Hormone Fix for Treatment-Resistant High Blood Pressure

You may never have heard of aldosterone — many people haven’t — but this hormone is vital to your body’s healthy function. Produced by the adrenal glands that sit atop the kidneys, aldosterone conducts a veritable symphony of body functions, speeding up and slowing down changes in levels of potassium, sodium and other electrolytes in your blood, all in order to keep blood pressure from fluctuating too much.

For many, many people, aldosterone does its job admirably, never causing a missed note or reason for concern — but if you are among the millions of people who have high blood pressure, you should pay careful attention to this story. We know from lots of research that aldosterone may play a role in what’s known as resistant hypertension — blood pressure that is extremely difficult to control. And now a new study sheds more light on why that is and provides insights that may help solve the problem.

Your Aldosterone, Your Brain and Your Heart

For more information on aldosterone, I called the study author, Wanpen Vongpatanasin, MD, associate professor of internal medicine at University of Texas Southwestern Medical Center in Dallas. Until lately, she told me, it was believed that the problems caused by elevated levels of aldosterone occurred primarily in the kidneys. New research demonstrates, however, that the hormone also affects many parts of the brain, which then in turn interact with the cardiovascular system.

Dr. Vongpatanasin’s study examined how aldosterone affected specific areas of the nervous system where chemicals signal the brain to constrict blood vessels. After measuring these signals in patients with high aldosterone levels, researchers found that there was heightened activity that led to greater vessel constriction and hence elevated blood pressure.

While there are several causes for elevated aldosterone, for the most part, people who have this condition remain unaware of it unless, or until, it affects their blood pressure. Among the causes of high aldosterone are several rare genetic conditions… age… certain illnesses (heart failure, cirrhosis, kidney failure)… and having a tumor (usually a benign one) on the adrenal gland.

What to Do?

If you have hypertension that proves resistant to treatment, you may want to ask your doctor to test your aldosterone level, because that’s the cause in an estimated 10% to 20% of people with this problem. Knowing that you are among them will allow you and your doctor to address and possibly correct the problem.

Here are the steps that Dr. Vongpatanasin typically recommends…

  • Get tested for aldosterone. The starting point is a blood test that specifically checks your aldosterone level. If this test establishes that there is a problem, you will need to do a 24-hour urine catch to determine more precisely how high your aldosterone level is. This is called a salt-loading test because you consume a lot of dietary salt for five days beforehand. Why? Excess dietary salt normally shuts down aldosterone production, but this doesn’t happen in people who produce too much of the hormone. As a result, people with this problem tend to retain excess sodium.
  • Have a CT scan to learn whether you have an adrenal tumor. For reasons unknown, tumors on the adrenal gland trigger a hyperactive mode for aldosterone production. Ninety percent of the time, these tumors are benign and surgical removal of them solves the problem. Malignancies, of course, may require more complex treatment.
  • Consider whether you need medications to control aldosterone. In people who don’t have a tumor, the drug spironolactone (Aldactone), which blocks aldosterone from its receptors in the brain and the kidney, is useful, says Dr. Vongpatanasin, noting that it’s also helpful for those with a tumor who aren’t candidates for surgical removal.
  • Reduce dietary sodium, and increase fruits and vegetables in your diet. Cutting sodium helps bring aldosterone levels back in line. For most people, the general guideline for salt intake is now about one teaspoon per day, according to the National Institute of Medicine, but for those who are more sensitive (including people who have high aldosterone), the recommended upper limit should be no more than half that amount. And Dr. Vongpatanasin told me that research shows that while people who live in places without lots of processed foods have high aldosterone levels at the same rate as the rest of the world, they don’t tend to develop elevated blood pressure. It’s likely that the lower sodium intake from their fresh- and whole-food diets deters hypertension.

This adds an important and newsworthy bit of information to the quest to learn better ways to control blood pressure!