Cholesterol Levels and Hemorrhagic Stroke Risk in East Asian Versus Non-East Asian Populations: A Systematic Review and Meta-Analysis.

BACKGROUND: The aim of this work was to evaluate the relationships between cholesterol levels and risk of hemorrhagic stroke [including intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH)] in East Asian versus non-East Asian populations.

MATERIALS AND METHODS: Relevant prospective studies were identified from systematic searches of PubMed and EMBASE. A random-effects model was used to calculate summary relative risks (RRs) and 95% confidence intervals (CIs) that were used to compare the relationships between cholesterol levels and risk of hemorrhagic stroke in East Asian versus non-East Asian populations.

RESULTS: In terms of overall hemorrhagic stroke risk, both East Asians and non-East Asians displayed no significant difference between high versus low total cholesterol (TC) (RR=1.26, 95% CI, 0.92-1.72; I=74.4%, P<0.001; RR=1.69, 95% CI, 1.15-2.49; I=92.4%, P<0.001, respectively). In terms of ICH risk, East Asians displayed no significant difference between high versus low TC (RR=1.30, 95% CI, 0.89-1.90; I=78.6%, P<0.001), whereas non-East Asians displayed a significant difference between high versus low TC with low TC showing a higher ICH risk (RR=1.70, 95% CI, 1.08-2.67; I=91.2%, P<0.001). With respect to SAH risk, East Asians displayed a significant difference between high versus low TC with low TC showing a higher SAH risk (RR=1.48, 95% CI, 1.057-2.08; I=0%, P=0.682), whereas non-East Asians displayed no significant difference between high versus low TC (RR=1.14, 95% CI, 0.56-2.31; I=89.9%, P<0.001).

CONCLUSIONS: Under low cholesterol conditions, East Asian ethnic status favors SAH development, whereas non-East Asian ethnic status favors ICH development.