Low-renin hypertension is a subtype of high blood pressure where a person has lower than typical renin levels. Renin is an enzyme that regulates blood volume and blood pressure.
While it can affect anyone, it is more prevalent in African Americans and Caribbean Hispanics. Various genetic or acquired syndromes can also cause low-renin hypertension. Diagnosing the cause is vital for treatment since low-renin hypertension may not respond well to standard high blood pressure treatments.
Renin is part of a cascade of chemical processes that ultimately influence blood pressure. The kidneys release renin, which triggers the release of angiotensin and aldosterone. The latter regulates blood pressure and salt levels in the blood. High aldosterone can increase salt sensitivity, raising blood pressure.
Read on to learn more about low-renin hypertension.
Low-renin hypertension occurs when a person has atypically lower renin levels, which leads to high blood pressure.
However, in low-renin hypertension, aldosterone levels are often either typical or high. Measuring aldosterone levels may help diagnose the underlying cause.
Researchers do not fully understand why some people with low renin develop high blood pressure. Some research suggests that increased salt sensitivity has associations with low circulating renin levels.
Like other causes of hypertension, low-renin hypertension
However, when symptoms do occur, they may include:
When a person has hyperaldosteronism — or elevations in aldosterone — they may have symptoms. Aldosterone regulates blood pressure and salt levels in the blood.
Symptoms of hyperaldosteronism
However, low renin does not necessarily cause elevated aldosterone.
Several inherited syndromes can cause low-renin hypertension. It can also be a symptom of a very high salt diet.
To determine the cause, doctors will
- Low-normal aldosterone may signal Gordon syndrome, a rare inherited disorder that can also affect the joints.
- Low aldosterone can signal several genetic and acquired causes, including:
- High-normal aldosterone may signal primary hyperaldosteronism, the most common cause of low-renin hypertension. Primary hyperaldosteronism can occur for
various reasons, including cancers and rare genetic syndromes.
Diagnosis begins with multiple blood pressure readings to confirm a person has high blood pressure. A person may need to check their blood pressure at home over several days or weeks.
A doctor will review a person’s medical or family history, including their medications and general lifestyle habits. Other helpful tests to assess for low-renin hypertension involve:
- blood tests, potentially to evaluate levels of renin and aldosterone
- urine tests
- genetic testing, especially if doctors suspect a person has a rare genetic disease
- aldosterone suppression tests, if doctors suspect a person has primary hyperaldosteronism
Treatment depends on the cause of low-renin hypertension. It can involve the following.
Doctors may prescribe drugs according to a person’s underlying diagnosis. For example, people with Liddle syndrome often respond well to amiloride or triamterene drugs.
Learn more about diuretics.
Doctors may recommend surgery for hyperaldosteronism due to adrenal adenoma, which refers to a benign tumor, from one adrenal gland. When hyperaldosteronism is due to adrenal hyperplasia — or swelling — that affects both adrenal glands, medication is usually the best course of action.
Learn more about adrenal gland removal.
Other measures a doctor may recommend include:
- quitting smoking, if applicable
- maintaining or attaining a moderate body weight
- treating obstructive sleep apnea
Learn more about how to improve heart health.
Because people with low-renin hypertension are often sensitive to salt, a low sodium diet can improve symptoms. Table salt is only one source of sodium in the diet, so people need to check food labels, especially for highly processed and preprepared packaged meals.
Low renin-hypertension is a subtype of high blood pressure where a person has reduced levels of renin. People with this condition may not respond well to standard high blood pressure treatments.
Only a healthcare professional can diagnose low renin and help determine its cause, so seek medical care for high blood pressure. Consult a doctor if there is a family history of low renin or metabolic syndromes, as these are risk factors for low-renin hypertension.
A doctor may recommend treatments that treat the underlying cause of low renin levels or lifestyle modifications to help someone manage their condition better, such as eating a low sodium diet.