Abstract

Objectives: To critically review evidence for associations between long-term cortisol levels, mood, and lifestyle factors.Systematic searches of electronic databases (MEDLINE, EMBASE, PsycINFO, WoS, and CINAHL) were conducted up to 21/11/2020 to identify observational and interventional studies (n = 4971) reporting associations between one or more lifestyle or mood factor with cortisol outcomes measured over ≥4 weeks in healthy adults. Quality of included studies was assessed using Downs and Black checklist. The quality of evidence supporting the associations of lifestyle and mood with long-term cortisol levels was assessed as being of moderate-to-poor quality. Observational studies (n = 25) indicated positive associations for BMI/body weight (ESr, pooled effect size correlation = 0.15, p<.001), physical activity (ESr=0.16, p<.001), perceived stress (ESr=0.114, p = .02), and depression (ESr = 0.133, p = .02), but not stressors (ESr = 0.06, p = .29), anxiety (ESr = 0.08, p = .14), or specific features of stress (ESr = 0.25, p = .10). There was insufficient evidence to reliably estimate associations between long-term cortisol levels and sleep, smoking, alcohol consumption, caffeine consumption, and PTSD. Findings from interventional studies (n = 27) were mixed and did not always support the relationships found in observational studies. The findings of this review were limited by the quality of the evidence. Current evidence for associations between mood and lifestyle factors with long-term levels of cortisol is mixed. For many factors, there was considerable uncertainty regarding the size of association with long-term cortisol due to a paucity of evidence. Future research should aim to (1) follow more consistent sampling protocols between studies and (2) clearly describe the hypothesised mechanisms through which interventions would affect cortisol levels.

摘要

目的：严格审查长期皮质醇水平、情绪和生活方式因素之间关联的证据。截至 2020 年 11 月 21 日对电子数据库（MEDLINE、EMBASE、PsycINFO、WoS 和 CINAHL）进行了系统搜索，以确定观察性干预研究 (n = 4971) 报告了一种或多种生活方式或情绪因素与在 ≥ 4 周内测量的健康成人皮质醇结果之间的关联。使用 Downs 和 Black 清单评估纳入研究的质量。支持生活方式和情绪与长期皮质醇水平相关的证据质量被评估为中等至差质量。观察性研究（n = 25）表明 BMI/体重呈正相关（ESr，合并效应大小相关 = 0.15，  p<.001)、身体活动 (ESr=0.16,  p <.001)、感知压力 (ESr=0.114,  p = .02) 和抑郁 (ESr = 0.133,  p = .02)，但不是压力源 (ESr = 0.06,  p = .29)、焦虑 (ESr = 0.08,  p = .14) 或压力的特定特征 (ESr = 0.25,  p= .10)。没有足够的证据来可靠地估计长期皮质醇水平与睡眠、吸烟、饮酒、咖啡因摄入和 PTSD 之间的关联。干预性研究（n = 27）的结果好坏参半，并不总是支持观察性研究中发现的关系。本综述的结果受到证据质量的限制。目前关于情绪和生活方式因素与长期皮质醇水平之间关联的证据好坏参半。对于许多因素，由于缺乏证据，与长期皮质醇相关的大小存在相当大的不确定性。未来的研究应旨在 (1) 在研究之间遵循更一致的抽样协议，以及 (2) 清楚地描述干预措施影响皮质醇水平的假设机制。