Primary aldosteronism
Primary aldosteronism | |
---|---|
Other names | Primary hyperaldosteronism, Conn's syndrome |
low salt diet[1] | |
Frequency | 10% of people with high blood pressure[1] |
Primary aldosteronism (PA), also known as primary hyperaldosteronism, refers to the excess production of the hormone aldosterone from the adrenal glands, resulting in low renin levels and high blood pressure.[1] This abnormality is caused by hyperplasia or tumors. About 35% of the cases are caused by a single aldosterone-secreting adenoma, a condition known as Conn's syndrome.[7][8]
Many patients experience fatigue,
Primary
Some cases may be cured by removing the adenoma by surgery after localization with adrenal venous sampling (AVS).
Primary aldosteronism is present in about 10% of people with high blood pressure.
Signs and symptoms
People often have few or no symptoms.[1] They may get occasional muscular weakness, muscle spasms, tingling sensations, or excessive urination.[1]High blood pressure, manifestations of muscle cramps (due to hyperexcitability of neurons secondary to low blood calcium), muscle weakness (due to hypoexcitability of skeletal muscles secondary to hypokalemia), and headaches (due to low blood potassium or high blood pressure) may be seen.[citation needed]
Secondary hyperaldosteronism is often related to decreased cardiac output, which is associated with elevated renin levels.[13]
Causes
The condition is due to:[14]
- Bilateral idiopathic (micronodular) adrenal hyperplasia: 66% of cases[1]
- Adrenal adenoma (Conn's disease): 33% of cases[1]
- Primary (unilateral) adrenal hyperplasia: 2% of cases
- Aldosterone-producing adrenocortical carcinoma: <1% of cases
- Familial Hyperaldosteronism (FH)
- Glucocorticoid-remediable aldosteronism (FH type I): <1% of cases
- FH type II (APA or IHA): <2% of cases
- Ectopic aldosterone-producing adenoma or carcinoma: < 0.1% of cases
Genetics
40% of people with an adrenal aldosterone producing adenoma have somatic gain-of-function mutations in a single gene (KCNJ5).[15] This gene is mutated in inherited cases of early onset primary aldosteronism and bilateral adrenal hyperplasia, albeit less frequently.[16] These mutations tend to occur in young women with the adenoma in the cortisol secreting zona fasciculata. Adenomas without this mutation tend to occur in older men with resistant hypertension.[citation needed]
Other genes commonly mutated in aldosterone producing adenomas are
Pathophysiology
Aldosterone has effects on most or all cells of the body but, clinically, the most important actions are in the
In summary, hyperaldosteronism causes hypernatremia, hypokalemia, and metabolic alkalosis.[13]
Finer notes on aldosterone include the fact that it stimulates sodium-potassium ATPase in muscle cells, increasing intracellular potassium and also increases sodium reabsorption all along the intestine and nephron, possibly due to widespread stimulation of sodium-potassium ATPase. Finally, epithelial cells of sweat gland ducts and distal colon surface respond exactly the same as the principal cells of the nephron. These responses are important in climate adaptation and as a cause of constipation with elevated aldosterone[citation needed].
The sodium retention leads to plasma volume expansion and
Diagnosis
Screening may be considered in people with high blood pressure presenting with low blood potassium, high blood pressure that is difficult to treat, other family members with the same condition, or a mass on the adrenal gland.[1]
Measuring aldosterone alone is not considered adequate to diagnose primary hyperaldosteronism. Rather, both renin and aldosterone are measured, and a resultant aldosterone-to-renin ratio (ARR) is used for case detection.[20][21] A high aldosterone-to-renin ratio suggests the presence of primary hyperaldosteronism. The diagnosis is made by performing a saline suppression test, ambulatory salt loading test, or fludrocortisone suppression test.[22]
Measuring sodium and potassium concentrations simultaneously in serum and urine specimens has been suggested for screening purposes. Calculating the serum sodium over urinary sodium to serum potassium over urinary potassium (SUSPUP) and the (serum sodium to urinary sodium to (serum potassium)2 (SUSPPUP) ratios delivers calculated structure parameters of the RAAS, which may be used as a static function test.[23][24] Its results have to be confirmed by calculating the ARR.[citation needed]
If primary hyperaldosteronism is confirmed biochemically, CT scanning or other cross-sectional imaging can confirm the presence of an adrenal abnormality, possibly an adrenal cortical
The diagnosis is best accomplished by an appropriately-trained subspecialist, though primary care providers are critical in recognizing clinical features of primary aldosteronism and obtaining the first blood tests for case detection.[citation needed]
Classification
Some people only use Conn's syndrome for when it occurs due to an adrenal adenoma (a type of benign tumor).[29] In practice, however, the terms are often used interchangeably, regardless of the underlying physiology.[1]
Differential diagnosis
Other causes of treatment-resistant hypertension include
Treatment
The treatment for hyperaldosteronism depends on the underlying cause. In people with a single benign tumor (
In the absence of treatment, individuals with hyperaldosteronism often have poorly controlled high blood pressure, which may be associated with increased rates of
Esaxerenone, the first non-steroidal mineralocorticoid blocker, was approved in 2019 in Japan to treat essential hypertension. Finerenone, a drug belonging to the same class, reached phase 3 clinical trial in 2020, but is not yet considered for hypertension. More importantly, next-generation Aldosterone Synthase Inhibitors have entered the research pipeline with CIN-107 undergoing Phase 2 clinical trial as of 2021[32]
Epidemiology
In the past, the prevalence of primary aldosteronism was considered to be less than 1% of patients with hypertension. More recent studies have reported much higher prevalence of primary aldosteronism, up-to 12.7% in primary care and to 29.8% in referral centers.[33] Very low rates of compliance with screening guidelines lead to the underdiagnoses of primary aldosteronism.[34][35]
Society and culture
The Primary Aldosteronism Foundation[36] is a patient-driven initiative committed to creating the paradigm shift that will lead to optimum diagnosis and treatment of primary aldosteronism by raising awareness, fostering research, and providing support to patients and healthcare professionals worldwide.[citation needed]
Eponym
Conn's syndrome is named after
References
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- ^ a b "Primary hyperaldosteronism (Conn's syndrome or aldosterone-producing adrenal tumor)". Archived from the original on 19 April 2015. Retrieved 8 April 2015.
- ^ PMID 20498828.
- ^ a b c d "Primary hyperaldosteronism (Conn's syndrome or aldosterone-producing adrenal tumor)". Archived from the original on 28 March 2015. Retrieved 8 April 2015.
- ^ ISBN 9781846288814. Archivedfrom the original on 2016-06-30.
- ^ a b "Primary hyperaldosteronism (Conn's syndrome or aldosterone-producing adrenal tumor)". Archived from the original on 9 April 2015. Retrieved 8 April 2015.
- ISBN 978-0-323-53113-9.
- ISBN 978-1-264-26850-4.
- ^ PMID 30969601.
- ^ ISSN 2542-7075.
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- ISBN 9780080920467. Archivedfrom the original on 2016-06-30.
- ^ a b c "Hyperaldosteronism". The Lecturio Medical Concept Library. Retrieved 25 July 2021.
- ISBN 978-1-4160-2911-3.
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- PMID 21311022.
- ^ S2CID 205346722.
- ^ S2CID 205347424.
- PMID 26815163.
- PMID 15483077.
- ^ "Renin/Aldosterone Protocol". United Bristol Healthcare NHS Trust. Archived from the original on 2007-08-13.
- ^ PMID 18552288.
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- ISBN 978-0-7216-0187-8.
- ^ "Inspra (eplerenone) [prescribing information]". Archived from the original on 2011-08-08. Retrieved 2011-07-17.
- ^ "Hyperaldosteronism (Conn's Syndrome)". Columbia Adrenal Center. Archived from the original on 2011-05-26.
- ^ "Spark-PA – Spark-PA is a clinical research study exploring an investigational study drug that may help people with primary aldosteronism (PA) lower their blood pressure". Archived from the original on 2021-08-02. Retrieved 2021-03-05.
- S2CID 13922901.
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- ^ "Welcome to the Primary Aldosteronism Foundation". Retrieved 2021-03-05.
External links
- Funder JW, Carey RM, Mantero F, Murad MH, Reincke M, Shibata H, et al. (May 2016). "The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment: An Endocrine Society Clinical Practice Guideline". The Journal of Clinical Endocrinology and Metabolism. 101 (5): 1889–1916. PMID 26934393.