May 2 (UPI) -- University of Western Ontario researchers have found that the use of two blood tests can drastically improve treatment for resistant hypertension in three countries in Africa.
Researchers used two simple blood tests on patients with hard-to-treat hypertension, or high blood pressure, living in Nigeria, Kenya and South Africa to create a more personalized and accurate therapy.
The tests identify levels of plasma renin, a protein secreted by the kidneys, in combination with levels of aldosterone, a hormone that causes salt and water retention, to identify the physiological changes that cause hypertension.
Researchers analyzed 94 patients with hypertension, with 42 receiving the usual course of treatment and 52 given the blood tests and then receiving treatment based on the results.
They found that just 11.1 percent of the patients who underwent the usual treatment had controlled blood pressure after one year compared to 50 percent of patients who were blood tested and received personalized treatment based on test results.
"If a patient has salt and water retention, it causes high blood pressure and also feeds back and shuts down both renin and aldosterone," Dr. David Spence, a professor at Western's Schulich School of Medicine and Dentistry, said in a press release.
Spence said that patients with low levels of both renin and aldosterone are more likely to have salt and water retention as a result of mutations affecting the kidney tubules. These patients respond specifically to the drug amiloride.
"The biggest difference is that there were more people being prescribed amiloride in the physiological treatment group," Spence said.
The study was published in the American Journal of Hypertension.