Low blood pressure in elderly linked to mortality

NEW YORK (Reuters Health) - Aggressive treatment of high blood pressure (hypertension) in patients who are 80 years or older is associated with lower five-year survival rates than their counterparts with blood pressure levels at or higher than treatment target levels, researchers report.

Physicians should therefore “use caution in their approach to blood pressure-lowering in this age group,” they advise in the Journal of the American Geriatric Society.

Dr. Daniel J. Oates of the Boston Medical Center and his co-workers evaluated five years of data from 10 Veterans Affairs sites and Social Security files. The study group involved 4,071 ambulatory patients 80 years or older with hypertension.

The researchers found that patients with normal or higher blood pressures were less likely to die during follow-up than those with lower blood pressures. Specifically, for each 10-point increase in blood pressure, the researchers estimated that the mortality risk increased by about 17 percent.

This effect was seen up to a systolic blood pressure of 139 mmHg (the top number) and a diastolic blood pressure of 89 mmHg (the bottom number).

However, in patients with uncontrolled hypertension, defined as systolic pressure of 140 mmHg or higher and diastolic pressure of 90 mmHg or higher, there was “no significant association between survival and blood pressure levels.”

These findings “suggest that overly aggressive control of blood pressure might be harmful in this age group,” the investigators conclude. They cite other studies that also show higher blood pressures are protective in older patients.

Older patients with low blood pressure need to be monitored for fainting, which would put them at risk of falls, the team notes. This group should also be watched for nonspecific symptoms, such as weakness, weight loss and memory loss.

SOURCE: Journal of the American Geriatric Society, March 2007.