Adrenal
Hyperaldosteronism
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Hyperaldosteronism
, Aldosteronism, Conn's Disease, Conn's Syndrome
Epidemiology
Represents under 6% of
Hypertension Causes
Most common cause of drug
Resistant Hypertension
Peak age 30-50 years
More common in women
Pathophysiology
Inappropriate
Aldosterone
Hypersecretion
Primary Hyperaldosteronism (See Causes below)
Increased
Aldosterone
is initiating event
Results in
Sodium
retention and volume increase
Renin
decreases
Secondary Hyperaldosteronism (See Causes below)
Decreased circulating volume is initiating event
Results in increased renin and
Aldosterone
Results in
Sodium
retention
Physiologic response to
Aldosterone
Excess
Increased renal distal tubular
Sodium
reabsorption
Increased total body
Sodium
content
Increased water retention
Escape phenomenon
Compensatory increased ANF secretion
Hypertension
may not be solely volume expansion
Increased
Peripheral Vascular Resistance
Hypokalemia
:
Potassium
lost in distal renal tubule (
Potassium
wasting)
Alkalosis: Ammoniagenesis
Hydrogen Ion
loss (avid
Sodium
retention)
Polyuria
: Decreased renal concentrating ability
Plasma renin suppressed
Unresponsive to intravascular volume depletion
Causes
Primary Hyperaldosteronism (Conn's Disease)
Solitary
Adrenal Adenoma
s (80-90%)
Bilateral adrenal hyperplasia (10-20%)
Idiopathic Hyperaldosteronism
Accounts for 50% of cases at some referral centers
Adrenal Carcinoma (rare)
Unilateral Adrenal Hyperplasia (very rare)
Secondary Hyperaldosteronism
Hypertensive States
Primary
Renin
ism (rare renin producing tumor)
Secondary reninism due to decreased renal perfusion
Edematous State
s
Cirrhosis
Nephrotic Syndrome
Miscellaneous causes
Excessive
Growth Hormone
(
Acromegaly
)
Symptoms
Often Asymptomatic
Frontal
Headache
Muscle Weakness
to
Flaccid Paralysis
(
Hypokalemia
)
Polyuria
and Polydipsia (carbohydrate intolerance)
Signs
Hypertension
May be severe
Rarely malignant
Motor Exam
with decreased
Muscle Strength
Labs
Serum
Electrolyte
s
Serum Potassium
decreased (
Hypokalemia
)
Hypokalemia
is the most prominent feature of Hyperaldosteronism
However,
Potassium
is normal in 50% of Hyperaldosteronism causes
Serum Sodium
increased (Mild)
Metabolic Alkalosis
Morning
Aldosterone
to PRA ratio
Ratio over 20-25 (esp if >100) suggests Hyperaldosteronism
Aldosterone
>15 ng/dl and plasma renin low
Serum
Aldosterone
alone may be normal in 25% of Hyperaldosteronism patients
Technique
Obtain 2 hours after waking and in upright position
Stop
Spironolactone
,
Eplerenone
,
Amiloride
,
Triamterene
,
Potassium
-wasting
Diuretic
s 4 weeks before test
Consider stopping antihypertensives and
NSAID
s before test
May use
Verapamil
XR,
Hydralazine
or
Alpha Adrenergic Antagonist
for
Blood Pressure
control
Saline suppression
IVF: 300-500 cc/hour for 4 hours
Normal response
Aldosterone
usually under 0.28
Renin
usually suppressed
Differential Diagnosis
Hypertension
with
Hypokalemia
Cushing's Disease
Low
Aldosterone
and Low Plasma
Renin
Renal Artery Stenosis
or other renal cause
High
Aldosterone
and High Plasma
Renin
Management
Adrenal Adenoma
Surgical excision
Adrenal Hyperplasia
First-Line Agents
Spironolactone
(
Aldactone
)
Alternative agents if
Gynecomastia
develops on
Spironolactone
Eplerenone
(
Inspra
)
Amiloride
(
Midamor
)
Precautions
Follow
Serum Potassium
and
Serum Creatinine
every 6 months with these agents
References
Charles (2017) Am Fam Physician 96(7): 453-61 [PubMed]
Mosso (2003) Hypertension 42(2): 161-5 [PubMed]
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