N Engl J Med 2001;344:1111-6 Survival after Dementia
wistar_rat at hotmail.com
Sun Apr 15 00:55:02 EST 2001
I haven't read the article but I saw a report on the news about it. One
criticism put forward was that the mean age of people they studied was
around the low to mid 80s. People of that age would be expected to have
a shorter lifespan anyway compared to previous studies of dementia which
studied much younger people. The fact that this group found a shorter
lifespan for people with dementia than previous studies doesn't say that
previous studies were wrong or inaccurate. What do you think?
James Michael Howard wrote:
> I just sent the following to the New England Journal of Medicine regarding,
> "A Reevaluation of the Duration of Survival after the Onset of Dementia,"
> which is in the most recent issue
> (http://www.nejm.org/content/2001/0344/0015/1111.asp ). I thought you might
> be interested in reading it.
> "I suggest the findings of Wolfson, et al., represent excessive loss of
> dehydroepiandrosterone (DHEA). It is my hypothesis that DHEA evolved to
> optimize transcription and replication of DHEA and cortisol evolved as the
> chief antagonist to DHEA. This follows from my hypothesis that nervous
> tissue uses DHEA more than other tissues. Loss of DHEA would undermine
> maintenance of the nervous system while continued, or increased cortisol,
> would exert antagonistic effects on the nervous system. (It is known that
> continued, high levels of cortisol damage nervous tissues.) Since the brain
> is most sensitive to levels of DHEA, the maintenance defect, called
> dementia, represents severe loss of DHEA. This is directly supported in
> vascular dementia and dementia of the Alzheimer's type in the levels of DHEA
> and the ratio of DHEA to cortisol. "By comparison to vascular dementia,
> patients with Alzheimer's disease exhibited the highest cortisol
> concentrations throughout the 24h.
The serum DHEAS levels were
> significantly lower in elderly subjects and even more in demented patients
> than in young controls. Consequently, a significant increase of the
> cortisol/DHEAS molar ratio was evident when going from young controls to
> healthy elderly subjects and to demented patients." Exp Gerontol 2000; 35:
> I suggest shorter survival times in the study subjects, who exhibited
> dementia of the Alzheimer's type or vascular dementia, represent severe
> reduction of DHEA."
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