• Serum creatinine

    Creatinine is the final product of the breakdown of creatine, which plays an important role in the energy metabolism of muscle and other tissues. Creatine is synthesized mainly in the liver, from where it flows with blood flow into the muscle tissue. Here, creatine, phosphorylated, turns into cre-atinphosphate. Creatine phosphate belongs to the macroergic compounds and participates in energy transfer in the cell between mitochondria and myofibers. The concentration of creatinine in the blood depends on its formation and excretion. The formation of creatinine directly depends on the state of muscle mass. Creatinine is excreted by the kidneys by means of club filtration, but, unlike urea, it is not reabsorbed, which has found application in laboratory diagnostics( Reberga-Tareev's test).

    Concentration of creatinine in the blood of healthy people - the value is fairly constant and depends little on nutrition and other extrarenal factors. The reference values ​​of the concentration of serum creatinine in the are presented in Table.[Titz N, 1997].

    Determination of serum creatinine concentration is widely used in the diagnosis of kidney disease. Creatinine is less dependent on the level of catabolism, it is not reabsorbed in the kidneys, and therefore reflects the degree of impairment of the excretory and filtration functions of the kidneys. Reduction of creatinine in the blood has no diagnostic value.

    Table Reference values ​​for serum creatinine concentration

    Table Reference values ​​for serum creatinine concentration

    Creatinine levels in the blood naturally increase with renal insufficiency, which is of great importance for its diagnosis. The diagnosis of OPN is set at a serum creatinine concentration of 200-500 μmol / L( 2-3 mg%), an increase of 45 μmol / l( 0.5 mg%) with a baseline below 170 μmol / l( <2mg%) or when the level of creatinine is increased 2 times compared to the initial level. In severe arterial hypertension, the serum creatinine concentration is greater than 500 μmol / L( > 5.5 mg%).It should be noted that an increase in the concentration of creatinine and urea in the blood with OPN - rather late its signs. They occur when more than 50% of nephrons are affected. In severe arteries, the content of creatinine in the blood can reach 800-900 μmol / l, and in some cases 2650 μmol / l and above. In uncomplicated cases of OPN, the concentration of creatinine in the blood increases by 44-88 μmol / L per day, in cases of arthritis accompanied by muscle damage( extensive trauma), the level of creatinine in the blood increases more noticeably as a result of a significant increase in the rate of its formation. The concentration of blood cretinin in the blood and GFR is used as the main laboratory criteria in the classification of CRF

    It should be remembered that such diseases as hyperthyroidism, acromegaly, gigantism, diabetes, intestinal obstruction, muscular dystrophy, extensive burns, may also be accompanied by an increase in creatinine concentration inblood.