Closing the Sex Gap in Obesity Research: Abdul-samad Ahmed's Cardiac Muscle Study

Preclinical obesity research has a well-documented problem: female animals are significantly underrepresented in studies, despite known differences in fat storage, energy metabolism, and cardiovascular response between sexes. This summer, PURE award recipient Abdul-samad Ahmed took on this challenge with his project investigating the effects of a high-fat, high-sucrose diet on cardiac muscle in female rats.

The Research Problem

Obesity is strongly linked to cardiovascular disease, and the mechanisms are partly structural. In a healthy heart, adaptation to increased demand involves both eccentric hypertrophy (cavity enlargement) and concentric hypertrophy (wall thickening). In obesity, however, the heart often develops eccentric hypertrophy alone — a maladaptive response that impairs cardiac output and can progress to heart failure.

Beyond structural changes, mitochondrial dysfunction plays a central role in metabolic disorders. Mitochondria are responsible for energy production, and when they are compromised by metabolic stress, the consequences cascade through the entire cardiovascular system. Understanding how a high-fat, high-sucrose diet disrupts both cardiac structure and mitochondrial function is essential for developing effective interventions.

Study Design

Abdul-samad’s project used a controlled 12-week feeding protocol with female Sprague-Dawley rats, comparing standard chow against a high-fat, high-sucrose diet. By sampling the left ventricle and assessing both structural integrity and mitochondrial function, the study was designed to capture the early changes that precede overt cardiac failure.

The hypothesis was straightforward: that the diet-induced metabolic stress would produce measurable structural compromise and elevated markers of mitochondrial dysfunction.

Why Female Subjects Matter

The decision to study female rats was deliberate and important. Most preclinical obesity studies have been conducted in male animals, leaving a significant gap in our understanding of how the female cardiovascular system responds to metabolic overload. Given the differences in how males and females store fat and regulate energy metabolism, findings from male-only studies do not necessarily translate. Abdul-samad’s work helps address this gap, contributing data that is relevant to maternal and women’s cardiovascular health.

Dissemination

Abdul-samad presented his findings as a poster at the McCaig Institute Summer Student Symposium on August 13, 2025, where he engaged with researchers and clinicians from across the institute’s broad community.

This project exemplifies the Digital Athlete Lab’s approach to student mentorship: giving undergraduate researchers the opportunity to work on questions that matter, with rigorous methods and meaningful outcomes.