SIRT1 and cardiomyopathy: Low to moderate (2.5- to 7.5-fold) cardiac-specific Sirt1 overexpression in transgenic mice has been demonstrated to protect cardiomyocytes from apoptosis and age-dependent degeneration, whereas its greater increase (12.5-fold) has a detrimental effect on these cells, leading to cardiomyopathy [30].