In general, yes.
Now if you have a dynamic DNS entry pointing to your connection, then if a purported attacker has the DNS name, they can still target you easily.
Other than that (and maybe a few other things I'm not thinking about at the moment), assuming some sort of attack based on targetting a specific IP, having dynamic IP assignment is inherently more secure than a static one.
I'm sure others can chime in with other points as well.
HTH,
Bobby