INFLUENCE OF TOTAL CHOLESTEROL, HIGH-DENSITY-LIPOPROTEIN CHOLESTEROL,AND TRIGLYCERIDES ON RISK OF CEREBROVASCULAR-DISEASE - THE COPENHAGENCITY HEART-STUDY

Objective-To estimate the influence of plasma total cholesterol, high density lipoprotein cholesterol, and triglycerides on risk of cerebrov ascular disease.Design-The Copenhagen city heart study is a prospectiv e observational survey with two cardiovascular examinations at five ye ar intervals. Non-fasting plasma lipids were measured in participants once at each examination, along with other variables. The Cox regressi on model was used to establish the effect of the factors recorded on c erebrovascular events of mostly, but not exclusively, ischaemic origin . Subjects-19 698 women and men at least 20 years old, randomly select ed after age stratification from an area of central Copenhagen. Main o utcome measures-Initial cases of stroke and transient ischaemic attack recorded from hospital records and death certificates from 1976 throu gh 1988. Results-660 non-haemorrhagic and 33 haemorrhagic events were recorded. Total cholesterol was positively associated with risk of non -haemorrhagic events, but only for levels > 8 mmol/l, corresponding to the upper 5% of the distribution in the study population. For lower p lasma cholesterol values the relative risk remained nearly constant. P lasma triglyceride concentration was significantly, positively associa ted with risk of non-haemorrhagic events. The relative risk correspond ing to an increase of 1 mmol/l was 1.12 (95% confidence interval 1.07 to 1.16). There was a negative, log linear association between high de nsity lipoprotein cholesterol and risk of non-haemorrhagic events (0.5 3 (0.34 to 0.83)). There was no indication that the effects of plasma lipids were different in women and men. Conclusions-The pattern of the association between plasma cholesterol and risk of ischaemic cerebrov ascular disease was not log linear, and the increased risk was confine d to the upper 5% of the cholesterol distribution. Further studies sho uld concentrate on the association between plasma cholesterol and veri fied haemorrhagic stroke.