More than 900 million adults worldwide and nearly one in three adult Americans have high blood pressure — one of the most common conditions among middle-aged and older adults. The National Institutes of Health (NIH) now has launched a large, clinical trial to determine whether maintaining blood pressure levels lower than current recommendations can further reduce the risk of cardiovascular and kidney diseases or age-related cognitive decline.

Called the Systolic Blood Pressure Intervention Trial (SPRINT), the nine-year, $114 million study will be conducted in more than 80 clinical sites across the country; the University of Colorado School of Medicine will participate and lead the trial in the Denver area.

"This is one of the largest NIH studies ever done around blood pressure control in patients with cardiovascular and kidney diseases," said Michel Chonchol, M.D., associate professor of Renal Medicine at the School of Medicine and principal investigator for the Denver site. "The patient population that will be enrolled in this trial — 7,500 people nationwide — will provide forceful and definitive study outcomes around the proper regulation of blood pressure as relates to decreasing the risk of cardiovascular and kidney disease."

High blood pressure is a leading risk factor for stroke, heart disease, kidney failure, and other conditions and also is a key contributor to the development and progression of chronic kidney disease. SPRINT will examine the hypothesis that more aggressive blood pressure control will slow the development of chronic kidney disease beyond the benefit achieved by current blood pressure goals.

Current clinical guidelines recommend systolic pressure (the top number in a blood pressure reading) of less than 140 millimeters of mercury (mm Hg) for healthy adults, and 130 mm Hg for adults with kidney disease or diabetes. SPRINT will evaluate the potential benefits of maintaining systolic blood pressure at less than 120 mm Hg for adults who are at risk for heart disease or kidney disease. The study also will assess possible risks of this therapeutic strategy.

"If this study shows that maintaining a lower systolic blood pressure has significant benefits for middle-aged and older adults — and doctors and patients meet the lower goal levels — we could see hundreds of thousands fewer heart attacks and stroke each year in the United States alone," said Elizabeth G. Nabel, M.D., director of the National Heart, Lung, and Blood Institute (NHLBI).