Effects of Statins on Metabolic Adaptations to Aerobic Exercise Training: Preliminary Findings

Abstract

Emerging evidence suggests statins, unlike exercise, may cause deleterious effects on skeletal muscle oxidative capacity and insulin sensitivity.Purpose: The purpose of this study was to determine if daily statin therapy altered the ability of exercise to lower fasting plasma insulin and glucose and improve cardiorespiratory fitness.Methods: Fifteen obese, sedentary adults with ≥ 2 MSynd risk factors were recruited and randomized into 1) exercise (Ex; treadmill 45 min ·day -1 , 5 day·week -1 at 65% VO 2 max) or 2) statin plus exercise (St+Ex; 40 mg·day -1 simvastatin plus exercise) therapies for 12 weeks.Results: Baseline age, body weight, and body mass index (BMI) of St+Ex and Ex were as follows: 41±2.5 and 40±4.7 yr, 98.2±7.0 and 84.7±4.0 kg, 33.6±1.6 and 30.3±1.0 kg·m -2 , respectively. Body weight and BMI were unchanged in response to both therapies. Fasting insulin levels decreased significantly with Ex therapy (10.6±5.0 to 8.8±4.8 uIU·ml -1 , p<0.05), while no difference was observed after St+Ex therapy (8.7±3.3 to 9.9±3.9 uIU·ml -1 ). Fasting blood glucose did not change in response to St+Ex (94.4±3.2 to 90.7±3.4 mg·dL -1 ) or Ex (83.7±3.6 to 85.5±3.8 mg·dL -1 ) therapy. Only exercise improved maximal oxygen consumption (fitness) (33.8±2.6 to 36.3±3.4 ml·kg -1 ·min -1 ) while no improvements were observed in response to combined St+Ex therapy (25.7±1.4 to 26.0±1.3 ml·kg -1 ·min -1 ). Conclusion:Preliminary findings suggest St-therapy may have deleterious effects on the capacity for exercise training to lower fasting insulin and improve cardiorespiratory fitness in obese, sedentary subjects. Further investigation utilizing a larger study population is needed to definitively determine the scope of effects that St-therapy may have on insulin sensitivity and cardiorespiratory fitness.