Supplementary Material for: Combined higher frequency fish consumption and healthy lifestyle may lower the triglyceride/HDL-C ratio in middle-aged Japanese males: Anti-atherosclerotic effect of fish consumption

Background: Fish consumption may be associated with a low risk of coronary artery disease. We aimed to investigate whether higher fish consumption results in improved lifestyle behaviors and thus lower triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio––a predictor of atherosclerotic cardiovascular disease (ASCVD). Methods and results: This cross-sectional study included 2947 middle-aged Japanese males with no history of ASCVD or lipid-modifying therapy, who presented at the Health Planning Center of Nihon university hospital between April 2018 and March 2019. We performed an analysis of variance using fish consumption as a categorical variable (0-2 days, 3-4 days, or 5-7 days per week). The serum TG/HDL-C ratio in the 5-7 days fish consumption group was significantly lower than those in the 0-2- and 3-4-days fish consumption groups (p < 0.0001 and p < 0.01, respectively). Multiple regression stepwise analysis revealed that weekly fish consumption negatively and independently determined the TG/HDL-C ratio (β = -0.061, p = 0.001). As fish consumption increased, the proportion of subjects with smoking habits decreased (p = 0.014), those engaging in aerobic exercises and aggressive daily physical activity increased (p < 0.0001 for both), and those with alcohol habit increased (p < 0.0001). In addition, we developed the risk stratification for ASCVD by combining the serum HDL-C level and the serum TG/HDL-C ratio with fish intake. Conclusion: Increased frequency of fish consumption and improved lifestyle behaviors due to daily fish intake may work additively to lower the serum TG/HDL-C ratio. These associations may explain why high fish consumption is associated with a lower risk of ASCVD. Our findings may help physicians and nutritionists in treating patients with heart diseases and metabolic conditions by recommending a high fish diet in middle-aged Japanese males.

研究背景：食用鱼类可能与较低的冠状动脉疾病发病风险相关。本研究旨在探讨较高的鱼类摄入频率是否可改善生活方式，进而降低甘油三酯/高密度脂蛋白胆固醇（TG/HDL-C）比值——该比值是动脉粥样硬化性心血管疾病（Atherosclerotic Cardiovascular Disease, ASCVD）的预测因子。
研究对象与结果：本横断面研究纳入2018年4月至2019年3月期间，于日本大学医院健康管理中心就诊的2947名无ASCVD病史及调脂治疗史的日本中年男性。以鱼类摄入频率为分类变量（每周0~2天、3~4天、5~7天）进行方差分析。结果显示，每周鱼类摄入5~7天组的血清TG/HDL-C比值显著低于0~2天组与3~4天组（分别为p<0.0001与p<0.01）。逐步多元回归分析表明，每周鱼类摄入频率对血清TG/HDL-C比值具有独立的负向影响（β=-0.061，p=0.001）。随着鱼类摄入频率升高，研究对象的吸烟比例显著降低（p=0.014），进行有氧运动及高强度日常体力活动的比例均显著升高（两组均为p<0.0001），而饮酒比例亦显著升高（p<0.0001）。此外，本研究结合血清HDL-C水平、血清TG/HDL-C比值与鱼类摄入情况，建立了ASCVD风险分层模型。
研究结论：鱼类摄入频率的提升，以及因日常鱼类摄入所改善的生活方式，可能通过协同作用降低血清TG/HDL-C比值。上述关联或可解释高鱼类摄入何以降低ASCVD发病风险。本研究结果可为临床医师与营养学家针对日本中年男性患者推荐高鱼类饮食方案，进而辅助治疗心血管疾病及代谢性疾病提供参考依据。