# Lifestyle intervention to reduce apathy in the elderly

> **NIH NIH K99** · LSU PENNINGTON BIOMEDICAL RESEARCH CTR · 2020 · $143,640

## Abstract

PROJECT SUMMARY/ABSTRACT
Apathy, defined as the absence or lack of motivation and emotional detachment, is a clinical feature of
depression. Depressive symptoms and insulin resistance are conditions that are interdependent. Apathy, being
a common depressive symptom in the elderly (> 70 years of age) and among individuals with diabetes, is a
particularly attractive therapeutic target in interventions designed to improve glucose metabolism. The
presence of apathy predicts chronicity of depression and poor response of depressive symptoms to treatment.
Current interventions lack the precision needed to address apathy and its underlying mechanisms. We
hypothesize that increasing insulin sensitivity in apathetic insulin resistant individuals will reduce apathy. Our
preliminary studies show that a low glycemic index (GI) diet and exercise (D+E) intervention for seven days
and 12 weeks increases insulin sensitivity in older adults with obesity. The key feature of a low GI diet is its
high dietary fiber (DF) content. However, to maintain the benefits of a low GI diet in an elderly population, the
fiber must be delivered in DF-dense portions of soft foods. Further, the exercise dose must be sustainable in a
real-world setting. We will compare the traditional low GI diet with a low GI diet containing a novel dietary
intervention using whole soybean pods (soy). To achieve Aim 1, we will conduct a dose escalation trial in the
elderly with obesity and determine the maximum tolerated dose of DF delivered in soft foods including 10g,
20g, and 30g of soy and containing 4g, 8g, and 12g of DF respectively. At each dose, eight subjects will
incorporate the foods into their usual diet for one week. We will evaluate tolerability to each dose and measure
fecal short chain fatty acids as a biomarker of compliance. The results from Aim 1 will guide the design and
implementation of Aim 2 that will determine the effect of a low GI D+E program on insulin sensitivity in elderly
subjects with obesity and insulin resistance. To complete this aim we will conduct a 12-week randomized
controlled trial of a low GI D+E program (controlled feeding and supervised exercise) with and without soy in
40 insulin resistant subjects with obesity and depressive symptoms including apathy. Aim 3 will determine the
effect of the D+E intervention on apathy and whether the effect was mediated by changes in insulin sensitivity.
The impact of social, psychosocial, and socioeconomic factors, and the acceptability of the intervention will
also be evaluated. This research and training will: 1) provide the advanced transdisciplinary training needed to
advance the delivery of D+E interventions in the elderly; 2) position the applicant to emerge as a leader in the
development of efficacious D+E regimens for healthy aging; 3) facilitate the exploration of the effect of insulin
resistance on apathy in age-related neurodegenerative disorders and; 4) precipitate exploration of the
interaction between nutriti...

## Key facts

- **NIH application ID:** 10054083
- **Project number:** 1K99AG065419-01A1
- **Recipient organization:** LSU PENNINGTON BIOMEDICAL RESEARCH CTR
- **Principal Investigator:** Candida Joan Rebello
- **Activity code:** K99 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $143,640
- **Award type:** 1
- **Project period:** 2020-09-15 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10054083

## Citation

> US National Institutes of Health, RePORTER application 10054083, Lifestyle intervention to reduce apathy in the elderly (1K99AG065419-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10054083. Licensed CC0.

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