Hi onestep
Yes, sleep apnea is a 'reputable' condition, but it's hard for me to say where you would score points, because this is individual. You know how it affects you. Go through every question and see if it applies to you. If you are short of sleep and have difficulty concentrating it could affect your safety in the kitchen, preparing food, it could make it unsafe for you to be in a shower, you may find that you avoid people socially because of a lack of sleep. Have a look at the Guide to PIP Claims and Reviews and go through the questions and see what might be applicable - every person is different.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems