Description of Research Expertise:
Dr. Rickels conducts patient-oriented diabetes research that aims at understanding the pathogenesis of different types of diabetes and the in vivo mechanisms of new diabetes treatments. Dr. Rickels' studies involve methodologies for quantifying insulin secretion, insulin sensitivity, and glucose counterregulatory responses to hypoglycemia, and include the frequently-sampled intravenous glucose tolerance test, the glucose-potentiated arginine test, and hyperinsulinemic euglycemic and hypoglycemic clamps. Present work in Type 1 Diabetes is focused on patients with long-standing disease and is examining the effects of isolated islet transplantation on insulin secretion and sensitivity, and the effects of islet transplantation or real-time continuous glucose monitoring on glucose counterregulatory defenses against hypoglycemia. Current work in Type 2 Diabetes is focused on understanding early defects in insulin secretion, the impact on early impairments of different strategies for enhancing GLP-1 effects, and the mechanisms of diabetes associated with atypical antipsychotic drugs. Additional work is directed at investigating genetic determinants of insulin secretory reserve in humans and on understanding the pathophysiologic defects involved in the etiology of Cystic Fibrosis Related Diabetes in order to inform novel treatment approaches.
Rickels MR, Fuller C, Dalton-Bakes C, Markmann E, Palanjian M, Cullison K, Tiao J, Kapoor S, Liu C, Naji A, Teff KL: Restoration of glucose counterregulation by islet transplantation in long-standing type 1 diabetes Diabetes 64 (5): 1713-1718,2015.
Vetter ML, Wadden TA, Teff KL, Khan ZF, Carvajal R, Ritter S, Moore RH, Chittams JL, Iagnocco A, Murayama K, Korus G, Williams NN, Rickels MR: GLP-1 plays a limited role in improved glycemia shortly after roux-en-Y gastric bypass: a comparison with intensive lifestyle modification Diabetes 64 (2): 434-446,2015.
Rickels MR, Goeser ES, Fuller C, Lord C, Bowler AM, Doliba NM, Hegele RA, Cuchel M: Loss-of-function mutations in ABCA1 and enhanced beta-cell secretory capacity in young adults Diabetes 64 (1): 193-199,2015.
Gudipaty L, Rosenfeld N, Fuller C, Gallop R, Schutta MH, Rickels MR: Effect of exenatide, sitagliptin or glimepiride on beta-cell secretory capacity in early type 2 diabetes Diabetes Care 37 (9): 2451–2458,2014.
Rickels MR, Kong SM, Fuller C, Dalton-Bakes C, Ferguson JF, Reilly MP, Teff KL, Naji A: Insulin sensitivity index in type 1 diabetes and following human islet transplantation: comparison of the minimal model to euglycemic clamp measures American Journal of Physiology - Endocrinology and Metabolism 306 (10): E1217-E1224,2014.
Rickels MR, Kong SM, Fuller C, Dalton-Bakes C, Ferguson JF, Reilly MP, Teff KL, Naji A: Improvement in insulin sensitivity after human islet transplantation for type 1 diabetes Journal of Clinical Endocrinology & Metabolism 98 (11): E1780-E1785,2013.
Teff KL, Rickels MR, Grudziak J, Fuller C, Nguyen H-L, Rickels K: Antipsychotic-induced insulin resistance and postprandial hormonal dysregulation independent of weight gain or psychiatric disease Diabetes 62 (9): 3232-3240,2013.
Rickels MR, Liu C, Shlansky-Goldberg R, Soleimanpour SA, Vivek K, Kamoun M, Min Z, Markmann E, Palangian M, Dalton-Bakes C, Fuller C, Chiou AJ, Barker CF, Prak ETL, Naji A: Improvement in beta-cell secretory capacity following human islet transplantation according to the CIT07 protocol Diabetes 62 (8): 2890-2897,2013.
Weinstock RS, Xing D, Maahs DM, Michels A, Rickels MR, Peters AL, Bergenstal RM, Harris B, DuBose SN, Miller KM, Beck RW; T1D Exchange Clinic Network: Severe hypoglycemia and diabetic ketoacidosis in adults with type 1 diabetes: results from the T1D Exchange clinic registry Journal of Clinical Endocrinology & Metabolism 98 (8): 3411-3419,2013.
Liu C, Koeberlein B, Feldman MD, Mueller R, Wang Z, Li Y, Lane K, Hoyt CC, Tomaszewski JE, Naji A, Rickels MR: Accumulation of intrahepatic islet amyloid in a non-human primate transplant model Endocrinology 153 (4): 1673-1683,2012.