I think the "official announced" diagnosis was Cronic Venus Insufficency". Basically a weakening of the veins in his legs. From what I've read it's serious, but not necessarily fatal. There is a risk of blood clots in the legs, especially in older obese individuals from what I've read.
It makes sense, especially if you watch his gait when he walks. He is obese and I really don't consider swinging a golf club while riding around in a golf cart serious exercise.
But then I not a doctor, so what do I know