Assessment of new predictors of kidney disease in patients with type 2 diabetes

This study evaluated the accuracy of four new predictors of kidney damage and disease are compared to the standard test for patients with Type 2 diabetes (T2D). The authors found that these new predictors were as accurate as the standard test at detecting kidney disease.

Many patients with Type 2 diabetes (T2D) develop other health problems, such as kidney disease.  Kidney disease can have a serious impact on a patient’s health, so it is essential to diagnose it as early as possible. The most common test used to detect kidney disease measures a protein called albumin. This protein is found in the urine. Very low levels of albumin are a common symptom of kidney disease.

However, the albumin test does not detect early kidney disease. Most patients with T2D start showing signs of kidney disease before albumin levels decrease. New biomarkers are needed to better predict the progression of kidney disease in patients with T2D. Four new biomarkers of kidney damage are under investigation for patients with T2D.

This study included 257 patients with T2D.  67 patients had rapidly progressing or advanced kidney disease. 190 patients did not have kidney disease. This study investigated whether cystatin-C, angiotensinogen, kidney injury molecule-1 (KIM-1) and neutrophil-gelatinase associated lipocalin (NGAL) were more accurate than albumin in detecting signs of kidney disease in these patients. All biomarker levels were measured at the beginning of the study and during follow-up. Patients were followed-up for an average of 40.8 months.

At follow-up, 14.4% of patients had rapidly progressing kidney disease, and 11.7% of patients had advanced kidney disease. 

The average levels of all four biomarkers were significantly higher in patients with rapidly progressing or advanced kidney disease compared to patients who had normal kidney function. These included cystatin-C (4.09 µg/g vs. 2.72 µg/g), angiotensinogen (4.67 µg/g vs. 1.77 µg/g), KIM-1 (90.1 ng/g vs. 60.8 ng/g), and NGAL (858.3 ng/g vs. 628.6 ng/g).

Cystatin-C, angiotensinogen, KIM-1, and NGAL were as accurate as albumin in detecting rapidly progressing kidney disease and advanced kidney disease.  However, albumin combined with angiotensinogen and NGAL was 75.1% predictive of kidney disease. This predictive association was slightly higher than albumin alone (73.1%).

This study concluded that cystatin-C, angiotensinogen, KIM-1, and NGAL levels may indicate kidney disease in patients with T2D. The authors suggest that using these biomarkers in combination may make the detection of kidney disease more accurate.

The number of patients with early or advanced kidney disease was quite small. Also, the follow-up period was relatively short (3 years). More studies are needed to confirm these results.

Talk to your doctor if you have concerns regarding kidney disease.