Blood tests to measure "bad" cholesterol are common and used to identify the risk of a heart attack.
Now, researchers are exploring whether other types of fat molecules (ie, lipids) found in the blood can provide new insight into heart health.
One of the researchers advancing this field is
Dr. Krista Lanctôt, an Affiliate Scientist at Toronto Rehabilitation Institute and Senior Scientist at Sunnybrook Health Sciences Centre.
Dr. Lanctôt led a recent study that showed that blood levels of lipids known as sphingolipids could serve as a readout of improvements in fitness in patients undergoing cardiac rehabilitation.
"Cardiac rehabilitation is an important way to improve the health of patients with coronary artery disease," Dr. Lanctôt explains. "However, patients' response to these programs can be highly variable, which is why we explored whether we could identify a new, more objective way to gauge cardiac fitness in this these patients.
"We focused on sphingolipids because levels of these lipids were recently shown to be elevated in elderly individuals with poor cardiopulmonary fitness."
The study enrolled 100 patients with a history of coronary artery disease who were participating in a six-month cardiac rehabilitation program. In these patients, the researchers measured blood levels of 45 different sphingolipids, as well as cardiopulmonary fitness at the beginning of the program and then again at three months and six months.
Cardiopulmonary fitness, which is a readout of how well the body uses oxygen during vigorous and sustained workout, was measured using a "stress test," where participants wear a mask to measure oxygen levels while rigorously exercising.
"Our results revealed that blood levels of five key sphingolipids decrease as cardiopulmonary fitness improves during cardiac rehabilitation," says Dr. Lanctôt.
"The findings, while emphasizing the importance of lifestyle changes to improve heart health, also provide detailed data that will inform future studies on the role that sphingolipids play in cardiovascular health."
Supported by the Canadian Institutes of Health Research, the Alzheimer's Society of Canada, the National Institutes of Health (including the National Institute on Aging), and the Toronto Rehab Foundation. AC Andreazza holds a Tier 2 Canada Research Chair in Molecular Pharmacology of Mood Disorders.