Primary hyperaldosteronism = Conn syndrome

There are several factors that can correlate with the hypokalemia together with the primary hyperaldosteronism:

1. increased secretion of aldosterone (increased renal K wasting)
2. sufficient intravascular volume (facilitation of sufficient water delivery to the distal convoluted tubule & collecting duct to facilitate K loss )
3. adequate K dietary intake (this increases total body K, renal Na delivery, increasing renal K loss.)

Physiologic and, thus, normal regulation of aldosterone secretion is mediated by renin, serum K, serum Na, intravascular volume, corticotropin.

Morbidity & mortality in Conn syndrome are primarily related to level of hypokalemia (can causes life-threatened arrhythmia) and hypertension.

Primary Hyperaldosteronism

=

autonomous aldosterone production

+

low levels of plasma renin

+

moderately expanded IntraVascular & ExtraVascular fluid volumes

  

Causes of Primary Hyperaldosteronism:

• APA - High aldosterone, low PRA
• IHA - Responds to posture (bilateral adrenal hyperplasia)
• Primary adrenal hyperplasia - Responds to posture (unilateral disease)
• FH-I (GRA) - Sustained suppression of aldosterone (< 4 ng/dL) with dexamethasone
• FH-II/FH-III - Familial (probably autosomal dominant)

 
Causes of conditions that mimic aldosterone excess include the following:

• Congenital adrenal hyperplasia (11β-hydroxylase deficiency and 17α-hydroxlyase deficiency) - Low aldosterone, low PRA, elevated steroid intermediates
• Primary glucocorticoid resistance - High glucocorticoid secretion unsuppressed by dexamethasone
• Deoxycorticosterone-secreting tumors - Elevated deoxycorticosterone levels
• Syndrome of apparent mineralocorticoid excess
• Liddle syndrome
• Licorice ingestion
• Carbenoxolone

 

 

 

 

 

Clinical picture:

Usually these patients don't have distinctive clinical findings, most common findings:

• hypertension, especially diastolic
• abdominal distention
• weakness
• different findings, which from hypertension: carotid & bruits, hypertensive encephalopathy, cardiac failure, hypertensive retinal changes
• fatigue
• polyuria
• polydipsia
• headaches.

Labs:

• hypo K
• low renin
• metabolic alkalosis
• hyper Na
• failure to suppress aldosterone with the sault loading