Trial Outcomes & Findings for A Study to Determine Iatrogenic Hyperinsulinemia's Contribution to Insulin Resistance and Endothelial Dysfunction in Type 1 Diabetes (NCT NCT04118374)

Last Updated: 2025-10-28

Results Overview

Participants completed both a one-week RCD and a one-week SCD, separated by a three-week washout. After each intervention, we measured insulin sensitivity using a hyperinsulinemic-euglycemic clamp.To express GIR in mg of glucose per kg of fat-free mass per minute (mg/kg FFM/min), we divided the dextrose infusion rate by the fat-free mass determined by DEXA. Insulin sensitivity showed no significant difference between diets. GIR was 8.1 mg/kg FFM/min after the RCD and 8.6 mg/kg FFM/min after the SCD.

Recruitment status

COMPLETED

Study phase

Target enrollment

14 participants

Primary outcome timeframe

week 1 and week 5

Results posted on

2025-10-28

Participant Flow

14 patients were screened for eligibility between November 2021 and March 2024. We recruited adults with type 1 diabetes (age 18-60 years, BMI 18-33 kg/m2, HbA1c 5.9-9.0%) from the Vanderbilt Eskind Diabetes Clinic and community sources in Nashville, TN.

In the full study, 14 participants enrolled and completed the screening visit. Two did not proceed past the run-in period due to scheduling conflicts and inconsistent nutrition logging.

Participant milestones

Participant milestones
Measure	Standard Carb Diet then Low Carb Diet Standard Carb Diet: Approximately 50% of caloric intake will come from carbohydrate consumption. Low Carb Diet: Approximately 25% of caloric intake will come from carbohydrate consumption.	Low Carb Diet then Standard Carb Diet Standard Carb Diet: Approximately 50% of caloric intake will come from carbohydrate consumption. Low Carb Diet: Approximately 25% of caloric intake will come from carbohydrate consumption.
First Intervention (7 days) STARTED	6	6
First Intervention (7 days) COMPLETED	6	6
First Intervention (7 days) NOT COMPLETED	0	0
Washout Period (21 days) STARTED	6	6
Washout Period (21 days) COMPLETED	6	6
Washout Period (21 days) NOT COMPLETED	0	0
Second Intervention (7 days) STARTED	6	6
Second Intervention (7 days) COMPLETED	6	6
Second Intervention (7 days) NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

A Study to Determine Iatrogenic Hyperinsulinemia's Contribution to Insulin Resistance and Endothelial Dysfunction in Type 1 Diabetes

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	All Study Participants n=12 Participants Standard Carb Diet: Approximately 50% of caloric intake will come from carbohydrate consumption. Low Carb Diet: Approximately 25% of caloric intake will come from carbohydrate consumption. then all study participants crossed over to Low Carb Diet: Approximately 25% of caloric intake will come from carbohydrate consumption. Standard Carb Diet: Approximately 50% of caloric intake will come from carbohydrate consumption.
Age, Continuous	33.9 years n=5 Participants
Sex: Female, Male Female	7 Participants n=5 Participants
Sex: Female, Male Male	5 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	1 Participants n=5 Participants
Race (NIH/OMB) White	11 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Region of Enrollment United States	12 participants n=5 Participants
BMI	26.5 kg/m^2 n=5 Participants
Weight	75.3 kg n=5 Participants
Height	1.75 m n=5 Participants
Waist-to-hip ratio	0.83 ratio n=5 Participants
HbA1c	54 mmol/mol n=5 Participants
Type 1 diabetes duration	20.5 years n=5 Participants
Systolic blood pressure	120 mmHg n=5 Participants
Diastolic blood pressure	82 mmHg n=5 Participants
Heart rate	65 bpm n=5 Participants
Insulin analog used Lispro	6 Participants n=5 Participants
Insulin analog used Aspart	5 Participants n=5 Participants
Insulin analog used Fast-acting insulin aspart	1 Participants n=5 Participants

PRIMARY outcome

Timeframe: week 1 and week 5

Population: 12 participants received both interventions in this crossover study and were included in the analysis.

Outcome measures

Outcome measures
Measure	Standard Carb Diet n=12 Participants Standard Carb Diet: Approximately 50% of caloric intake will come from carbohydrate consumption.	Low Carb Diet n=12 Participants Low Carb Diet: Approximately 25% of caloric intake will come from carbohydrate consumption.
Change in Insulin Sensitivity Assessed as Glucose Infusion Rates	8.6 mg/kg FFM/min Interval 7.0 to 11.0	8.1 mg/kg FFM/min Interval 6.7 to 10.1

Adverse Events

Standard Carb Diet

Serious events: 0 serious events

Other events: 2 other events

Deaths: 0 deaths

Low Carb Diet

Serious events: 0 serious events

Other events: 1 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Standard Carb Diet n=12 participants at risk Standard Carb Diet: Approximately 50% of caloric intake will come from carbohydrate consumption.	Low Carb Diet n=12 participants at risk Low Carb Diet: Approximately 25% of caloric intake will come from carbohydrate consumption.
Nervous system disorders Headache	16.7% 2/12 • Number of events 3 • through study completion, an average of 1 year Participants self-report	0.00% 0/12 • through study completion, an average of 1 year Participants self-report
Nervous system disorders Shakiness	0.00% 0/12 • through study completion, an average of 1 year Participants self-report	8.3% 1/12 • Number of events 1 • through study completion, an average of 1 year Participants self-report

Additional Information

Justin M Gregory, MD, MSCI

Vanderbilt University Medical Center

Phone: (615) 322- 7427

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place