A non-invasive test that can provide an early warning of heart attacks in Caucasian diabetics is just as effective for Arab and South Asian diabetic populations, say researchers from Weill Cornell Medical College in Qatar.
The AGE Reader, a device first developed in the Netherlands by DiagnOptics in 1996 and approved for commercial use a decade later, is designed to provide patients with major chronic diseases with an immediate cardiovascular risk prediction by analyzing the concentration of a specific protein in their bodies. But while its application had been validated among Caucasian populations in the United States and Europe, it was unclear if it could predict vascular risks in people with darker skin with similar accuracy.
In a new study, researchers from Weill Cornell in Qatar say that the device can, in fact, successfully predict vascular risk among diabetic Arabs and South Asians by taking the difference in skin color into consideration.
"The manufacturers of the machine at first believed that the ethnicity of the person being tested would be inconsequential to the results delivered," said Dr. Dennis Mook-Kanamori, a research associate at Weill Cornell Medical College in Qatar. "We showed, however, that a person's ethnicity did affect the results — but that the machine could be recalibrated to provide an accurate indication of potential future cardiovascular problems whatever a person's ethnicity."
Here's how the AGE Reader works: A patient rests his or her arm on the device, which shines an ultraviolet light on the person's skin. The skin's glow can then be used to determine the body's concentration of advanced glycation end products, miniscule fragments of degrading, sugar-containing proteins that accumulate in the body over a lifetime. The higher the concentration of these fragments, the more likely a patient is to have heart problems later in life.
Diabetics are at particular risk for a higher concentration due to spikes in their blood sugar levels. Researchers say the test is akin to using cholesterol levels to predict people's risk of cardiovascular problems.
To investigate the efficacy of the AGE Reader among darker-skinned populations, lead investigator Dr. Karsten Suhre, professor of physiology and biophysics at Weill Cornell in Qatar, in conjunction with Hamad Medical Corporation's dermatology department, tested the device on 200 Arabs, 99 South Asians, 37 Filipinos and 14 people from other countries. Approximately half of the subjects were men and half were women, and none were Caucasian.
"To our knowledge, this was the largest study performed so far that uses the AGE Reader in South Asians, Filipinos and Arabs," Dr. Suhre said.
The researchers discovered that skin auto-fluorescence differs among ethnicities, and therefore the existing statistical reference curve used to analyze protein particles in Caucasian patients would have to be modified to take skin color into account. The researchers add that larger studies in specific ethnicities are required to create the modified statistical reference values.
With type 2 diabetes increasing in prevalence in Qatar and the Gulf States, these researchers say it's more important than ever to identify techniques for early detection and prevention of complications from the disease.
"For diabetics in particular, this is an important tool," Dr. Mook-Kanamori said. "By applying the AGE Reader test, doctors can give their patients an early warning of potential heart problems and take action to reduce those problems."
The research was conducted as a side study to Dr. Suhre's main focus, which involves searching for biomarkers — telltale molecules present in samples of blood, urine or saliva that are associated with the metabolic processes known to cause diabetes — in order to develop additional early-detection tests for the disease.