Letters Section Editor: Robert M. Golub,
MD, Senior Editor.
In Reply: Dr Daniell raises possible confounders
of the results of our study that demonstrated an inverse relationship between
brain levels of testosterone and development of AD. Although we were unable
to directly control for obesity, we believe that the contribution of an association
with low testosterone to our observations is minimal. Obesity is also associated
with elevated estradiol levels and we observed no significant relationship
between brain levels of estradiol and neuropathological status. We also do
not think that expectant care and opioid use as features of the agonal state
explain our results. While it is likely that agonal state may significantly
differ between individuals with and without AD, our design indirectly controlled
for this possibility with the use of a third group, men with mild neuropathological
changes who also showed low levels of testosterone. We reason that because
death in this group was unrelated to neurological disease, agonal state in
the control group and the mild neuropathological changes group should be similar.
Moreover, our findings are consistent with the recent results of Moffat et
al,1 who reported that serum levels of testosterone
are negatively associated with clinical measures of AD. In their longitudinal
study, agonal state was not a relevant factor, and the relationship between
testosterone and AD was unaffected by variables such as obesity.
Pike CJ, Rosario ER, Stanczyk FZ. Dementia and Testosterone Levels in Men—Reply. JAMA. 2005;293(5):551-552. doi:10.1001/jama.293.5.552-a