Untreated High Blood Pressure Significantly Increases Odds of Brain Bleed

Left untreated, high blood pressure may significantly increase the risk of developing a brain bleed, according to research presented at the American Stroke Association's International Stroke Conference 2016. The study, authored by Kyle Walsh, MD, assistant professor of emergency medicine at the University of Cincinnati, found that the risk is even higher for blacks and Hispanics.

"The average age for a brain hemorrhage is much younger in minorities, especially in African-Americans, so they may suffer more disability earlier in life than others," says Walsh.

Intracerebral hemorrhage is a type of stroke caused by a weakened blood vessel that ruptures and bleeds into brain tissue. High blood pressure is a powerful determinant of risk for intracerebral hemorrhage.

Researchers examined six years of data from 4,646 patients who were white, black or Hispanic. Exactly half of them had an intracerebral hemorrhage.

The research found:

Compared to people without high blood pressure, untreated high blood pressure increased the odds of a brain bleed by 9.5 times in whites, 9.7 times in Hispanics, and 11.1 times in blacks.

For people with high blood pressure, untreated high blood pressure was linked to a 3.7 to 5.5 times higher odds of brain bleed compared to when it's treated.

For patients with brain bleed and a previous diagnosis of high blood pressure, high blood pressure was more likely to not be treated in blacks (43.3 percent untreated) and Hispanics (48.3 percent) compared to whites (33.2 percent).

Even when high blood pressure was treated, blacks still had 75 percent higher odds and Hispanics had 50 percent higher odds of brain bleed, compared to whites.

Although it's not completely clear why racial minorities have higher rates of untreated high blood pressure, a possible reason is access to medical care, Walsh says.

The study analyzed data from the Ethnic/Racial Variations of ICH (ERICH) study, which followed people from 42 different sites. Each of the 2,323 people with bleeding stroke was matched with another person similar in age, gender, race/ethnicity, and geographic area, but who did not have a history of this type of stroke.

Researchers gathered blood pressure information based on participants' medical history. They analyzed the number of cases with high blood pressure, including treated versus untreated high blood pressure, and the associated risk of bleeding stroke. The researchers also controlled for the effects of several factors including alcohol, cholesterol, education, insurance status and blood thinning medications.

"It's important to be aware of having high blood pressure in the first place, and once diagnosed, to have it treated appropriately," Walsh says.

Co-authors are Daniel Woo, MD; Padmini Sekar, MS; Jennifer Osborne, RN, BSN; Charles Moomaw, PhD; and Opeolu Adeoye, MD, of the University of Cincinnati; and Carl Langefeld, PhD, of Wake Forest University. Author disclosures are on the abstract.

The ERICH study was funded by the National Institute of Neurological Disorders and Stroke.