Prevalence of Overt Hypothyroidism and Subclinical Hypothyroidism in Metabolic Syndrome: A Systematic Review and Meta-Analysis Publisher Pubmed

Summary: Could thyroid screening matter in metabolic syndrome? A review finds thyroid problems may be common; whether treating them improves metabolic health remains unclear. #Thyroid #MetabolicHealth

Shekarian A ; Mazaheri Tehrani S ; Shekarian S ; Setudeh M ; Pourbazargan M ; Amani Beni R ; Heidarpour M
Source: BMC Endocrine Disorders Published:2026

Abstract

Background: Thyroid hormones regulate insulin sensitivity and lipid metabolism, both of which are central to metabolic syndrome (MetS). While previous systematic reviews have identified an association between MetS and hypothyroidism, the prevalence of overt hypothyroidism and subclinical hypothyroidism (SCH) in this population remains unclear, with reported rates varying widely. The present study aimed to estimate the prevalence of overt hypothyroidism and SCH in individuals with MetS. Methods: We searched PubMed, Embase, Scopus, and Web of Science from inception to February 10, 2025. Observational studies that reported the prevalence of overt hypothyroidism or SCH in more than 30 individuals with MetS were included. The risk of bias was assessed using the Joanna Briggs Institute (JBI) checklist for prevalence studies. Pooled prevalence estimates, corresponding 95% confidence intervals (CIs), and 95% prediction intervals (PIs) were calculated using the random-effects model. Results: Forty studies with a total of 25,008 MetS cases were included. The pooled prevalence estimates were 9.2% (95% CI: 6.2%; 12.7%) (95% PI: 0.0%; 32.7%) for overt hypothyroidism and 20.7% (95% CI: 15.6%; 26.3%) (95% PI: 0.1%; 60.1%) for SCH. Subgroup analysis and meta-regression indicated that high-risk-of-bias studies reported higher prevalence rates. Estimates from low-risk-of-bias studies, which are likely less affected by methodological biases, were 4.8% (95% CI: 1.9%; 8.9%) (95% PI: 0.0%; 24.8%) for overt hypothyroidism and 13.1% (95% CI: 9.1%; 17.8%) (95% PI: 0.5%; 38.2%) for SCH. Conclusion: Based on low-risk-of-bias studies, the prevalence of overt hypothyroidism in MetS does not appear substantially higher than estimates reported in the general population, whereas SCH is more common. The high prevalence of SCH in MetS and its potential adverse effects on MetS components highlight the potential clinical relevance of thyroid function testing in these individuals. Further cohort and trial studies are necessary to clarify the metabolic significance of SCH in patients with MetS and to determine whether its treatment provides clinical benefit. Systematic review registration number in PROSPERO: CRD42024541953. Trial registration: Not applicable. © The Author(s) 2026.