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Low renin hypertension.

Sahay M, Sahay RK - Indian J Endocrinol Metab (2012)

Bottom Line: Low renin hypertension is an important and often underdiagnosed cause of hypertension.It may be associated with high aldosterone levels as in Conn's syndrome or low aldosterone levels as in Liddle syndrome, and syndrome of apparent mineralocorticoid excess, glucocorticoid remediable hypertension etc.Some forms of essential hypertension are also associated with low renin levels.

View Article: PubMed Central - PubMed

Affiliation: Deparment of Nephrology, Osmania General Hospital, Hyderabad, Andhra Pradesh, India.

ABSTRACT
Low renin hypertension is an important and often underdiagnosed cause of hypertension. It may be associated with high aldosterone levels as in Conn's syndrome or low aldosterone levels as in Liddle syndrome, and syndrome of apparent mineralocorticoid excess, glucocorticoid remediable hypertension etc. Some forms of essential hypertension are also associated with low renin levels. Hypokalemia may be an important finding in low renin hypertension. The aldosterone to renin ratio helps in correct diagnosis. The treatment varies with etiology hence an accurate diagnosis is essential. Aldosterone antagonists play an important role in medical management of some varieties of low renin hypertension.

No MeSH data available.


Related in: MedlinePlus

Mutation in glucocorticoid remediable hypertension
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Figure 2: Mutation in glucocorticoid remediable hypertension

Mentions: Glucocorticoid- remediable aldosteronism (GRA) is a rare form of hyperaldosteronism in which the hyper secretion of aldosterone is under the control of ACTH. Normally two isozymes of 11-beta-hydroxylase encoded by two genes on chromosome 8 are responsible for the biosynthesis of aldosterone and cortisol. The isozyme in the zona glomerulosa (CYP11B2, aldosterone synthase, P450as) catalyzes the conversion of deoxycorticosterone to corticosterone (controlled by ACTH) and of 18-hydroxycorticosterone to aldosterone. The isozyme in the zona fasciculata (CYP11B1, P450c11) catalyzes the conversion of 11-deoxycortisol to cortisol and does not contribute to aldosterone synthesis. The mutation in patients with GRA is fusion of the promoter region of the gene for CYP11B1 and the coding sequences of CYP11B2, resulting in ACTH-dependent activation of the aldosterone synthase effect on cortisol, corticosterone, and cortisol precursors [Figure 2]. Glucocorticoid-remediable aldosteronism is inherited as an autosomal dominant trait. It is characterized by positive family history and onset of hypertension before age 21. The plasma potassium concentration is normal in more than 50% of cases of GRA in contrast to primary aldosteronism due to an adrenal adenoma. This is because aldosterone release in GRA is under the influence of ACTH; with the normal circadian rhythm of ACTH release, aldosterone secretion is above normal for only part of the day. Aldosterone release is insensitive to potassium loading due to location of aldosterone synthesis in the zona fasciculata. The lack of aldosterone response to dietary potassium also reduces net al.dosterone release. There is marked hypokalemia after thiazide diuretic (which increases sodium delivery to the aldosterone-sensitive potassium secretory site in the cortical collecting tubule). GRA is associated with bilateral adrenal hyperplasia. In patients with GRA, 20 percent can have a cerebrovascular complication, 70 percent of which are hemorrhagic strokes due to ruptured intracranial aneurysms. The increase in hemorrhagic stroke is due to early onset hypertension during the early stages of cerebrovascular development. All patients with genetically proven GRA should undergo screening MR angiography at puberty and every five years thereafter. The diagnosis is suspected on the basis of the history. The plasma aldosterone is elevated and plasma renin activity is suppressed, but the aldosterone-renin ratio is typically not as high as with primary aldosteronism caused by an aldosterone-producing adenoma. The diagnosis is established by dexamethasone suppression testing and demonstration of hyper secretion of 18-carbon oxidation products of cortisol: 18-hydroxycortisol and 18-oxocortisol. However, genetic testing is the gold standard.[910] Indications for genetic screening include primary aldosteronism patients with onset at a young age (e.g., <20 years), or a family history of primary aldosteronism or of strokes at a young age (e.g., <40 years).[7]


Low renin hypertension.

Sahay M, Sahay RK - Indian J Endocrinol Metab (2012)

Mutation in glucocorticoid remediable hypertension
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3475896&req=5

Figure 2: Mutation in glucocorticoid remediable hypertension
Mentions: Glucocorticoid- remediable aldosteronism (GRA) is a rare form of hyperaldosteronism in which the hyper secretion of aldosterone is under the control of ACTH. Normally two isozymes of 11-beta-hydroxylase encoded by two genes on chromosome 8 are responsible for the biosynthesis of aldosterone and cortisol. The isozyme in the zona glomerulosa (CYP11B2, aldosterone synthase, P450as) catalyzes the conversion of deoxycorticosterone to corticosterone (controlled by ACTH) and of 18-hydroxycorticosterone to aldosterone. The isozyme in the zona fasciculata (CYP11B1, P450c11) catalyzes the conversion of 11-deoxycortisol to cortisol and does not contribute to aldosterone synthesis. The mutation in patients with GRA is fusion of the promoter region of the gene for CYP11B1 and the coding sequences of CYP11B2, resulting in ACTH-dependent activation of the aldosterone synthase effect on cortisol, corticosterone, and cortisol precursors [Figure 2]. Glucocorticoid-remediable aldosteronism is inherited as an autosomal dominant trait. It is characterized by positive family history and onset of hypertension before age 21. The plasma potassium concentration is normal in more than 50% of cases of GRA in contrast to primary aldosteronism due to an adrenal adenoma. This is because aldosterone release in GRA is under the influence of ACTH; with the normal circadian rhythm of ACTH release, aldosterone secretion is above normal for only part of the day. Aldosterone release is insensitive to potassium loading due to location of aldosterone synthesis in the zona fasciculata. The lack of aldosterone response to dietary potassium also reduces net al.dosterone release. There is marked hypokalemia after thiazide diuretic (which increases sodium delivery to the aldosterone-sensitive potassium secretory site in the cortical collecting tubule). GRA is associated with bilateral adrenal hyperplasia. In patients with GRA, 20 percent can have a cerebrovascular complication, 70 percent of which are hemorrhagic strokes due to ruptured intracranial aneurysms. The increase in hemorrhagic stroke is due to early onset hypertension during the early stages of cerebrovascular development. All patients with genetically proven GRA should undergo screening MR angiography at puberty and every five years thereafter. The diagnosis is suspected on the basis of the history. The plasma aldosterone is elevated and plasma renin activity is suppressed, but the aldosterone-renin ratio is typically not as high as with primary aldosteronism caused by an aldosterone-producing adenoma. The diagnosis is established by dexamethasone suppression testing and demonstration of hyper secretion of 18-carbon oxidation products of cortisol: 18-hydroxycortisol and 18-oxocortisol. However, genetic testing is the gold standard.[910] Indications for genetic screening include primary aldosteronism patients with onset at a young age (e.g., <20 years), or a family history of primary aldosteronism or of strokes at a young age (e.g., <40 years).[7]

Bottom Line: Low renin hypertension is an important and often underdiagnosed cause of hypertension.It may be associated with high aldosterone levels as in Conn's syndrome or low aldosterone levels as in Liddle syndrome, and syndrome of apparent mineralocorticoid excess, glucocorticoid remediable hypertension etc.Some forms of essential hypertension are also associated with low renin levels.

View Article: PubMed Central - PubMed

Affiliation: Deparment of Nephrology, Osmania General Hospital, Hyderabad, Andhra Pradesh, India.

ABSTRACT
Low renin hypertension is an important and often underdiagnosed cause of hypertension. It may be associated with high aldosterone levels as in Conn's syndrome or low aldosterone levels as in Liddle syndrome, and syndrome of apparent mineralocorticoid excess, glucocorticoid remediable hypertension etc. Some forms of essential hypertension are also associated with low renin levels. Hypokalemia may be an important finding in low renin hypertension. The aldosterone to renin ratio helps in correct diagnosis. The treatment varies with etiology hence an accurate diagnosis is essential. Aldosterone antagonists play an important role in medical management of some varieties of low renin hypertension.

No MeSH data available.


Related in: MedlinePlus