College of Nursing, University of South Florida, 12912 USF Health Drive, Tampa, FL, USA; College of Nursing, University of Rhode Island, 39 Butterfield Rd., Kingston, RI, USA.
College of Nursing, University of Rhode Island, 39 Butterfield Rd., Kingston, RI, USA; Center for Primary Care & Prevention, Care New England Medical Group, Primary Care &, Specialty Services, 111 Brewster St., Pawtucket, RI, USA.
Psychoneuroendocrinology. 2019 Apr;102:204-211. doi: 10.1016/j.psyneuen.2018.12.223. Epub 2018 Dec 18.
Infants who begin life in the medicalized environment of the neonatal intensive care unit (NICU) do so under stressful conditions. Environmental exposures are often abrasive to vulnerable infants, while invasive and noninvasive lifesaving interventions provide additional pain and/or stress. The most commonly selected biomarker to measure stress is cortisol. The skin is the barrier between the external environment and communicates with our neurological, endocrine and immune regulatory networks. To examine if skin cortisol may be a reliable biomarker of stress, NICU stress exposure and repeated measurements of skin cortisol in very preterm infants were examined retrospectively during the first 6 weeks of life. The temporal relationship between skin cortisol and NICU stress exposure was also analyzed.
Participants included 82 preterm infants born weighing less than 1500 g, admitted to a level III NICU, with a mean gestational age of 28.5 weeks. Infants were studied from birth through 6 weeks of life. NICU stress data was collected using the Neonatal Infant Stressor Scale. Skin samples were collected using d-squame tape as soon after birth as possible and every two weeks thereafter.
On average, infants experienced approximately 43 stressful events per day during the first 6 weeks of life in the NICU. Stress level and cortisol reactivity varied by gestation age. Higher stress resulted in higher cortisol for infant >28 weeks; lower stress scores were associated with higher stress for infants <28 weeks. Stress exposure during 7 days prior to cortisol sampling yielded the highest AUC for the 2 groups. A statistically significant interaction was identified between gestational age and stress exposure during the previous 7 days (p < 0.01).
This is the first study to demonstrate skin cortisol as a preterm infant biomarker of chronic stress exposure. For infants with appropriate skin maturation, this non-invasive sampling method provides several benefits. Importantly, this method may be less intrusive and disruptive for preterm infants.
婴儿在新生儿重症监护病房（NICU）的医学化环境中开始生命，处于应激状态。环境暴露对脆弱的婴儿往往具有刺激性，而侵入性和非侵入性的救生干预措施会带来额外的疼痛和/或压力。最常选择的测量压力的生物标志物是皮质醇。皮肤是外部环境与我们的神经、内分泌和免疫调节网络之间的屏障。为了研究皮肤皮质醇是否可以作为压力的可靠生物标志物，回顾性地检查了非常早产儿在生命的头 6 周内的 NICU 压力暴露和皮肤皮质醇的重复测量。还分析了皮肤皮质醇与 NICU 压力暴露之间的时间关系。
参与者包括 82 名出生体重不足 1500 克、入住三级 NICU 的早产儿，平均胎龄为 28.5 周。从出生到 6 周龄对婴儿进行研究。使用新生儿应激量表收集 NICU 应激数据。在出生后尽快并在随后的每两周使用 d-squame 胶带采集皮肤样本。
在 NICU 的前 6 周内，平均每个婴儿每天经历约 43 次应激事件。应激水平和皮质醇反应性随胎龄而变化。对于 28 周以上的婴儿，应激水平越高，皮质醇水平越高；对于 28 周以下的婴儿，较低的应激评分与较高的应激相关。皮质醇采样前 7 天的应激暴露产生了 2 组的最高 AUC。胎龄和前 7 天的应激暴露之间存在统计学上显著的相互作用（p <0.01）。
这是第一项证明皮肤皮质醇作为早产儿慢性应激暴露生物标志物的研究。对于具有适当皮肤成熟度的婴儿，这种非侵入性采样方法具有多项优势。重要的是，这种方法对早产儿的侵入性和干扰性可能较小。
