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 Approx 258 calories in one large 4 diameter, boiled/steamed potato. 2  Approx 278 calories in one large (10.5 oz or 299g) baked potato (no butter or toppings).