Does HRT benefit postmenopausal women at risk for dementia?

by Medical XPress:When initiated soon after menopause, hormone therapy with estradiol prevented degeneration in key brain regions of women who were at heightened dementia risk, according to a new study led by Stanford University School of Medicine researchers.The investigators also found that another type of hormone therapy, marketed under the brand name Premarin, was far less protective. Premarin is a mixture of 30-plus substances derived from the urine of pregnant mares. Estradiol—the dominant sex-steroid hormone in woman—accounts for about 17 percent of Premarin's total content. Other Premarin components exert various endocrinological effects on different tissues.The randomized study sought to understand the effects of continuing versus stopping hormone therapy on cerebral metabolism. It will be published March 12 in PLOS ONE. The findings indicate that hormone therapy's neurological effect on woemn at risk for dementia depends critically on when they begin therapy and on whether they use estradiol or Premarin, said lead author Natalie Rasgon, MD, PhD, professor of psychiatry and behavioral sciences and director of the Stanford Center for Neuroscience in Women's Health.The researchers observed brain regions in and around the hippocampus that are associated with memory and executive function. These regions are among the earliest to show deterioration in metabolic activity in many forms of dementia, ranging from mild cognitive impairment to Alzheimer's disease.When women who had started an estradiol regimen within a year of menopause stayed on the regimen, metabolic activity in a number of these brain regions was preserved. But it declined significantly among those who stopped using the hormone.Staying on Premarin, however, actually appeared to accelerate some of these brain regions' metabolic decline. If another hormone, progestin (essentially, synthetic progesterone), was taken along with either estradiol or Premarin, it obliterated estradiol's neurological benefit and steepened the decline seen with Premarin.The study, while too small to give meaningful results for direct tests of cognition, was large enough to achieve a high level of statistical significance for its imaging results.Source: http://bit.ly/1klLagX