Ist Cholesterin ein Risikofaktor für den Schlaganfall?

Zusammenfassung

Überraschenderweise ist die Evidenz hinsichtlich der Frage, ob Cholesterin ein Risikofaktor für den Schlaganfall ist, kontrovers und vielfach kontraintuitiv. So konnte in großen Feldstudien im Gegensatz zur koronaren Herzkrankheit keine eindeutige Korrelation zwischen erhöhten Serumcholesterinspiegeln und der Schlaganfallhäufigkeit gezeigt werden. Vielmehr gibt es Hinweise für eine Häufung von intrakraniellen Blutungen bei niedrigen Cholesterinspiegeln. Weiterhin konnten auch verschiedene Interventionsstudien keinen Einfluss einer cholesterinsenkenden Therapie auf die Schlaganfallrate nachweisen. In den 90er Jahren wurden große randomisierte Studien mit HMG-CoA-Reduktasehemmern (Statinen) an Herzinfarktpatienten durchgeführt, die eine deutliche Senkung der Schlaganfallinzidenz zeigten. Eine lipidsenkende Therapie mit Statinen kann also zur Schlaganfallprophylaxe bei Patienten mit manifester KHK eingesetzt werden. Die Frage jedoch, ob die protektiven Effekte allein durch die cholesterinsenkende Wirkung oder vielmehr durch andere, cholesterinunabhängige Wirkungen der Statine bedingt werden, und ob auch Patienten ohne eine begleitende KHK von einer Behandlung mit Statinen zur Schlaganfallsekundärprävention profitieren können, bleibt kontrovers. Die Pro- und Kontradarstellung verdeutlicht, dass die gegenwärtige Datenlage in vielen Aspekten gegensätzliche Schlüsse zulässt.

Abstract

Surprisingly, the question whether or not cholesterol is a stroke risk factor has remained controversial and somewhat counterintuitive. In contrast to coronary heart disease, large trials failed to demonstrate a correlation between elevated serum cholesterol levels and stroke incidence. There is even evidence for an inverse relation between cholesterol levels and risk of intracerebral hemorrhage. Moreover, clinical trials in the pre-statin era failed to demonstrate an effect of cholesterol-lowering on stroke incidence. On the other hand, in the 1990s large randomized trials demonstrated unequivocally that HMG-CoA reductase inhibitors (statins) lower stroke risk in patients with coronary heart disease (CHD). Hence, lipid-lowering therapy with statins is established for stroke prophylaxis in patients with CHD. The question, however, whether these protective effects are cholesterol-dependent or rather mediated by cholesterol-independent („pleiotropic”) effects, and whether statins may be beneficial for secondary prevention of stroke in patients without CHD, remains controversial.

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