I have medical issues that are completely unrelated to lifestyle. Unfortunately, autoimmune issues often don't respond to anything but drugs with horrible side effects.
But what of Rome, and Paris? Do people with your condition live in them? Those cities aren't built around cars, yet have millions of people from all walks of live.
If we make cities built around cars, and people don't walk, then people get more health problems and die younger. That has to be considered alongside cases like yours.