Creatinine is a natural waste product that is formed in the processes of muscle metabolism. Creatinine is derived from creatine, which plays an important role in producing the energy needed for muscles.
Every day, 2% of creatine (an amino acid) in the body is converted to creatinine. The kidneys remove it from the body, as a result of which it is presented in the blood and urine.
Creatinine can build up in the blood if a person has a kidney problem, but it can also due to high protein intake, intense exercise or the usage of certain medications or supplements.
Monitoring of creatinine levels is often used as a guide for kidney function. High levels of creatinine in the blood or urine could mean that the kidneys are not filtering the blood effectively or for a serious health problem, such as chronic kidney disease.
Causes of high creatinine levels
A routine blood test can measure creatinine levels, as factors that might affect its levels are:
• certain medicines, including some antibiotics and non-steroidal anti-inflammatory creatine supplements
• dietary factors, such as high protein intake
• intensive exercises
• impaired renal function
• low blood flow
• dehydration
Other factors such as shock, different infections and diseases(for example cancer)can also cause elevated creatinine levels due to kidney damage.
High levels of creatinine in the body might be a sign that the kidneys are not working properly. Glomerulus – the part of the kidneys that filters waste products – does not function properly, may cause high levels of creatinine in the blood but low in the urine. This indicates that the kidneys are not functioning optimally.
Diseases that can affect kidney function and increase creatinine levels include:
• diabetes
• tumors
• some infections, such as hepatitis B and C, HIV and syphilis
• systemic lupus erythematosus, called SLE
Blood and urine tests are done to assess the current function of the kidneys. Тo check if an existing disease is progressing, and to monitor kidney function in people who are taking strong medications.