Epidemiologist K.M. Venkat Narayan is engaging experts from around the world
to find a global solution
By Valerie Gregg and Pam Auchmutey
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Science has been much the same kind of force for K.M. Venkat Narayan, one of the world's foremost experts on diabetes epidemiology. A "global citizen"—having lived in five countries on three continents—and a physician with master's degrees in public health and business, Narayan is a prolific scientist and author who joined the RSPH in 2006 as the Ruth and O.C. Hubert Professor in Global Health and Epidemiology. He came to Emory from the CDC, leaving a position as chief of the Diabetes Epidemiology and Statistics Branch of the Division of Diabetes Translation. The RSPH, he says, provided an opportunity to build "something big and something global."
"The school offered immense potential—the vision, energy, and genuine support to build a chronic disease research program,"says Narayan, who also holds a joint appointment as professor of medicine. "The sense of positive energy, all the way up to Emory President James Wagner, showed me a commitment to global health. And the timing was good, as I had become very interested in globalization and how it affects the world."
Diabetes is among the world's most daunting public health challenges in the 21st century. Worldwide, 240 million people have diabetes. CDC experts believe that number will double by 2030.
The statistics are sobering in the United States as well. An estimated 9% of the U.S. adult population has diabetes at any given time. In a startling paper published in the Journal of the American Medical Association in 2004, Narayan estimated that lifetime risk for diabetes among Americans is one in three and even higher in certain subgroups. For example, Latino women living in the United States have a one in two risk. Narayan and his colleagues also projected that 50 million people will have diabetes by 2050 in the United States alone. Tackling the diabetes epidemic—nationally and globally—requires extraordinary efforts.
"Lessening the burden of chronic disease is always complex," Narayan says. "It is ironic that prosperity can be hazardous to the health of citizens of developing countries. As these countries become more affluent, westernized, and have higher standards of living, some markers of health improve, and some—like chronic diseases—grow."
For the first time ever, more people in the world are overweight rather than underweight. Obesity is a large factor in the diabetes equation but not the only one. Genetics also may play a role. Native Americans, Hispanics, and some other nonwhite groups have up to 10 times the rate of diabetes as Caucasians. Changes in diet, activity, and environment are also factors. To complicate matters, diabetes risk varies from subgroup to subgroup and among native-born citizens and immigrants from other countries.
Learning more about diabetes in populations worldwide is crucial to helping scientists identify genes and new risk factors for study and translating research in ways that benefit those populations. All have policy implications for diabetes prevention and use of resources at home and abroad.
"More and more, Americans will be affected," Narayan says. "There are about 40 million foreign-born people in the United States, and this number is growing. Something like 20% of people under 18 years are first- or second-generation immigrants, and in some places 40% to 50% of Americans will have parents who are foreign born. We are not isolated."
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In a startling paper published in the Journal of the American Medical Association in 2004, Narayan estimated that the lifetime risk for diabetes among Americans is one in three. | |
Born and raised in Bangalore, India, Narayan has a unique take on the global situation, indeed on life in general. His father died before he was born, and he contracted polio just as he was learning to walk.
"My right lower leg has mild residual weakness," he says. "It left me with a limp, but it has not bothered me much. It has given me a better perspective on life, greater resilience, and creative adaptability as an individual. It is just a part of who I am."
A voracious reader as a child, Narayan enjoyed studying theoretical subjects like abstract physics, literature, and mathematics. When he was accepted at one of the most prestigious medical schools in India at the age of 18, he felt compelled to attend.
"I can't say I enjoyed it very much or performed particularly well," he says. "When professors said to do thus and so in the case of myocardial infarction, I asked them: ‘Why?' They always answered: ‘Because the book says so.' That was never enough to satisfy me. I wanted to know how specific knowledge became part of the text—how they arrived at these conclusions."
His mindset prompted him to pursue a master's degree in epidemiology and public health, which led to a tenured faculty position at the Grampian Health Board and the University of Aberdeen in Scotland before age 32. He became a British citizen, thinking he had procured "a dream job for life." There he collaborated on research showing that cardiovascular disease was the leading cause of death among people with diabetes in Scotland.
But in 1992 came the opportunity to work in Arizona with Peter Bennett, an NIH epidemiologist doing groundbreaking diabetes research with the Pima Indians, a group with the highest diabetes prevalence rates in the world. Narayan added the United States to his citizenship list and narrowed his focus to the study of diabetes.
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When Narayan joined the RSPH, he dreamed of bringing researchers together on a global scale to better understand and solve the problems associated with diabetes. Bringing disparate groups, opinions, and people together is one of Narayan's favorite occupations, in science, philosophy, conversation, and life in general. "It helps me think, and it's good fun," he says.
While at the CDC, he brought ideas and experts together to create a team of internationally respected diabetes epidemiologists, statisicians, economists, and other public health experts. He is applying the same formula at the RSPH. His philosophy: "Connect good ideas to good people, and good things will happen."
Since joining the RSPH, he has hired three postdoctoral students, one a Rhodes Scholar and the other two graduates of the University of Pennsylvania. He also works with six PhD students, several postdoctoral students and clinical fellows, two research coordinators, and a host of faculty across Emory, nationally, and worldwide. He advises several MPH students and has sent three of them to Chennai, India, for summer field experiences. In many respects, Chennai and the RSPH represent how two rivers of science can merge to become even more powerful.
Last year, Emory's Global Health Institute awarded a seed grant to the RSPH and the Madras Diabetes Research Foundation (MDRF) in Chennai to establish the Global Diabetes Research Center. The partnership combines resources and expertise to expand research and training for scientists in the United States, South Asia, and throughout the world.
India offers a special window into the study of diabetes. As of 2007, 40.9 million people there had diabetes—the highest number of cases in the world. In Chennai alone, diabetes increased by more than 70% from 1989 to 2005.
Through the Global Diabetes Research Center, the RSPH and the MDRF are combining their respective strengths to better assess the diabetes burden, test cost-effective treatments, shape health policy, and—most important—delay or prevent disease onset.
Much of the partnership is virtual. The RSPH and MDRF conduct monthly meetings via teleconferencing. Last fall, the center launched a mentoring program for researchers to expand study of the causes of and solutions for diabetes. Epidemiology professor David Kleinbaum conducts his ActivEpi course for 32 researchers who are located 10,000 miles away in Chennai.
The MDRF—led by Viswanathan Mohan, who co-directs the Global Diabetes Research Center with Narayan—has a lot of offer: a strong research base, a 150-bed hospital, a new 20,000-square-foot research building with space for Emory investigators, and the largest electronic medical record system of diabetes patients in the world.
Together, the RSPH and MDRF are laying the groundwork for new research, including a national representative survey study of 100,000 people to help explain regional differences in diabetes and a study of metabolic differences in pregnant women and how those differences may affect their children, both in India and in the United States. Researchers also are looking to prevent and treat diabetes through lifestyle intervention. Doctoral student Mary Beth Weber, 02MPH, is developing a randomized study involving 700 people in India. As part of the study, Weber and others will teach lifestyle trainers there how to coach study participants and other people after the study is complete. "We want the program to be culturally appropriate and sustainable," says Weber. "The interventions we develop will also help prevent other diseases in addition to diabetes."
Ensuring that diabetes treatments are readily available and affordable is also a center priority. "India has world-class pharmaceutical companies that are able to produce drugs at very low cost," says Narayan. "So the question is, are there versions of drugs or vaccines that can be produced inexpensively? Are there lessons we can learn about innovations in mass delivery? How can we in public health get those innovations to the masses and not just to those who can afford it? Those solutions could be applied in the United States as well."
The RSPH and the MDRF plan to look more broadly at the South Asian population, both in and outside of the United States. People from these countries—some 1.5 billion worldwide—have a very high risk of developing diabetes. They tend to be more insulin resistant, prone to adiposity, and develop diabetes and heart disease at a younger age. Scientists have yet to discover why.
With time, future study results can be applied to South Asians, including those in Georgia, where the Indian population alone stands at 80,000. Weber is looking to launch a diabetes intervention program for South Asians in Atlanta to promote exercise.
"Folk dancing is a tradition in India and other countries. People love to dance at festivals and celebrations. It's something that people feel comfortable with and are likely to do." Weber hopes to develop a DVD of folk dances in collaboration with an Atlanta trainer who operates a gym geared toward South Asians. They will first test the DVD in focus groups to ensure that it is culturally appropriate and appealing. "We want it to be something that the community takes ownership of," says Weber.
During the past 60 years, researchers have noticed an alarming trend among U.S. immigrants. Most arrive healthy. As they adapt to their new culture, their health habits change. "They start catching up with the mainstream population within 15 years in terms of obesity," says Narayan. "We're trying to figure out what can be done to prevent that. We need to target children and young people the most."
Hence, Narayan and Julie Gazmararian, associate professor of health policy and management, are developing intervention programs for schools to encourage children to eat properly and exercise more. Other intervention programs will target minority groups, such as African Americans who use Grady Memorial Hospital. Narayan also works closely with Larry Phillips, professor of medicine, and Joe Lipscomb, professor of health policy and management, to evaluate innovative screening methods for prediabetes and diabetes.
A larger challenge is how diabetes affects U.S. immigrants in general. For her dissertation research, Rena Oza-Frank is working with Narayan to analyze nine years (1997 to 2005) of data from the National Health Interview Survey. Her data sample includes more than 30,000 foreign-born and 170,000 native-born people.
"Their health is going to have an enormous impact on the nation's health care," says Oza-Frank. "It's important to determine their level of risk and target prevention in this subgroup."
A registered dietitian, Oza-Frank is shifting gears professionally to focus on diabetes research. Like Narayan, she is a former clinician. "He understands diabetes from all perspectives," says Oza-Frank.
Narayan receives much in return from Oza-Frank and other students. "Being surrounded by young minds adds a tremendous force to our work," he says.
Thus, the RSPH is a good fit for a scientist like Narayan, who studies and writes poetry—"when the inspiration hits me"—and reads classic English literature to his 10-year-old daughter at bedtime. His wife and he named Sarayu after the beautiful tributary of the Ganges River.
Just recently, Narayan received word that the RSPH was awarded a grant to establish a Center of Excellence for Prevention and Control of Diabetes and Cardiometabolic Diseases in South Asia. The center, one of eight in the world, involves multiple partners: the Public Health Foundation of India, the All India Institute of Medical Sciences, MDRF, and Aga Khan University in Pakistan.
"Whatever we do," says Narayan, "the fruits of our research have to be available to people everywhere."
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• Some of the oldest references to diabetes are found in ancient texts from 3,000 years ago in India and Egypt. In Sanskrit, the word for diabetes means “sweet urine.” The language has 25 words that describe the disease.
• In the United States, 21 million people suffer from diabetes. According to CDC estimates, that number will rise to 48 million by 2050. Approximately 95% of U.S. cases are type 2.
• While China has the largest population in the world, India has the highest number of people with diabetes. As of 2007, China’s population of 1.32 billion included 39.8 million people with diabetes. In India, 40.9 million of the nation’s 1.1 billion people live with diabetes. By 2025, 69.9 million people in India and 59.3 million people in China will have diabetes.
• NIH researchers began studying the Pima Indians in 1964 after observing a high prevalence of type 2 diabetes in this population of 11,000 in Arizona. Pimas rarely marry outside their group, making it possible to study the disease in multiple generations. Today, 4% of girls and 5% of boys develop type 2 diabetes by age 19.
• Type 1 diabetes is more prevalent among white children up to age 9. Type 2 diabetes is more common among American Indian, Asian, black, and Hispanic children ages 10 to 19. Worldwide, type 1 diabetes is rising by 2.5% a year across all populations. Researchers have yet to understand why.
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