14 Jun New diabetes test to identify kidney failure before it happens
There are two common tests for kidney function. These are urinary albumin to creatinine ratio (ACR) and estimated glomerular filtration rate.
How do these tests work? Your kidneys contain millions of tiny filters, or ‘glomeruli.’ Blood passes through them to remove waste and excess water. People with diabetes or pre-diabetes have high blood sugar levels, unless they take medications or change their diet. High blood sugar is toxic to the kidneys. Over time, the glomeruli become damaged, and cannot filer properly.
How doctors measure kidney damage
There are two bio-markers that can show damage has occurred. A ‘bio-marker’ is a molecule that reflect how well the body is functioning.
- The estimated GFR measures how well your kidneys are working. The bio-marker used in this test is creatinine. This is a compound that glomeruli filter from blood. So, damage to the ‘filters’ will change the amount of creatinine in your blood. A GFR of 60 or higher is normal. A lower GFR is a sign of kidney damage.
- The ACR bio-marker is a protein called albumin. Blood and protein should not be in urine. If the test finds albumin, it is a sign that glomeruli have become damaged and ‘leaky.’
Why so much focus on diabetes and kidney function? Diabetes is the leading cause of end-stage renal disease in the United States. End-stage renal disease (ESRD) occurs when kidney damage is so severe that the organs stop working. These patients must go on dialysis or receive a transplant. Identifying who will develop ESRD can save thousands of lives.
Can we predict kidney failure?
ACR and GFR can measure kidney damage that has already occurred. But how can doctors know if a patient with damage will go on to develop kidney failure?
Researchers at the Joslin Diabetes Center discovered that molecule called TNFR 1 is a biomarker for kidney failure in people with diabetes. The test has a strong prognostic value, meaning it can identify people will develop ESRD. It identified 81% of all study participants who developed ESRD within three years.
This test is not currently available. Researchers hope to develop it in order to identify patients who will develop ESRD before kidneys fail.
But it’s important to remember that these patients developed ESRD within three years. This means that their kidney damage was already very advanced. Diabetic patients should strive to maintain normal blood sugar levels. Even if your kidneys seem to function normally. This includes testing blood sugar daily with a glucometer. It is also importnat to see your doctor regularly to test your HbA1c. HbA1c uses another biomarker in your blood. It is a measure of your average blood sugar levels over time (several months). Even if your blood sugar level is normal at one time in the day, a high HbA1c means that on average, your blood sugar is high.
We may be able to identify patients at risk of kidney failure. But treatment and prevention of kidney damage has not changed: maintain healthy blood sugar levels.