Kaiser Permanente Division of Research, 2101 Webster St, Oakland, CA 94612, USA.
Psychosom Med. 2011 Sep;73(7):533-40. doi: 10.1097/PSY.0b013e318229acfc. Epub 2011 Aug 26.
To examine associations between autonomic nervous system and adrenocortical reactivity to laboratory stressors and buccal cell telomere length (BTL) in children.
The study sample comprised 78 children, aged 5 to 6 years, from a longitudinal cohort study of kindergarten social hierarchies, biologic responses to adversity, and child health. Buccal cell samples and reactivity measures were collected in the spring of the kindergarten year. BTL was measured by real-time polymerase chain reaction, as the telomere-to-single-copy gene ratio. Parents provided demographic information; parents and teachers reported children's internalizing and externalizing behavior problems. Components of children's autonomic (heart rate, respiratory sinus arrhythmia [RSA], and preejection period [PEP]) and adrenocortical (salivary cortisol) responses were monitored during standardized laboratory challenges. We examined relationships between reactivity, internalizing and externalizing behaviors, and BTL, adjusted for age, race, and sex.
Heart rate and cortisol reactivity were inversely related to BTL, PEP was positively related to BTL, and RSA was unrelated to BTL. Internalizing behaviors were also inversely related to BTL (standardized β = -0.33, p = .004). Split at the median of reactivity parameters, children with high sympathetic activation (decreasing PEP), and parasympathetic withdrawal (decreasing RSA) did not differ with regard to BTL. However, children with both this profile and high cortisol reactivity (n = 12) had significantly shorter BTL (0.80 versus 1.00; χ² = 7.6, p = .006), compared with other children.
The combination of autonomic and adrenocortical reactivity was associated with shorter BTL in children. These data suggest that psychophysiological processes may influence, and that BTL may be a useful marker of, early biologic aging.
探讨儿童自主神经系统和肾上腺皮质对实验室应激源的反应与口腔细胞端粒长度（BTL）之间的关系。
本研究样本包括来自幼儿园社会等级纵向队列研究的 78 名 5 至 6 岁儿童，该研究还涉及生物对逆境的反应和儿童健康。口腔细胞样本和反应性测量在幼儿园年的春季进行采集。BTL 通过实时聚合酶链反应测量，作为端粒到单拷贝基因的比值。家长提供人口统计学信息；家长和教师报告儿童的内化和外化行为问题。在标准化实验室挑战期间监测儿童自主神经（心率、呼吸窦性心律失常[RSA]和射血前期[PEP]）和肾上腺皮质（唾液皮质醇）反应的成分。我们调整了年龄、种族和性别后，检验了反应性、内化和外化行为与 BTL 之间的关系。
心率和皮质醇反应性与 BTL 呈负相关，PEP 与 BTL 呈正相关，而 RSA 与 BTL 无关。内化行为也与 BTL 呈负相关（标准化β=-0.33，p=0.004）。根据反应参数的中位数进行分割，具有高交感神经激活（PEP 降低）和副交感神经撤退（RSA 降低）的儿童，其 BTL 无差异。然而，具有这种特征且皮质醇反应性高的儿童（n=12）的 BTL 明显更短（0.80 与 1.00；χ²=7.6，p=0.006），与其他儿童相比。
自主神经和肾上腺皮质反应的组合与儿童的 BTL 较短有关。这些数据表明，心理生理过程可能会影响，并且 BTL 可能是早期生物衰老的有用标志物。
