Myocardial Mitochondrial Metabolismin Diastolic Heart Failure: The Influence of Different Exercise Training Intensities

Abstract

Background – Diastolic heart failure (DHF) has a growing prevalence and current treatment options have not improved this prognosis. To better understand DHF, this study, as part of a multicenter study denominated OptimEx, looked into the myocardial mitochondrial metabolism in DHF in female Dahl salt sensitive (SS) rats and the influences of different exercise training intensities on this metabolism.

Methods – In a hypertension animal model, 120 female Dahl SS rats were randomized into five groups. One group was fed a normal diet (LS, n = 20) and was used as a sedentary control group. The other four groups were fed a 8 % NaCl diet. Of these four groups, one was sedentary (HS, = 40) and three were subjected to different training intensities; high intensity intervals (HIT) at a low volume of two intervals (HIT-LV, n = 20), HIT at a high volume of four intervals (HIT-HV, n = 20) and moderate continuous training (MCT, n = 20). Rats from every group were regularly controlled for blood pressure, signs of DHF and tested for oxygen uptake to adjust the exercise training protocol. Examiners were blinded. Study endpoint was DHF in HS.

Results – Exercise training decreased the limitation of oxidative phosphorylation of HIT-HV compared to LS. Further, after merging all exercise groups into one, improved mitochondrial efficiency could be seen for exercised groups compared with HS.

Conclusion – Myocardial mitochondrial metabolism is not influenced by the development of DHF. However, exercise training has positive effects on the myocardial mitochondrial efficiency and at high intensities also on the limitations of oxidative phosphorylation.