Serum fatty acids and ischemic stroke subtypes in middle- and late-onset acute stroke patients

Abstract

Summary: Introduction: Among stroke patients, the dietary lipid content is likely associated with the age at stroke onset and ischemic stroke subtype. Specifically, middle-onset stroke patients may have a higher serum level of saturated fatty acids and higher incidence of lacunar or atherosclerotic stroke, whereas late-onset stroke patients may have a higher serum level of n-3 polyunsaturated fatty acids (PUFA; a fish oil component) and lower incidence of lacunar or atherosclerotic stroke. This retrospective study aimed to investigate the relationships among serum fatty acid levels, age at stroke onset and stroke subtype in ischemic stroke patients. Methods: Our analysis included ischemic stroke patients aged ≥50 years who were admitted to our institution within 24 h of stroke onset between September 2015 and March 2017 and underwent blood evaluations of saturated fatty acids (lauric, myristic, palmitic, stearic acids), a monounsaturated fatty acid (MUFA; oleic acid), n-6 PUFAs [linoleic, arachidonic acids (AA)] and n-3 PUFAs [alpha-linoleic, eicosapentaenoic (EPA), docosahexaenoic acids (DHA)]. We excluded patients who used statins, n-3 PUFA supplements or purified EPA drugs, fibrates or ezetimibe at onset. To compare serum levels of fatty acids and incidence rates of stroke subtypes, we stratified patients by age at stroke onset as Middle onset (50–74 years) or Late onset (≥75 years). Results: One hundred ninety-one patients with an average age of 74.4 years met our inclusion criteria. Ninety-one and 100 patients were classified as Middle- and Late-onset, respectively, and these groups differed significantly in terms of mean body mass index values (23.9 vs. 22.9 kg/m2, p < 0.05). Significant differences were also observed in the serum levels of various fatty acids between the Middle- and Late-onset groups, with the following respective serum levels (all μg/ml): myristic, 25.2 and 20.9 (p < 0.05); palmitic, 763 and 663 (p < 0.001); stearic, 224 and 193 (p < 0.0001); oleic, 702 and 586 (p < 0.0001); linoleic, 882 and 746 (p < 0.0001); AA, 158 and 140 (p < 0.005); EPA, 64 and 79 (p < 0.05) and DHA, 131 and 142 (p = 0.09). The EPA/AA and n-6/n-3 ratios also differed significantly (0.43 vs. 0.57, p < 0.001; 5.2 vs. 4.0, p < 0.0001). Middle- and Late-onset patients had respective lacunar or atherosclerotic stroke incidence rates of 66% and 42% and cardiogenic stroke incidence rates of 16% and 36% (p < 0.01). Conclusions: People with higher serum levels of saturated fatty acids, MUFAs and n-6 PUFAs more frequently experienced lacunar or atherosclerotic stroke during middle age, whereas those with lower serum levels of these fatty acids and higher serum levels of n-3 PUFAs, such as EPA, more frequently experienced all types of ischemic stroke at an older age. Keywords: Serum fatty acids, Ischemic stroke subtype, Middle-onset stroke, Late-onset stroke