Long-term atorvastatin treatment decreases heart maximal oxygen consumption and its vulnerability to in vitro oxidative stress in Watanabe heritable hyperlipidemic rabbit

Statins are currently used in prevention of cardiovascular diseases in high-risk populations, and could be considered in primary prevention. However, few studies are available on the long-term effects of low doses of statins, especially on mitochondrial function and reactive oxygen species (ROS) metabolism at cardiac level. This study aimed to determine potential effects of a long-term atorvastatin treatment, at low-dose concentration, on the myocardium mitochondrial respiration. Thirty-four Watanabe rabbits were treated or not with atorvastatin (2.5 mg·kg⁻¹·day⁻¹) from the age of 3 to 12 months. Every 3 months, proton leak, basal (V ₀), and maximal (V _max) mitochondrial respiration on cardiac permeabilized fibers were measured. Additionally, the vulnerability to ROS, cardiac enzymatic antioxidant defenses, and oxidative damage (lipoperoxidation) were analyzed. Proton leak increased over the duration of the experiment (up to 60% from V _max at 12 months). Moreover, the statin treatment induced a decrease of V _max and a decrease of ROS susceptibility of cardiac mitochondria. However, the lipoperoxidation and the antioxidant defenses were not dependent on the presence of statin treatment, or on its duration. This is the first study showing a protective effect of long-term statins treatment against the ROS susceptibility in the cardiac muscle.