Endrighi Romano, Hamer Mark, Steptoe Andrew
Department of Medical and Clinical Psychology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
Division of Behavioral Science Research, Department of Health Policy and Health Services Research, Boston University, Henry M. Goldman School of Dental Medicine, 560 Harrison Ave, 3rd floor, Boston, MA, 02118, USA.
Ann Behav Med. 2016 Aug;50(4):564-71. doi: 10.1007/s12160-016-9783-y.
Acute stress triggers innate immune responses and elevation in circulating cytokines including interleukin-6 (IL-6). The effect of sex on IL-6 responses remains unclear due to important limitations of previous studies.
The purpose of this study was to examine sex differences in IL-6 responses to mental stress in a healthy, older (post-menopausal) sample accounting for several moderating factors.
Five hundred six participants (62.9 ± 5.60 years, 55 % male) underwent 10 min of mental stress consisting of mirror tracing and Stroop task. Blood was sampled at baseline, after stress, and 45 and 75 min post-stress, and assayed using a high sensitivity kit. IL-6 reactivity was computed as the mean difference between baseline and 45 min and between baseline and 75 min post-stress. Main effects and interactions were examined using ANCOVA models.
There was a main effect of time for the IL-6 response (F 3,1512 = 201.57, p = <.0001) and a sex by time interaction (F 3,1512 = 17.07, p = <.001). In multivariate adjusted analyses, IL-6 reactivity was significantly greater in females at 45 min (M = 0.37 ± 0.04 vs. 0.20 ± 0.03 pg/mL, p = .01) and at 75 min (M = 0.57 ± 0.05 vs. 0.31 ± 0.05 pg/mL, p = .004) post-stress compared to males. Results were independent of age, adiposity, socioeconomic position, depression, smoking and alcohol consumption, physical activity, statin use, testing time, task appraisals, hormone replacement, and baseline IL-6. Other significant predictors of IL-6 reactivity were lower household wealth, afternoon testing, and baseline IL-6.
Healthy, post-menopausal females exhibit substantially greater IL-6 responses to acute stress. Inflammatory responses if sustained over time may have clinical implications for the development and maintenance of inflammatory-related conditions prevalent in older women.
急性应激会引发先天性免疫反应，并导致包括白细胞介素-6（IL-6）在内的循环细胞因子水平升高。由于既往研究存在重要局限性，性别对IL-6反应的影响仍不明确。
本研究旨在考察在一个健康的老年（绝经后）样本中，考虑多个调节因素后，IL-6对心理应激反应的性别差异。
506名参与者（年龄62.9±5.60岁，55%为男性）接受了由镜像追踪和Stroop任务组成的10分钟心理应激测试。在基线、应激后、应激后45分钟和75分钟采集血样，并用高灵敏度试剂盒进行检测。IL-6反应性计算为基线与应激后45分钟以及基线与应激后75分钟之间的平均差异。使用协方差分析模型检验主效应和交互作用。
IL-6反应存在时间主效应（F 3,1512 = 201.57，p = <.0001）以及性别与时间的交互作用（F 3,1512 = 17.07，p = <.001）。在多变量调整分析中，与男性相比，女性在应激后45分钟（M = 0.37±0.04 vs. 0.20±0.03 pg/mL，p =.01）和75分钟（M = 0.57±0.05 vs. 0.31±0.05 pg/mL，p =.004）时的IL-6反应性显著更高。结果不受年龄、肥胖、社会经济地位、抑郁、吸烟和饮酒、身体活动、他汀类药物使用、测试时间、任务评估、激素替代和基线IL-6的影响。IL-6反应性的其他显著预测因素是家庭财富较低、下午测试和基线IL-6。
健康的绝经后女性对急性应激表现出显著更强的IL-6反应。如果炎症反应持续存在，可能对老年女性中普遍存在的炎症相关疾病的发生和维持具有临床意义。
