Doctors must use caution in reducing blood pressure in patients with diabetes and coronary disease, a University of Florida researcher has urged.
According to Rhonda Cooper-DeHoff, an associate professor of pharmacy and medicine at UF, new data show an increased risk of heart attack, stroke or death for patients having blood pressure deemed too high or too low.
She suggests raising the systolic bar above 120 for blood pressure in patients with diabetes and coronary artery disease, saying that levels between 130 and 140 appear to be the most healthful.
Based on hypertension treatment guidelines, doctors have assumed that with regard to blood pressure, "the lower, the better," Cooper-DeHoff said. But, The International Verapamil SR-Trandolapril study, known as INVEST, suggests that the range considered normal for healthy Americans may actually be risky for those with a combined diagnosis of diabetes and coronary artery disease.
Cooper-DeHoff said: "Our data suggest that in patients with both diabetes and coronary artery disease, there is a blood pressure threshold below which cardiovascular risk increases."
Nearly two out of three adults with diabetes have high blood pressure. Normal blood pressure as defined by the American Heart Association is less than 120 systolic and less than 80 diastolic. Blood pressure greater than 140 is still associated with a nearly 50 percent increase in cardiovascular risk in patients with diabetes. But efforts to reduce systolic blood pressure to below 130 did not appear to offer any additional benefit to diabetics with coronary artery disease compared with reduction of systolic blood pressure to between 130 and less than 140.
Cooper-DeHoff's research reveals for the first time that this group of patients also had a similar increase in risk when their blood pressure was controlled to lower than 115 systolic - the range recommended as normal by the American Heart Association.
Stephan Brietzke, an endocrinologist who did not participate in the research, said Cooper-DeHoff's findings parallel recent studies looking at blood sugar control, which suggest a U-shaped curve with higher cardiovascular risks at both "too high" and "too low" extremes.
Cooper-DeHoff's presented the findings of her study on March 14 at the American College of Cardiology's 59th annual scientific session in Atlanta.