Causal associations of blood lipids with risk of ischemic stroke and intracerebral hemorrhage in Chinese adults.
Sun L., Clarke R., Bennett D., Guo Y., Walters RG., Hill M., Parish S., Millwood IY., Bian Z., Chen Y., Yu C., Lv J., Collins R., Chen J., Peto R., Li L., Chen Z., China Kadoorie Biobank Collaborative Group None., International Steering Committee None., International Co-ordinating Centre, Oxford None., National Co-ordinating Centre, Beijing None., Regional Co-ordinating Centres None.
Stroke is the second leading cause of death worldwide and accounts for >2 million deaths annually in China1,2. Ischemic stroke (IS) and intracerebral hemorrhage (ICH) account for an equal number of deaths in China, despite a fourfold greater incidence of IS1,2. Stroke incidence and ICH proportion are higher in China than in Western populations3-5, despite having a lower mean low-density lipoprotein cholesterol (LDL-C) concentration. Observational studies reported weaker positive associations of LDL-C with IS than with coronary heart disease (CHD)6,7, but LDL-C-lowering trials demonstrated similar risk reductions for IS and CHD8-10. Mendelian randomization studies of LDL-C and IS have reported conflicting results11-13, and concerns about the excess risks of ICH associated with lowering LDL-C14,15 may have prevented the more widespread use of statins in China. We examined the associations of biochemically measured lipids with stroke in a nested case-control study in the China Kadoorie Biobank (CKB) and compared the risks for both stroke types associated with equivalent differences in LDL-C in Mendelian randomization analyses. The results demonstrated positive associations of LDL-C with IS and equally strong inverse associations with ICH, which were confirmed by genetic analyses and LDL-C-lowering trials. Lowering LDL-C is still likely to have net benefit for the prevention of overall stroke and cardiovascular disease in China.