A Systematic Review of the Bidirectional Relationship Between Post-traumatic Stress Disorder (PTSD) and the Development of Type 2 Diabetes.

Emerging evidence suggests a bidirectional relationship between post-traumatic stress disorder (PTSD) and type 2 diabetes (T2D), though the underlying mechanisms and population-specific risks remain unclear. This systematic review synthesizes current research on the PTSD-T2D link, focusing on biological pathways, behavioral mediators, and demographic disparities. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive search across PubMed/Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (Embase), PsycINFO, and Web of Science. Eligible studies examined PTSD as a risk factor for T2D or vice versa in adults (≥18 years). Two reviewers independently screened articles, extracted data, and assessed bias using the Newcastle-Ottawa Scale (NOS) and Cochrane tools. Thirteen studies met the inclusion criteria. PTSD increased T2D risk and was associated with worse glycemic control (e.g., elevated glycated hemoglobin A1c (HbA1c)). T2D populations exhibited higher PTSD prevalence (30%-50% in high-trauma groups), particularly among women, refugees, and veterans. Biological mechanisms (hypothalamic-pituitary-adrenal (HPA) axis dysregulation, chronic inflammation) and behavioral factors (sedentary lifestyle, poor adherence) drove the bidirectional relationship. Conflict-affected populations showed heightened vulnerability, with war-displaced individuals facing compounded metabolic and mental health burdens. PTSD and T2D share a complex, bidirectional relationship influenced by neuroendocrine, inflammatory, and behavioral pathways. High-risk groups (e.g., refugees, veterans, and women) may benefit from integrated screening and trauma-informed diabetes care. Future research should prioritize longitudinal designs to clarify causality and evaluate targeted interventions.