Creatine is what forms when protein is converted into energy through metabolization. When creatine is broken down, it becomes creatinine, a waste product which your kidneys take out of your blood and excrete through your urine, says HealthlinkBC.If you have kidney disease, the amount of creatinine in your blood increases, while the level in your urine decreases. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.