Description of Research Expertise

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.

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-E301,2024.

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): 151-160,2024.

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): 762-769,2023.

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): 704-713,2023.

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): 302-314,2023.

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): 2153-2165,2022.

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): 737-748,2022.

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): 2967-2975,2022.

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): 2617-2634,2021.

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): 40-54,2021.

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Academic Contact Information

12-134 Smilow Center for Translational Research
3400 Civic Center Boulevard
Philadelphia, Pa 19104
Phone: 215-746-0025
Patient appointments: 800-789-7366