A genetic risk score based on blood pressure has been shown to potentially help determine the increased risk for heart attack or stroke in people with type 2 diabetes, suggesting that glucose control alone won’t be enough to control a person’s genetic risk for other cardiometabolic diseases.
The study analyzed genetic data from 6,335 participants, characterized as a high-risk multiethnic type 2 diabetes population, in the Action to Control Cardiovascular Risk in Diabetes study (ACCORD). Investigators developed a multivariable-adjustable model that found that, with each degree increase in the genetic score, the risk of cardiovascular disease (CVD) events increased 12%. However, the study found no relationship between glycemic control therapy and BP genetic risk score in CVD risk (P < .10).
Researchers at the University of Alabama at Birmingham reported on the risk score in a research letter
“This study highlights that commonly occurring changes in our DNA that cumulatively contribute to a higher risk of BP and hypertension can predispose T2DM [type 2 diabetes mellitus] patients to a higher risk of CVD events,” lead author Pankaj Arora, MD, said in a comment. The genetic risk score used in the study was effective at identifying CVD risks among the study participants even after accounting for conventional CV risk factors, added Dr. Arora, who’s director of the cardiovascular clinical and translational research and cardiovascular genetics clinic programs at UAB. “We recognize that cardiometabolic diseases travel together. Simply controlling the blood glucose level in isolation without considering an individual’s genetic risk for other cardiometabolic diseases may not yield a reduction of CVD risk in T2DM.”
The study used a map of more than 1,000 common genetic variants known to affect BP and compared that with the DNA of study participants to determine their genetic risks. Dr. Arora and colleagues wrote that the “results invigorate the potential implications” of using a BP polygenic risk score to address CVD risks through early intervention with lifestyle modifications such as diet, exercise, smoking cessation, weight management, and BP control in people with high genetic risk.
Gene profiles like the model the UAB researchers developed are still far away from the clinic, Dr. Arora said. “While such gene profiles are being used regularly in cancer management, these gene profiles are not easily available for cardiologists and endocrinologists to order.” He noted that the cardiogenomics clinic at UAB is one of the few centers that provide this kind of gene profiling in the United States. “Studies like this are bringing gene profiling closer to the doorstep of all cardiology and endocrinology clinics.”
The next step for the research is to expand the genetic variants used in the profiles. “We are now trying to develop a gene profile that encompasses more than 1 million common genetic variations and will be more informative,” Dr. Arora said. He added that few randomized clinical trials have shown using a BP genetic risk score in the clinic would improve outcomes of people with T2DM.
Kiran Musunuru, MD, PhD, MPH, director of the genetic and epigenetic origins of disease program at the University of Pennsylvania’s cardiovascular program in Philadelphia, provided context on what the study adds to the understanding of CVD risk in people with T2DM. “We know that patients with type 2 diabetes are at increased risk of cardiovascular disease, some of which is due to coexisting risk factors like abnormal lipids and hypertension,” he said in a comment. “This study shows that genetic predisposition to high blood pressure is one of the drivers of risk in these patients.” Dr. Musunuru is also chair of the writing group for the American Heart Association scientific statement on the use of genetics and genomics in clinical care.
However, he noted that collecting that kind of genetic data is challenging because few companies offer the tests and few centers do routine genetic testing. “As more studies like this one demonstrate the potential benefits of genetic testing, we can expect to see broader adoption by clinicians,” Dr. Musunuru said.
Dr. Arora receives funding from the National Heart, Lung, and Blood Institute and the Doris Duke Charitable Foundation. The ACCORD study received funding from Abbott Laboratories, Amylin Pharmaceutical, AstraZeneca, Bayer, Closer Healthcare, GlaxoSmithKline Pharmaceuticals, King Pharmaceuticals, Merck, Novartis, Novo Nordisk, Omron Healthcare, Sanofi-Aventis US, and Schering-Plough. Dr. Musunuru has no relevant relationships to disclose.