Well if you don't count the dark side as a lessened ability no, but physical, Vader could barely breath much less fight, only Vaders insane force ability kept him alive after Mustafar and the subsequent transformation. That would have killed any normal person and most Jedi-Sith.
His power would decrees over time, due to the dark side, "eating" away at his body, and the suit deteriorating (Its what 21-22 years old during ANH), I doubt replacing the suit is an option, it would probably kill him. So what is left, a broken shell of jedi in an ancient life support suit, with organ damage so severe that only his hatred for the Emperor, himself, and the galaxy keeps him alive, he's a broken man.
That is only my personal canon of course.
Freude, schöner Götterfunken Tochter aus Elysium, Wir betreten feuertrunken, Himmlische, dein Heiligtum! Deine Zauber binden wieder Was die Mode streng geteilt; Alle Menschen werden Brüder, Wo dein sanfter Flügel weilt.