I'm sure that undiagnosed OSA ended up killing my grandfather back in 1999, after years of all kinds of problems, including hypertension, heart disease, diabetes, double bypass operation, strokes, and finally colon and liver cancer. Now that I know what OSA is and that I have it, I'm certain he had it for decades and did not have the slightest idea.
It's never too late to treat the OSA. Keep it up! I'm no doctor but I'm convinced that it's the one treatment that is going to do us all the most good in the long run.