Am J Epidemiol 2002; 156:785.
Copyright © 2002 by the
Johns Hopkins Bloomberg School of Public Health
LETTERS TO THE EDITOR |
RE: "PROSPECTIVE ASSESSMENT OF ESTROGEN REPLACEMENT THERAPY AND COGNITIVE FUNCTIONING: ATHEROSCLEROSIS RISK IN COMMUNITIES STUDY"
Laboratory of Personality and Cognition National Institute on Aging Baltimore, MD 21224
de Moraes et al. (1) recently reported no effect of hormone replacement therapy on cognitive decline in a well-characterized sample of 2,859 women (4867 years of age) participating in the Atherosclerosis Risk in Communities Study. The cognitive tests included the Delayed Word Recall Test, the Digit Symbol Subset of the Wechsler Adult Intelligence Scale-Revised, and the Word Fluency Test. In studies of hormone effects on cognition, it is essential to use tests of verbal memory that are sensitive to age, because evidence suggests that hormone therapy might be most beneficial to verbal memory (2). It is not at all surprising that the authors found no effect of hormone therapy on age-related declines in verbal memory, because the study failed to show decline in verbal memory between the first cognitive assessment (19901992) and the follow-up assessment (19961998). Specifically, on average estrogen users showed no decline (i.e., 0.0 words on a 10-item list), and nonusers showed a decline of 0.1 words. These data show that the test lacked sufficient sensitivity to detect age-related changes in verbal memory, especially in a relatively young sample of women, some of whom were "premenopausal." Without a test that is sensitive to age-related cognitive decline and without a sample that demonstrates memory decline, it is impossible to test the influence of hormone therapy on age-related memory decline. The conclusion that hormone replacement therapy has no effect on age-related changes in verbal memory is misleading.
The authors are correct in indicating that there is no consensus on the effects of hormone therapy on age-related cognitive decline. Randomized trials of the effects of hormone therapy on cognition, using memory tests shown to be sensitive to age and hormone therapy (3, 4), are under way through the Womens Health Initiative Study of Cognitive Aging.
REFERENCES
- de Moraes SA, Szklo M, Knopman D, et al. Prospective assessment of estrogen replacement therapy and cognitive functioning: Atherosclerosis Risk in Communities Study. Am J Epidemiol 2001;154:7339.
[Abstract/Free Full Text] - Sherwin BB. Estrogen effects on cognition in menopausal women. Neurology 1997;48(suppl 7):S216.
- Maki PM, Zonderman AB, Resnick SM. Enhanced verbal memory in nondemented elderly women receiving hormone-replacement therapy. Am J Psychiatry 2001;158:22733.
[Abstract/Free Full Text] - Resnick SM, Metter EJ, Zonderman AB. Estrogen replacement therapy and longitudinal decline in visual memory: a possible protective effect? Neurology 1997;49:14917.
[Abstract/Free Full Text]
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