Why Your Diabetes Doctor Requires Serum Creatinine Tests
The creatinine in our bloodstream is a waste product of muscle activity. Our kidneys, when functioning well, filter this waste product from our system.
Creatinine is created from creatine, a molecule involved in muscle energy production. Every day, roughly two percent of our body’s creatine becomes creatinine, traveling through the bloodstream and kidneys to be excreted in our urine.
Doctors measure our blood level of creatinine to determine how well our kidneys are doing their job. If creatinine levels are high, it indicates our kidneys’ filter function might be faltering.
If you have type 1 or 2 diabetes, or have high blood pressure, your physician may recommend a serum creatinine test once a year to watch for signs of kidney complications. Your blood level of creatinine will be used to estimate your kidney GFR, or glomerular filtration rate. People with GFR values below 30 are usually referred to a nephrologist, or kidney specialist, for further diagnosis and care.
(For those who are curious, a glomerulus is a “tuft” of capillaries situated at the beginning of a kidney’s nephrons (tubules). Glomeruli constitute the first stage of the filtering process that cleans our blood of waste products.)
With people who already have kidney disease, the serum creatinine test may regularly be given to monitor their condition.
About the Test
Serum creatinine is a common laboratory test performed on blood drawn from an arm vein. The test typically requires no patient preparation, though doctors might give pre-test instructions. Normal activity can resume immediately following the blood draw.
The normal blood creatinine range is 0.84 to 1.21 milligrams per deciliter, or 74.3 to 107 micromoles per liter—give or take a few milligrams or micromoles. Since men have greater muscle mass than women they tend to have higher creatinine values; age is a factor as well.
Serum creatinine can be temporarily elevated because of low blood volume, dehydration, heavy meat consumption, certain medications, or the dietary supplement creatine. The elderly, and people with malnutrition, extreme weight loss, or a long-standing illness can have lower than expected creatinine values.
To more accurately assess creatinine levels and the presence of possible kidney problems, physicians may also ask for urine creatinine measurements.
Ounce of Prevention
As with many tests doctors regularly prescribe for patients with diabetes, serum creatinine is primarily for catching a problem in its early stages, so prompt treatment can retard its development. It is an ounce of progression prevention because there is yet no cure for damaged kidney tissue.
So, if you’ve been putting off that annoying diabetes doctor visit, your annual eye, or dental exam, now might be the perfect time to call and schedule an appointment.