Puri Basant K, Heard Christopher R, Monro Jean A
C.A.R, Cambridge, UK.
University of Winchester, Winchester, UK.
J Oral Biol Craniofac Res. 2023 Mar-Apr;13(2):364-366. doi: 10.1016/j.jobcr.2023.03.008. Epub 2023 Mar 15.
Measurement of salivary caffeine (1,3,7-trimethylpurine-2,6-dione or 1,3,7-trimethylxanthine) clearance can, in principle, be used to assess hepatic function, diagnose chronic hepatic disease and conduct investigations of substrates of hepatic cytochrome P450 (CYP) isozymes in children, without recourse to venepuncture. However, little is known about childhood sexual dimorphism of hepatic CYP isoforms. Furthermore, the association, if any, between salivary caffeine clearance and age in children has not hitherto been established. The aims of this study were to assess whether salivary caffeine clearance differs between boys and girls and whether it varies with age during childhood.
Following at least 24 h' abstinence from dietary caffeine, nine boys (mean (standard error) age 9.6 (1.1) y) and eight girls (mean age 11.0 (1.2) y), none of whom was a smoker or suffered from chronic hepatic disease, ingested an oral caffeine dose titrated by body mass, namely 3 mg kg. Salivary samples collected two and 14 h later underwent spectrophotometric caffeine analysis.
The boys and the girls were age matched. The mean caffeine clearance in the boys was 2.47 (0.33) mL min kg, while that in the girls was 2.20 (0.31) mL min kg ( = 0.56). The salivary caffeine clearance was negatively correlated with age ( = -0.59, = 0.01).
Stratification by sex appears to be unnecessary when considering childhood salivary caffeine clearance or when conducting investigations in children of CYP1A2 and xanthine oxidase substrates. Furthermore, childhood salivary caffeine clearance is negatively correlated with age.
唾液咖啡因（1,3,7 - 三甲基嘌呤 - 2,6 - 二酮或1,3,7 - 三甲基黄嘌呤）清除率的测定原则上可用于评估肝功能、诊断慢性肝病以及在不进行静脉穿刺的情况下研究儿童肝脏细胞色素P450（CYP）同工酶的底物。然而，关于肝脏CYP同工型的儿童性别差异知之甚少。此外，唾液咖啡因清除率与儿童年龄之间的关联（如果存在）迄今尚未确立。本研究的目的是评估唾液咖啡因清除率在男孩和女孩之间是否存在差异，以及在儿童期是否随年龄变化。
在至少24小时不摄入膳食咖啡因后，9名男孩（平均（标准误）年龄9.6（1.1）岁）和8名女孩（平均年龄11.0（1.2）岁），他们均不吸烟且无慢性肝病，摄入按体重滴定的口服咖啡因剂量，即3毫克/千克。在2小时和14小时后收集的唾液样本进行分光光度法咖啡因分析。
男孩和女孩年龄匹配。男孩的平均咖啡因清除率为2.47（0.33）毫升/分钟/千克，而女孩为2.20（0.31）毫升/分钟/千克（P = 0.56）。唾液咖啡因清除率与年龄呈负相关（r = -0.59，P = 0.01）。
在考虑儿童唾液咖啡因清除率或对CYP1A2和黄嘌呤氧化酶底物的儿童进行研究时，按性别分层似乎没有必要。此外，儿童唾液咖啡因清除率与年龄呈负相关。
