Abstract
Background Traditional association studies of cardiovascular disease (CVD) categorizations and polyunsaturated fatty acids (PUFAs) yielded conflicting findings. We propose a novel classification system based on fundamental characteristics of cardiovascular patients, such as age, body mass index, waist-hip ratio, etc., to more accurately assess the impact of PUFAs (plasma measures) such as omega-3 and omega-6 on mortality in cardiovascular patients. Methods Principal component analysis and k-means clustering were used to determine the CVD subtype. Variables included age, body mass index, waist-hip ratio, diastolic blood pressure, systolic blood pressure, total cholesterol, total triglycerides, high-density lipoprotein-cholesterol, apolipoprotein B: apolipoprotein A1, glycated hemoglobin, creatinine, albumin, C-reactive protein, white blood cell count, platelet count, hemoglobin concentration. The association of PUFAs with all-cause, cardiovascular, and ischemic heart disease (IHD) mortality in CVD patients was prospectively evaluated using restricted cubic splines and Cox proportional risk models. Results Among the 35,096 participants, 3,786 fatalities occurred. Three distinct CVD subtypes were identified, with Cluster 3 characterized by older age, male gender, and low high-density lipoprotein cholesterol, having the highest risk of mortality. Cluster 2 and Cluster 3 have the highest DHA and omega-6/omega-3 ratios, respectively, compared to Cluster 1. The protective effects of total PUFAs, omega-3 and DHA were mainly reflected in all-cause mortality, and were more significant in Cluster 2 and Cluster 3. Furthermore, the omega-6/omega-3 ratio of the highest quartile increased the risk of all-cause (Q3: HR=1.14, 95% CI: 1.00-1.29; Q4: HR=1.41, 95% CI: 1.24-1.61), CVD (Q4: HR=1.36, 95% CI: 1.07-1.75), and IHD mortality (Q4: HR=1.17, 95% CI: 1.12-2.03) in Cluster 3 compared to the first quartile. Conclusions Our findings highlight the heterogeneity of associations observed for the same type of PUFAs across distinct clusters. This association may be elucidated by the intricate interplay of various factors, encompassing inflammation, lipid metabolism, and cardiovascular health.</p>