Remodeling metabolic memory: persistent epigenetic injury and therapeutic reversal strategies in diabetic cardiomyopathy

Myocardial injury in diabetic cardiomyopathy (DCM) can persist despite improved metabolic control, indicating that current glycemic or metabolic status alone cannot fully explain disease progression. This phenomenon supports the concept of metabolic memory, in which prior metabolic stress is retained through relatively stable epigenetic and transcriptional changes. Recurrent hyperglycemia, lipotoxicity, insulin resistance, and chronic inflammation reshape DNA methylation, histone modifications, chromatin accessibility, and non-coding RNA regulation. Several molecular and regulatory alterations have been shown to persist after glycemic normalization or stimulus withdrawal, whereas others have been characterized only during ongoing diabetes or metabolic stress. These programs sustain oxidative stress, mitochondrial dysfunction, inflammation, endothelial injury, fibrosis, and abnormal intercellular communication within the diabetic heart. This review distinguishes alterations directly shown to persist after metabolic normalization from DCM-associated epigenetic changes for which persistence remains unverified, and integrates these findings across cardiomyocytes, endothelial cells, fibroblasts, and immune cells. It also discusses metabolic modulation, epigenetic interventions, RNA-based strategies, and targeted delivery as complementary approaches to reduce ongoing injury, prevent persistent regulatory programs, improve DCM during active diabetes, and potentially reverse residual abnormalities after metabolic normalization. Together, these approaches extend treatment beyond current metabolic control to the persistent molecular consequences of prior metabolic injury.