The association between the dietary inflammatory index and gestational diabetes mellitus: A systematic review of observational studies

Background & aims: Unhealthy dietary habits contribute to low-grade chronic inflammation that is known to be associated with metabolic disorders and pregnancy complications such as gestational diabetes mellitus (GDM). The dietary inflammatory index (DII) is a scoring system for assessing the inflammatory potential of various nutrients and foods. This systematic review aims to investigate the current state of evidence on the association between DII and GDM in pregnant women.Methods: PubMed, Scopus and Web of Science electronic databases were systematically searched for relevant English-language articles published up to February 2023. This study was developed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (CRD42022382813).Results: This review included seven studies (98,115 participants) from five countries. In total, two case -control studies have shown a positive association between DII and GDM. In contrast, three of five cohort studies found no association between dietary inflammatory potential and the risk of developing GDM.Conclusion: We found some controversial results due to the small number of studies, with major heterogeneity in research design and findings. Collectively, the current study does not support an association between the DII score and the risk of gestational diabetes. Further, longitudinal studies are needed to elucidate the association between dietary inflammatory potential and GDM. & COPY; 2023 Published by Elsevier Ltd on behalf of European Society for Clinical Nutrition and Metabolism.