Researchers developing non-invasive test for dangerous condition

High blood pressure affects more than six million Canadians and is a leading cause of heart attacks and strokes. About a fifth of these individuals suffer from primary aldosteronism, a condition in which one or both adrenal glands produce too much salt-retaining hormone. 

Primary aldosteronism is a dangerous condition, as sufferers are far more likely to develop a stroke, heart attack, irregular heart rhythm, or kidney damage than their counterparts with high blood pressure from other causes. 

According to Alex Leung, MD, an endocrinologist and researcher, it’s relatively simple to determine whether an individual is overproducing the salt-retaining hormone. However, the challenge comes in determining whether one or both adrenal glands are involved.  

It is important for doctors to know which gland is involved, because if only one gland is involved, surgery is possible and preferred as it can completely reverse symptoms. If both glands are involved, patients are treated with medications, which often have side effects. But the existing test that is used to determine which gland is overactive is difficult and invasive, says Leung. 

“It’s involves inserting a catheter at the top of both legs near the groin. This procedure is only performed by a small number of experts in a handful of places around the world. That means many people don’t have access to the test and may be overlooked for potentially curative surgery." 

Leung is part of team that is developing a simple alternative to the invasive test. 

Leung, along with co-principal applicant Dr. Gregory Kline, MD, and their team developed a simple test that relies on non-invasive imaging to determine which adrenal glands are involved. 

In this test, patients receive a medication called CETO and are sent for a PET-CT scan. The medication, CETO, hones in on the malfunctioning adrenal gland. 

“It’s relatively easy to see, because the overactive adrenal gland lights up brightly in the scan,” says Leung, adding results can be seen within two hours. 

According to Leung, this builds on previous work done by researchers at Cambridge University over the last decade. Originally, the medication used for the PET-CT scan had an extremely short lifespan, making it difficult to perform at other centers. 

Leung and his team will be using an alternative form of the medication, CETO, which lasts much longer.

“This makes it easier and more practical to use in many centers around the world,” says Leung. 

The team received a $253,216 CIHR project grant to support this work. They will conduct a three-year clinical trial involving 30 patients to prove the effectiveness of the test. 

“It’s an exciting step,” says Leung. “We estimate that primary aldosteronism impacts at least 100,000 people in the province.” 

Dr. Alex Leung is an endocrinologist and an associate professor in the departments of Medicine and Community Health Sciences in the Cumming School of Medicine, and a member of the Libin Cardiovascular Institute of Alberta and the O'Brien Institute for Public Health.

Dr. Gregory Kline is an endocrinologist and clinical professor in the Department of Medicine in the Cumming School of Medicine.