Relationship between serum lipid levels and ischemic stroke in patients with atrial fibrillation: a nested case–control study based on the China Atrial Fibrillation Registry

Background Atrial fibrillation (AF) is an important risk factor for acute ischemic stroke. Methods A nested case–control study was conducted among patients diagnosed with AF, whose information was acquired from the prospective China Atrial Fibrillation Registry (China-AF), from August 2011 to December 2018. Results This study compared patients with stroke group (n = 145) with a matched control group (n = 577). Demographic data were similar except for body mass index (BMI), diastolic blood pressure (DBP) which were higher, and new oral anticoagulant (NOAC) treatment rate which was lower in the stroke group (all P < 0.05). Baseline median [IQR] levels of including triglyceride (TG) were higher in the stroke group (21.96 [16.74, 21.52], mg/dL) than the control group (19.62 [14.76, 27.36], mg/dL) ( P = 0.012), while the total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were similar between the two groups. Elevated TG and HDL-C were positively associated with ischemic stroke (OR 1.01, 95% CI 1.00–1.02, P = 0.032; OR 1.03, 95% CI 1.00–1.05, P = 0.025), after adjustment for BMI, systolic blood pressure, DBP, CHA 2 DS 2 -VASc score, HAS-BLED score, NOAC, LDL-C and HDL-C. However, NOAC (OR 0.20, 95% CI 0.05–0.84, P = 0.029) could decrease the likelihood of ischemic stroke in patients with AF. In subgroup analysis, higher TG level remained significantly associated with ischemic stroke for AF patients without a history of smoking (OR 1.26, 95% CI 1.02–1.55, P = 0.028). Conclusion Higher level of TG and HDL-C were positively associated with ischemic stroke in patients with AF.