Creatinine is a waste metabolite produced by muscles after they have finished contracting. It is introduced into the blood and excreted into the urine by the kidneys. Elevated creatinine levels generally indicate a decline in kidney function. Impaired kidney function can happen gradually without a person being aware of it. A routine blood test showing an increased level of creatinine is often the first indication of kidney disease.
The kidneys filter large volumes of blood to remove extra water and waste products. A common waste product removed by the kidneys is creatinine, which is produced from the breakdown of creatine phosphate in muscles. Generally, healthy people will have a constant level of creatinine over time. Men typically have a higher concentration than women, because they have more muscle tissue. Vegetarians and the elderly frequently have lower levels of this compound.
When the filtering units inside the kidney become damaged, people start to develop kidney disease. Waste products that would normally be excreted in the urine build up in the blood and can cause toxic effects. When this happens slowly, over time, the condition is referred to as chronic renal disease. Creatinine is one of the compounds that builds up in the blood as kidney damage occurs. A blood test for this chemical is one of the most common measurements to indicate the status of kidney function.
The laboratory test for creatinine involves measuring the number of milligrams in one deciliter of blood, or mg/dl. Typically, the normal range is from 0.5 to 1.2 mg/dl. Levels above that amount generally indicate that one has kidney disease. Elevated creatinine levels can be due to transient effects, such as dehydration, or increased amounts of weight training or meat consumption. Due to this, the values are generally tested over time and tracked, over a period of time, to see if there is a pattern of increase.
Unfortunately, by the time elevated creatinine levels have been detected, a substantial amount of kidney function can already have been lost. The major causes of increased creatinine levels are the same as the major causes of kidney disease — high blood pressure and diabetes. High blood pressure damages the kidney’s small blood vessels, which can no longer filter wastes properly. This can be treated with medications known as ACE inhibitors. The use of this medication alone may result in elevated creatinine levels, however.
When a person has diabetes, there is extra sugar in the blood, which can cause a number of health complications. One of them is damage to nerves and blood vessels. In the kidneys, damage to the filtering units is known as diabetic nephropathy. Keeping one’s blood sugar levels under control can delay or prevent this condition. Treatment with ACE inhibitors is often used as a preventative measure to protect kidney function in people who have diabetes.
Some common medications, like over-the-counter painkillers, can also cause elevated levels if taken for too long. This is particularly true for combinations of acetaminophen, aspirin, and ibuprofen. It is wise to check with a doctor, if one is prone to kidney problems and has to take these drugs regularly.