Studies of the Relationship between Blood Pressure and Cognitive Impairment Require Participants Be Free of Dementia at Time of Enrollment

Business Wire, Jan 18, 2005

PASADENA, Calif. -- A study published in the January, 2005 edition of the Archives of Neurology indicates that contradictory results of various studies into the relationship between high blood pressure and dementia may be caused by inconsistencies in the ages and conditions of study participants.

"We believe because studies are performed on people late in life when many may or may not have unrecognized dementia, many may have lower blood pressure than when they were younger," said Diana B. Petitti, MD, MPH, Senior Scientific Advisor, Kaiser Permanente, Southern California Department of Research and Evaluation. "This leads us to believe that valid conclusions can only be drawn from data collected from subjects who are free of dementia or cognitive impairment at the time of enrollment in the study."

Of the 6,042 women asked to take part in the study, 2,930 were using hormone therapy and 3,612 were not. The final study group consisted of 1,944 hormone therapy users and 1,980 nonusers.

The identification of study subjects began at the Women's Memory Study, the goal of which was to assess the relationship between hormone therapy, dementia and Alzheimer's disease between January 1, 1992 and July 1, 1998. A comparison group of women age 75 and older not using hormone therapy as of July 1, 1998 and who had not filled prescriptions for estrogen during the same period was also gathered.

"It would be very beneficial to monitor the blood pressure of dementia patients more carefully anticipating that their blood pressure may decline and require possible modification of their medications," said Petitti.

Dementia is a progressive brain disorder that usually leads to lessening of daily activities and in most cases, the need for long-term care. Although a number of diseases can result in dementia, the most common cause is Alzheimer's disease.

In addition to Dr. Petitti, the study's other authors are Valerie C. Crooks, DSW, J. Galen Buckwalter, PhD, and Vicki Chui, MS; all of the Kaiser Permanente Southern California Department of Research and Evaluation.

Kaiser Permanente is America's leading integrated health plan. Founded in 1945, it is a not-for-profit, group practice prepayment program headquartered in Oakland, CA. The Kaiser Permanente Southern California Region has more than 3.1 million members. They are cared for by the 3,600 physicians of the Southern California Permanente Medical Group (SCPMG) and 47,300 Kaiser Foundation Health Plan and Hospitals and medical group employees. The Kaiser Permanente Southern California Region is served by 11 major medical centers.

www.kaiserpermanente.org