[zlopikanikanz]

Do obe's like throw off your sleep pattern or no? The practice of OBE cultivation does mess with your sleep cycle, and the long answer belongs in the second part of your question.

aren't obe's basically sleeping anyways? OBEs happen while you sleep, but you don't remember them, just like dreaming.
When we practice OBE induction, what we are basically training to do is
1-stay awake while our bodies fall asleep
2-remember the event.
When you go to sleep normally, your brain goes through a series of patterns, from alpha all the way to delta, and from there it wakes up slowly back to alpha- this last part of the cycle is when you remember whatever you were dreaming/experiencing, and where hypnopomps happen.
When you practice OBE, what you are training for is to remain in alpha even after you are in theta- what scientists call 'alpha intrusion'- that way your conscious mind experiences what is happening as you move from body awareness to nonphysical awareness- something that you don't do consciously while you sleep.
On top of that, when you are starting out you tend to stay awake as you train yourself to observe yourself falling asleep- something that messes with your sleep patterns.
The good news is that this 'traumatic' sleep interruption smoothes out as your psyche begins to get used to this practice, and you go back to 'normal'. But it is recommended that you get more sleep to begin with (after a while you don't need the extra time) or move your practice to the morning.