# Artificial Pancreas - Adolescent Physiology and Psychology Longitudinal Evaluation (A.P. APPLE)

> **NIH NIH R01** · UNIVERSITY OF VIRGINIA · 2024 · $536,057

## Abstract

SUMMARY / ABSTRACT
This project addresses what is perhaps the biggest challenge in the clinical care of Type 1 diabetes (T1D): the
incredible rise in HbA1c levels seen during the adolescent age span of 11-15 years. This rise appears to be
driven by physiologic changes (an increase in insulin resistance) that are not adequately addressed, in part
because of psychosocial challenges (including family conflict, peer influence, and diabetes distress). We
propose to follow adolescents longitudinally for two years, with assessment of these physiologic factors and
exploratory aim following psychosocial factors, as well as testing a promising intervention in the artificial
pancreas (AP). This study is titled A.P. APPLE for Artificial Pancreas Adolescent Physiology and Psychosocial
Longitudinal Evaluation.
We hypothesize that long-term use of an AP system (Tandem's Control-IQ, compared to Usual Care+CGM)
will in part blunt the rise in HbA1c that is typically seen. However, even apart from testing this intervention, this
project offers valuable observational data on the natural history of changes seen in participants in the control
group. We will follow changes in insulin resistance by body compartment (liver vs. muscle/adipose tissue)
during pubertal progression using stable-isotope triple-tracer mixed meal tests, revealing novel information
about how puberty-related insulin resistance evolves over time by body compartment—as well as how the AP
might respond to these changes. We will also follow key psychosocial processes of family conflict, peer
influence, diabetes distress, depression and quality of life to evaluate their temporal relationships to sub-
optimal control. Following these processes may help in the application of pharmacologic or psychologic
approaches to improve adolescent control—either with or without AP use. Finally, we will follow modern
markers of T1D control, including time-in-range and glycemic variability to document for providers how these
factors change during pubertal progression and how they are related to physiologic and psychosocial changes.
This study takes advantage of the University of Virginia Center for Diabetes Technology as an environment
with expertise in each of the domains of glycemia, physiology and psychosocial factors—as well as
development of an AP system that is effective in short-term trials at reducing HbA1c.
The sub-optimal control during adolescence has gotten more pronounced in recent studies and contributes to
long-term complications. This project will provide valuable clues about the durability of AP use among
adolescents as well the contribution of rising insulin resistance and psychosocial barriers—with a long-term
goal of improving control and long-term health of adolescents with T1D.

## Key facts

- **NIH application ID:** 10829344
- **Project number:** 5R01DK124886-05
- **Recipient organization:** UNIVERSITY OF VIRGINIA
- **Principal Investigator:** MARC D BRETON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $536,057
- **Award type:** 5
- **Project period:** 2020-04-01 → 2026-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10829344

## Citation

> US National Institutes of Health, RePORTER application 10829344, Artificial Pancreas - Adolescent Physiology and Psychology Longitudinal Evaluation (A.P. APPLE) (5R01DK124886-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10829344. Licensed CC0.

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