It's a paradox that science is only now seeking to understand: Women live longer and appear to age better than men—but when they do develop disease, they suffer worse outcomes.

"The idea that women are healthier and live longer is an oversimplification of what's going on with us as we age," says Susan Cheng, MD, MPH, MMsc, director of Public Health Research in the Smidt Heart Institute. "It's not a phenomenon that is widely recognized, but when women develop disease, we tend to carry a heavier burden."

Cheng's lab is interrogating a trove of existing population health data—decades of blood work, physical measurements, cognitive tests, lifestyle information and disease outcomes collected from tens of thousands of people—in hopes of illuminating intricate biological pathways that lead to disease across the sexes. She hopes that better clarity will fuel the development of more personalized, sex-specific guidelines on how to diagnose and treat disease. The ultimate goal is better care for both women and men.

Among the questions Cheng seeks to answer: In older age, why are women more predisposed to certain types of heart failure than men? Why do women in the earliest stages of Alzheimer's disease suffer worse cognitive decline? When women develop impairment in kidney function, why are they prone to worse cardiovascular outcomes? 

"We need to reorient ourselves, drop the assumptions we've made about male/female differences and start with a blank slate," Cheng says. "Then we can begin to make more progress in terms of better understanding how women and men really are different in health as well as in disease."