McCoy was 137, or right around there. 
Fesarius is correct; there is very little canon information about lifespans, even for humanity (heck, more is understood about the Vulcan and Klingon lifespans).
Of course, you can always go thumbing through FASA stuff, as they have information on "critical ages" for species (which generally equates to middle age).
Davy Jones
"Frightened? My dear, you are looking at a man who has laughed in the face of death, sneered at doom, and chuckled at catastrophe! I was petrified."
-- The Wizard of Oz