Glomerular filtration rate (GFR) as kidney value
The so-called glomerular filtration rate or GFR is a parameter for how much blood is filtered through the kidneys and how much urine is produced from it. The glomerular filtration rate also drops in the case of diseased kidneys and is therefore a good value for the diagnosis of kidney disease. In addition to kidney disease, the glomerular filtration rate can also be lower in older patients.
A young person usually has a higher glomerular filtration rate. The standard value of the GFR is, for example, up to 110 ml/min in 25-year-old patients and approx. 60 ml/min in 75-year-old patients.
The GFR is also important when it comes to dosing a drug. Since most drugs are excreted through the kidneys, a reduced glomerular filtration rate would allow the drug to accumulate in the body and thus possibly increase its effect. Depending on the medication, this can be dangerous.
Glomerular filtration is calculated using a formula. This can be done manually, usually the laboratory calculates this value. Age, creatinine value and body surface area are incorporated into this so-called MDRD formula.
What diseases can be detected in altered kidney values?
With the help of the above-mentioned kidney values, disturbances in kidney function can be determined. In case of a disturbed function of the kidney, these substances are less filtered through the kidneys into the urine, which increases their concentrations in the blood. Elevated blood concentrations of the kidney values are therefore an indication of acute or chronic renal insufficiency, a restricted function of the kidneys.
In addition, individual kidney values can also be used to detect other diseases. Elevated uric acid concentrations in the blood can be an indication of increased cell death in the body, since a lot of uric acid is released when the body’s own cells are destroyed. This process occurs, for example, in the context of a so-called tumor lysis syndrome, in which tumor cells destroy the body’s own cells.
In addition, increased uric acid concentrations can also indicate a so-called Lesch-Nyhan syndrome, a genetically determined metabolic disorder that leads to the accumulation of uric acid. However, infections and inflammations of the kidneys can be better diagnosed by means of infection parameters (CRP, leukocytes in the blood, procalcitonin) and urine stix (with determination of the leukocytes in the urine and the nitrite content). A detailed overview of the significance of the individual laboratory values can be found in our article: Laboratory values – What you should know
