SGLT2i, Hepatic Glucose Production, and SNS

Protocol: 22 T2D Subjects will be randomized to receive empagliflozin (n=20). Each subject will participate in two studies performed in random order. In Study 1, EGP will be measured with a prime-continuous 6,6, D2-glucose infusion and lipolysis will be measured with prime-continuous infusion of U-2H-glycerol. The rate of ketogenesis will be determined by infusion of 13C palmitate and quantitating the enrichment of 13C in 3-hydroxybutyrate (BHB). Total body NE turnover will be measured with 3H-norepinephrine (3H-NE) infusion before and after empagliflozin administration.

Visit 2 (Study 1): At approximately 6:00PM on the night prior to study subjects will ingest D2O (3 grams/kg ffm) to quantitate gluconeogenesis and de novo lipogenesis. At 6:00AM at Visit 1 prime-continuous infusions of 6,6, D2-glucose and U-2H-glycerol or U-14C-glycerol are started and continued to study end to measure rates of hepatic glucose production (HGP) and lipolysis. At 8:00AM a prime-continuous infusion of 3H-norepinephrine is started and continued to 9:00 AM at which time it will be stopped. Empagliflozin 25mg is administered at this time, 9:00 AM. At 1:00 PM (240 minutes after administration of Empagliflozin) a second prime-continuous 3H-Norepinephrine infusion is started for 60 minutes. Detailed explanation on page 52-53.

Visit 3 (Study 2, Optional): At approximately 6:00PM on the night prior to study subjects will ingest D2O (3 grams/kg ffm) to quantitate gluconeogenesis and de novo lipogenesis. This visit will be identical to Visit 2 for Aim 2 (Sub-study I) with one exception. At 8:30AM, 30 minutes prior to the ingestion of the Empagliflozin 25mg, a prime (200 ug/kg over 20 minutes)-continuous (80 ug/min) infusion of propranolol is started and continued to study end. Principal Investigator (PI) previously have shown that the steady state propranolol concentration achieved by this infusion rate is sufficient to significantly inhibit insulin-mediated glucose disposal.

Patients with T2D

Inclusion criteria

• Ages 30-75
• BMI (Body Mass Index) 21-45 kg/m2
• HbA1c = 7.0-11%
• eGFR (estimated glomerular filtration rate)> 60 ml/min/1.73m2
• Blood Pressure (BP)≤160/90 mmHg
• Participants must be in general good health based on medical history, physical exam, screening blood chemistries, CBC (Complete Blood Count), TSH/T4 (thyroid/thyroxine hormone), EKG (electrocardiogram), and urinalysis (UA)
• Stable body weight (±1.5 kg) over the last 3 months and must not participate in an excessively heavy exercise program
• Patients treated with diet, Sulfonylureas, Metformin, or Sulfonylureas/Metformin (Sulfo/MET)
• Participants receiving a Glucagon like peptide -1 receptor agonist (GLP1-RA) must be on a stable dose for at least three months prior to study enrollment.
• Participants receiving a Dipeptidyl peptidase 4 inhibitors (DPP-4 inhibitor) must be on a stable dose for at least two months prior to study enrollment.
• SGLT2 inhibitors must be discontinued at least two months prior to study enrollment.

Exclusion criteria

An individual who meets any of the following criteria will be excluded from participation in this study:

• Patients treated with Thiazolidinediones (TZDs), or Insulin are excluded.
• Patients taking medications other than Sulfonylureas/Metformin (SU/MET), stable dose of GLP1-RA and DPP4i known to affect glucose metabolism are excluded. Patients taking SGLT2i within 2 months of screening visit will be excluded from participating in this study, however they may be asked whether they would agree to discontinue the medication for two months to become eligible. (Please see clarification below.) *
• Subjects with evidence of proliferative retinopathy or estimated glomerular filtration rate (eGFR) < 60 are excluded
• Women of childbearing potential are excluded unless they are taking/using appropriate contractive medications/devices * Only participants who are taking SGLT2 inhibitors during the prescreening period will be asked to discontinue the medication at least two months prior to the screening visit. If they agree, they will return for an HbA1c measurement four weeks after stopping the SGLT2 inhibitor.

If their HbA1c rises to greater than 10%, treatment will be initiated with either metformin, a DPP-4 inhibitor, or a sulfonylurea. We do not anticipate any adverse effects during this initial period, provided the HbA1c remains below 10%.

HbA1c will be measured using a fingerstick test, which requires only a minimal amount of blood. No compensation will be provided during this phase.

After two months of medication discontinuation, participants will return for a screening visit. If they meet all eligibility criteria, they will be enrolled in the study and payment done by protocol.