In this article. Creatinine is a waste product from the normal breakdown of muscle tissue. As creatinine is produced, it's filtered through the kidneys and excreted in urine. Doctors measure the blood creatinine level as a test of kidney function.The kidneys ' ability to handle creatinine is called the creatinine clearance rate, which helps to estimate the glomerular filtration rate (GFR) -- the rate of blood flow through the kidneys.s creatinine is produced, it's filtered through the kidneys and excreted in urine. Doctors measure the blood creatinine level as a test of kidney function.
There are 163 calories in 1 medium White Potato (Flesh and Skin, Baked). Calorie breakdown: 1% fat, 90% carbs, 9% protein.
1 Long white potato: The White Rose is one of the better-known varieties of all-purpose potatoes. When new, they are thin-skinned and waxy; when mature, they are starchy and weigh an average of half a pound.  Marble potato: These are tiny (yes, marble-sized) potatoes.