# Therapeutic Strategies for Microvascular Dysfunction in Type 1 Diabetes

> **NIH NIH K23** · UNIVERSITY OF VIRGINIA · 2024 · $192,031

## Abstract

PROJECT SUMMARY/ABSTRACT
Cardiovascular disease (CVD) is markedly elevated in type 1 diabetes (T1D), and two prevalent conditions in
T1D, insulin resistance and endothelial dysfunction, precede and predict CVD. In health, insulin action at the
endothelial cell dilates blood vessels, which promotes glucose and insulin delivery to muscle for glucose uptake.
We recently showed, in adults with uncomplicated T1D, insulin commonly fails to enhance muscle microvascular
perfusion, indicating microvascular insulin resistance, and even youth with T1D have apparent microvascular
endothelial dysfunction. This is significant since the microvasculature is critical for muscle health as the direct
supplier and exchange site of substrates. Possibly due to impaired muscle health from microvascular
dysfunction, the T1D population has diminished cardiorespiratory fitness, even when matched for activity.
Mechanisms of microvascular dysfunction in T1D remain ill-defined, but oxidative stress (OS) contributes to
endothelial dysfunction at large arteries and likely the microvasculature as well. OS is clearly amplified in T1D.
Adjuvant treatments to improve endothelial function and fitness are critically needed in T1D, and such therapies
have potential to prevent CVD in future studies. Glucagon-like peptide-1 (GLP-1) and GLP-1 receptor agonists
(GLP-1RA) improve: microvascular function in insulin resistant states, OS outside of glucose effects,
cardiorespiratory fitness, and CVD outcomes in type 2 diabetes (T2D). Exercise attenuates large artery
endothelial function and OS in T1D, and it improves microvascular endothelial function in T2D. Whether GLP-
1RA or exercise training improve muscle microvascular endothelial function in T1D is unknown. This project will
test the hypothesis that, in adults with T1D, GLP-1RA and exercise training each enhance insulin-stimulated
muscle microvascular perfusion via attenuating endothelial OS and improving endothelial cell function. Using
cutting-edge contrast enhanced ultrasound before and after randomization to 14-wks of: 1) GLP-1RA, 2) exercise
training, or 3) placebo, this study will assess whether GLP-1R agonism (Aim 1) or exercise training (Aim 2)
improves insulin-mediated microvascular perfusion and muscle function in adults with T1D. Finally, harvesting
and analyzing endothelial cells using an innovative technique will assess whether these therapies attenuate
endothelial cell OS and improve endothelial function in vivo (Aim 3). Significantly, completion of the proposed
studies will increase mechanistic knowledge of microvascular endothelial dysfunction in T1D and ascertain if
larger studies examining GLP-1RA and exercise alone/combined are merited and feasible. The proposed
research and training will support the candidate’s long-term goal to conduct larger clinical studies in T1D aiming
to reverse endothelial dysfunction/prevent CVD. Preparing for that end, goals for this award are training in T1D-
focused clinical trial work, ...

## Key facts

- **NIH application ID:** 10754581
- **Project number:** 5K23DK131327-02
- **Recipient organization:** UNIVERSITY OF VIRGINIA
- **Principal Investigator:** Kaitlin M Love
- **Activity code:** K23 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $192,031
- **Award type:** 5
- **Project period:** 2023-01-01 → 2027-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10754581

## Citation

> US National Institutes of Health, RePORTER application 10754581, Therapeutic Strategies for Microvascular Dysfunction in Type 1 Diabetes (5K23DK131327-02). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10754581. Licensed CC0.

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