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BACKGROUND: exercise-based Cardiac Rehabilitation Programme (CRP) is established as adjuvant therapy in heart failure (HF), nevertheless it is underutilized, especially in the elderly. While the functional and hemodynamic effects of CRP are well known, its underlying molecular mechanisms have not been fully clarified. The present study aims to evaluate the effects of a well-structured 4-week CRP in patients with stable HF from a molecular point of view. RESULTS: A prospective longitudinal observational study was conducted on patients consecutively admitted to cardiac rehabilitation. In fifty elderly HF patients with preserved ejection fraction (HFpEF), levels of sirtuin 1 (Sirt1) in peripheral blood mononuclear cells (PBMCs) and of its targets, the antioxidants catalase (Cat) and superoxide dismutase (SOD) in serum were measured before (Patients, P) and at the end of the CRP (Rehabilitated Patients, RP), showing a rise of their activities after rehabilitation. Endothelial cells (ECs) were conditioned with serum from P and RP, and oxidative stress was induced using hydrogen peroxide. An increase of Sirt1 and Cat activity was detected in RP-conditioned ECs in both the absence and presence of oxidative stress, together with a decrease of senescence, an effect not observed during Sirt1 and Cat inhibition. CONCLUSIONS: In addition to the improvement in functional and hemodynamic parameters, a supervised exercise-based CRP increases Sirt1 activity and stimulates a systemic antioxidant defence in elderly HFpEF patients. Moreover, CRP produces antioxidant and anti-senescent effects in human endothelial cells mediated, at least in part, by Sirt1 and its target Cat.

The aim of this study was to test the effects of age and chronic exercise training on antioxidant and heat shock protein (Hsp) expression by comparing the hearts of young (Y), sedentary old (SO) and trained old (TO) rats. In SO rats, there were: (a) changes in myocardial structure and function; (b) increased malondialdehyde levels; (c) no changes in superoxide-dismutase (SOD) enzymes; (d) reduced Hsp70 expression; and (e) increased Hsp27 expression. In TO rats, SOD enzymes and Hsp70 expression were increased and Hsp27 was further increased. Malondialdehyde level did not differ between TO and SO rats, which shows that chronic exercise did not affect the peroxidation index. In summary, by increasing Hsp27 and Hs70 levels, prolonged exercise partially counterbalanced the heart age-related effects in the antioxidant system without altering peroxidation levels. These findings suggest that the beneficial effects on aged-related cardiovascular changes could be connected to the "anti-oxidant" effects of prolonged exercise training.