Metabolic Syndrome Causes Cardiovascular Disease under Stable Statin Medication

ABSTRACT

OBJECTIVE: Statins are known to prevent only 30–50% of cardiovascular disease(CVD) by reducing low-density lipoprotein cholesterol (LDL-C). There is a controversy about whether metabolic syndrome(MS) can increase the risk of CVD. The aim of this study is to investigate whether MS can increase the risk of CVD, even after LDL-C is ideally controlled by taking statins. METHODS: As a retrospective observational study, we investigated CVD events of 909 patients (61.3±10.2 years old) by reviewing medical records for at least 1 year before and after taking statins respectively, from June 2005 to February 2008, and analyzed the risk factors of CVD. RESULTS: During the study period (881.4±232.8 days), 46 cases of CVD events occurred in patients with a very high risk of CVD and in patients with a high risk of CVD. In patients with a very high risk of CVD, 56.8% (21 cases over 37) of CVD events occurred in patients who achieved LDL-C goal (< 70 mg/dL). A total of 9 events developed among high risk patients who reached LDL-C goal (< 100 mg/dL). The patients with MS revealed significantly higher rates of CVD events [p=0.015; hazard ratio (HR) 3.033; 95% confidence interval (CI) 1.184–7.768]. Significantly higher rates of CVD events were also found in subgroup analysis of the patient with a past history of CVD events [p=0.017; HR 3.431; 95% CI 1.183–9.956]. Similar pattern was demonstrated in patients with diabetes [p=0.049; HR 2.738; 95% CI 0.963–7.782]. Cox regression analysis identified metabolic syndrome [p=0.025; HR 5.237; 95% CI 1.235–22.204], a past history of CVD events [p=0.000; HR 5.349; 95% CI 2.321–12.327], basal LDL-C level [p=0.024; HR 1.013; 95% CI 1.002–1.025] and total cholesterol level after statin therapy [p=0.024; HR 0.978; 95% CI 0.959–0.997] as independent predictors of CVD among LDL-C goal achieved patients. CONCLUSION: Metabolic syndrome is the independent risk factor of CVD events in high risk patients with or without a past history of CVD events or diabetes. In these patients, statins could not prevent CVD events effectively.