Institute for Stress and Wellbeing Research, Ryerson University, Toronto, Ontario, Canada,
Institute for Stress and Wellbeing Research, Ryerson University, Toronto, Ontario, Canada.
Gerontology. 2020;66(2):131-137. doi: 10.1159/000502143. Epub 2019 Sep 5.
Stress exposure over the lifespan is robustly associated with accelerated cognitive decline in later life. Brain-derived neurotrophic factor (BDNF) is shown to regulate activity of the hypothalamic-pituitary-adrenal axis. The objective of this study was to evaluate the association betweenthe BDNF polymorphism and indices of stress among adults aged 50+. Community-dwelling middle-aged and older adults provided a blood sample for BDNF genotyping. Participants also sampled their saliva 5 times/day for 3 consecutive days for the measurement of diurnal cortisol and underwent the Trier Social Stress Test (TSST) for the measurement of stress reactivity. Among 121 adults aged 50-67 years (78% female; 89% Caucasian), 74 participants were Val/Val carriers and 47 carried 1 copy of the Met allele. Repeated-measures analyses did not reveal an association between BDNF genotype and diurnal salivary cortisol (p = 0.63); however, analyses revealed that Met+ carriers displayed lower levels of cortisol secretion in response to the TSST compared with Val/Val carriers; F(4.43, 496.238) = 2.57, p = 0.032. This is the first study to evaluate the role of the BDNF polymorphism in stress physiology among older adults. Future studies are needed to evaluate the lifespan interconnections between BDNF and stress physiology.
一生中经历的压力与晚年认知能力加速下降密切相关。脑源性神经营养因子（BDNF）被证明可以调节下丘脑-垂体-肾上腺轴的活性。本研究的目的是评估 BDNF 多态性与 50 岁以上成年人压力指数之间的关系。居住在社区的中年和老年人提供血液样本进行 BDNF 基因分型。参与者还连续 3 天每天 5 次采集唾液样本，以测量日间皮质醇水平，并进行 Trier 社会应激测试（TSST）以测量应激反应性。在 121 名年龄在 50-67 岁的成年人（78%为女性；89%为白种人）中，74 名参与者为 Val/Val 携带者，47 名参与者携带 1 份 Met 等位基因。重复测量分析并未显示 BDNF 基因型与日间唾液皮质醇之间存在关联（p=0.63）；然而，分析显示，与 Val/Val 携带者相比，Met+携带者对 TSST 的皮质醇分泌水平较低；F(4.43, 496.238)=2.57, p=0.032。这是第一项评估 BDNF 多态性在老年人大脑应激生理学中的作用的研究。需要进一步研究来评估 BDNF 和应激生理学之间在整个生命周期中的相互关系。
