Faculty of Sport and Health Science, Ritsumeikan University, Shiga, Japan.
Japan Society for the Promotion of Science, Tokyo, Japan.
Am J Physiol Heart Circ Physiol. 2023 Dec 1;325(6):H1318-H1324. doi: 10.1152/ajpheart.00573.2023. Epub 2023 Oct 6.
High cardiorespiratory fitness levels achieved through regular aerobic exercise are associated with reduced cardiometabolic risk. The exercise-induced myokine irisin possibly mediates these associations, but these relationships are unclear. This study aimed to clarify the relationships between circulating irisin levels, cardiorespiratory fitness levels, and cardiometabolic risk factors adjusted for sex and age. This cross-sectional study included 328 Japanese participants aged between 18 and 88 yr. We measured serum irisin levels and peak oxygen uptake (V̇o) as cardiorespiratory fitness indicators, and body fat percentage, blood pressure, fasting blood glucose, hemoglobin A1c (HbA1c), high-density lipoprotein (HDL) cholesterol, and triglycerides as cardiometabolic risk factors. Cardiometabolic risk scores were calculated from the -scores of the cardiometabolic risk factors. Quintiles based on V̇o or irisin values, categorized by sex, showed a gradual increase in HDL cholesterol and a gradual decrease in other cardiometabolic risk factors with an increase in cardiorespiratory fitness levels or irisin. Serum irisin levels were negatively correlated with body fat percentage, blood pressure, fasting blood glucose, HbA1c, triglyceride levels, and cardiometabolic risk score and positively correlated with HDL cholesterol levels and V̇o in both sexes and young, and middle-aged and older adults. The same relationship was observed in all participants after adjusting for sex and age. These results suggest that circulating irisin levels may be involved in the association between cardiorespiratory fitness and cardiometabolic risk factors, regardless of sex and age. Circulating irisin levels gradually increased, and cardiometabolic risks gradually decreased with increasing cardiorespiratory fitness levels. The fitness levels required to increase irisin levels were moderate for young adults and lower than moderate for middle-aged and older adults. Moreover, circulating irisin levels are correlated with a reduction in cardiometabolic risk and an increase in cardiorespiratory fitness. These data suggest that circulating irisin levels are involved in the association between cardiorespiratory fitness and cardiometabolic risk.
高水平的心肺适能通过定期的有氧运动来实现，与降低心血管代谢风险有关。运动引起的肌因子鸢尾素可能介导了这些关联，但这些关系尚不清楚。本研究旨在阐明循环鸢尾素水平与心肺适能水平以及经过性别和年龄调整的心血管代谢危险因素之间的关系。这项横断面研究纳入了 328 名年龄在 18 至 88 岁之间的日本参与者。我们测量了血清鸢尾素水平和作为心肺适能指标的峰值摄氧量（V̇o），以及体脂百分比、血压、空腹血糖、糖化血红蛋白（HbA1c）、高密度脂蛋白（HDL）胆固醇和甘油三酯作为心血管代谢危险因素。心血管代谢风险评分是根据心血管代谢危险因素的分数计算得出的。根据性别对 V̇o 或鸢尾素值进行五分位分组显示，随着心肺适能水平或鸢尾素的升高，高密度脂蛋白胆固醇逐渐升高，其他心血管代谢危险因素逐渐降低。血清鸢尾素水平与体脂百分比、血压、空腹血糖、HbA1c、甘油三酯水平和心血管代谢风险评分呈负相关，与 HDL 胆固醇水平和男女及年轻、中年和老年成年人的 V̇o 呈正相关。在调整性别和年龄后，所有参与者均观察到相同的关系。这些结果表明，循环鸢尾素水平可能与心肺适能和心血管代谢危险因素之间的关联有关，而与性别和年龄无关。随着心肺适能水平的增加，循环鸢尾素水平逐渐升高，心血管代谢风险逐渐降低。提高鸢尾素水平所需的适应水平对于年轻成年人来说是适度的，而对于中年和老年成年人来说则低于适度。此外，循环鸢尾素水平与心血管代谢风险的降低和心肺适能的增加相关。这些数据表明，循环鸢尾素水平与心肺适能和心血管代谢风险之间的关联有关。
