High-Fat/High-Sucrose Diet Effects on Cardiac Muscle in Female Rats

Investigating structural properties and mitochondrial function of cardiac muscle in response to diet-induced obesity

This undergraduate research project investigates how a high-fat, high-sucrose diet affects cardiac muscle structure and mitochondrial function in female rats. Led by PURE award recipient Abdul-samad Ahmed, the study addresses a critical gap in preclinical obesity research by focusing specifically on female subjects.

Project Overview

Obesity is strongly linked to cardiovascular disease, largely driven by structural and energetic alterations in heart tissue. In healthy cardiac adaptation, eccentric (cavity enlargement) and concentric (wall thickening) hypertrophy occur together. However, obesity often produces eccentric hypertrophy alone, impairing cardiac output and promoting heart failure.

Mitochondrial dysfunction is another hallmark of metabolic disorders. Understanding how diet-induced obesity influences mitochondrial health is crucial because mitochondria regulate energy production, oxidative stress, and metabolic function. Female animals are significantly underrepresented in preclinical research despite known differences in fat storage, energy metabolism, and cardiovascular response. This study directly addresses that gap.

Hypothesis

Female rats fed a high-fat, high-sucrose diet for 12 weeks will show compromised cardiac structure (likely maladaptive hypertrophy) and elevated mitochondrial stress markers indicating disrupted energy metabolism.

Methods

  • Subjects: 12-week-old female Sprague-Dawley rats
  • Groups: Standard chow (n=7) vs. high-fat/high-sucrose diet (n=7)
  • Duration: 12 weeks
  • Tissue sampled: Left ventricle
  • Analyses: Structural and mitochondrial function assessments

Significance

This project contributes to several important themes:

  • Female-specific cardiac responses: Clarifying how diet-induced obesity affects the female heart, an area critical for maternal and women’s health
  • Mechanistic insight: Understanding mitochondrial stress provides clues about why obesity impairs cardiac performance, potentially informing therapeutic strategies
  • Prevention-focused research: By focusing on early structural and energetic changes, the project supports prevention of cardiac failure arising from chronic metabolic overload

Research Team

  • Abdul-samad Ahmed — PURE Award recipient (2025)
  • Dr. Robert John Holash — Supervisor, Digital Athlete Lab
  • In collaboration with Dr. Walter Herzog’s lab, Human Performance Lab

Dissemination

  • McCaig Institute Summer Student Symposium (August 13, 2025) — Poster presentation