LEP and obesity due to melanocortin 4 receptor deficiency: Leptin treatment reduces cardiac wall thickness and cardiomyocyte hypertrophy in leptin-deficient ob/ob mice independent of obesity (Barouch et al., 2003), and protects cardiomyocytes from hypoxia-induced apoptosis (Shin et al., 2009), suggesting leptin exhibits cardioprotective effects against obesity and hypoxia.