Associations of erythrocyte polyunsaturated fatty acids with incidence of stroke and stroke types in adult Chinese: a prospective study of over 8000 individuals

Purpose There is limited and inconsistent evidence about the relationships of erythrocyte polyunsaturated fatty acids (PUFAs) with stroke and stroke types, particularly in China where the stroke rates are high. We aimed to investigate the associations of different erythrocyte PUFAs with incidence of total stroke, ischemic stroke (IS), and intracerebral hemorrhage (ICH) in Chinese adults. Methods In the prospective China Kadoorie Biobank, erythrocyte PUFAs were measured using gas chromatography in 10,563 participants who attended 2013-14 resurvey. After a mean follow-up of 3.8 years, 412 incident stroke cases (342 IS, 53 ICH) were recorded among 8,159 participants without prior vascular diseases or diabetes. Cox regression yielded adjusted hazard ratios (HRs) for stroke associated with 13 PUFAs. Results Overall, the mean body mass index was 24.0 (3.4) kg/m(2) and the mean age was 58.1 (9.9) years. In multivariable analyses, 18:2n-6 was positively associated with ICH (HR = 2.33 [95% CIs 1.41, 3.82] for top versus bottom quintile, P-trend = 0.007), but inversely associated with IS (0.69 [0.53,0.90], P-trend = 0.027), while 20:3n-6 was positively associated with risk of IS (1.64 [1.32,2.04], P-trend < 0.001), but not with ICH. Inverted-U shape curve associations were observed of 20:5n-3 with IS (P-nonlinear = 0.002) and total stroke (P-nonlinear = 0.008), with a threshold at 0.70%. After further adjustment for conventional CVD risk factors and dietary factors, these associations remained similar. Conclusion Among relatively lean Chinese adults, erythrocyte PUFAs 18:2n-6, 20:3n-6 and 20:5n-3 showed different associations with risks of IS and ICH. These results would improve the understanding of stroke etiology.