Association Between Dyslipidemia and Vascular Events in Patients Treated with Statins: Report from the UK General Practice Research Database

Objective: A retrospective cohort study was conducted to evaluate the association between low high-density lipoprotein cholesterol (HDL-C) and/or elevated triglycerides (TG) and cardiovascular (CV) and/or cerebrovascular (CB) events among patients with elevated low-density lipoprotein cholesterol (LDL-C) despite statin treatment.

Methods: Patient demographics, clinical characteristics, laboratory data, and CV/CB events, were collected from the UK General Practice Research Database. Abnormal lipid levels were defined using US and European clinical guidelines. The association between the frequency of CV/CB events among patients with HDL-C/TG abnormalities versus patients with isolated low LDL-C was estimated using multivariate Cox proportional hazards regression.

Results: Of 19,843 statin-treated patients, 6823 had elevated LDL-C despite therapy for a mean follow-up of 1.99+/-1.06 years. Among these patients, 3115 (45.7%) also had HDL-C/TG abnormalities. A total of 715 patients (10.5%) experienced CV/CB events. In statin-treated patients not at LDL-C goal, the relative risk of a vascular event was 24% higher in patients with HDL-C/TG abnormalities (HR=1.24, 95% CI: 1.06-1.46, p=0.006) than in patients without HDL-C/TG abnormalities. Additional variables that were associated with a significantly increased risk of CV/CB events included age (p<0.0001), gender (p=0.027), and medication possession ratio (p<0.0001), while diabetes mellitus (p<0.0001), hypertension (p<0.0001), 10-year Framingham risk score>30% (p=0.005), statin dose (p<0.0001), and LDL-C level at baseline (p<0.0001) were associated with a significantly decreased risk of CV/CB events.

Conclusion: Among statin-treated patients with elevated LDL-C from UK clinical practices, reduced HDL-C and/or elevated TGs were associated with a significantly increased relative risk of CV/CB events.