By Andrew Holleran Legendary NBA big man Shaquille O’Neal was a regular at the doctor’s office during his playing days, but it had been a while since he stepped foot in the office. O’Neal opened up to GQ Magazine about his latest doctor’s visit, which revealed a potentially life-threatening condition. Sleep apnea. O’Neal was diagnosed with the potentially life-threatening condition. The Hall of Fame big man now sleeps with a sleep machine. “When you play, you go to the doctor to get checked and a physical, right? But I ain’t played in 11, years so if I’m not playing, what would I go to the doc…