Aldosterone

Morning Aldosterone-to- renin ratio with serum aldosterone

Draw plasma renin activity and aldosterone level between 8am and 10am

Serum aldosterone level > 15 ng/dL and ARR >20 have sensitivity and specificity >90%.

-Discontinue low sodium diet

-Replete hypokalemia

-Avoid chewing tobacco and licorice

-Stop K-sparing diuretics and aldosterone inhibitors x4 weeks (can continue if high level of suspicion for aldosteronoma, but will require repeat testing after holding medications if renin activity is detectable)

-Ok to continue anti-HTN medication in screening setting

In patients with hypokalemia, plasma aldosterone concentration > 20 ng/dL, and plasma renin activity below limit of detection, confirmatory testing is not required to confirm hyperaldosteronism.

Otherwise, refer to endocrine for confirmatory testing.

Adrenal vein sampling is required to confirm unilateral aldosterone excess prior to surgical resection, EXCEPT in patients <35 with hypokalemia, marked aldosterone excess, and clear unilateral adrenal lesions consistent witha adenoma.

Cortisol

Low dose dexamethasone suppression testing (LDDST)

-1mg dexamethasone taken 11pm-12am

-Cortisol level drawn between 8am and 9am

-optional dexamethasone level at time of cortisol level

-Cortisol >5 mcg/dL 95% specific but 18% false negative

-Cortisol >1.8 mcg/dL 90% sensitive, 80% specific

-Dexamethasone levels should be >0.22mcg/dL

-None required. Can consider holding oral contraceptives or stopping other medications which may interact with steroid metabolism

-Repeat with oral contraceptive pills held x7 days if LDDST abnormal.

-Otherwise confirmation only required if equivocal.

-Patients testing positive should be screened for hypertension, diabetes, and vertebral fractures

-Morning ACTH level required for further workup of etiology

Late-night salivary cortisol

Saliva sample taken between 11pm and 12am

Cortisol >145ng/dL has >90% sensitivity and specificity

Inaccurate results may be caused by

-altered circadian rhythm

-acute or chronic illness

-tobacco products used on the day of testing

Metanephrines

Plasma free metanephrines

Blood draw

- Patient ideally in supine position with reference ranges based on supine patients

- Liquid chromatography-based test

The following are highly specific:

- Elevation of BOTH metanephrine and normetanephrine

- Elevation of either >3x the upper limit of normal (ULN)

Lesser elevations still > ULN should prompt confirmatory testing

Hold the following medications:

-alpha-1 antagonists (esp phenoxybenzamine)

-tricyclic antidepressants and cyclobenzaprine

-caffeine (24 hours)

-acetaminophen (5 days)

Confirmation only required if equivocal. Options include:

- Repeat testing under strict testing conditions (i.e. supine position for 20 minutes prior to blood draw + hold full list of medications and supplements that might interfere. See Discussion)

- Measurement of plasma catecholamines

- Clonidine suppression testing

24-hour urinary fractionated metanephrines

24-hour urine collection. Test:

-metanephrine

-normetanephrine

-total metanephrine

-creatinine

Adrenal Sex Steroids

serum: DHEA-S, testosterone, estradiol, 17-OH progesterone, androstenedione

Blood Draw

Only recommended to measure if high suspicion for ACC or in cases of new excessive virilization or feminization

Elevation of one or multiple of these is suggestive of adrenocortical carcinoma. Can be used as tumor markers in monitoring of adrenocortical caricnoma. Does not generally affect preoperative management

None