Simvastatin improves the attenuated heart rate recovery of type 2 diabetics

Heart rate recovery at 1 min (HRR1) is a strong predictor of all-cause mortality. The effects of statins on the autonomic nervous system may account for their beneficial effects in survival. Our aim was to determine if statin therapy improves heart rate recovery in hypercholesterolemic patients with type 2 diabetes mellitus. Thirty type 2 diabetic patients without known coronary artery disease and low density lipoprotein cholesterol > 100 mg/dl and 30 age and sex matched non-diabetic controls were included in a prospective study. Patients with diabetes were treated with simvastatin 40 mg/day for 1 year. No lipid-lowering therapy was administered to the control group. Exercise testing with 2 min cool-down period was performed at baseline, 6, 12 weeks and at 1 year. The diabetics had significantly lower HRR1 compared with non-diabetics at baseline (19.2 ± 5.4 bpm versus 24.2 ± 4 bpm, p < 0.0001). Simvastatin therapy significantly improved HRR1 after 12 weeks compared to baseline (19.2 ± 5.4 bpm versus 24 ± 5 bpm, p < 0.0001) and this improvement remained significant at 1 year (26 ± 4.4 bpm, p < 0.0001 compared to baseline). HRR1 did not change in the control group (p = 0.39 by ANOVA). This study demonstrates that treatment with simvastatin might improve the attenuated heart rate recovery of diabetic subjects. In patients with diabetes, the mortality benefit provided by statins might involve their effects on the autonomic nervous system.