The National Institute of Aging awarded the Emory University Global Diabetes Research Center a $22 million grant toward the Cardiometabolic Risk Reduction in South Asia (CARRS) Cohort’s research on the link between Alzheimer’s disease and insulin resistance, which the National Institutes of Health classifies as Type 3 diabetes.
CARRS Cohort co-Director Venkat Narayan believes the grant opens numerous possibilities for research on the link between diabetes and cognitive disorders.
“Diabetes, cardiovascular disease, dementia, are related to genetics, they are related to socio-behavioral factors, they are related to metabolic and vascular factors,” Narayan said. “By combining all of it, we’ll be able to look at not one disease at a time, but multiple diseases.”
CARRS Cohort and Emory Global Diabetes Research Center co-Director Mohammed Ali also emphasized the importance of studying the link between cardiovascular and cognitive disorders. He added that “it was almost nonsensical” to not study the diseases as a group.
“Diabetes, hypertension, heart disease and strokes and related conditions like vascular dementia, etc., they actually all go together,” Ali said. “For example, as you get fat around your liver, it contributes to your risk of diabetes, and vice versa. Diabetes increases your risk of kidney disease, which also, in parallel, increases your risk of heart disease.”
CARRS collaborates with Emory, the Centre for Chronic Disease Control, the Madras Diabetes Research Foundation and many other organizations to study the development of diabetes within South Asian populations. Narayan explained that low and middle-income countries face 80% to 90% of the “burden” of diabetes, but only 2% to 3% of diabetes research is conducted there.
“By doing a study in South Asia, we are beginning to address some of that gap,” Narayan said. “Some of those findings may not just be applicable to South Asians and people in South Asia, but might be applicable to some populations in the United States, might be applicable to populations in Africa, might be applicable to populations in China.”
Additionally, CARRS researches South Asian populations because they exhibit diabetes differently from other populations. Narayan hypothesizes this may correlatively affect dementia and Alzheimer’s.
“The presentation of diabetes is quite different in South Asians in certain ways, and the kind of phenotypes of diabetes may be different,” Narayan said. “We're discovering that there's a lot of diabetes related to insulin deficiency or not being able to secrete insulin, rather than insulin resistance.”
Narayan, who also teaches at Emory’s School of Medicine, said the cohort is focused on studying communities in two Indian cities: Chennai and Delhi. He added that, to fully measure the suspected 12 factors related to early onset of dementia, the cohort studies community members as young as 40 years old.
Ali emphasized the importance of studying potential environmental risk factors in the development of diseases such as Alzheimer’s.
“Delhi is one of the most air-polluted cities in the world, and the idea that that could be contributing to heart and lung disease is somewhat already starting to be established,” Ali said. “But if we can really do a better job of packaging that information for political leaders and others to really say, ‘Hey, we need to work on this. We need to improve the air quality for our residents because otherwise, they’ll literally die,’ … that can be a very big positive outcome.”
Ram Jagannathan, a core faculty member of the CARRS Cohort and associate professor in the medical school, believes the grant will help uncover and contribute to advancing medical practices for both diabetes and Alzheimer’s disease.
“Through this grant, we can clarify both the mechanisms and to advance the precision medicine efforts for this understudied patient population,” Jagannathan said.
Jagannathan hopes that, with the discoveries made through this next phase of research, the global pharmaceutical industry will be able to develop treatments that can prevent or even cure Alzheimer’s disease.
“We are at the beginning of a renaissance in neuroscience where new technologies are allowing us to understand the brain in unprecedented ways,” Jagannathan said. “By tailoring the treatment strategies based on an individual’s genetic profile and specific disease mechanisms, we can optimize the interventions for those at risk of both diabetes and dementia.”
