Anemia in pre-d/ckd patients

http://ihatedialysis.com/forum/index.php?topic=21512.msg355789#new

I was reading the above article posted by okarol, and I have a question. I am CKD4 late stages, ie egfr anywhere between 15-18 after being above 20 for about 5 years, and through all that time, I have never been anemic. At my last appt 2 months ago, my neph asked me if I was being treated for anemia, my labs were so good in that regard (I can't expect him to have memorized by labs!). Why am I not anemic? I should be by all accounts.

(Actually, I was anemic about 2 years ago and was put on epo, but I was suffering through "lady problems", and a hysterectomy solved the anemia. I was relieved to see that the anemia was not kidney failure related.)

Anyone have any scientific explanations for this? Thanks.