Out of curiosity, what form of T are you on Kreuz? I have heard reports of oral T affecting kidney/liver function, and my doctor only had me on oral tablets for a short while to avoid such problems. That said, I really don't know all that much about it.
As you said yourself though, it's good to keep in mind that certain levels will rise a lot with the introduction of T, and every body will respond differently. Maybe ask around, or call some doctors with more trans experience, and find out if this is just a regular part of the change?
From what I can gather from ten minutes of google research, creatinine is a waste product produced by the muscles. Because of this men usually have a higher creatinine level than women, and by this point on T I should think that your muscles -and all related levels- are definitely parts of you which should be tested against the male range. It's also worth noting that it's normal for young to middle-aged men to have higher than average creatinine levels, especially if they eat a lot of meat or fish.
While this may be a kidney related problem, don't forget that something as simple as what you ate that day, or whether or not you're dehydrated, can raise your creatinine levels a lot. This really does require further looking into; I would save your worry until your doctor has had a chance to look into it properly.
