Does proteome analysis help delay the onset of diabetes-related kidney disease?

Photo of patient and doctor (PantherMedia / pasiphae)

People who have diabetes and high blood pressure are at greater risk of kidney disease. A specific urine test known as proteome analysis is thought to detect kidney damage sooner than previously possible, improving treatment outcomes. But due to a lack of research in this area, the actual benefit can't yet be determined.

Many people with diabetes not only have high blood sugar levels, but also have high blood pressure too. This increases the risk of diabetes-related complications such as cardiovascular disease or kidney disease (nephropathy).

Over time, diabetes and high blood pressure can damage the small blood vessels in the kidneys. As a result, the kidneys can no longer effectively remove metabolic waste products from the body. This is known as kidney failure (renal insufficiency). Chronic (permanent) kidney failure develops gradually over many years and may eventually lead to end-stage kidney failure. Dialysis would then be necessary. Dialysis cleans the blood – meaning that it can help the kidneys to do their job, or can do their job for them.

Standard diagnosis of diabetes-related kidney disease

Diabetes-related kidney disease (diabetic nephropathy) usually doesn't cause any symptoms at first. But there are already higher protein levels in the person's urine. A urine test is done to measure how much of the protein albumin is present, or to see how much albumin there is compared to creatinine (a byproduct of muscle metabolism). Slightly elevated levels of albumin (microalbuminuria) are a sign that a kidney is damaged but can still perform its functions. Very high levels of albumin (macroalbuminuria) indicate that a kidney is no longer working properly.

Even if they have normal levels of albumin in their urine and they don't have any signs of kidney damage, people who have diabetes and high blood pressure are generally given treatment to keep their blood sugar levels and blood pressure as low as possible. The aim of treatment is to prevent diabetes-related kidney disease.

Proteome analysis for the diagnosis of kidney damage

Unlike the current standard test, proteome analysis not only detects albumin, but can also detect many other proteins in the urine in order to provide an overall picture of how healthy the kidneys are. This new test is said to be able to detect kidney damage earlier than the current standard test – in other words, before higher levels of albumin can be measured in urine. It is thought that this will make it possible to treat diabetes-related kidney disease sooner and more effectively, or even prevent it from developing in the first place.

No suitable studies on proteome analysis

Researchers at the Institute for Quality and Efficiency in Health Care (IQWiG, Germany) wanted to look into the advantages and disadvantages of proteome analysis in people with diabetes and high blood pressure. More specifically, they wanted to see whether diabetes-related kidney damage can be detected earlier in this group of people if proteome analysis is used rather than the standard test. Another important question is how the test influences the treatment options and outcomes – for instance, whether it can lower the number of people who end up having end-stage kidney failure, or reduce the need for hospital stays. The researchers were also interested in whether the test can lead to an improvement in quality of life and reduce the number of related deaths.

But they didn't find any suitable studies with which to answer these questions. So it's not clear whether people with diabetes and high blood pressure can benefit from proteome analysis. In Germany, the costs of proteome analysis are currently not covered by statutory health insurance funds.