Major Study to Track Blood Pressure's Impact on Kidneys
Medical science knows that high blood pressure is bad, but researchers continue to question the benefits of keeping blood pressure low.
University of Colorado Denver is among 80 U.S. institutions participating in a new nine-year, $114 million study of 7,500 hypertensive patients to see whether holding their blood pressure at or below the level considered normal is better for hearts, minds and kidneys.
Blood pressure highs and lows
Michel Chonchol, MD
High blood pressure causes about 25,000 cases of kidney failure each year in the United States, according to the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), one of the study’s major sponsors.
Past research has shown that lowering blood pressure too far, however, can trigger cardiovascular problems, which was one of the reasons the NIH wanted to do the study, says Michel Chonchol, MD, a University of Colorado Hospital nephrologist and associate professor of Renal Medicine at UCD, and principal investigator for Colorado’s $1 million piece of the greater study.
Kidneys share the spotlight
Kidneys will be a major focus of the local take on the National Institutes of Health-funded Systolic Blood Pressure Intervention Trial (SPRINT), says Chonchol. UCD and UCH will host 120 to 150 patients once the study ramps up sometime next summer, he adds.
Study participants will be treated with commonly available blood pressure medications to achieve one of two different levels of blood pressure control – either less than 140 mmHg (standard group) or less than 120 mmHg (treatment group).
Patients participating in the UCH study will arrive with systolic blood pressure above 130 mmHg and low kidney function, indicated by estimated glomerular filtration rates (eGFRs) – which measure the volume of fluid filtered by the kidney’s capillaries – below 59.
“What is very unique is that, of the 7,500 patients, 3,500 will have chronic kidney disease,” Chonchol notes. “There have been lots of clinical trials examining the effect of blood pressure on cardiovascular outcomes, but most of these trials actually exclude patients with chronic kidney disease.”
The study will depend on patients taking their medicine for years on end. Chonchol says one can’t guarantee they will faithfully do so. But the study’s design will include checks to help keep patients on track.
Plus, he says, “there’s no question that patients in clinical trials tend to be more compliant than not.”
Find out more about the study
Contact Dr. Chonchol at (303) 399-6997.
This page is adapted from a story written by Todd Neff that appeared in the UCH Insider, the hospital's candid e-newsletter. The Insider, which is published biweekly, is available to people outside the hospital via a free e-mail subscription. Tyler Smith (email@example.com) is managing editor of the Insider.