Supplementary Material for: Association of platelet count and mean platelet volume with fish intake frequency: Implication for the cardioprotective effect of fish intake

Introduction: Mean platelet volume (MPV) measures platelet activity, and high values indicate increased atherosclerotic cardiovascular disease (ASCVD) risk. Intake of n-3 polyunsaturated fatty acids (n-3 PUFAs) found in fish can lower platelet count (PLC) and platelet activity, potentially reducing the risk of ASCVD. We aimed to investigate the relationship of fish intake with PLC, MPV, and n-3 PUFA intake.
Methods: This cross-sectional study was conducted among 9870 participants (average age: 47.5 ± 12.9 years; 55.9% men). N-3PUFA intake was calculated based on fish intake frequency (days/week) and information from the Nutritional Health Survey of Japan.
Results: The average fish intake frequency was 2.14 ± 1.26 days/week. As fish intake frequency increased, PLC decreased (p < 0.0001) and MPV increased (< 0.034). Multi-regression analysis showed that PLC was an independent determinant of MPV (β = -0.081, p < 0.0001). Naturally, though, n-3 PUFA intake significantly increased with increased fish intake frequency (p < 0.0001).
Conclusion: Higher fish intake was associated with lower PLC and larger MPV. The anti-platelet effect of n-3PUFAs, which intensifies with higher fish intake, may suppress platelet activity with larger MPV. Further studies are required to clarify the causal relationship between these factors.

引言：平均血小板体积（Mean platelet volume, MPV）可反映血小板活化水平，其升高提示动脉粥样硬化性心血管疾病（atherosclerotic cardiovascular disease, ASCVD）风险增加。鱼类中含有的n-3多不饱和脂肪酸（n-3 polyunsaturated fatty acids, n-3 PUFAs）可降低血小板计数（platelet count, PLC）并抑制血小板活化，或可降低ASCVD发病风险。本研究旨在探讨鱼类摄入量与血小板计数、平均血小板体积以及n-3多不饱和脂肪酸摄入量之间的关联。
方法：本研究为横断面研究，共纳入9870名参与者（平均年龄：47.5±12.9岁；男性占比55.9%）。基于日本营养健康调查的相关数据及鱼类摄入频率（周摄入天数）计算n-3多不饱和脂肪酸摄入量。
结果：参与者平均鱼类摄入频率为2.14±1.26天/周。随着鱼类摄入频率升高，血小板计数显著降低（p<0.0001），平均血小板体积显著升高（p<0.034）。多元回归分析显示，血小板计数是平均血小板体积的独立影响因素（β=-0.081，p<0.0001）。此外，随着鱼类摄入频率增加，n-3多不饱和脂肪酸摄入量亦显著升高（p<0.0001）。
结论：鱼类摄入量越高，血小板计数越低，平均血小板体积越大。n-3多不饱和脂肪酸的抗血小板活化作用随鱼类摄入量增加而增强，或可通过升高平均血小板体积抑制血小板活化。未来仍需开展进一步研究以明确上述因素间的因果关联。