Dr. Rickels conducts patient-oriented diabetes research focused on understanding the pathogenesis of diabetes and hypoglycemia and the in vivo mechanisms of new diabetes treatments. Dr. Rickels' research program investigates the physiology of islet function and replacement and glucose counteregulation in defense against hypoglycemia in type 1 diabetes and pancreatogenic forms of diabetes such as cystic fibrosis-related diabetes. Dr. Rickels' studies involve methodologies for quantifying insulin and incretin secretion, insulin sensitivity, and glucose counterregulatory, and include oral glucose and mixed-meal tolerance tests, the frequently-sampled intravenous glucose tolerance test, the glucose-potentiated arginine test, and hyperinsulinemic euglycemic and hypoglycemic clamps with stable isotope tracers to measure glucose fluxes and tissue-specific insulin action. Current work in type 1 diabetes is focused on patients with impaired awareness of hypoglycemia and is examining the mechanisms of defective glucose counterregulation and treatment by islet transplantation or hypoglycemia avoidance achieved with automated insulin delivery. Additional work involves the study of residual and post-transplant islet function and disease modifying therapy in type 1 diabetes, and early islet dysfunction and the impact of different strategies for enhancing incretin effects on β- and α-cell function in cystic fibrosis.
Dr. Rickels specializes in the diagnosis and treatment of diabetes, hypoglycemia disorders, and general endocrinologic problems. Dr. Rickels predominantly cares for patients with type 1 and type 2 diabetes, those receiving pancreas or islet allotransplantation as treatment for type 1 diabetes, and those receiving islet autotransplantation following pancreatectomy. Coupled to his research interests in islet function and transplantation as well as closed-loop insulin delivery technology, Dr. Rickels is committed to translating complimentary approaches for cellular and artificial pancreas replacement as treatments for patients with type 1 and pancreatogenic diabetes.
Selected Publications
Rickels MR, Bellin MD, Stefanovski D, Peleckis AJ, Dalton-Bakes C, Markmann E, Nguyen HL, Townsend RR, Hering BJ, Naji A: α- or β-Adrenergic blockade does not affect transplanted islet cell responses to hypoglycemia in type 1 diabetes. American Journal of Physiology - Endocrinology & Metabolism 327(3): E290-E301, September 2024.
Flatt AJ, Sheikh S, Peleckis AJ, Alvarado P, Hadjiliadis D, Stefanovski D, Gallop RJ, Rubenstein RC, Kelly A, Rickels MR: Preservation of beta-cell function in pancreatic insufficient cystic fibrosis with highly effective CFTR modulator therapy. Journal of Clinical Endocrinology & Metabolism 109(1): 151-160, January 2024.
Matus A,* Flatt AJ,* Peleckis AJ, Dalton-Bakes C, Riegel B, Rickels MR: Validating and establishing a diagnostic threshold for the hypoglycemia awareness questionnaire impaired awareness subscale Endocrine Practice 29(10): 762-769, October 2023 Notes: *Contributed equally as primary authors.
Riddell MC, Li Z, Gal RL, Calhoun P, Jacobs PG, Clements M, Martin CK, Doyle FJ III, Patton SR, Castle JR, Gillingham MB, Beck RW, Rickels MR; T1DEXI Study Group: Examining the acute glycemic effects of different types of structured exercise sessions in type 1 diabetes in a real-world setting: The Type 1 Diabetes and Exercise Initiative (T1DEXI). Diabetes Care 46(4): 704-713, April 2023.
Flatt AJ, Peleckis AJ, Dalton-Bakes C, Nguyen HL, Ilany S, Matus A, Malone SK, Goel N, Jang S, Weimer J, Lee I, Rickels MR: Automated insulin delivery for hypoglycemia avoidance and glucose counterregulation in long-standing type 1 diabetes with hypoglycemia unawareness. Diabetes Technology & Therapeutics 25(5): 302-314, May 2023 Notes: Commentary by Amiel SA. Diabetes Technol Ther. 2023 May 1;25(5):299-301.
Nyirjesy SC, Peleckis AJ, Eiel JN, Gallagher K, Doliba A, Tami A, Flatt AJ, De Leon DD, Hadjiliadis D, Sheikh S, Stefanovski D, Gallop R, D’Alessio DA, Rubenstein RC, Kelly A, Rickels MR: Effects of GLP-1 and GIP on islet function in glucose intolerant, pancreatic insufficient cystic fibrosis. Diabetes 71(10): 2153-2165, October 2022.
Flatt AJ, Chen E, Peleckis AJ, Dalton-Bakes C, Nguyen HL, Collins HW, Millar JS, Gallop RJ, Rickels MR: Evaluation of clinical metrics for identifying defective physiologic responses to hypoglycemia in long-standing type 1 diabetes. Diabetes Technology & Therapeutics 24(10): 737-748, October 2022.
Rickels MR, Eggerman TL, Bayman L, Qidwai JC, Alejandro R, Bridges ND, Hering BJ, Markmann JF, Senior PA, Hunsicker LG; Clinical Islet Transplantation Consortium: Long-term outcomes with islet-alone and islet-after-kidney transplantation for type 1 diabetes in the Clinical Islet Transplantation Consortium: The CIT-08 Study. Diabetes Care 45(12): 2967-2975, December 2022.
Kelly A, Sheikh S, Stefanovski D, Peleckis AJ, Nyirjesy SC, Eiel JN, Sidaye A, Localio R, Gallop R, De Leon DD, Hadjiliadis D, Rubenstein RC, Rickels MR: Effect of sitagliptin on islet function in pancreatic insufficient cystic fibrosis with abnormal glucose tolerance. Journal of Clinical Endocrinology & Metabolism 106(9): 2617-2634, September 2021 Notes: Commentary by Ismail HM. J Clin Endocrinol Metab. 2021 Oct 21;106(11):e4786-e4788.
Flatt AJS, Greenbaum CJ, Shaw JAM, Rickels MR: Pancreatic islet reserve in type 1 diabetes. Annals of the New York Academy of Sciences 1495(1): 40-54, July 2021.
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Last updated: 10/02/2024
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