Population Health & Biostatistics, University of Texas Rio Grande Valley - School of Medicine, 2102 Treasure Hills Boulevard, Harlingen, TX 78550, United States.
Department of Public Health Sciences, Penn State College of Medicine, Pennsylvania State University, 500 University Drive, MC CH69, Hershey, PA 17033, United States.
Int J Psychophysiol. 2023 Apr;186:24-32. doi: 10.1016/j.ijpsycho.2023.02.001. Epub 2023 Feb 9.
Cortisol in saliva, urine and plasma follows a diurnal rhythm typically characterized as a morning peak and a decline throughout the waking day. While often measured under controlled conditions, inter-individual differences in cortisol diurnal rhythms in free living populations are not well characterized. Cortisol levels may vary substantially between individuals and the level of variation may differ depending on the time of day. Further, associations with individual characteristics such as nicotine dependence on cortisol rhythms have not been adequately determined. We developed a Liquid Chromatography-Tandem Mass Spectrometry method to measure cortisol in saliva of 180 smokers from the Pennsylvania Adult Smoking Study. Diurnal patters of cortisol were determined by obtaining five timed samples throughout the day for a total of 900 determinations. Adherence to the protocol was estimated by asking participants to record the time of sample collection. Longitudinal linear mixed effects models were developed to measure the predictors of mean levels. Phenotypic groups were constructed based on the minimum and maximum cortisol levels. Mixed method modelling was conducted to determine the effects of phenotype and study adherence as well as reported measures of stress, nicotine dependence and cigarette smoking frequency. Nicotine metabolites were measured to accurately quantify dose of smoking intake. Results showed that there was moderate compliance to the timed protocol. Descriptive and analytic findings showed that some smokers had atypical cortisol patterns, and that the cortisol profiles based on experience of maximum and minimum cortisol levels can predict how cortisol varies throughout the day. There was no association with reported stress, cigarettes per day, and nicotine metabolites. There was no association with the Fagerstrom Test for Nicotine Dependence. The Hooked on Nicotine Checklist (HONC) score was associated with decreased cortisol levels. Overall these results show new approaches and expectations to population-based studies of cortisol.
唾液、尿液和血浆中的皮质醇呈现典型的昼夜节律，通常表现为早晨高峰，然后在清醒期间逐渐下降。尽管经常在受控条件下进行测量，但在自由生活人群中，皮质醇昼夜节律的个体间差异尚未得到很好的描述。皮质醇水平在个体之间可能有很大差异，而且这种差异的程度可能取决于一天中的时间。此外，个体特征与皮质醇节律之间的关联，如尼古丁对皮质醇节律的依赖，尚未得到充分确定。我们开发了一种液相色谱-串联质谱法，用于测量宾夕法尼亚州成人吸烟研究中 180 名吸烟者的唾液皮质醇。通过在一天中获得五个时间点的样本，总共进行了 900 次测定，确定了皮质醇的昼夜模式。通过要求参与者记录样本采集时间来估计对方案的遵守情况。开发了纵向线性混合效应模型来测量平均水平的预测因子。根据皮质醇的最低和最高水平构建了表型组。采用混合方法模型来确定表型和研究依从性以及报告的应激、尼古丁依赖和吸烟频率测量值的影响。测量尼古丁代谢物以准确量化吸烟摄入量。结果表明，对定时方案的遵守程度中等。描述性和分析结果表明，一些吸烟者的皮质醇模式不典型，基于最大和最小皮质醇水平的皮质醇特征可以预测皮质醇在一天中的变化方式。与报告的应激、每天吸烟量和尼古丁代谢物没有关联。与尼古丁依赖 Fagerstrom 测试（FTND）没有关联。尼古丁依赖检查表（HONC）评分与皮质醇水平降低有关。总的来说，这些结果为皮质醇的基于人群的研究展示了新的方法和预期。
