a case of AIMAH that showed an aberrant response to angiotensin II via AT1 receptor in cortisol hypersecretion. A 53-yr-old man was admitted to our division seeking further examinations for the possible diagnosis of Cushing's syndrome. He had hypertension, diabetes mellitus, and physical stigmata, such as moon face and central obesity. His plasma ACTH level was undetectable, and plasma cortisol level was high. Plasma cortisol showed no normal diurnal rhythm and was not suppressed after the administration of 8 mg of dexamethasone. Abdominal computed tomography demonstrated nodular enlargement of bilateral adrenal glands. He was diagnosed with Cushing's syndrome owing to AIMAH. An injection of arginine vasopressin (AVP) increased plasma cortisol and aldosterone levels, whereas ACTH remained undetectable. After 4 h in an upright position, plasma cortisol and aldosterone levels were increased. Pretreatment with candesartan, angiotensin II receptor AT1 antagonist, blocked the increase in plasma cortisol level. These results suggested a possibility of adrenal hypersensitivity to angiotensin II and AVP in cortisol secretion. Bilateral laparoscopic adrenalectomy was performed. The histological findings of the specimen were compatible with AIMAH. In summary, we have made the first report on a case of AIMAH with possible hypersensitivity to angiotensin II.
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PMID:Case of adrenocorticotropic hormone-independent macronodular adrenal hyperplasia with possible adrenal hypersensitivity to angiotensin II. 1157 27


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