Medical Xpress
http://medicalxpress.com/news/2012-01-expensive-egos-narcissism-higher-health.html

"Narcissistic men may be paying a high price in terms of their physical health, in addition to the psychological cost to their relationships," says Sara Konrath, a University of Michigan psychologist who co-authored the study.
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Why should narcissism affect males differently? "Given societal definitions of masculinity that overlap with narcissism – for example, the belief that men should be arrogant and dominant – men who endorse stereotypically male sex roles and who are also high in narcissism may feel especially stressed," Konrath suggests.

original article in PLoS ONE - http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0030858