Does cardio effect muscle growth?

Kenan, I was in the exact same situation as you, i went to the gym alot before i started mma and brazillian jui juitsu and i was scared id lose muscle m aswell. And from all the cardio training i didn't lost any m, just keep going to the gym as often as you normally do. My adice is if your fighting competitively NEVER drop down a few kilos to fight. Trust me its not worth dieting for weeks and because i wasnt eating much cause of my diet i started to lose muscle m.