SGLT2i, Ketoacidosis, Volume Contraction, and Insulinopenia

Protocol III: SGLT2i, Ketoacidosis, Volume Contraction, and Insulinopenia

To examine the 2-HIT hypothesis that the SGLT2i-induced stimulation of EGP, lipolysis, and ketone production requires the combination of volume depletion plus insulinopenia in T2D individuals.

Study Overview

• Status: Recruiting
• Conditions: Type 2 Diabetes
• Intervention / Treatment: Drug: Empagliflozin 25 MG

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 29
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Ralph Defronzo, MD; Phone Number: 210-567-6691; Email: defronzo@uthscsa.edu
• Study Contact Backup: Name: Aurora Merovci, MD; Phone Number: 210-567-6691; Email: merovci@uthscsa.edu

Study Locations

• United States
  • Texas
    • San Antonio, Texas, United States, 78229-3900
      • Recruiting
      • Texas Diabetes Institute/UH
      • Contact: Ralph DeFronzo, MD; Phone Number: 210-358-7200; Email: defronzo@uthscsa.edu
      • Principal Investigator: Ralph DeFronzo, MD
      • Contact: Aurora Merovci, MD; Phone Number: 210-567-6691; Email: merovci@uthscsa.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Patients with T2D

Inclusion Criteria:

• Ages 30-75 years
• Body Mass Index (BMI) 21-45 kg/m2
• Hemoglobin A1C (HbA1c) = 7.0-11%
• Estimated glomerular filtration rate (eGFR) > 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, complete blood chemistry (CBC), thyroid stimulating hormone/thyroxine (TSH/T4), electrocardiogram (EKG), and urinalysis
• 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, sulfonylurea (SU), metformin (MET), or SU/MET
• Statin therapy is permissible if the dose has been stable for at least 3 months

Exclusion Criteria:

• Patients treated with Glucagon-like peptide 1 receptor agonists (GLP-1 RA), Dipeptidyl Peptidase IV inhibitors (DPP-4i), Thiazolidinediones (TZD), or insulin are excluded
• Patients taking medications (other than SU/MET) known to affect glucose metabolism are excluded
• Subjects with evidence of proliferative retinopathy or eGFR < 60 are excluded
• Women of childbearing potential are excluded unless they are taking/using appropriate contractive medications/devices

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Empagliflozin; Empagliflozin 25 mg/day	Drug: Empagliflozin 25 MG; A medication used in the management and treatment of type 2 diabetes mellitus. It is in the sodium-glucose co-transporter (SGLT-2) class of medications.; Other Names: Jardiance

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ketone Body Turnover (ketogenesis)	Measurement of ketone body turnover rate during the baseline state and 240-300-minute time period, before and after Empagliflozin administration.	0 and 300 minutes

Collaborators and Investigators

• Sponsor: The University of Texas Health Science Center at San Antonio
• Collaborators: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
• Investigators: Principal Investigator: Ralph DeFronzo, MD, University of Texas Health Science Center San Antonio

Study record dates

Study Major Dates

• Study Start (Actual): April 29, 2025
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: June 26, 2025
• First Submitted That Met QC Criteria: June 26, 2025
• First Posted (Actual): July 8, 2025

Study Record Updates

• Last Update Posted (Actual): July 11, 2025
• Last Update Submitted That Met QC Criteria: July 8, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: Gluconeogenesis; Lipolysis; Endogenous glucose production; Pancreatic clamp; Ketogenesis
• Additional Relevant MeSH Terms: Metabolic Diseases; Acid-Base Imbalance; Acidosis; Ketosis; Sodium-Glucose Transporter 2 Inhibitors; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Hypoglycemic Agents; Empagliflozin
• Other Study ID Numbers: 20230457HU - 504076; R01DK024092 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Deidentified data will be shared with NIH and as a publication in a peer reviewed journal once data are published.
• IPD Sharing Time Frame: At study end after analysis of data.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No