Department of Clinical Psychology and Psychotherapy, University of Zurich, Zurich, Switzerland.
Psychoneuroendocrinology. 2013 Aug;38(8):1381-7. doi: 10.1016/j.psyneuen.2012.12.003. Epub 2013 Jan 9.
The incidence and prevalence of cardiovascular disease (CVD) increases with age. Some evidence suggests that mental stress may increase plasma homocysteine (Hcy), an amino acid relating to CVD. However, none of these studies assessed age effects on Hcy stress reactivity, nor did they control for age. The objective of this study was (a) to investigate whether Hcy reactivity to psychosocial stress differs between younger and middle-aged to older men and (b) to study whether psychosocial stress induces Hcy increases independent of age.
Twenty eight younger (20-30 years) and 22 middle-aged to older (47-65 years) apparently healthy men underwent an acute standardized psychosocial stress task combining public speaking and mental arithmetic in front of an audience. Blood samples for Hcy measurements were obtained immediately before and after, as well as 10 and 20min after stress. Moreover, salivary cortisol was repeatedly measured to test the effectiveness of the stress task in triggering a neuroendocrine stress response.
Hcy reactivity to stress differed between age groups (F(1.4, 60.7)=5.41, p=.014). While the older group displayed an increase in the Hcy response to stress (F(2.5, 39.8)=3.86, p=.022), Hcy levels in the younger group did not change (p=.27). Psychosocial stress per se did not change Hcy levels independent of age (p=.53).
Our findings suggest that psychosocial stress does not evoke an Hcy response per se, but only in interaction with age pointing to a mechanism by which mental stress may increase CVD risk in older individuals.
心血管疾病（CVD）的发病率和患病率随着年龄的增长而增加。有证据表明，心理压力可能会增加血浆同型半胱氨酸（Hcy），一种与 CVD 相关的氨基酸。然而，这些研究都没有评估 Hcy 对心理应激的反应性随年龄的变化，也没有对年龄进行控制。本研究的目的是：（a）探讨心理社会应激对年轻、中年和老年男性 Hcy 反应性是否不同；（b）研究心理社会应激是否会引起 Hcy 增加，而与年龄无关。
28 名年轻（20-30 岁）和 22 名中年至老年（47-65 岁）健康男性接受了急性标准化心理社会应激任务，在观众面前进行公开演讲和心算。在应激前后以及应激后 10 分钟和 20 分钟，采集血液样本测量 Hcy。此外，还反复测量唾液皮质醇，以检验应激任务是否能有效引发神经内分泌应激反应。
Hcy 对压力的反应在年龄组之间存在差异（F(1.4, 60.7)=5.41, p=.014）。虽然老年组在应激时 Hcy 反应增加（F(2.5, 39.8)=3.86, p=.022），但年轻组 Hcy 水平没有变化（p=.27）。心理社会应激本身并不改变 Hcy 水平，与年龄无关（p=.53）。
我们的研究结果表明，心理社会应激本身不会引起 Hcy 反应，而是与年龄相互作用，提示心理应激可能通过某种机制增加老年人 CVD 的风险。
