Kennedy J S, von Moltke L L, Harmatz J S, Engelhardt N, Greenblatt D J
Department of Psychiatry, Tufts University School of Medicine, Boston, MA.
J Clin Pharmacol. 1991 Jul;31(7):677-80. doi: 10.1002/j.1552-4604.1991.tb03756.x.
The relationship between self-reports of caffeine ingestion on two occasions and measured plasma concentrations of caffeine and its major metabolites was examined. A subject population [25 men and 25 women, age 20-45 years (mean: 28.7 yr)] that was enrolled in a benzodiazepine pharmacokinetic study underwent general medical screening on two occasions, each including detailed caffeine histories. Before beginning their scheduled study, plasma samples were obtained and evaluated by HPLC for caffeine, paraxanthine, theophylline, and theobromine. These values were compared with estimates of caffeine consumption in mg/day generated from both histories. There was no significant difference between plasma levels of caffeine, metabolites, or caffeine plus metabolites for categories corresponding to reports of low, intermediate or high caffeine use. A self-reported caffeine consumption of greater than 300 mg/day (high) did correlate, however, with a significant smoking history. The authors conclude that self-reports of caffeine ingestion do not accurately reflect acute exposure, and that if caffeine use is of importance in a given setting, reports should be confirmed by biochemical means.
研究了两次咖啡因摄入量的自我报告与测得的咖啡因及其主要代谢物血浆浓度之间的关系。纳入一项苯二氮䓬类药物动力学研究的受试者群体（25名男性和25名女性，年龄20 - 45岁，平均28.7岁）接受了两次常规医学筛查，每次筛查都包括详细的咖啡因摄入史。在开始其预定研究之前，采集血浆样本并用高效液相色谱法评估咖啡因、副黄嘌呤、茶碱和可可碱。将这些值与根据两次摄入史得出的每日咖啡因摄入量（毫克）估计值进行比较。对于对应低、中、高咖啡因摄入量报告的类别，咖啡因、代谢物或咖啡因加代谢物的血浆水平之间没有显著差异。然而，自我报告的每日咖啡因摄入量大于300毫克（高）确实与显著的吸烟史相关。作者得出结论，咖啡因摄入量的自我报告不能准确反映急性暴露情况，并且如果在特定情况下咖啡因的使用很重要，报告应该通过生化方法进行确认。
