Welcome to the CODA study website!
The COVID and Diabetes Assessment Study is a study funded by the National Institute for Diabetes and Digestion and Kidney Diseases (NIDDK) of the National Institutes of Health (NIH). The study’s goal is to gain a deeper understanding of the link between COVID-19 and diabetes. This study will observe patients recently diagnosed with diabetes who have and have not had recent COVID-19. Some studies have suggested that infection with COVID-19 may result in a higher risk of developing Type 1 diabetes (T1D) or Type 2 diabetes (T2D), and also make one’s diabetes progress more rapidly. This study will help us to better understand these issues.
Who can participate in this study?
The Study will enroll about 1,600 patients. All participants must be age 11 or older, and have been diagnosed with diabetes in the last three months. Within that group of people, the study is looking for people who have and have not recently had COVID-19 (defined as COVID-19 infection in the past year).
- Diagnosed with Type 1 or Type 2 diabetes in the last 3 months
- Age 11 years or older
- Had — or didn’t have — COVID-19 recently
How will this study work?
Individuals who agree to participate in the study will be surveyed by phone, online or in person and will provide regular blood samples. A subset of participants will be offered the chance to participate in additional tests that measure pancreas activity, biomarkers and blood vessel stiffness. Participants will be followed for two years. The study will also examine electronic health record data.


The CODA study will explore:
- How COVID-19 affects blood sugar control, inflammation, and insulin resistance in patients with T2D
- How COVID-19 affects blood sugar control, inflammation, and beta cell function in patients who develop T1D
- If COVID-19 worsens vascular function, inflammation, and tendency to form blood clots in patients with diabetes
- The role of genetic, social, and environmental factors on inflammation and metabolic function.
- The impact of COVID-19 and its treatments on the development of diabetes and on diabetes-related outcomes over the course of time.
Where will this study take place?
This map shows the locations of all the CODA study sties. City names in the adjacent list, that also includes the participating medical facilities, link to that study site's section on the Study Sites page on the website.

- Atlanta, GA: Emory University
- Baltimore, MD: Johns Hopkins
- Charleston, SC: Medical University of South Carolina
- Columbus, OH: Nationwide Children's Hospital
- Dallas, TX: Baylor, Scott & White Health
- Denver, CO: Children's Hospital Colorado
- Durham, NC: Duke University
- Houston, TX: Texas Children's Hospital - Baylor College of Medicine
- Iowa City, IA: University of Iowa
- Nashville, TN: Vanderbilt University Medical Center
- New Orleans, LA: Oschner Health System
- Palo Alto, CA: Stanford Children's Hospital
- Philadelphia, PA: Children's Hospital of Philadelphia
- Pittsburgh, PA: University of Pittsburgh Medical Center
- Rochester, MN: Mayo Clinic
Researchers at Vanderbilt University Medical Center have received a four-year grant from the National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health, to study the relationship between COVID-19 and diabetes. The study will partner with Harvard, Children’s Hospital of Philadelphia, Weil Cornell Medical Center, Stanford University, the Type 1 Diabetes Exchange, University of Pittsburgh Medical Center, and other health systems across the country.
Several studies have found that COVID-19 is linked with a higher risk of developing both Type 1 and Type 2 diabetes, and that it can make the diabetes progress more rapidly. We don’t yet know why this happens, but it may be that COVID-19 damages the cells that make insulin, makes it harder for cells to respond to insulin, and/or causes inflammation and other problems.
The COVID-19 and Diabetes Assessment (CODA) Study will identify and recruit participants through the T1D Exchange and PCORnet. The T1D exchange is a non-profit research network of diabetes centers, dedicated to improving outcomes for people with Type 1 Diabetes. PCORnet is a national research network funded by the Patient-Centered Outcomes Research Institute, which engages hundreds of health care sites with access to electronic health record data from more than 30 million patients annually.
The Study will enroll about 1,600 patients. All participants must be age 11 or older, and been diagnosed with diabetes in the last three months. Within that group of people, the study is looking for people who have and have not recently had a COVID-19 infection in the past year.
CODA’s goal is to gain a deeper understanding of the link between COVID-19 and diabetes that can guide future treatment interventions and public health approaches. CODA will be led by a team of scientists with significant experience in treating COVID-19, obesity and diabetes in children and adults.
“This study will greatly expand our knowledge about the relationship between COVID-19 and diabetes and will also provide us novel information about what factors influence the early course of diabetes in children and adults with Type 1 or Type 2 diabetes,” said principal investigator and project leader Russell Rothman, MD, MPP.
Rothman, the Ingram Professor of Integrative and Population Health and professor of Internal Medicine, Pediatrics, and Health Policy at Vanderbilt, is also VUMC Senior Vice President for Population and Public Health, and director of the Vanderbilt Institute for Medicine and Public Health.
Co-principal investigators are:
- Alvin Powers, MD, the Joe C. Davis Professor of Biomedical Science, professor of Medicine and of Molecular Physiology and Biophysics, director of the Vanderbilt Diabetes Center and of the Vanderbilt Diabetes Research and Training Center, and chief of the Division of Diabetes, Endocrinology and Metabolism.
- Jonathan Schildcrout, PhD, professor of Biostatistics at VUMC. Leading the Vanderbilt Biostatistics Data Coordinating Center.
- Jason Block, MD, MPH, associate professor of Population Health in the Harvard Pilgrim Health Care Institute.
Diabetes is an illness characterized by high levels of blood glucose, which increase the risk for heart and kidney disease, nerve and eye damage, and other serious complications. It results from the body’s inability to make or respond to insulin, a hormone that promotes glucose uptake by the tissues. Type 1 diabetes, which usually is diagnosed in children, results from destruction of the beta cells of the pancreas, which make insulin. Type 2 diabetes is the most common form of the disease. It usually develops later in life and occurs when body tissues do not respond (become resistant) to insulin.
CODA will explore:
- Whether participants diagnosed with COVID-19 who then developed Type 2 diabetes are more likely to have worse blood sugar control, increased inflammation, and increased insulin resistance than patients with Type 2 diabetes but without a recent COVID-19 diagnosis.
- Whether participants with a recent diagnoses of COVID-19 who then developed Type 1 diabetes are more likely to have worse blood sugar control, increased inflammation and a more rapid reduction in the function of their beta cells than those without a recent COVID-19 diagnosis.
- Whether COVID-19 is associated with worse vascular function, increased inflammation, and an increased tendency to form blood clots within blood vessels in a subset of participants with diabetes.
- The role of genetic, social, and environmental factors on inflammation and metabolic function.
- The impact of COVID-19 and its treatments on the development of diabetes and on diabetes-related outcomes over the course of time.
- Individuals who agree to participate in the study will be surveyed by phone, online or in person and will provide regular blood samples. Some participants will have glucose tolerance, biomarkers and vascular function testing. The study will also use longitudinal electronic health record data from participating sites and across PCORnet.
The research is supported by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), a branch of the U.S. National Institutes of Health (NIH).