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4 Questions for David Siscovick, MD, MPH expert in prevention and heart health

Billions are spent searching for often elusive answers to preventing heart disease—the leading cause of death in the United States and in the world. In a new Viewpoint, published in the journal Circulation Research, David Siscovick, MD, MPH the Academy’s senior vice president for Research and immediate past chair of the American Heart Association Council on Epidemiology and Prevention, suggests a new path of inquiry. He makes a case for greatly expanding the vision and scope of heart disease research beyond daily lifestyle factors to include environmental exposures that may occur at critical points during the lifespan in order to understand the full range of risks to the public’s cardiometabolic health.

Q: There are many approaches to understanding heart disease. What did you choose to publish in  your Viewpoint, a commentary in the American Heart Association’s official journal of basic cardiovascular science , and why?

A: For this commentary, I looked at our understanding of the current epidemic of overweight and obesity from a perspective that includes not only genes and recent health behaviors, but also incidents that take place across the life cycle and generations. The suggestion is that this paradigm shift offers the best chance to uncover important, contextual factors that will have a meaningful, long-term impact on the cardiometabolic health of the public.

Q: Why look over such a long span of time to find out why someone might develop heart disease at say, age 50?

A: If you focus exclusively on cell biology and the present, when investigating the causes of poor cardiometabolic health, you may lose the opportunity to identify important issues related, for example, to epigenetics—modifications in gene expression in response to the environment that can be carried over many generations. The article is a basic advisory to scientists to call their attention to these issues, including the importance of the broader determinants of health across the lifecycle and generations. This approach is at the center of our work here at the Academy.

When you take this long term (back to the future) approach, you consider that someone’s heart disease risk may be linked to something their mother endured before or during pregnancy, a famine or toxic stress survived by a great grandmother, or even being part of the third generation of a family that lived in a dense, polluted urban environment.

Q: Are you saying that a person may struggle with obesity because of issues that may have occurred before they were even born?

A: Yes, there is mounting evidence that there are critical time windows over the lifespan that may influence body weight, not only for current, but also for future generations. Preconception obesity and overweight, or excessive weight gain during pregnancy, due in part to environmental factors and genetic variation, affect the long-term cardiometabolic health of offspring.

In utero exposure to famine—early in pregnancy, weeks 1 to 10, rather than 11 to 20, for instance, has even been connected to an increase in obesity and risk for poor cardiometabolic health. Famine may seem like a foreign experience, but it was endured by the fairly recent ancestors of the more than 150 million American’s whose ancestors are from Ireland, Germany, Africa and Holland. 

Q: What do you want scientists to do with this more detailed and advanced knowledge on the broader determinants of cardiometabolic risk?

A: I am advocating for this to be seen as an opportunity to impact heart health now and for future generations, possibly the next 100 years! This would mean supporting basic and population research that requires a long-term investment, but scientific discovery needs to take into account context—historical, current, and across the lifespan—if we want to understand the full range of influences on cardiometabolic health. Research on overweight and obesity, key heart health risk factors, is now focused on person and place. I argue that the focus should expand to include person, place and time.