SGLT2i, Ketoacidosis, Volume Contraction, and Insulinopenia

After screening visit, subjects will participate in four additional visits and or at least one of the four visits that will be performed in random order starting at 6:00 AM to the Clinical Research Center at University Hospital-Texas Diabetes Institute.

Visit 2 (Study 1): At 6:00AM at (Study 1), a prime-continuous infusions of 6,6, D2-Glucose or U-3H-glucose and U-2H-glycerol or U-14C-Glycerol are started and continued to study end (2:00 PM) to measure rates of hepatic glucose production (HGP) and fat break down (lipolysis).3H-Glucose infusion to be given: (Prime=25µCi x (FPG/100), Continuous=0.25µCi/min x 480 min=120µCi). At time zero (9:00 AM) subjects will ingest Empagliflozin (25 mg). Plasma substrate, hormone concentrations, U-3H-glucose and U-14C-glycerol specific activities will be measured every 5-30 minutes for 300 minutes (2:00 PM) and 295 minutes. If Principal Investigator (PI) use U-2H-glycerol instead of U-14C Glycerol, PI will measure plasma U-2H-glycerol enrichment instead of U-14C-glycerol specific activities. Detailed explanation on page 54, if PI will use U-6,6, D2-Glucose instead of U-3H Glucose, PI will measure plasma 2H-Glucose enrichment instead of 3H Glucose specific activities. Detailed explanation on page 54.

Visit 3 (Study 2, Optional): At 6:00AM prime-continuous infusions of 6,6, D2-Glucose or U-3H-Glucose and U-2H-glycerol or U-14C-Glycerol are started and continued to study end (2:00 PM) to measure rates of hepatic glucose production (HGP) and lipolysis. 3H-Glucose infusion to be given: (Prime=25µCi x (FPG/100), Continuous=0.25µCi/min x 480 min=120µCi). At 7 AM an infusion of normal saline will be started at the rate of 150 ml/hour and continued to the end of study at 2 PM (total volume = 1050 ml; total Na and Cl = 154 meq) to provide volume replacement for blood loss. At time zero (9:00 AM) subjects will ingest Empagliflozin (25 mg). Plasma substrate, hormone concentrations, 3H-glucose and 14C-glycerol specific activities will be measured every 5-30 minutes for 300 minutes (2:00 PM) and 295 minute. If PI use U-2H-glycerol instead of U-14C Glycerol, PI will measure plasma U-2H-glycerol enrichment instead of U-14C-glycerol specific activities. Detailed explanation on page 55. If PI use U-6,6, D2-Glucose instead of U-3H Glucose, PI will measure plasma 2H-Glucose enrichment instead of 3H Glucose specific activities. Detailed explanation on page 55.

Visit 4 (Study 3, Optional): At 6:00AM prime-continuous infusions 6,6, D2-Glucose or U-3H-Glucose and U-2H-glycerol or U-14C-Glycerol are started and continued to study end (2:00 PM) to measure rates of Hepatic Glucose Production (HGP) and fat break down (lipolysis). 3H-Glucose infusion to be given: (Prime=25µCi x (FPG/100), Continuous=0.25µCi/min x 480 min=120µCi). At time zero (9:00 AM) subjects will ingest Empagliflozin (25 mg) and octreotide or somatostatin with insulin and glucagon will be given to reduce volume without insulinopenia. Plasma substrate and hormone concentrations and 3H-glucose/14C-glycerol specific activities will be measured every 5-30 minutes for 300 minutes (2:00 PM) and 295 minute. If PI use U-2H-glycerol instead of U-14C Glycerol, PI will measure plasma U-2H-glycerol enrichment instead of U-14C-glycerol specific activities. Detailed explanation on page 55-56. If PI uses U-6,6, D2-Glucose instead of U-3H Glucose, PI will measure plasma 2H-Glucose enrichment instead of 3H Glucose specific activities. Detailed explanation on page 56.

Visit 5 (Study 4, Optional): At 6:00AM prime-continuous infusions of 6,6, D2-Glucose or 3H-Glucose and U-2H-glycerol or U-14C-Glycerol are started and continued to study end (2:00 PM) to measure rates of hepatic (liver) glucose production (HGP) and fat break down (lipolysis). 3H-Glucose infusion to be given: (Prime=25µCi x (FPG/100), Continuous=0.25µCi/min x 480 min=120µCi). At 7 AM an infusion of normal saline will be started at the rate of 150 ml/hour and continued to the end of study at 2 PM (total volume = 1050 ml; total Na and Cl = 154 meq) to provide volume replacement for blood loss. At time zero (9:00 AM) subjects will ingest empagliflozin (25 mg) and octreotide or somatostatin with insulin and glucagon will be given. Plasma substrate and hormone concentrations and 3H-glucose/14C-glycerol specific activities will be measured every 5-30 minutes for 300 minutes (2:00 PM) and 295 minute. If PI uses U-2H-glycerol instead of U-14C Glycerol, PI will measure plasma U-2H-glycerol enrichment instead of U-14C-glycerol specific activities. Detailed explanation on page 56. If PI use U-6,6, D2-Glucose instead of U-3H Glucose, PI will measure plasma 2H-Glucose enrichment instead of 3H Glucose specific activities. Detailed explanation on page 56.

In Substudy II, PI will use stable isotopes (6,6-D2-glucose and U-2H-glycerol) or radioisotopes (U-3H-glucose and U-14C-glycerol) to measure endogenous glucose production (EGP) and fat breakdown (lipolysis), depending on isotope availability and cost. Both sets of isotopes will provide the necessary data to address research objectives.