A slim, fit, 50-year-old Korean sushi chef with high blood pressure visits his cardiologist, who notices his blood sugar is also a bit high at 120. Just months ago, his doctor Edward Kersh might’ve said “Don’t worry about it, let’s watch this.”

But this time Kersh has access to a new fasting blood test — the PreDx Diabetes Risk Score — created by Tethys Bioscience in Emeryville. The DRS predicts the patient’s possibility of getting diabetes within five years.
When the results return, the patient scores an 8 on a scale of 1 to 10, meaning that without making lifestyle changes now, he has a 12.2 percent chance of converting to diabetes by the time he reaches , nearly four times the risk of the general population.

“With this guy, no one would have had a clue about it. You look at him and think he’s not a candidate for diabetes until the day he goes into a diabetic coma or has one of the complications of diabetes,” said Kersh, chief of cardiology at St. Luke’s Hospital in San Francisco.. Kersh is so enthusiastic about the results he’s seen with the DRS that he may work with Tethys Bioscience in the future.

In this case, it turned out that the patient ate lots of rice, didn’t realize soy sauce had excessive sodium, and, Kersh thinks, probably drank a lot of beer (It’s in the culture of sushi chefs, he explained).

Now the patient is altering his diet by cutting carbohydrates and hoping to head off the disease before he truly becomes a diabetic.

The DRS is already available in Northern California and is gaining both momentum and attention. Unlike existing methods of determining risk for Type 2 diabetes, which look at single markers including BMI, fasting glucose or HbA1c, the DRS measures multiple biomarkers, including ferritin, glucose, adiponectin, insulin, HbA1c, interleukin-2 receptor-alpha and C-reactive protein. These biomarkers are linked to biological pathways like cardiovascular disease and inflammation, cell death, obesity, glucose metabolism and other metabolic disorders that lead to Type 2 diabetes.
The DRS was developed using blood samples from 8,700 participants in two long-range European studies. Hersh noted the subjects were primarily Caucasian and that there’s no evidence that the biomarkers are the same for minorities, like blacks and Hispanics, who have higher conversion rates to diabetes. But, he added, “I don’t see any reason why [biomarkers] wouldn’t be the same.”

Tethys Bioscience analyzes blood samples using an algorithm that translates marker measurements into a score that correlates with the patient’s chance of developing diabetes within five years. Patients with the highest category of scores — from 8 to 10 — have anywhere from a 12 to a 60 percent chance of conversion, depending on their risk factors.
The DRS is recommended for people over the age of 30 who have at least one risk factor for diabetes, including obesity, family history, high glucose, inactivity, high cholesterol, metabolic syndrome, high blood pressure or a previous history of gestational diabetes. Though the test and analysis costs $465, Tethys is not billing patients right now, but rather working to get insurance companies to cover the cost.

And Tethys contended that the DRS provides better risk discrimination than existing tests because it’s personalized and specific. Some doctors say high PreDX scores have a greater impact on patient’s behavior than previous tests. “The patient doesn’t live in a world of statistics, but seeing something graphic, color-coded helps them to feel the fear of developing diabetes,” one doctor responded to Tethys Biosciences’ anonymous survey.

And the PreDx even changes doctor behavior. “When I see a high or even a moderate score, it changes my tone and I’m going to be more aggressive with [patients],” said another doctor surveyed.

Patients are considered at risk for diabetes if they have impaired glucose tolerance, impaired fasting glucose (IFG), or both conditions.

More than 57 million Americans over age 20 had IFG in 2007 and were considered at risk, but according to Tethys Biosciences , the Inter99 study showed that conversion rates of IFG patients ages 39 and up with a BMI greater than 25is nine percent. (The CDC follows studies that show 1.5 to 23 percent of patients with IFG will develop diabetes within a year and the majority will become diabetic within 10 years.)

Some may ask, why is it necessary to know one’s exact risk for diabetes — why not put all 57 million pre-diabetics on a plan to change their lifestyle? According to Kersh it is unrealistic to expect the majority of people to make life changes.

Additionally, Kersh has found that the DRS is a more effective motivator than other tests.

“I’ll sit here with a patient and [tell them they have] slightly elevated blood pressure and blood sugar. They walk out feeling the same as when they walked in,” Kersh explained. “When you show them this paper, ‘You’re going to get diabetes. Here’s the evidence,’ they walk out with a different psychological headset. Now they’re told to really do something. There are consequences.”

But Christian Vaisse, M.D., a UCSF associate professor of medicine, told the San Francisco Chronicle that it’s unclear whether people would change their ways because of the DRS. It could be wiser to regularly give more people an inexpensive blood sugar test to determine whether they already have diabetes, he added, citing the fact that about a quarter of the 24 million people who have diabetes don’t realize it.

Vaisse said pre-diabetes can be detected by an inexpensive oral glucose tolerance test, which typically costs in the ballpark of $40. After the patient swallows a sugar cube, clinicians measure how fast the sugar levels in the blood subside. “It’s clear it’s not 100 percent predictive, but it is very sensitive,” he said.

Tethys president Michael Richey, however, doesn’t see the DRS as being at odds with Vaisse’s position. “If you use a fasting glucose test and you find undiagnosed diabetics, it’s good news. Wouldn’t you like to prevent this disease?” he asked, adding that some models say the health care system can save  up to $30,000 per case of diabetes avoided.

Diabetes affects 8 percent of Americans and was the seventh leading cause of death in the United States in 2006. It can lead to serious complications including kidney disease, stroke, heart disease, blindness and amputations. Diabetes cost $174 billion in 2007, according to the Centers for Disease Control and Prevention.

One key way to reduce the devastation is through early detection, so potential patients can make lifestyle changes — and to a lesser extent use medications — to prevent or delay the onset of disease.

And as a result, medical experts across the board are calling for better ways to assess diabetes risk.

“Diagnostic tests should be developed to better distinguish patients who will progress to diabetes from those who will not,” recommended the American College of Endocrinology and the American Association of Clinical Endocrinologists in their 2008 consensus statement on the diagnosis and management of pre-diabetes. They added, “It is clear that the risks and adverse consequences of high blood glucose occur at much lower glucose levels than those at which we currently define as diabetes.”

The DRS may be just the tool to make those early diagnoses.

Alice Chen is a freelance writer based in the Bay Area.