Difference Between Creatine and Creatinine

Main Difference – Creatine vs Creatinine

Creatine and creatine are two protein derived compounds found in the animal body. Creatine is produced in the liver, kidney, and pancreas and transported into skeletal muscles through the blood. Creatinine is produced in the skeletal muscles and transported through the blood into kidney in order to be excreted from the body. Creatinine has diagnostic uses in determining muscle mass and kidney function. The main difference between creatine and creatinine is that creatine is a naturally occurring amino acid in vertebrates which helps to supply energy to muscles and nerve cells whereas creatinine is a biological waste formed by the metabolism of creatine and excreted from the body in urine.

Key Areas Covered

1. What is Creatine
      – Definition, Features, Importance
2. What is Creatinine
      – Definition, Features, Importance
3. What are the similarities between Creatine and Creatinine
      – Outline Of Common Features
4. What is the difference between Creatine and Creatinine
      – Comparison of Key Differences

Key Terms: Blood Creatinine, Creatine Supplements, Creatine, Creatinine Clearance Test, Creatinine, Glomerular Filtration Rate (GFR), Half-life, Phosphocreatine, Serum Creatinine

What is Creatine

Creatine is an amino acid produced in the human body by the liver, kidney, and pancreas. It is also a naturally-occurring amino acid in animals and fish as well. Creatine is transported into the skeletal muscles through the blood and is stored as creatine phosphate or phosphocreatine. Phosphocreatine is produced by the action of enzyme, the creatine kinase. Phosphocreatine is converted into ATP during highly intense, short duration exercises like sprinting and weight lifting. Creatine is converted into creatinine by non-enzymatic degradation. The biological half-life of creatine is three hours. Creatine supplements may increase lean muscle mass and enhance athletic performance. The supplements of creatine may also decrease the levels of triglycerides, lowering the risk for heart diseases. The low creatine amounts in muscles may lead to muscular dystrophy. The conversion of creatine into phosphocreatine in skeletal muscles is shown in figure 1.

Difference Between Creatine and Creatinine

Figure 1: Conversion of creatine into phosphocreatine

What is Creatinine

Creatinine is a biological waste product formed by the degradation of creatine in muscle cells. It is transported into the kidney through the blood and eliminated from the body in urine. The amount of creatinine in blood is proportional to the muscle mass in the body in a healthy person. Blood creatinine levels also reflect the amount of the kidney function. The blood creatinine level of a man with normal kidney function is around 0.6 to 1.2 mg/mL. Since women have a low muscle mass compared to men, their blood creatinine levels are lower than that of men. Blood creatinine level also depends on the activity of the body and medications. Serum creatinine level is tested for the determination of glomerular filtration rate (GFR). The low GFR elevates the blood creatinine level. The detection of high creatinine levels in the ordinary blood is a symptom of weak kidney function. Blood creatinine level is increased in chronic kidney disease and it is one of the factors used in recommending dialysis for a patient. Creatinine clearance test measures the clearing out of creatinine from the blood. It is done by measuring creatinine levels in blood and urine. Creatinine is shown in figure 2.

Figure 2: Creatinine

Similarities Between Creatine and Creatinine

Both creatine and creatinine are formed in the body.

Both of the compounds can be found in the blood.

Definition

Creatine: Creatine is a compound formed during the protein metabolism, and is involved in the supply of energy for muscular contractions.

Creatinine: Creatinine is a compound formed during the metabolism of creatine and is excreted in urine.

Compound

Creatine: Creatine is 2-(carbamimidoyl-methyl- amino)acetic acid.

Creatinine: Creatinine is 2-amino-1-methyl-5h-imidazol-4-one.

Molecular Formula

Creatine: Creatine is C₄H₉N₃O₂.

Creatinine: Creatinine is C₄H₇N₃O.

Molecular Structure

Creatine: Creatine is a linear molecule.

Creatinine: Creatinine is a heterocyclic structure.

Significance

Creatine: Creatine is used as a supplement to increase the muscle mass.

Creatinine: Creatinine is a waste produced by the metabolism of creatine.

Produced in

Creatine: Creatine is produced in liver, kidney, and pancreas and send it to skeletal muscles.

Creatinine: Creatinine is produced in the skeletal muscles by the breakdown of creatine phosphate.

Role

Creatine: Creatine helps to supply energy to muscles.

Creatinine: Creatinine helps in diagnosing the functioning of the kidney.

Conclusion

Creatine and creatinine are two compounds derived from amino acid found in the body. Creatine is produced in liver, kidney, and pancreas and transported into skeletal muscles through the blood. Creatine can also be taken as a supplement. The non-enzymatic degradation of creatine in the skeletal muscles produces creatinine, which is excreted from the body as a waste. Creatine is used in providing energy to the skeletal muscles during their high intensive functioning. Creatinine is used in revealing kidney function. The main difference between creatine and creatinine is the function of each compound in the body.

Reference:

1. “Creatine.” University of Maryland Medical Center. N.p., n.d. Web. Available here. 27 June 2017.
2. “Definition and Symptoms of Chronic Kidney Disease.” Symptoms of Kidney Disease – DaVita. N.p., n.d. Web. Available here. 27 June 2017.

Image Courtesy:

1. “Creatine kinase rxn” By Boghog2 – Own work (Public Domain) via Commons Wikimedia
2. “Creatinine” By Jesse – Own work (CC BY-SA 3.0) via Commons Wikimedia