Linagliptin exacerbates heart failure due to energy deficiency via downregulation of glucose utilization and absorption in a mouse model.

Use of dipeptidyl peptidase-4 (DPP4) inhibitor in some clinical trials might have caused heart failure (HF), leading to increased hospitalizations. The aim of the present study was to determine whether linagliptin has any effect on chronic dilated HF, and its underlying mechanisms. Physiologic and pathologic studies were conducted on heart/muscle-specific manganese superoxide dismutase-deficient mice, which exhibited dilated cardiomyopathy, and were randomized to receive a low dose (1 mg/kg, HF-L group) or high dose (10 mg/kg, HF-H group) mixed with food, or normal food (HF group), for 8 weeks. Linagliptin increased mortality and heart/body weight ratio in mice with HF. Cardiac contractility and fibrosis worsened, whereas hepatic glycogen content and individual carbohydrate consumption decreased significantly in the HF-H group, when compared with the HF control group. Therefore, we performed a complementary experiment by supplementing glucose to the mice treated with high-dose linagliptin (HF-HG group). Adequate glucose supplementation reduced heart/body weight ratio and cardiac fibrosis, and improved cardiac contractility, without changing mortality. Following oral administration of 13C glucose, the respiratory 13C decreased in the HF-H and HF-HG groups, when compared with that in the HF group; the fecal 13C increased, suggesting that linagliptin inhibited glucose absorbance in the intestine. In addition, the expression of GLUT2, a glucose transporter was downregulated in the small intestine. Linagliptin treatment exacerbated HF, which increased mortality, cardiac function, and fibrosis. DPP4 inhibitors might boost cardiac cachexia and exacerbate HF, at least in part, through the modification of glucose utilization and absorption.

GLP-1 analog liraglutide-induced cardiac dysfunction due to energetic starvation in heart failure with non-diabetic dilated cardiomyopathy.

BACKGROUND: Glucagon-like peptide-1 (GLP-1) reduces cardiovascular events in diabetic patients; however, its counter-protective effects have also been suggested in patients with heart failure and the clear explanation for its mechanisms have not yet been offered. METHODS: The effects of GLP-1 analog on cardiac function and energy metabolism, especially glycemic and lipid metabolisms were elucidated using non-diabetic J2N-k hamsters which showed spontaneous dilated cardiomyopathy. J2N-k hamsters were treated with PBS (HF group), low-dose (HF-L group) or high-dose liraglutide (HF-H group). RESULTS: In failing heart, GLP-1 analog exerted further deteriorated cardiac function (e.g. positive and negative dP/dt; p = 0.01 and p = 0.002, respectively) with overt fibrosis and cardiac enlargement (heart/body weight, 5.7 ± 0.2 in HF group versus 7.6 ± 0.2 in HF-H group; p = 0.02). The protein expression of cardiac muscles indicated the energy starvation status. Indirect calorimetry showed that failing hearts consumed higher energy and carbohydrate than normal hearts; moreover, this tendency was augmented by GLP-1 analog administration. Upon 10% glucose solution loading with GLP-1 analog administration (HF-H-G group) as complementary experiments, the cardiac function and fibrosis significantly ameliorated, whereas carbohydrate utilization augmented further and lipid utilization reduced more. The prognosis of HF-H-G group also significantly improved (p = 0.025). CONCLUSIONS: Glucagon-like peptide-1 analog caused the relative but desperate shortage of glycemic energy source for the failing cardiac muscles and it may restrict ATP synthesis, resulting in cardiac function deterioration. Therefore, appropriate energy supply and amount of carbohydrate intake should be carefully considered when administrating incretin-related drugs to patients with heart failure.

EGCG, a green tea catechin, attenuates the progression of heart failure induced by the heart/muscle-specific deletion of MnSOD in mice.

BACKGROUND: Manganese superoxide dismutase (MnSOD) is an important antioxidant enzyme affected in heart/muscle-specific MnSOD-deficient mice (H/M-SOD2-/-), which develop progressive congestive heart failure and exhibit pathology typical of dilated cardiomyopathy. METHODS: In this study we investigated the beneficial effects of epigallocatechin gallate (EGCG) on the cardiac remodeling and telomere biology in H/M-SOD2-/- mice. H/M-SOD2-/- mice were divided into three groups: those receiving normal drinking water (KO), a low dose of EGCG (L: 10mg/L), and a high dose of EGCG (H: 100mg/L) beginning at eight weeks of age and lasting for eight weeks. RESULTS: The mice in the KO group exhibited significantly dilated cardiac remodeling with reduced contractility, which was prevented by the administration of EGCG. Although the mortality of KO mice was about 50% at 16 weeks of age, the mice that received EGCG had a high survival rate. The cardiac dilatation with reduced cardiac contraction in KO mice was prevented by EGCG treatment. The levels of myocardial oxidative stress and free fatty acids were lower in the group treated with EGCG compared with the KO group. The increased expression of nitric oxide synthase 2, nitrotyrosine, fatty acid synthase, Toll-like receptor 4, and Sirt1 in the KO mice were prevented by EGCG treatment. The shortening of the telomere length, decreased telomerase activity in KO mice were also prevented by EGCG. CONCLUSIONS: H/M-SOD2-/- mice receiving EGCG have a lower mortality rate and exhibit less inflammation and a better preserved cardiac function and telomere biology.