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Archived Comments for: A parsimonious explanation for intersecting perinatal mortality curves: understanding the effects of race and of maternal smoking

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  1. These findings may represent reduced DHEA...

    James Howard, independent biologist

    24 May 2004

    It is my hypothesis that DHEA was selected by evolution because DHEA optimizes replication and transcription of DNA. Therefore, all tissues, and all growth and development, rely on levels of DHEA.

    Black women produce more testosterone than white women. Since it is known that testosterone reduces steroid sulfatase, the conversion of DHEA sulfate, the large, background source of DHEA, to DHEA is reduced. Smoking also increases DHEA sulfate (Eur J Epidemiol. 1997 Jul;13(5):553-8.). Both of these may reduce the availability of DHEA for proper growth and development of fetuses and subsequently affect the viability of neonates.

    I suggest the findings of Joseph, et al., may result from the effects of testosterone and/or smoking on increasing levels of DHEA sulfate.

    Competing interests

    None declared