I think it is worth trying to feed him to see if he is hungry. You don't want to ignore it if he is. His tummy could be what is speaking loudest - he doesn't care what time it is! I am not a fan of letting babies cry it out, but you have to do what is best for your family. I would try a sippy over a bottle, since he probably takes a sippy during the day, and he's never taken a bottle.
My daughter also wakes at 4:30 AM, and it drives me crazy! She's 13 months. I am still breastfeeding, though, so I nurse her and often she falls back asleep. My children ARE early birds, though. I have decided I need to just accept this. My 3 year old has always woken early. NOw his "sleeping late" is 6:30 or 7. My 13 month old rarely sleeps past 6. I go ahead and nurse at 4:30 and try to get her back to sleep!
12 months is still a baby, despite what some people think. Others may tell you that he is old enough to "not need to eat", but he doesn't know that! He doesn't listen to other people and he doesn't read the books. All he listens to is his tummy. My son ate in the night for many months past his first birthday, until he decided to stop. I couldn't allow him to cry as I could tell he was hungry. Some babies just need to eat more often than others. My daughter still nurses, but also eats 3 full (and I mean full!) meals a day, always needs a mid morning and mid afternoon snack, plus nurses a few times a day. She's also a very normal and well sized 20 lb 13 month old, not a huge nor a skinny baby. Very healthy. Breastfed babies especially do not gorge themselves - they eat until they are satisfied. Chances are your little man IS still hungry. Go with your instincts on this one, mama. If he doesn't take a sippy with some milk (whether breast or cow) at that time, maybe a little rocking will get him down. Isn't the most important thing be that he feels loved and safe? I think that whatever his reasons (hunger or loneliness) he needs you right now, and you are right on to think there is something you can do.
I've never heard that we stop being parents from 10 PM to 8 AM. Many babies still need to be parented in the middle of the night and it's perfectly ok. They will outgrow that need when they are ready. My son did. (I am not lecturing you by any means. I just know you will get many responses telling you to let that baby cry because he doesn't "need" to eat, and I think that is bad advice.)