Increased and decreased blood creatinine
What is creatinine?
Creatinine is one of the metabolites of biochemical reactions of amino acid-protein metabolism in the body. The formation of this compound occurs constantly and is associated with metabolic processes in muscle tissue. Since muscles constitute one of the main masses of the human body, and contraction requires a constant energy substrate, powerful energy carriers must be embedded in their structure. This is necessary in order to meet the emergency energy needs.
The main donor of ATP for muscle tissue is creatine phosphate, a phosphorylated nonessential amino acid creatine. After synthesis in the liver, it enters the muscles, where it is dephosphorylated by the enzyme creatine phosphokinase. The result of these processes is the formation of energy and creatinine. ATP is consumed by the muscles to meet energy needs, and the kidneys excrete creatinine in the urine after filtration.
Creatinine, as the final product of decomposition reactions, is not consumed in the body for other metabolic processes. This is a compound harmful to tissues, which should be excreted from the body as much as possible. Disruption of creatinine metabolism can occur at the stages of its intake, metabolism and excretion!
Creatinine rate
All creatinine cannot be filtered and excreted by the kidneys. This is due to the fact that it is constantly released into the blood until the muscle tissue is viable. Plasma should contain a relatively stable concentration of creatinine, which can vary depending on age, muscle activity and nutrition. Therefore, there are maximum and minimum limits for the creatinine norm, which take into account all these points and speak of the normal functioning of organs.
To exclude errors in the results of a biochemical blood test according to the creatinine level, it is imperative to adhere to the general rules for blood sampling. The study is necessarily carried out in the morning on an empty stomach. It is advisable to avoid strong muscle loads and overheating or hypothermia before direct blood sampling.
For clarity of variations in creatinine standards, they are shown in the form of a table:
| Small children | Pupils | Men | Women | |
| Creatinine norm in μmol / l | 45-105 | 27-62 | 74-110 | 44-80 |
The rate of creatinine in women
The plasma creatinine concentration in women should be lower than in men. This is due to the physiological mechanisms of its formation, distribution and circulation in the blood.
The mechanisms of this phenomenon are as follows:
- The muscle mass of a woman is less than that of a man;
- Less muscle stress;
- The activity of metabolic processes in the female body is reduced;
- Foods in the female diet contain less exogenous creatinine entering the body;
- Influence of sex hormones and pregnancy.
The norm of creatinine in men
The creatinine of the male body should almost always be higher than that of women of a similar age group. This is due to the peculiarities of the lifestyle and differences in the functioning of organs and systems. Age characteristics also affect the process of creatinine metabolism, both upward and downward. Recently, many men visit gyms and use doping containing creatine to increase muscle performance. This must be taken into account when assessing the creatinine rate.
The norm of creatinine in children
The concentration of creatinine in the plasma of a child is largely dependent on his age. The main fluctuations in this indicator are associated with the activity of growth and the degree of increase in muscle mass over a certain period of time. Newborns, due to the high stress that their body had to experience during childbirth, have creatinine levels the same as in adults. The same feature is typical for adolescents, which is explained by the active growth of the body. School-age children grow relatively stable, so their creatinine levels are slightly lower than in adults.
Elevated creatinine levels
When assessing creatinine metabolism, most often, one has to deal with an increase in the concentration of this metabolite. It is very important to correctly interpret the obtained indicators, taking into account the possibility of physiological and pathological increase, age and gender standards. The condition in which an increase in plasma creatinine is recorded is called hypercreatinemia.
Hypercreatininemia does not cause severe abnormalities in the body, since creatinine itself is low-toxic. Its harmful effects on tissues can manifest itself only with sharp deviations from the norm of its concentration. This metabolite is more related to the consequences of various conditions and diseases, signaling their presence. Therefore, isolated hypercreatininemia practically does not cause manifestations.
It is usually combined with other pathological symptoms that may suggest the need for this study:
- Muscle pain;
- Fatigue and muscle weakness;
- Swelling;
- An increase or a sharp decrease in the amount of daily urine;
- Pathological changes in the general analysis of urine (protein, leukocytes, erythrocytes).
The pathogenesis of hypercreatinemia can be associated with any of the stages of the metabolism and circulation of creatinine in the body. The nature of the diet, the mode of physical activity, the amount of fluid consumed, the intake of medications, the anatomical features of muscle tissue and its condition, the functional abilities of the excretory system and the liver can affect it.
What does elevated creatinine mean?
An increase in creatinine concentration in a biochemical blood test can indicate:
- Increased intake of creatine-containing substances from the environment with enhanced protein nutrition;
- Excessive or very rapid muscle gain
- High loads performed by muscles;
- The destruction of muscle tissue;
- Redistribution of blood and water imbalance in the body;
- Impaired renal function to detoxify and eliminate creatinine;
- Toxic effects on the body;
- Endocrine disorders that regulate metabolic processes in the body.
In some cases, one has to deal with a relative increase in the level of creatinine, which does not occur due to its excess production or retention in the body. It is associated with a decrease in the volume of circulating plasma as a result of its redistribution, blood loss or dehydration. Relative hypercreatininemia is combined with other signs of hemoconcentration and blood thickening, which helps in its correct assessment. It never reaches great values.
The increase in creatinine levels can be physiological, not due to disease, and pathological. In the second case, the main cause of hypercreatinemia is renal failure in all types of kidney damage, in which creatinine numbers can increase several times. Physiological hypercreatinemia can never be represented by a large deviation from the norm!
Causes of increased creatinine
The immediate causes of hypercreatinemia, taking into account the severity of the increase in creatinine, are presented in the table.
Pathological causes of increased creatinine
| Physiological causes of increased creatinine | ||
| Moderate hypercreatinemia | Severe hypercreatinemia | |
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How to lower blood creatinine?
After a detailed examination and clarification of the cause of hypercreatinemia, the following recommendations can be given:
- Hospitalization in medical institutions according to the profile in case of detection of diseases. These can be general therapy hospitals and specialized departments for the treatment of renal or other types of pathology;
- taking medications to normalize protein metabolism and remove toxic products of protein metabolism (ketosteril, lespeflan, lespenephril);
- Normalization of water exchange by selecting the optimal volume of fluid for a particular case, taking into account the capabilities of the kidneys. If hypercreatinemia is caused by physiological mechanisms, then an increase in the daily volume of pure high-quality water will lead to a decrease in the concentration of creatinine and accelerate its excretion by the kidneys;
- Normalization of the diet in qualitative and quantitative terms. It involves the complete elimination or restriction of the use of protein foods and salt, which contribute to an increase in nitrogenous compounds or retain fluid in the tissues. This, in addition to the absolute increase in creatinine, causes its relative increase due to hemoconcentration;
- Correction of lifestyle and physical activity. They must be adjusted to the actual capabilities of the organism. If the pathological reasons for the increase in creatinine have not been identified and the only option for this condition is excessive physical activity, they are minimized as much as possible;
- Folk remedies (rice infusion and broth, medicinal plants and fees);
- Extracorporeal detoxification procedures (hemodialysis and its analogues). The use of an artificial kidney is advisable only for severe types of hypercreatinemia caused by decompensated renal pathology or intoxication.
In no case should you even try to cope with the increased level of creatinine in the blood on your own. This symptom may turn out to be the small tip of a large iceberg of disease. Any corrective and therapeutic measures must be supervised by a specialist!
Diet with high creatinine
Diet therapy is considered one of the most important measures to reduce creatinine levels. Its common characteristics are to limit the intake of protein foods, salt and potassium, enrich the diet with antioxidants and foods that cleanse the body.
Excluded:
- Fatty meats of animals and poultry (pork, duck, goose);
- Fatty fish;
- Whole milk;
- Spicy dishes and spices;
- Coffee and strong tea;
- Dishes from butter yeast dough;
- Fried foods and smoked meats.
Limited to:
- Diet meats (chicken, rabbit, turkey, young beef). You can introduce meat days twice a week, when they are included in small quantities in the dishes;
- Eggs - up to 2-3 per week;
- A fish. Fish days are organized by analogy with meat days;
- Salt and sugar. With a pronounced increase in creatinine, they are generally excluded;
Recommended:
- Fresh or boiled vegetables and fruits in any quantity;
- Berries, fruit drinks and compotes based on them;
- Nuts and dried fruits. They are limited or completely excluded only in renal failure, when the level of potassium is sharply increased;
- Fermented milk products (yogurt, kefir, fermented baked milk);
- Cheese and cottage cheese;
- Butter and vegetable oil;
- Cereals and cereals based on them. Rice is especially useful in this respect;
- Wholemeal bread with bran and pasta;
- Honey;
- Mineral and additional purified plain water at least one liter per day. Water loads are minimized only in case of renal failure.
- Dishes are allowed:
- Boiled;
- Steamed;
- Stewed;
- In the form of soup, mashed potatoes, cream soup, salad, jelly, porridge, casseroles, cutlets, meatballs;
Creatinine lowered
Conditions in which a decrease in plasma creatinine levels is recorded are extremely rare. Their appearance indicates a violation of metabolic processes, accompanied by profound disorders of protein metabolism in the body in general, or in isolation in muscle tissue. If hypercreatinemia mainly depends on the functional ability of the kidneys, then in the case of hypocreatinemia (decrease in creatinine levels), their state does not play a role. Consequently, the main mechanism should be such a depletion of energy reserves in the body that protein resources, which are most in the muscles, are used to extinguish them. A decrease in creatine phosphate reserves naturally leads to a decrease in the concentration of its metabolites in the blood, which is creatinine.
Causes of low creatinine
The immediate causes of hypocreatinemia can be:
- Cachexia against the background of chronic diseases and starvation;
- Depletion of the body with a vegetarian diet or strict diets;
- Weight loss due to a mismatch between physical activity and the nature of nutrition;
- Muscle dystrophy against the background of their diseases;
- Atrophy of large muscle masses when they are disabled;
- Treatment with glucocorticoids;
- First trimester of pregnancy.
A decrease in blood creatinine levels is not a diagnostic criterion for any pathology. This is a sign, which is an absolute regularity in typical cases, does not require special treatment measures!
Author of the article: Alekseeva Maria Yurievna | Therapist
Education: From 2010 to 2016 Practitioner of the therapeutic hospital of the central medical-sanitary unit No. 21, city of elektrostal. Since 2016 she has been working in the diagnostic center No. 3.
