Blood Lipids are Important Independent Risk Factors for Ischemic Stroke or TIA: A prospective Follow-up of Over 11,000 patients in The BIP Registry
Background: Despite clear associations between blood lipids and coronary heart disease [CHD], and increasing evidence that HMG-CoA reductase inhibitors (statins) reduce the incidence of stroke the associations of blood lipids with stroke are not clear. Methods: We followed up 11,177 patients with documented CHD who were screened for but not included in the Bezafibrate Infarction Prevention (BIP) study, a secondary prevention randomized clinical trial of lipid modification, and had no history of stroke, for subsequent cerebrovascular disease (CVD). During a 6 to 8 year follow- up period 941 patients had a non-hemorrhagic CVD, of whom 487 were verified ischemic strokes or TIAs. Results: Age-adjusted rates of non-hemorrhagic CVD (per 1000 person-years)increased with increasing quintiles of total cholesterol and of LDL cholesterol from 10 to 14, increased with increasing quintiles of triglycerides from 9 to 17, and decreased with increasing quintiles of HDL cholesterol and percent of total serum cholesterol contained in the HDL moiety (%HDL) from 15 to 9 and from 18 to 9 per 1000 person years, respectively (p<0.01 for all). Similar trends appeared for the end-point of verified ischemic stroke/TIA. In separate logistic regression models, adjusting for clinical covariates, the following odds ratios (95% CI) were identified for lipid values in the upper versus the lower tertile for the end-point of ischemic stroke/TIA: total cholesterol 1.50 (1.18 to 1.90); LDL cholesterol 1.43 (1.12 to 1.82), HDL cholesterol 0.72 (0.56 to 0.93) and %HDL 0.68 (0.53 to 0.86). Odds ratio associated with triglycerides >200mg/dl compared to lower levels was 1.47 [95%CI 1.19 to 1.80]. Conclusions: These findings clearly support the role of blood lipids including total cholesterol, LDL cholesterol, HDL cholesterol, %HDL, and triglycerides in prediction of ischemic stroke/TIA among patients with established CHD.