From various things I've read (research into causes of autism) I believe that hormones and hormonal cycles have some, or a lot of influence on autism and mood disorders. My mood issues kicked in full force when I was pregnant at age 30. Before that, not much .
For me, though, it's too much of a stretch to relate sensory issues with mood swings. I do think coping mechanisms can be affected by them. Sensory integration requires learned coping mechanisms (blocking out noise, remembering to eat right, backing out of an uncomfortable situation etc). I think that if you're dealing with the irritability aspect or depressed aspect of cyclothymia, you may completely be unable to utilize any skill you have for coping with the sensory. For example, my son has a very predictable pattern of behavior and expectations that I can deal with most of the time. But during a depressive state, I'm afraid of him and can't stand being around him, I want to flee. During an irritable state, I'm angry and get really ugly thoughts and wonder why he's such a rotten kid. When it's happening, I "blame" the noise, the flashing tv, the pacing around the house. But those are things that are normal and that I can deal with on my good days. I might try unsuccessful coping mechanisms, like napping or leaving the house. These don't help but I do them because they are like a default-like drugs.
While I do think they can have similar origins, I think they are distinct disorders. The mood swings seem to follow a biological pattern or calendar. The sensory issues with AS are always external.