Want to Know Your Risk of Diabetes? Genetic Test May Offer Warning

With Michael Multhaup, PhD, and Miriam S. Udler, MD PhD 

When pursing your genetic ancestry, is it necessary or even sensible to request a genetic analysis regarding your risk  for developing type 2 diabetes?

The researchers behind the popular, consumer-oriented, genetic and ancestry testing company, 23andMe, have identified a very effective way of alerting consumers to their risk for diabetes simply by assessing for a genetic predisposition to the disease.1

In a white paper prepared by the company scientists that describes the process—the use of existing genotype technology has been applied in the development of a polygenic risk score.1 The effort, led by Michael Multhaup, PhD, senior product scientist with 23AndMe in San Francisco, California, utilized existing genetic data known about the involvement of multiple genes found to affect the development of diabetes.

Genetic testing can produce a risk estimator for development of diabetes.Beyond informing your ancestry, genetic testing may offer a tool to determine your risk of type 2 diabetes. Image: 123rf

These researchers created a genetic calculation that represents the possibility that an individual might have a higher risk of diabetes based on individual genetic data.

Approach Used to Develop Formula to Assign Risk of Type 2 Diabetes

The genetic profiling was derived from data collected from more than 2.5 million customers who had agreed to be part of the research project.1 Along with information from this genetic data, the Dr. Multaup and his team applied data taken from responses shared about individual patient experiences with their physicians regarding any discussion about diabetes and related topics taking place between them such as body weight (based on body mass index [BMI]), blood pressure, fast food eating frequency, and other lifestyle issues.1

Since there are known risk factors beyond genetics that play a role in determining a patient’s likelihood of developing type 2 diabetes (T2D),2,3 the 23andMe researchers created an interactive “prevalence explorer tool” to help customers interpret their results.

The tool takes in to account demographic, lifestyle, and genetic information to create a number that reflects the prevalence of the disease developing depending on the specific criteria entered.

This prevalence explorer tool was created with input from physicians, certified diabetes educators, nurses, and other stakeholders,1 says Dr. Multhaup, emphasizing the term prevalence, not likelihood, because the information used is based on actual data from customers who opted in to the study and voluntarily reported back that they had received a diagnosis of T2D.

View of Your Diabetes Risk Now and in the Future

Along with the assessment calculation, the report also provides consumers with their remaining lifetime risk, a 10-year estimation of the likelihood of developing the disease in people with similar genetic profiles.

This tool takes reflects information about lifestyle choices that can ameliorate risk, general information about type 2 diabetes, reporting on the methodology used to generate the personal report, and a list of limitations of the report.

To clarify, the authors made a distinction between prevalence and likelihood of type 2 diabetes developing; the result you’ll gets at the top of your report is your likelihood of developing diabetes—so, basically, you receive a lifetime risk score of getting the condition in addition to a more immediate risk score, Dr. Muthaup tells EndocrineWeb.

Limitations to Consider Before Paying for this Feature

The research findings indicate that about 22% of the people in the 23andMe database have a risk of type 2 diabetes—equivalent to that conferred just by being overweight,4 he says.

And, there are limitations to the test, at present. For instance, Dr. Multhaup that there are more data from people of European descent than of African, Asian, Latino, or Native American, which can skew the risk profiles.

To address this shortcoming, the 23andMe researchers are doing outreach with underrepresented groups to boost the data in populations beyond Caucasians. The fact that there are still millions of people voluntarily participating in this data collection makes it one of the more robust datasets available for study, according to the authors.

Also, while the White Paper doesn’t have the benefit of being peer-reviewed, Dr. Multhaup says they are currently preparing on an article that will be submitted to a professional journal for publication.

How Much Good Comes from Knowing Your Genetic Risk for Diabetes ?

The Centers for Disease Control and Prevention (CDC) estimates that more than one in three adults in the United States has prediabetes– with the vast majority (90%) of these individuals having no idea of these risk.5

Add to that number that as many as 70% of those with prediabetes are likely to develop type 2 diabetes most of whom are also averse to going to the doctor regularly, so will have no idea of the health risks they are facing.6

In the future, the researchers at 23andMe foresee anticipate more diseases for which people will be able to learn their genetic risk. Dr. Multhaup says, “the hope is that the reports act as a conversation starter between patients and providers.”

In fact, people have contacted the company to say that since they got their report, they have talked to their physician or have been encouraged by the results to make changes to their lifestyles in order to reduce their risk of diabetes.

Is the Diabetes Prevalence Tool Ready for Prime Time?

That the company put anything out is a testament to their desire to be transparent, says Miriam S. Udler, MD PhD, director of the Massachusetts General Hospital Diabetes Genetics Clinic in Boston, Massachusetts. “There is a lot of thought that went into [developing the tool] to present to patients in a way that is understandable.”

 “Genetics only accounts for between 30 and 70% of the risk for T2D, so at least for now, clinical data including blood glucose levels, lipid levels, age, and body weight, for example, are still better predictors,” Dr. Udler tells EndocrineWeb.

But potentially, the 23andMe tool is a way for patients who elect to calculate their genetic predictive score and share it with their physicians have another avenue to help prevent development of diabetes. “Often, once patients have the clinical factors associated with increased risk of type 2 diabetes, they have already begun to suffer the effects of disease,” she said.

Dr. Udler also has some concerns about patients who consider the results of genetic testing on their own because they don’t have the benefit of appropriate medical context or informed recommendations for ways to appropriately address the results. Yet, she thinks that the company was extremely thoughtful with the report they put together for patients. In addition, the information seems to be enough to motivate some people to make necessary changes.

“Having medical professionals weigh in can be important,” she says, “It’s not always straightforward to know what to do with this kind of information.”

Read this: Reduce Diabetes Risk to Achieve Heatlthy Aging: 

She would like to see patients bring their 23andMe reports to their doctors for discussion so the information can be combined with the individual’s clinical information gathered by the  physician.

One reason to see a physician quickly is support by findings from The Diabetes & Aging Study,7 which indicated that patients with type 2 diabetes who are not aggressively treated during the first year post-diagnosis fared worse than their counterparts who received treatment early.

What this means is that there could be harm to people who are at risk for diabetes—or those with prediabetes— that progresses to diabetes but who do nothing?

“I believe this [opportunity to learn about your risk of diabetes] is another step in the paradigm shift that has patients more involved in their own care,” Dr. Ulder says.

For now, this kind of report seems limited to people who want to know the results and can afford the test. In time, she believes that insurance will cover genetic risk testing, but we aren’t there yet. “The company is pushing the envelope,” which is ultimately good, she says.

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