FIBRINOGEN AND LIPID CONCENTRATIONS AS RISK-FACTORS FOR TRANSIENT ISCHEMIC ATTACKS AND MINOR ISCHEMIC STROKES

Objective - To determine whether fibrinogen and lipid concentrations are risk factors for ischaemic stroke. Design-Case - control study with a population based comparison within the overall study. Setting - Oxfordshire community stroke project and a neurology clinic. Subjects - 105 patients who had a transient ischaemic attack or minor ischaemic stroke and 352 randomly chosen controls matched for age and sex from the same general practitioners as the incident cases. 52 controls were ineligible or refused interview. 104 cases and 241 controls gave blood samples for analysis. Main outcome measures - Response to structured questionnaire, height, weight, blood pressure, and serum concentrations of fibrinogen and lipids. Results - Adjusted for other variables, odds ratios of ischaemic stroke were 1.78 (95% confidence interval 0.91 to 3.48; p = 0.009) for fibrinogen concentrations > 3.6 g/l; 1.73 (0.90 to 3.29; p = 0.009) for total cholesterol concentrations > 6.0 mmol/l; 1.34 (0.69 to 2.61; p > 0.4) for low density lipoprotein cholesterol concentrations > 3.5 mmol/l; and 0.32 (0.15 to 0.69; p = 0.002) for high density lipoprotein cholesterol concentration > 1.2 mmol/l. Similar results emerged comparing only community derived cases with transient ischaemic attacks and controls. The effects of fibrinogen, total cholesterol, and high density lipoprotein cholesterol were significant in a test of trend after adjusting for all other variable in the study (chi-2 = 4.14, p < 0.05; chi-2 = 4.31, p < 0.05, and chi-2 = 12.15, p > 0.001, respectively). History of ischaemic heart disease and hypertension were the only other variables that showed significance, though both lost significance after adjustment (2.06, p = 0.08 and 1.53, p = 0.2, respectively). Conclusions - Fibrinogen and lipids are important risk factors for ischaemic stroke. The pattern of changes mirrors that found in ischaemic heart disease.