From the Heart
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She sought counsel from Irwin Rosenberg, dean of the Friedman School of Nutrition at the time. Though Tufts offered no formal program that coupled a Ph.D. at the Friedman School with an M.D., he encouraged her to see if it could be done. Landry convinced deans at both schools that that if anyone could meet such an ambitious goal, she could.
Katherine Tucker, Landry's thesis advisor and a senior scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging, saw that Landry's talents extended beyond laboratory research and introduced her to the Jackson Heart Study.
Landry carefully planned her personal and academic future. In 2005, she married Alden, a tall, handsome Harvard medical student with roots in Texas and Louisiana, and the two moved to Roslindale to begin a new life together. She decided she would enroll in one year of med school, stop to finish her Ph.D., then fulfill the last three years of the M.D., making her just 31 when she would graduate with four degrees and begin a career in academic medicine.
Landry at her family reunion in July 2008.
A week before her med school board exams, she got an urgent call from her mother in Virginia. Her pregnant sister Cherita was being prepped for an emergency C-section after tests revealed the fetus had stopped growing at 25 weeks. Landry had more than a gut feeling that Cherita's hypertension was directly to blame. Although her sister had been careful to monitor her diet, only weeks before her blood pressure had spiked at a stroke-level high of 220 over 100—probably the point at which the placenta began to decline.
At birth, her niece weighed just 13 ounces, less than three sticks of butter. After months of intensive care, the baby began to thrive, but Landry was shaken. Her family had been through tremendous strain. Medical research had to offer something better.
Getting to the Heart of the Problem
Nearly everything that is known about heart disease and what causes it—high blood pressure, high blood cholesterol, smoking, obesity, diabetes and physical inactivity—comes from a landmark experiment begun in Framingham, Massachusetts in 1948. The Framingham Heart Study, which surveyed three generations of Yankee stock, is considered one of the most successful clinical inquiries of all time.
Fewer than ten African-Americans took part, but researchers claimed that the study's results applied to everyone, regardless of race. While the known risk factors may apply across the board, curiously higher levels of heart disease for African-Americans, especially Southerners, suggest the portrait is more complex.
"The question that arose in any academic conference, in any cardiologist meeting, was always, do the results in Framingham apply to non-Caucasian Americans? Are there unique aspects for African Americans, particularly in the South?" says Dr. Herman A. Taylor, principal investigator of the Jackson Heart Study.
He and his fellow researchers are the first to focus on the complex interplay of nutritional, genetic and socio-economic factors in a sizeable African-American population. Structurally, the Jackson Heart Study is similar to Framingham. But the Jackson study also monitors social stresses that may be unique in their degree and effect on the African-American, Southern population. These could include perceived discrimination, cultural differences such as religious faith or regional factors like high unemployment rates.
According to Dr. Taylor, the Jackson data has revealed some interesting differences from Framingham. In all ethnic populations, the risk for cardiovascular disease tends to run in groups or clusters, a phenomenon called the metabolic syndrome. For example, a person who is likely to develop heart disease is also likely to have multiple risk factors—he or she might not only suffer from high blood pressure, but might also be overweight, a smoker or diabetic.
In African Americans, however, the prevalence for multiple risk factors is extraordinarily high, and the factors themselves are slightly different from those seen in the white population. While whites at risk for cardiovascular disease typically have high triglyceride levels, African Americans tend to have a combination of truncal obesity, hypertension and low HDL—the "good" cholesterol.
"That's surprising in some ways," says Dr. Taylor. "One, historically, it's been thought that if there's anything good about the risk profile for African Americans, it's that they have high HDL levels, and that protects them from having even more cardiovascular disease than they might otherwise have had. And there's old data to suggest that's true—that high levels of HDL were common in African-Americans and therefore they were protected against heart disease. In the Jackson Heart Study, we have found that's not the case." (continued)
Story and audio slideshows by Claire Vail, Web Communications Manager, School of Medicine. Photos by Melody Ko, University Photography.
This story originally ran on Sept. 15, 2008.