ARK, dont take real sugar in with your protein shake.
Protein shakes are DESIGNED to go into the body quickly. The type of protein used is a fast-realeasing protein in shakes. Meat, oils and so forth are slower releasing.
Insulin is used to drive the protein to the muscles, so taking in sugar is going to use up a bit of that insulin to break it down.
And taking one before bed wont "drip" into your system, like i said they are fast-release, no matter what its diluted with. If you want a progressive protein before bed take in flaxseed oil tablets or grounded flaxseed. Its the slowest releasing protein out there.