Total and HDL cholesterol and risk of stroke. EUROSTROKE: a collaborative study among research centres in Europe

Background: Controversy remains on the relation between serum lipids levels and stroke risk. This paper investigated the association of total and HDL cholesterol level to fatal and non-fatal, and haemorrhagic and ischaemic stroke in four European cohorts participating in EUROSTROKE. Methods: EUROSTROKE is a collaborative project among ongoing European cohort studies on incidence and risk factors of stroke. EUROSTROKE is designed as a nested case-control study. For each stroke case, two controls were sampled. Strokes were classified according to MONICA criteria or reviewed by a panel of four neurologists. At present, data on stroke and risk factors were available from cohorts in Cardiff (84 cases), Kuopio (74 cases), Rotterdam (157 cases), and Novosibirsk (79 cases). Results: Pooled analyses showed no significant association between total cholesterol and risk of stroke (odds ratio for increase of 1 mmol/l in cholesterol of 0.98 (95% CI 0.88 to 1.09)). Analyses for haemorrhagic stroke and cerebral infarction revealed odds ratios of 0.80 (95% CI 0.61 to 1.05) and 1.06 (95% CI 0.94 to 1.19), respectively. The association of HDL cholesterol to stroke was different in men compared with women. In men, there was a general trend towards a lower risk of stroke with an increase in HDL (odds ratio per 1 mmol/l increase in HDL cholesterol 0.68 (95% CI 0.40 to 1.16)). In women, however, an increase in HDL was associated with a significant increased risk of non-fatal stroke and of cerebral infarction (odds ratios of 2.46 (95% 0.1.20 to 5.04) and 2.52 (95% CI 1.15 to 5.50), respectively. The difference between men and women in the association of HDL with stroke seemed to differ mainly in smokers and never smokers, but not among ex smokers. Conclusion: This analysis of the EUROSTROKE project could not disclose an association of total cholesterol with fatal, non-fatal, haemorrhagic or ischaemic stroke. HDL cholesterol however, seemed to be related to stroke differently in men than in women