Do bedbugs not bite people who have low hemoglobin ?

I was wondering if bedbugs don't like biting someone who has very low hemoglobin.Can they smell that it is low or what ? I had to come to my friends to stay when I was released form the hospital and they have a terrible problem with bedbugs but I have been here for two weeks and have not been bitten so far.My hemoglobin is always around 6 instead of the 12 to 14 like most people's and I have to have blood transfusions.Do you think this may be why they don't bother me ? They seem to love my friends.They are soooooooo disgusting.I am so glad I haven't been bitten and hope I never am.But does anyone have any idea about this ? Thanks.