Nearly 30 years after enrolling in a diabetes prevention study at the University of Pittsburgh, Carol Washburn is still showing up for research visits.
What began as an effort to avoid the same diabetes diagnosis that affected her mother and grandmother has become part of a landmark study of healthy aging. As a longtime participant in the Diabetes Prevention Program Outcomes Study (DPPOS), Washburn has watched researchers follow thousands of volunteers from midlife into older adulthood, revealing new insights into how lifestyle choices can shape health decades later.
"I'm a big believer in research," Washburn said. "The study showed me how much I didn't know. And it's continued to motivate me."
That evolution is reflected in a new paper published in JAMA, which found that participants who received the study's original lifestyle intervention developed fewer chronic conditions as they aged than those who received placebo. The findings, based on Medicare data collected decades after the original clinical trial, suggest that lifestyle changes made in midlife can have lasting effects on health in older adulthood. Lifestyle intervention, but not metformin, was associated with a lower risk of multimorbidity, or the presence of multiple chronic conditions.
The paper builds on a longstanding collaboration among investigators at the University of Pittsburgh School of Public Health and the Department of Psychiatry at the University of Pittsburgh School of Medicine.
When the original Diabetes Prevention Program launched in 1996, researchers set out to answer a pressing question: Could type 2 diabetes be prevented through intensive lifestyle changes or medication?
Behavioral scientists in Pitt Psychiatry helped design and deliver the lifestyle intervention, combining nutrition, physical activity and behavior-change strategies to help participants adopt healthier habits. Researchers at Pitt Public Health contributed expertise in epidemiology, chronic disease and long-term population research.
"It was always an interdepartmental collaboration," said Elizabeth Venditti, PhD, professor emerita of psychiatry, who helped develop the lifestyle intervention and later served as principal investigator of the study. "Behavior change was a critical part of preventing diabetes, and that required bringing together people with different expertise, such as investigators studying nutrition, physical activity, and cardiometabolic health."
As participants aged, so did the scientific questions.
"What we're realizing is that we're not just studying diabetes anymore," said Elsa S. Strotmeyer, PhD, professor of epidemiology at Pitt Public Health and current principal investigator of DPPOS. "We're studying aging."
Today, investigators are studying how those early interventions influence frailty, physical function, cognitive decline and other conditions that affect health later in life.
"One of the strengths of this team is that people from different disciplines contribute different perspectives," Strotmeyer said. "As the participants have gotten older, we've been able to ask new questions because we've brought in new expertise in aging epidemiology, cognition, and behavioral neuroscience."
For Washburn, the study's impact has never been limited to a single research visit.
Although she was disappointed to learn she had been assigned to the placebo group, she continued attending education sessions, asking questions and returning for regular follow-up appointments. The study gave her something she found invaluable: information she could act on.
"The blood tests were very motivating," she said. "I did not want to convert to diabetes."
Over the years, she continued learning about nutrition, exercise and blood sugar management. She now uses a continuous glucose monitor to understand how food and activity affect her blood sugar and remains an advocate for research in her community.
Last month, Washburn reached a milestone she never expected. For the first time since entering the study, her A1C was no longer in the prediabetic range.
"So many people think getting diabetes is just normal because their parents had it," she said. "It's not normal. You have some agency over it."
For Strotmeyer, that message reflects why the study continues to matter.
"It's never too late," Strotmeyer said. "The choices people make, even later in life, can improve their health and help them age with better health."
-Clare Collins