本文采用双盲——配对(自身对照)设计,观察了饮料水平咖啡因对健康、平日较少摄入咖啡因的学龄儿童血压、心率及左心室功能的影响。研究结果表明,一次摄入30mg咖啡因引起心率减慢,持续2小时左右,对血压和左心室功能无明显影响;连续3天摄入咖啡因后,未观察到完全的耐受。 In this study, a double-blind-pair (self-control) design was used to investigate the effect of caffeine at beverage level on blood pressure, heart rate and left ventricular function in school-age children who were less likely to have caffeine intake during weekdays. The results showed that 30mg caffeine intake caused a slow heart rate, sustained about 2 hours, no significant effect on blood pressure and left ventricular function; 3 consecutive days after ingestion of caffeine, no complete tolerance was observed.