Bastyr Center for Natural Health

Bastyr Center for Natural Health

Clinic Shift of Eric Yarnell, ND

Last updated 8 Sept 2015

Hypertension Policies and Procedures

FOC Information to Obtain

1. When did the hypertension begin?

2. How was the hypertension diagnosed? (And was it by the clinical standard, of three consecutive elevated readings?)

3. Have there been any complications of the hypertension? (retinopathy, proteinuria, renal failure, TIA, stroke)

4. Is the hypertension symptomatic? (headache, pounding heart)

5. What treatments, natural or otherwise, have been and are being used? Are they effective?

6. Does the patient have a home BP cuff? Has it been checked against any other device for accuracy? Do they use it? How often? Do they record and track the results?

7. Is there a family history of hypertension or strokes?

Plasma Renin Activity and Aldosterone Assessment

Patients should have a fasting morning plasma renin activity test along with a serum aldosterone to help determine the cause of their hypertension if it is not known. If they are taking an ACEI, ARB, or beta-blocker, they must first be switched to a different drug class (preferably reserpine or a CCB) for 6 wk before a valid test can be determined.

Low-Renin hypertension: PRA <0.65 ng/ml/hr (~30% of patients), volume overload

Normal-Renin hypertension: PRA >0.65 ng/ml/hr (~50% of patients), vasoconstrictive

High-Renin hypertension: PRA >3.7 ng/ml/hr (~20% of patients), vasoconstrictive

Volume Hypertension
(“Wet” or Low-Renin Hypertension, Aldosteronism, Aldosterone dominance) / Renin Hypertension (“Dry,” Vasoconstrictive, or Inflammatory Hypertension)
PRA / <0.65 ng/ml/hr / >0.65 ng/ml/hr
Direct Renin
(less accurate) / <5 mU/ml / >5 mU/ml
Main etiology / Sodium-volume, r/o adrenal adenoma and hyperaldosteronism*
r/o unilateral renal artery stenosis (Kotliar 2010) / Renin-angiotensin-induced vasoconstriction/inflammation
r/o bilateral renal arterial stenosis (Kotliar 2010)
Frequency / 33% of patients
More common in elderly, blacks and Hispanics / 67% of patients
Complications / Uncommon, not related to severity of BP / Frequent, severe, out of proportion to BP

* Elevated morning (0800-1000) plasma aldosterone concentration to PRA ratio is main clue, followed by oral salt challenge followed by urine aldosterone concentration.

Treatment Based on Plasma Renin Activity

Volume Hypertension
(“Wet” or Low-Renin Hypertension, Aldosteronism, Aldosterone dominance) / Renin Hypertension (“Dry,” Vasoconstrictive, or Inflammatory Hypertension)
Diet indicated / Low salt / Anti-inflammatory
Herbs indicated / Diuretics (Urtica leaf, Taraxacum leaf, Solidago, Apium, etc.) / ACEi (Allium, Crataegus, Salvia miltiorrrhiza, Ganoderma, Olea, etc.)
Rauvolfia serpentaria
Inflammation modulators
Drugs indicated (bold = first-line therapy) / thiazide diuretic
aldosterone inhibitor*
calcium channel blocker
alpha blocker** / ACEi
ARB
beta blocker (reduce renin secretion)
reserpine
Drugs contraindicated / Glycyrrhiza / diuretics

* Spironolactone, eplerenone (the latter a mineralocorticoid receptor antagonist). These are potassium-sparing agents

** Not recommended, as studies show these drugs increase mortality long-term.

Treatment of Essential Hypertension

Volume Hypertension

1. Rule out renal artery stenosis (Kotliar, et al. 2010)

2. Salt restriction

Salt restriction does not cause rapid changes in blood pressure because renin synthesis goes up in response to salt restriction, leading to sodium retention by the kidneys and vasoconstriction (via angiotensins), which maintains blood volume and blood pressure.

Restricting dietary salt is helpful only in those patients who are salt sensitive or with low-renin hypertension, ie with PRA <0.65.

Do not restrict dietary salt in patients with high-renin (vasoconstrictive) hypertension unless they do not respond to anti-renin therapy.

3. Diuretic herbs and foods

4. If the above two measures have not lowered BP after three months, institute therapy with a thiazide diuretic.

5. If the thiazide diuretic doesn’t work, or causes problems, add Rauvolfia serpentina or reserpine.

6. If the combination of a thiazide and Rauvolfia doesn’t work, add an ACEi.

Renin Hypertension

1. No salt restriction.

2. Eat an anti-inflammatory diet (high in fruits, vegetables, legumes, nuts, and fish; low in other animal products)

3. Inflammation-modulating herbs

4. ACE-inhibiting herbs

5. If the above measures haven’t worked after three months, institute therapy with an ACEi or ARB drug.

6. If this doesn’t work, add a thiazide diuretic.

7. If this doesn’t work, add Rauvolfia or reserpine.

Malignant Hypertension

Definition: extremely high and rising BP, PRA highly elevated, serum aldosterone highly elevated, hypokalemia, damage to retina, kidneys, and heart

1. The patient should be transported to the hospital.

2. In the future, assess plasma renin activity and treat accordingly.

Primary Hyperaldosteronism

Definition: moderately elevated BP, PRA normal or low (<1 ng/ml/h), serum aldosterone elevated (>15 ng/dl or 415 pmol/L), serum aldosterone:PRA ratio elevated (>20 ng/dl/ng/ml/h or >555 pmol/L/ng/ml/h), hypokalemia, minimal cardiovascular, retinal or renal complications

Note: most common cause of secondary hypertension (and overall surprisingly common, perhaps as much as 10% of people with isolated hypertension)

Mechanism: benign adrenal tumors secretes excess aldosterone => high filtered sodium load =>

1) increased water retention by kidneys => increased blood volume => hypertension

2) suppresses renin synthesis => no feedback inhibition of tumor

1. Refer the patient for confirmation testing (imaging to detect large adrenal tumors or hypertrophied adrenals), subtyping, and assessment for appropriateness of surgery.

2. Patients should eat a low-sodium diet.

3. Patients should exercise regularly.

4. Patients should maintain a healthy body weight.

5. Patients should avoid tobacco products.

6. Patients with small or non-observable adenomas should be treated with mineralocorticoid blockers (typically spironolactone 12.5-25 mg qd, raised to 400 mg qd until normokalemia is achieved, then slowly dropped to 25-50 mg qd after 4-8 wk as BP normalizes). Do not combine with salicylates. Eplerenone 25 mg bid is an expensive alternative.

References

Kotliar C, Inserra F, Forcada P, et al. (2010) "Are plasma renin activity and aldosterone levels useful as a screening test to differentiate between unilateral and bilateral renal artery stenosis in hypertensive patients?" J Hypertens 28(3):594-601.

* Laragh J (2001) “Lesson I: A brief history of hypertension research: Renin is twice rejected” Am J Hypetension14:186-194.

* Young WF (2007) “Primary aldosteronism: Renaissance of a syndrome” Clin Endocrinol66:607-618.

Important Abbreviations

ACEi = angiotensin converting enzyme inhibitor

ARB = angiotension receptor blocker

BP = blood pressure

PRA = plasma renin activity