In elderly men with high blood pressure (hypertension), the duration of anti-hypertensive treatment is associated with a reduced risk of dementia and cognitive decline, according to a report.

Lead investigator Dr. Rita Peila told Reuters Health: “The study suggests that hypertension treatment in very old hypertensive subjects shows no harm and perhaps some benefits against dementia and cognitive decline. The results suggest that the longer is the duration of hypertension treatment the lower may be the risk for dementia.”

However, she added: “This is an observational study, not a clinical trial. Caution should be adopted in the interpretation of the results.”

Peila, of the National Institute of Aging, Bethesda, Maryland and colleagues note that there is controversy over the benefit of hypertension treatment in the elderly. One concern is that lowering of blood pressure might have a negative effect on cognitive function.

To investigate further, the researchers examined data from a study of Japanese-American men in Honolulu. The subjects were 848 men who had been followed since 1965 and were hypertensive from mid-life and dementia-free in 1991. At that point their mean age was 76.6 years. They were followed-up 3 and 6 years later. Some 446 patients with normal blood pressure served as the control group.

By the final examination, 706 of the men were being treated for hypertension and 146 had never been treated. In all, 362 had been treated for more than 12 years, 149 had been treated for 5 to 12 years and the remaining 195 had been treated for less than 5 years.

Compared to those never treated for hypertension, patients who had been treated for 12 years or more had a risk of dementia that was 60 percent lower, and was similar to that in controls.

For 5 to 12 years of treatment the corresponding risk was 48 percent lower and in those treated for fewer than 5 years, it was 6 percent lower.

“More results,” Peila added, “are expected from ongoing clinical trials among subjects 80-year-old or older.”

In practical terms, she added, “even very elderly subjects should check their blood pressure and discuss it with their physician.”

SOURCE: Stroke, May 2006.