DEAR MAYO CLINIC: I was surprised to learn that even though I have type 2 diabetes, I possibly could be a candidate to donate a kidney to my husband who has end-stage kidney disease. Would donating a kidney be safe for me and my husband? I thought diabetes could cause kidney failure. ANSWER: Thank you for considering the gift of life through organ donation. I am wishing all the best to you and your husband. You are correct; diabetes is…