Hormone therapy does not prevent dementia

NEW YORK (Reuters Health) - The long-term use of estrogen or estrogen plus progestin hormone therapy does not reduce the risk of dementia, according to findings published in the American Journal of Epidemiology.

“Results from (previous) studies of the relation between hormone therapy and Alzheimer’s disease conflict,” Dr. Valerie Crooks, of Kaiser Permanente Southern California, Pasadena, and colleagues write.

The researchers report the results of a forward-looking study of about 2,900 women, at least 75 years of age, who were recruited from a Southern California health plan in 1999. The subjects, who were free from dementia when the study began, were followed through 2003 with tests performed annually to assess their thinking ability.

Just over 1500 of the women in the study were hormone users. The average age at the start of hormone therapy was 48.3 years for those who used estrogen alone and 54.9 years for those who used estrogen/progestin. The average duration of hormone use was 30.5 years and 23.2 years for estrogen and estrogen/progestin users, respectively.

A total of 283 women developed dementia during follow-up. After accounting for age, education, and self-reported medical history, hormone use did not affect the risk of dementia.

“This study also determined that no protective effect against dementia was found for women who initiated hormone therapy at or near menopause,” Crooks told Reuters Health.

“How hormone therapy can affect dementia risk is not fully understood,” she said. “This study, however, adds to the evidence that hormone use does not prevent the development of dementia in older women.”

SOURCE: American Journal of Epidemiology, March 15, 2008.