Anderson Garcez1, Heloísa Marquardt Leite1, Elisabete Weiderpass2, Vera Maria Vieira Paniz1, Guilherme Watte3, Raquel Canuto4, Maria Teresa Anselmo Olinto5. 1. Post-graduate Program in Collective Health, University of Vale do Rio dos Sinos (UNISINOS), São Leopoldo, RS, Brazil. 2. 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. 3. Department of Respiratory Medicine and Thoracic Surgery, Pavilhão Pereira Filho, Irmandade da Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS, Brazil. 4. Department of Nutrition, Federal University of Rio Grande do Sul State (UFRGS), Porto Alegre, RS, Brazil. 5. Post-graduate Program in Collective Health, University of Vale do Rio dos Sinos (UNISINOS), São Leopoldo, RS, Brazil; Department of Nutrition, Federal University of Health Science of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil. Electronic address: mtolinto@gmail.com.
Abstract
OBJECTIVE: 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. METHODS: 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 I2 statistic was used to assess heterogeneity. Egger's and Begg's tests were used to evaluate publication bias. RESULTS: 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 (I2 = 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. CONCLUSION: 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.
OBJECTIVE: 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. METHODS: 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 I2 statistic was used to assess heterogeneity. Egger's and Begg's tests were used to evaluate publication bias. RESULTS: 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 (I2 = 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. CONCLUSION: 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.
Authors: Anastasiia S Boiko; Irina A Mednova; Elena G Kornetova; Nikolay A Bokhan; Arkadiy V Semke; Anton J M Loonen; Svetlana A Ivanova Journal: Neuropsychiatr Dis Treat Date: 2020-04-22 Impact factor: 2.570