STAT3 and cardiac hypertrophy: Research has shown that the expression of transcriptional activator-3 (signal transducer and activator of transcription-3, STAT-3) and AMPK can be upregulated by leptin and its receptor in cardiomyocytes, thereby exerting cardioprotective effects on patients with HF by improving myocardial hypertrophy, reducing cell apoptosis, and controlling inflammatory responses (12).