When we think about visceral fat, abdominal fat gets most of the attention—it’s the deep fat around organs that drives insulin resistance, type 2 diabetes, and heart disease. But did you know there’s another key player? Meet epicardial adipose tissue (EAT)—the fat that surrounds your heart. 💔
Let’s dive into how both types of fat contribute to insulin resistance and major health risks—right down to the molecular level. 🔬
1. Abdominal Fat & Insulin Resistance
What Happens? Abdominal visceral fat grows with excess calorie intake. It secretes inflammatory molecules like TNF-α and IL-6, which interfere with insulin signaling.
How?
These molecules block IRS-1 (Insulin Receptor Substrate 1), a key step in the insulin signaling cascade.
They also activate NF-κB, a transcription factor that promotes inflammation.
This disrupts glucose transport into cells by reducing GLUT4 expression, worsening blood sugar control.
Outcome: Chronic inflammation, reduced insulin sensitivity, and the onset of metabolic disorders.
2. Epicardial Fat & Heart Health
Unlike abdominal fat, EAT is in direct contact with your heart and coronary arteries—making its effects more localized and immediate. In people with insulin resistance, EAT expands and releases harmful molecules, leading to:
Inflammation:
Cytokines (e.g., TNF-α, IL-6, IL-1β) from EAT inflame the atrial and ventricular myocardium, promoting fibrosis (scarring) and atrial fibrillation (AF).
EAT also produces reactive oxygen species (ROS), which cause oxidative damage to cardiac cells.
Lipotoxicity:
EAT releases excess free fatty acids (FFAs) into the heart, leading to fat accumulation in cardiomyocytes.
This causes lipotoxic stress, mitochondrial dysfunction, and impaired heart contractions.
Insulin Resistance in the Heart:
Low GLUT4 expression in EAT reduces glucose utilization.
High FFA levels suppress insulin sensitivity and fuel inflammation in the myocardium.
Neurohormonal Effects:
EAT interacts with the renin-angiotensin-aldosterone system (RAAS), worsening heart dysfunction and remodeling.
3. Shared Pathways of Damage
Both abdominal fat and EAT:
Promote systemic and local inflammation via NF-κB and cytokine secretion.
Impair glucose metabolism through reduced GLUT4 activity.
Exacerbate oxidative stress, worsening insulin resistance and organ damage.
Visceral fat—whether around your organs or your heart—is more than a cosmetic concern. It’s an active endocrine organ driving metabolic dysfunction. Take steps now to protect your heart and health for the long term. 💪❤️
Yang, X., Feng, C., & Feng, J. (2023). Epicardial Adipose Tissue and Diabetic Cardiomyopathy. Journal of Cardiovascular Pharmacology and Therapeutics, 28, 10742484231151820. https://doi.org/10.1177/10742484231151820
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