Post-graduate Program in Collective Health, University of Vale do Rio dos Sinos (UNISINOS), São Leopoldo, RS, Brazil.
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Cancer Registry of Norway, Institute of Population-based Cancer Research, Department of Research, Oslo, Norway; Faculty of Health Sciences, Department of Community Medicine, University of Tromsø, Tromsø, Norway; University of Tromsø, The Arctic University of Norway, Tromsø, Norway; Genetic Epidemiology Group, Folkhälsan Research Center, Helsinki, Finland.
Psychoneuroendocrinology. 2018 Sep;95:50-62. doi: 10.1016/j.psyneuen.2018.05.023. Epub 2018 May 17.
To perform a qualitative synthesis (systematic review) and quantitative analysis (meta-analysis) to summarize the evidence regarding the relationship between basal cortisol levels and metabolic syndrome (MetS) in adults.
A systematic search was performed in the PubMed, Embase, and PsycINFO databases for observational studies on the association between basal cortisol levels and MetS. The quality of individual studies was assessed by the Newcastle-Ottawa score. A random effects model was used to report pooled quantitative results and the I statistic was used to assess heterogeneity. Egger's and Begg's tests were used to evaluate publication bias.
Twenty-six studies (19 cross-sectional and seven case-control) met the inclusion criteria for the systematic review. The majority was classified as having a low risk of bias and used established criteria for the diagnosis of MetS. Twenty-one studies provided data on basal cortisol levels as continuous values and were included in the meta-analysis; they comprised 35 analyses and 11,808 subjects. Pooled results showed no significant difference in basal cortisol levels between subjects with and without MetS (standardized mean difference [SMD] = 0.02, 95% confidence interval [CI]=-0.11 to 0.14). There was high heterogeneity between the studies when all comparisons were considered (I = 83.1%;p < 0.001). Paradoxically, meta-analysis of studies evaluating saliva samples showed no significantly lower basal cortisol levels among subjects with MetS (SMD=-0.18, 95% CI=-0.37 to 0.01), whereas those studies that evaluated serum samples (SMD = 0.11, 95% CI=-0.02 to 0.24) and urine samples (SMD = 0.73, 95% CI=-0.40 to 1.86) showed no significantly higher basal cortisol levels among subjects with MetS. In the subgroup and meta-regression analyses, a significant difference in basal cortisol levels was observed according to study design, population base, age, gender, cortisol level assessment method, and study quality.
This systematic review and meta-analysis does not reveal any association between basal cortisol levels and MetS based on results of observational studies. The results of a random-effect meta-analysis showed no significant difference in basal cortisol levels between subjects with and without MetS. The present findings should be considered in order to help future studies.
对基础皮质醇水平与成年人代谢综合征（MetS）之间关系的证据进行定性综合（系统评价）和定量分析（荟萃分析）。
在 PubMed、Embase 和 PsycINFO 数据库中对基础皮质醇水平与 MetS 相关的观察性研究进行系统检索。使用纽卡斯尔-渥太华量表评估个体研究的质量。使用随机效应模型报告汇总的定量结果，并使用 I 统计量评估异质性。使用 Egger 和 Begg 检验评估发表偏倚。
26 项研究（19 项横断面研究和 7 项病例对照研究）符合系统评价的纳入标准。其中大多数研究被归类为具有低偏倚风险，并使用了已确立的 MetS 诊断标准。21 项研究提供了基础皮质醇水平的连续值数据，并纳入荟萃分析；共包含 35 项分析和 11808 例受试者。汇总结果显示，有和无 MetS 的受试者之间基础皮质醇水平无显著差异（标准化均数差 [SMD] = 0.02，95%置信区间 [CI] = -0.11 至 0.14）。当考虑所有比较时，研究之间存在高度异质性（I = 83.1%；p < 0.001）。矛盾的是，对评估唾液样本的研究进行荟萃分析显示，MetS 受试者的基础皮质醇水平无显著降低（SMD = -0.18，95%CI = -0.37 至 0.01），而评估血清样本（SMD = 0.11，95%CI = -0.02 至 0.24）和尿液样本（SMD = 0.73，95%CI = -0.40 至 1.86）的研究显示，MetS 受试者的基础皮质醇水平无显著升高。在亚组和荟萃回归分析中，根据研究设计、人群基础、年龄、性别、皮质醇水平评估方法和研究质量，观察到基础皮质醇水平存在显著差异。
本系统评价和荟萃分析未发现观察性研究结果中基础皮质醇水平与 MetS 之间存在任何关联。随机效应荟萃分析的结果显示，有和无 MetS 的受试者之间基础皮质醇水平无显著差异。目前的研究结果应在未来的研究中加以考虑。
