Supplementary Material for: Association of higher n-3 polyunsaturated fatty acid consumption and aerobic exercise with lower neutrophil-to-lymphocyte ratio: Implications of anti-atherosclerotic effect of fish consumption

Introduction: N-3 polyunsaturated fatty acids (n-3 PUFAs), abundant in oily fish, exert anti-inflammatory cardiovascular protective effects. We aimed to investigate the association between fish-derived n-3 PUFAs, lifestyle habits, and neutrophil-to-lymphocyte ratio (NLR), which is an atherosclerotic cardiovascular disease (ASCVD) marker.
Methods: This cross-sectional study included 6,950 participants with no history of ASCVD, who underwent annual health check-ups (average age, 46.3 ± 13.0 years; male: female ratio, 58.8%) between April 2019 and March 2020 at the Health Planning Center, Nihon University Hospital. We calculated n-3 PUFA consumption using a questionnaire and the Japan National Health and Nutrition Survey.
Results: The average fish consumption frequency and fish-derived n-3 PUFA consumption were 2.20 ± 1.28 days/week and 5.20 ± 3.11 g/week, respectively. A higher fish-derived n-3 PUFA consumption was associated with a lower NLR. Multiple-stepwise regression analysis revealed that higher fish-derived n-3 PUFA consumption and more aerobic exercise habits were significant independent determinants of lower NLR. Furthermore, higher fish-derived n-3 PUFA consumption was associated with habitual aerobic exercise habits.
Conclusion: Thus, higher fish-derived n-3 PUFA consumption and more aerobic exercise habits may be synergistically associated with lower NLR. This association may explain the preventive effects of fish consumption on the ASCVD risk.

引言：n-3多不饱和脂肪酸（n-3 polyunsaturated fatty acids, n-3 PUFAs）大量存在于油性鱼类中，具有抗炎及心血管保护作用。本研究旨在探讨鱼类来源的n-3多不饱和脂肪酸、生活方式习惯与中性粒细胞与淋巴细胞比值（neutrophil-to-lymphocyte ratio, NLR）之间的关联，而NLR是动脉粥样硬化性心血管疾病（atherosclerotic cardiovascular disease, ASCVD）的标志物。

研究方法：本横断面研究纳入了2019年4月至2020年3月期间，在日本大学医院健康规划中心接受年度健康体检的6950名无动脉粥样硬化性心血管疾病病史的参与者，其平均年龄为46.3±13.0岁，男性占比为58.8%。研究通过问卷调查结合日本国民健康与营养调查数据，计算参与者的n-3多不饱和脂肪酸摄入量。

研究结果：参与者的平均鱼类食用频率为2.20±1.28天/周，鱼类来源的n-3多不饱和脂肪酸平均摄入量为5.20±3.11g/周。较高的鱼类来源n-3多不饱和脂肪酸摄入量与更低的中性粒细胞与淋巴细胞比值相关。多元逐步回归分析显示，更高的鱼类来源n-3多不饱和脂肪酸摄入量及更规律的有氧运动习惯是降低中性粒细胞与淋巴细胞比值的显著独立影响因素。此外，较高的鱼类来源n-3多不饱和脂肪酸摄入量与规律有氧运动习惯呈正相关。

结论：综上，更高的鱼类来源n-3多不饱和脂肪酸摄入量及更规律的有氧运动习惯可能与更低的中性粒细胞与淋巴细胞比值存在协同关联。这一关联或可解释鱼类食用对动脉粥样硬化性心血管疾病风险的预防作用。