NCT04118374

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

Completed NA Results posted Last updated 28 October 2025

What this trial tests

NA trial testing Standard Carb Diet in Diabetes Mellitus, Type 1 in 14 participants. Completed in 21 June 2024.

Timeline

24 November 2021

Primary endpoint
21 June 2024

21 June 2024

Quick facts

Lead sponsor	Vanderbilt University Medical Center
Phase	NA
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	crossover
Masking	none
Primary purpose	treatment
Enrollment	14
Start date	24 November 2021
Primary completion	21 June 2024
Estimated completion	21 June 2024
Sites	1 location across United States

Drugs / interventions tested

• Standard Carb Diet
• Low Carb Diet

Conditions studied

• Diabetes Mellitus, Type 1 — all drugs for Diabetes Mellitus, Type 1 →

Sponsor

Vanderbilt University Medical Center

Who can join

Adults 18 to 60, any sex, with Diabetes Mellitus, Type 1. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Change in Insulin Sensitivity Assessed as Glucose Infusion Rates Primary · week 1 and week 5

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.

Group	Value	95% CI
Standard Carb Diet	8.6	7.0 – 11.0
Low Carb Diet	8.1	6.7 – 10.1

Adverse events — posted to ClinicalTrials.gov

Time frame: through study completion, an average of 1 year. Reporting threshold: 0%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Standard Carb Diet

Serious: 0/12 (0%)

Deaths: 0/12

Low Carb Diet

Serious: 0/12 (0%)

Deaths: 0/12

Other adverse events (2 terms — click to expand)

Reaction	System	Standard Carb Diet	Low Carb Diet
Headache	Nervous system disorders	—	—
Shakiness	Nervous system disorders	—	—

Data from ClinicalTrials.gov NCT04118374 adverse events section.

Sponsor's own description

The investigators will test the hypothesis that reducing insulin doses using a low carbohydrate diet (LCD) will be associated with with improved insulin sensitivity (Aim 1) and blood vessel health (Aim 2).

Publications & conference data

2 peer-reviewed publications reference this trial (live from Europe PMC):

1. A one-week reduced-carbohydrate diet lowers insulin requirements and shifts the IGF axis with no detectable short-term change in endothelial function in a randomized, crossover trial of adults with type 1 diabetes.
   Akbar MN, Smith TJ, Chinnarasu S, Welch W, et al · · 2026 · PMID 41882799 · DOI 10.1186/s40842-026-00276-6
2. A one-week reduced-carbohydrate diet to mitigate iatrogenic peripheral hyperinsulinemia does not improve insulin sensitivity or endothelial function in a randomized, crossover trial in patients with type 1 diabetes.
   Gregory JM, Smith TJ, Duffus SH, Brooks D, et al · · 2025 · PMID 40045281 · DOI 10.1186/s12933-025-02658-z