Diabetes and Heart Failure: A Dual Epidemic

Kuo-Meng LiaoTaiwan Speaker Diabetes and Heart Failure: A Dual EpidemicDiabetes mellitus (DM) and heart failure (HF) are tightly interconnected disease states that interact through complex and bidirectional cardio-metabolic mechanisms. Among HF phenotypes, heart failure with preserved ejection fraction (HFpEF) shows the strongest association with DM, reflecting shared pathophysiological pathways beyond traditional ischemic heart disease. Epidemiologically, DM confers a two- to four-fold increased risk of incident HF, with a disproportionate burden of HFpEF. Patients with HFpEF exhibit a high prevalence of DM and insulin resistance, accompanied by worse exercise intolerance, higher hospitalization rates, and increased mortality. These observations support the concept that DM is not merely a comorbidity but a central contributor to HFpEF pathogenesis. Mechanistically, chronic hyperglycemia and insulin resistance initiate a cascade of systemic and myocardial abnormalities. Endothelial dysfunction, coronary microvascular inflammation, and impaired nitric oxide–cyclic GMP–protein kinase G signaling promote cardiomyocyte stiffness and diastolic dysfunction. Metabolic inflexibility, characterized by excessive fatty acid utilization and impaired glucose oxidation, reduces myocardial energetic efficiency. In parallel, advanced glycation end products, oxidative stress, mitochondrial dysfunction, and lipotoxicity drive myocardial fibrosis and adverse extracellular matrix remodeling. These myocardial changes are further amplified by extracardiac factors common in DM—obesity, chronic kidney disease, systemic inflammation, and autonomic imbalance—creating the multi-organ HFpEF syndrome. Conversely, HF exacerbates insulin resistance through neurohormonal activation, inflammation, and skeletal muscle hypoperfusion, reinforcing a vicious cycle between metabolic and cardiac dysfunction. Recognition of this cross-talk has important therapeutic implications, as exemplified by sodium–glucose cotransporter 2 inhibitors, which improve HF outcomes through mechanisms extending beyond glucose lowering. In summary, DM and HFpEF are linked through shared mechanistic pathways involving metabolism, microvascular dysfunction, and inflammation. A mechanistic understanding of this interaction is essential for developing integrated, phenotype-specific cardio-metabolic strategies.