Meet our Board of Directors

James Tai’s broad life sciences and health care experience spans a wide array of outpatient provider services for chronic diseases to venture capital for life sciences companies. He sits on the board of directors for a variety of transformational health care companies that aim to improve health equity and access for underserved communities. 

He is currently the chair of both the ADA’s Innovation Committee and ADA’s Board Development Committee. In these roles, James has been instrumental in shaping and accelerating the growth of the ADA Innovation Fund—helping to expand its strategic vision, strengthen its investment pipeline, and position the ADA Innovation Fund as a catalyst for novel diabetes and obesity solutions. 

Charles D. “Chuck” Henderson is the Chief Executive Officer of the American Diabetes Association® (ADA).

Chuck joined the ADA in January 2020 after spending 24-plus years in for-profit sectors and volunteering in the non-profit sector. Philanthropy and Sales/Fundraising are threaded through the fabric of his DNA. Chuck comes to the ADA from Champion Life Safety Solutions where he was CEO and President. Before that, he was a Field Sales Executive running multi-billion-dollar territories across the country for Dell Healthcare, Common ground Marketing (including executing special events in the field), and Viacom. His professional skill set and success, coupled with his passion and desire to give back, make this a perfect time to lead a non-profit organization. He is passionate about spending the balance of his career in a space that will make a significant impact on the lives of millions across the country.

Chuck is skilled in building trusted and collegial working relationships, relationship selling/fundraising, driving productivity, leading, and supporting change-management initiatives. He has deep experience developing best-of-breed, solution-selling leaders who think as strategic business partners, with a culture of winning as a team and over-delivering results.

A native Texan, Chuck has a strong commitment to his family, community, and church. An avid golfer, Chuck is also involved with his alma mater, Texas A&M where he serves on boards and leverages his professional skills to raise money for the school in different capacities. When he is not working on fundraising for A&M causes, he is working on raising capital funds for his church, where he serves on the Board of Trustees. Chuck is married to his beautiful wife Courtney, and together they have a bright teenage daughter, Charlie.

Mario Rivera is a senior executive with experience leading large-scale global operations for Fortune 500 companies, primarily within the health care industry. Most recently serving as chief supply chain & logistics officer for CVS Health, where he’s led a team of more than 10,000 colleagues that developed and executed the company’s strategy to transform their supply chain network to become America’s premier health and wellness destination. Mario has served on the ADA’s Finance Committee since 2023 and Innovation Committee since 2025. 

Enrique Caballero, MD, is an endocrinologist, investigator, and educator working as the director of international innovation programs in the Office for External Education at Harvard Medical School (HMS). He is also the director of Latino diabetes health in the Division of Endocrinology, Diabetes, and Hypertension, as well as associate scientist in the Division of Global Health Equity at the Brigham and Women's Hospital (BWH) in Boston, Massachusetts. He is the immediate past chair for the ADA’s Health Disparities Committee.

Dr. Caballero has a strong and long commitment to helping resource-limited populations. He founded the Latino Diabetes Initiative at the Joslin Diabetes Center and the Diabetes Program within the Spanish Clinic at the BWH, both affiliated with HMS

Amy Hess-Fischl, MS, RDN, LDN, BC-ADM, CDCES, has been an advanced practice registered dietitian nutritionist, diabetes care and education specialist, and certified pump trainer for over 25 years. For the last 19 years, she has worked at the University of Chicago within the departments of pediatric and adult endocrinology, directly caring for people with diabetes of all ages on insulin pumps and continuous glucose monitors. Additionally, she is the quality coordinator for their ADA Education Recognition Program (ERP). Amy served as co-chair of 2022 National Standards revision, and she was chair of the National ADA ERP committee from 2019–2023. Celebrated for her work, she received the 2022 ADA Outstanding Educator in Diabetes Award. She is currently the editor of the ADCES in Practice journal.

Amy is passionate about highlighting the role of diabetes self-management education and support (DSMES) and feels strongly that it should be available to all people with diabetes throughout the lifespan, as well as believes in incorporating diabetes community care coordinators into DSMES services.

Sean Pittman, JD, is the senior attorney and managing partner of Pittman Law Group, P.L., where he leads a nationally recognized practice spanning government affairs and administrative, education, and corporate law. He represents a broad and diverse client base, including private citizens, local governments, public authorities, small businesses, and Fortune 500 companies. Widely regarded as a trusted legal and strategic advisor in Florida and nationwide, Sean counsels cities and counties, hospitals and health systems, banking institutions, aviation and port authorities, universities, corporations, and professional associations, helping clients navigate complex regulatory environments and align legal strategy with long-term organizational goals at the regional, state, and federal levels.

Alongside his robust professional resume, Sean served as president of the Orange Bowl Committee and currently serves on its Board of Directors. His extensive leadership and governance roles include service on the National Football Foundation Board of Trustees, the Florida State University Foundation Board of Trustees, the Board of Directors for the College Football Hall of Fame, the Florida State University College of Law Board of Visitors, and Chairman of the Children's Home Society. Sean is the founder and chairman of the Big Bend Minority Chamber of Commerce, previously served as general counsel of the National Bar Association, and was honored as the recipient of the Johnnie L. Cochran, Jr. Lawyer of the Year Award. His contributions to the legal profession and public life have also been recognized with induction into the Tallahassee Barristers Hall of Fame, and he was a finalist in the search for President of Florida State University—reflecting the breadth of trust placed in his leadership, vision, and service. 

Beyond his legal practice and public service, Sean is a nationally recognized civic leader, political commentator, and the author of Amazon bestseller Disaffected: Access vs. Apathy, a widely discussed examination of power, participation, and civic engagement in modern America. He has also appeared on MSNBC, CNN, CBS, and Fox News and has been published in USA Today, the Palm Beach Post, Miami Herald, and more. 

John (Wig) Wigneswaran, MD, MBA, is a health care executive and board member with more than two decades of experience leading clinical strategy and operations, transformation, and innovation across some of the nation’s largest health care organizations spanning payer, provider, pharmaceutical, and retail sectors. He brings expertise in enterprise operations, quality and safety governance, workforce development, enterprise transformation, and long-term strategic planning to the boards he serves. 

Currently serving as chief clinical officer and senior vice president at UnitedHealth Group, Dr. Wigneswaran oversees clinical pharmacy operations and product and drug trends for more than 70 million members and 3,000 clients. He manages a $200 million P&L and leading initiatives focused on specialty drug strategy and transformation, medication affordability, and clinical innovation, including artificial intelligence. Previously, he held senior leadership roles at Walmart, where he built a national quality and safety framework across 5,000 pharmacies and 3,000+ optical centers, dental clinics, and virtual care operations, supporting health care delivery for 1.6 million employees and 160 million weekly customers (including 20 million pharmacy members). 

Earlier in his career, Dr. Wigneswaran served as chief medical officer and vice president at Cigna/Express Scripts, where he helped reposition clinical operations toward value-based care models and novel analytic frameworks in drug utilization and outcomes, as well as drove client retention, client acquisition efforts, and clinical product sales. He held a similar role at DaVita, where he led enterprise technology initiatives and strengthened patient safety and care. Prior to that, at Fresenius Medical Care, he created and expanded novel care delivery partnerships and reimbursement strategies to drive sustainable growth. 

Dr. Wigneswaran currently serves on the boards of the American Diabetes Association, the Milken Institute, and Nephroceuticals, and was formerly a board member for the National Kidney Foundation. His governance experience reflects a strong focus on strategy, financial performance oversight, talent management, strategic growth, and innovation-driven value creation. 

Dr. Wigneswaran holds an MD from Tufts University School of Medicine and an MBA from the Massachusetts Institute of Technology’s Sloan School of Management. He is board-certified in nephrology, completing his training at New York-Presbyterian Cornell with active medical licensure in Massachusetts, Rhode Island, and Ohio.

Jennifer Green, MD, is a professor of medicine in the Division of Endocrinology at Duke University and a faculty member of the Duke Clinical Research Institute (DCRI). Dr. Green’s research has focused on strategies to treat diabetes and reduce the risk of cardiovascular, kidney, and other complications. She is an executive committee member for GRADE, a federally funded, long-term comparative effectiveness study of glucose-lowering medications for type 2 diabetes, and has held clinical and operational leadership roles in numerous large, international trials designed to determine the cardiovascular effects of newer glucose-lowering medications (including TECOS, EXSCEL, and Harmony Outcomes). 

She is an executive committee member, principal investigator of the U.S. coordinating center at DCRI, and U.S. national representative for the global EMPA-Kidney and EASi-Kidney trials. Dr. Green has also held multiple roles with the ADA, including serving for several years on the organization’s Professional Practice Committee and as a member of the ADA-EASD consensus statement writing group. She is currently an associate editor of Diabetes Care®. 

Elizabeth A. Beverly, PhD, is a full professor of primary care at the Ohio University Heritage College of Osteopathic Medicine and the Ralph S. Licklider, D.O. Endowed Professor in Behavioral Diabetes. A nationally recognized expert in behavioral diabetes, she leads innovative research on the psychosocial aspects of diabetes, rural health disparities, and health care professional education. Dr. Beverly completed a five-year postdoctoral fellowship at the Joslin Diabetes Center and Harvard Medical School, following her PhD in biobehavioral health from The Pennsylvania State University. Dr. Beverly has served as principal investigator on 35 external research grants from the National Institute of Diabetes and Digestive and Kidney Diseases, the Health Resources and Services Administration, the Ohio Department of Medicaid, and the American Osteopathic Association. Her grants focus on diabetes quality improvement, virtual reality training, and psychosocial care in Appalachian communities.

She co-directs the Southeastern Ohio Regional Quality Improvement Hub and co-directs the NIH-funded Diabetes Institute Summer Interprofessional Research Experience for undergraduates. In 2023, she received the Ohio University Presidential Research Scholar Award for her work in diabetes. Her work is distinguished by its focus on team-based care, interdisciplinary education, and translating research into real-world solutions that improve care for rural and resource-limited populations.

Dr. Mandeep Bajaj is the vice chair for Clinical Affairs in the Department of Medicine and a professor of medicine and molecular and cellular biology at the Baylor College of Medicine in Houston. He is the chief of the Section of Endocrinology at Baylor St. Luke's Medical Center, as well as medical director of the Baylor St. Luke's Medical Center Diabetes Program and Baylor Medicine Endocrinology and Diabetes. Dr. Bajaj is a medical graduate of the All India Institute of Medical Sciences in New Delhi and received his fellowship training in endocrinology and diabetes at the Joslin Diabetes Center in Boston. 

Dr. Bajaj is a reputed clinical and translational researcher in obesity and type 2 diabetes and has over 100 publications. His patient-oriented research work has delineated the metabolic and molecular mechanisms of insulin resistance in the pathogenesis of type 2 diabetes. He is currently the editor in chief of British Medical Journal (BMJ), Open Diabetes Research and Care, published jointly by the ADA and the BMJ Group. He has served on the ADA Scientific Sessions Meeting Planning Committee, Finance Committee, and the Research Grant Review Committee. He has been awarded the Master Clinician Lifetime Award as well as the Fulbright & Jaworski Faculty Excellence Teaching Award by Baylor College of Medicine.

Rodica Busui, MD, PhD, is the Jordan Schnitzer-endowed chair in diabetes; professor and division head of endocrinology, diabetes, and clinical nutrition; director of the Harold Schnitzer Diabetes Health Center at the Oregon Health & Science University in Portland, OR; and professor emeritus at the University of Michigan.

Her research interests involve chronic complications of diabetes, including diabetes-related neuropathy, diabetes-related foot complications, cardiovascular disease, diabetes-related kidney disease, and novel technologies for diabetes management. She has been principle investigator (PI) and/or member of the Steering Committee in many landmark diabetes clinical trials, including ACCORD, DCCT/EDIC, PERL, BARI- 2D, GRADE, DEVOTE, REPLACE-BG, WISDM, MOBILE, SOUL. She is the chair of the NIDDK Diabetes Foot Consortium and a PI of Breakthrough T1D (former JDRF) Center of Excellence. She has also designed and leads several NIH- and industry-funded investigator-initiated studies to unveil disease-modifying agents for diabetes complications, and on the use of diabetes technologies to improve patients’ outcomes and diabetes care delivery.

Dr. Busui has published 350 peer-reviewed manuscripts and book chapters, as well as chaired the American Diabetes Association’s (ADA’s) 2017 Statement on Diabetic Neuropathy, the 2022 ADA/American College of Cardiology Heart Failure in Diabetes Consensus, and was the ADA’s 2023 president for medicine and science. She received awards for her research and advancement of diabetes care from many organizations, including the ADA, the European Association for the Study of Diabetes, the Fulbright Foundation, Harvard Medical School, the Romanian Diabetes Society, and the University of Michigan.
 

Christopher K. Ralston, JD, is a commercial litigation partner and office managing partner of the New Orleans office of Spencer Fane LLP. Mr. Ralston handles a range of commercial litigation and focuses on the areas of antitrust law, business torts, trade secret litigation and contract disputes, tax litigation, securities litigation and arbitration, direct selling, and intellectual property litigation. He also serves as a part of the firm’s appellate practice, having had successful appeals at all five of the Louisiana Courts of Appeal, as well as at the Fifth, Tenth, and the Federal Circuits of the federal Courts of Appeal. He earned his law degree from Tulane Law School and his undergraduate degree from the College of William and Mary. After law school, he served as a judicial law clerk to U.S. District Judge Eldon E. Fallon.

Mr. Ralston’s work in the legal field has received recognition in numerous forms from 2012–2021, including being named to the New Orleans CityBusiness’ Leadership in Law Hall of Fame, receiving both the Federal Bar Association’s New Orleans Chapter President’s Award and the Louisiana State Bar Association’s President’s Award, receiving the Louisiana Bar Foundation’s President’s Award, and receiving the David A. Hamilton Lifetime Achievement Award from the Louisiana State Bar Association. Mr. Ralston is recognized by many peer review publications, including Chambers USA: America’s Leading Lawyers for Business, Louisiana Super Lawyers, The Best Lawyers in America, Marquis Who's Who in America, and New Orleans Magazine.

After recognizing the devastating impact of diabetes in New Orleans, Mr. Ralston joined the ADA’s New Orleans Community Leadership Board (CLB) in 2009, and he has served as chair of the CLB since 2014. He has served in several national and local volunteer roles, including as chairman of the ADA’s National Board of Directors from 2021–2022 and in 2025, and on the National Board of Directors since 2018. In 2011, Mr. Ralston was awarded the ADA’s National Chair’s Citation (the seventh time the honor was bestowed in the ADA’s history) for raising awareness about the prevalence of diabetes in Louisiana through his walk of 300 miles in 10 days across Louisiana.

An ardent cyclist, Robin sets the healthy-living-standard for his colleagues by regularly traveling on two wheels. His daily commute takes him across the mighty Columbia River, to and from his home in Washington state. As a senior vice president at Moda, Robin leads the organization’s key Medicare and Medicaid departments. He is also responsible for Moda’s major state accounts, including the Oregon Educators Benefit Board, the Public Employees Retirement System, the Public Employees Benefit Board, and all strategic Systems of Care initiatives. 

Among his many innovations at Moda, Robin was the founder and continues to be the chairman of the Board of the Eastern Oregon Coordinated Care Organization (EOCCO) and the co-founder of the Portland Metropolitan region’s Oregon Health and Sciences University’s Integrated Delivery System (OHSU IDS). Combined, the organizations serve over 120,000 Medicaid members. Both organizations were formed to operate under a global budget incorporating value based payment methodologies, to have accountability for meeting specific quality metrics, and to recognize and address social determinants of health. Robin also established the NW Prescription Drug Consortium, pooling prescription drug purchasing and lowering costs, especially for the uninsured and underinsured, throughout Oregon and Washington. A graduate of Oregon State University, Robin is also a proud citizen of the Cherokee Nation.

Rhodes B. Ritenour is a native of New Market, Virginia in Shenandoah County, and is the Vice President for External and Regulatory Affairs with Bon Secours Health System. He represents the system in Virginia before local, state, and federal governments, in communities it serves, and to corporations; he also provides regulatory legal counsel and manages governance, serving as the corporate secretary of the Richmond Market Board.

Prior to joining Bon Secours, Rhodes served as the Deputy Attorney General of Virginia for Civil Litigation. Before joining the OAG, he was a partner in the Richmond office of LeClairRyan, where he focused on intellectual property litigation, regulated industries, and counseling campaigns and elected officials. He served as the firm’s Hospitality and Tourism Industry Team Leader and was a member of the Energy Industry Team. 

Preceding his time in private practice, Ritenour clerked for U.S. District Judge Jackson L. Kiser in the Western District of Virginia, served in the Policy Office of Virginia Governor Mark R. Warner, and worked in the Press Office of Vice President Al Gore. 

Ritenour earned his undergraduate and law degrees from the University of Virginia. He serves on the Virginia Business Council, and the Boards of the Virginia Chamber of Commerce, Lead Virginia (Immediate Past Chairman), ChamberRVA, and The Richmond Forum. He is a former Board member of Longwood University, the Virginia Bar Association, the Washington Commanders Charitable Foundation, the Virginia Museum of Frontier Culture, projectHomes, Venture Richmond, the River Road United Methodist Church Council, and served on the Virginia State Bar Professionalism Faculty.

A Type-I diabetic since the age of five, he has served the diabetes community in several roles with the American Diabetes Association, including as Chairman of the ADA National Board of Directors in 2024. Rhodes and his wife Alana are co-founders of TheDiabetesSupportGroup.org, a national on-line diabetes community, and have published two children’s books in their series, The Adventures of Rhodes and Alana.

He lives in Henrico County with his wife and two spirited children.

Patti is a certified diabetes care and education specialist and registered dietitian, currently working as diabetes staff development coordinator at St. Luke’s Hospital Diabetes Care Program in Duluth, Minnesota. Patti was a member of the ADA Nutrition Science Review Committee and the writing committee for the 2019 ADA nutrition consensus statement. She currently serves on the Science and Health Care Executive Council and has served on the ADA Professional Practice Committee and ADA Scientific Sessions Committee. She is a past chair of the Diabetes Dietetic Practice Group of the Academy of Nutrition and Dietetics and is a frequent author and international speaker on nutrition and diabetes education topics. Patti has a master’s degree in adult education from the University of Minnesota, a Bachelor of Science degree in applied nutrition from the Pennsylvania State University and completed her dietetic internship at the University of Minnesota Hospital and Clinics. She lives in Cloquet, Minnesota with her husband Tom.