Complex sentence: It did this by changing the mindset about diabetes even more than insulin had from seeing treatment of chronic diseases as mere slowing of "inexorable degeneration to a model of surveillance and early detection" (Greene 84).
Split into simpler sentences: It did this by changing the mindset about diabetes even more than insulin had. Treatment of this chronic disease was no longer seen as a mere slowing of "inexorable degeneration" but instead viewed through "a model of surveillance and early detection" (Greene 84).