Central apnea. Central apnea is from dysfunction of the systems that control your respiratory drive. It is seen in patients with cardiovascular disease like heart failure and strokes. It can also occur at high altitude. It is a completely different mechanism from obstructive sleep apnea and does not have to cccur during sleep.
A few thoughts. Some have daytime breathing problems. May not be daytime "apnea," more likely hypopnea (shallow breathing). Usually unrelated to what's called "sleep apnea." It's much less common. The treatment is usually different from the standard treatment for "sleep apnea." Daytime breathing problems would need to be evaluated by a different kind of doctor, not the ones experienced in treating sleep apnea.