By Dr. James Aw
The patient, in his early 20’s, was clinically depressed and struggled with sleep. His family physician prescribed him an antidepressant and medication to treat his insomnia. But his mood wasn’t lifting, and his sleep wasn’t improving. He had difficulty at school and was on a waiting list to see a psychiatrist.
The patient’s mother was concerned and brought him into Medcan Clinic for pharmacogenomics testing, which screens a person’s DNA to determine how the body responds to certain medications. Medcan, where I am the chief medical officer, is a Toronto-based JHI affiliate that provides patient care focusing on prevention and wellness.
The testing revealed that the patient metabolized his antidepressant too rapidly for it to be effective. His family physician changed the prescription—and the patient's mood and sleeping pattern improved. He was able to return to a functioning life and avoid unnecessary future visits (and costs) in the health care system.
Our patient’s experience is just one example of the way personalized medicine—tailoring medical care to a patient’s individual profile—is changing the health care profession, regardless of where we are in the world.
Years ago, doctors were limited in their ability to assess what was happening in the body. They could take a few key measurements—like body temperature, heart rate and blood pressure.
Today, the amount of data available is exponentially greater. Many of us wear trackers like the Apple Watch and Fitbit, which detail our sleep patterns and physical activity. We monitor the steps we take and the calories we burn. Researchers are now studying portable biosensors that allow frequent measurements of blood oxygen levels, skin temperature and physical activity that may uncover early signs of inflammation or detect disease before it surfaces.
In the future, we’ll be tracking even more health attributes 24/7. We’ll also complement this data with pharmacogenomics testing and whole-genome analysis, which spells out all 3 billion letters in a person’s genetic code in a single test. Physicians can use this complete DNA sequence to determine that patient’s most effective treatment for a disease. (Read more about this testing in a study Medcan genetic counselors conducted in collaboration with the University of Toronto to establish the medical efficacy of whole-genome analysis.)
There’s also microbiome testing, which doctors use to analyze bacteria in the body to determine GI and skin issues. Eventually, we’ll also have access to artificial intelligence algorithms that monitor our systems and help us better understand the patterns and precursors of various diseases.
All these tools will guide care in the future of personalized medicine. My colleague Dr. Stephen Scherer, who led the whole-genome study I mentioned, sums it up well: “There’s going to be an onslaught of information, and society needs to figure out how to deal with that.”
But how should the availability of this information affect the way we manage our health today? Much of the information available to us is confusing. For example, the genome study by Dr. Scherer and his co-investigators revealed many instances in which DNA indicated a person should have some genetic condition, but he or she was perfectly healthy. How do we use these new sources of medical data to improve our health—without driving ourselves crazy with anxiety?
Some health decisions are no-brainers. If your activity tracker shows you’re averaging just six hours of sleep a night, you should go to bed earlier. Other decisions—like whether to change your antidepressant—requires consultation with a professional.
The new world of personalized medicine is exciting, whether we’re talking about pharmacogenomics, whole-genome sequencing, microbiome analysis or just the data available from your activity tracker. The people who are taking advantage of such information are on the cutting edge of personalized medicine, but interpreting this new data requires experience and context. Defer to qualified professionals for advice, particularly before you let it affect your health now or down the line.
Dr. James Aw is the chief medical officer at Medcan Clinic, where he oversees the physician team, clinical protocols and medical programs and helps lead strategic research and business development. Dr. Aw is also a part-time faculty member in the Division of General Internal Medicine at the Johns Hopkins University. He has more than 20 years experience in corporate health and occupational medicine including disability management, critical incident planning, infectious diseases in the workplace, industrial hygiene, wellness and disease management programs. Dr. Aw is a member of the McLaughlin Oversight Committee, University of Toronto, which advises faculty on genomic research and innovation.