Letters Section Editor: Stephen J. Lurie,
MD, PhD, Senior Editor.
In Reply: Drs Brinton and Nilsen cite their
cellular-level research indicating that MPA interferes with the protective
effects of CEE on neurons, and conclude that their data are consistent with
our findings regarding an increased risk for AD associated with CEE plus MPA
(as compared with placebo). We agree that their data provide one possible
hypothesis regarding a mechanism that may have contributed to a null finding
and, perhaps, to our negative finding. However, we strongly disagree with
their conclusion regarding the demonstrated benefits of estrogen alone in
preventing AD. In our analysis we did not isolate the unique contribution
of MPA on global cognitive functioning or probable dementia (including AD).
At the end of the study we do plan to compare the effect of CEE alone (vs
placebo) with that of CEE plus MPA on the incidence of dementia. Until then,
however, we consider this as only an intriguing hypothesis.
Shumaker SA, Rapp SR, Espeland MA, Wallace RB, Hendrix SL, Henderson VW, Gass ML, Thal L. Effects of Estrogen Plus Progestin on Risk of Dementia. JAMA. 2003;290(13):1706-1708. doi:10.1001/jama.290.13.1706-a