Department of Psychology, Centre for Social Issues Research, Study of Anxiety, Stress and Health Laboratory, University of Limerick, Limerick, Ireland; Health Research Institute, University of Limerick, Ireland.
Department of Psychology, Centre for Social Issues Research, Study of Anxiety, Stress and Health Laboratory, University of Limerick, Limerick, Ireland; Health Research Institute, University of Limerick, Ireland.
Physiol Behav. 2024 Mar 1;275:114452. doi: 10.1016/j.physbeh.2023.114452. Epub 2023 Dec 28.
Loneliness and objective measures of social isolation (e.g., social network size) have been associated with increased risk of cardiovascular disease (CVD). However, the evidence is mixed and the precise causal mechanisms remain unclear. Cardiovascular reactivity (CVR) to acute stress has been posited as a proposed mechanism. This study aimed to investigate: (i) effects of loneliness and social isolation on CVR to stress and, (ii) whether the loneliness - CVR relationship was moderated by social network size. Two hundred and six participants from the Pittsburgh Cold Study underwent a modified version of the Trier Social Stress Task. Cardiovascular measures of systolic (SBP) and diastolic blood pressure (DBP) and heart rate (HR) were taken throughout the laboratory stress trial. Hierarchical regression analyses found that social network size was positively associated with DBP reactivity (β = 0.19 95 % CI [0.05, 0.29] p = 0.005), while loneliness was not. In addition, social network size moderated the loneliness - DBP reactivity relationship such that a higher number of outer social network ties were beneficial at lower levels of loneliness but not higher. The current study contributes new evidence linking loneliness and social network size to cardiovascular psychophysiology but raises questions about the loneliness - CVD relationship. The findings confirm the importance of social network size and highlight that the characteristics of the networks may be more important than the number of networks.
孤独感和客观的社会隔离指标（如社交网络规模）与心血管疾病（CVD）风险增加有关。然而，证据并不一致，确切的因果机制仍不清楚。急性应激下的心血管反应（CVR）被认为是一种可能的机制。本研究旨在调查：（i）孤独感和社会隔离对压力下 CVR 的影响，以及（ii）孤独感 - CVR 关系是否受社交网络规模的调节。匹兹堡冷应激研究中的 206 名参与者接受了特里尔社会应激测试的改良版。在整个实验室应激试验中，测量了收缩压（SBP）、舒张压（DBP）和心率（HR）的心血管指标。分层回归分析发现，社交网络规模与 DBP 反应呈正相关（β=0.19 95%CI[0.05, 0.29]，p=0.005），而孤独感则没有。此外，社交网络规模调节了孤独感与 DBP 反应的关系，即较高的外部社交网络联系在较低的孤独感水平下有益，但在较高的孤独感水平下则不然。本研究为孤独感和社会网络规模与心血管生理之间的关系提供了新的证据，但也对孤独感与 CVD 之间的关系提出了疑问。研究结果证实了社交网络规模的重要性，并强调了网络的特征可能比网络的数量更为重要。
