Gestational diabetes mellitus and inflammatory biomarkers of neutrophil-lymphocyte ratio and platelet-lymphocyte ratio: a systematic review and meta-analysis

Purpose To evaluate the association between two inflammatory biomarkers of neutrophil -lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) with gestational diabetes mellitus (GDM). Methods and materials Systematic search was performed up to June 2020 in databases such as PubMed, Embase, Scopus, Web of Science, and Google scholar. The random-effects model was utilised to combine the weighted mean differences (WMDs) and their 95% confidence intervals (CIs). Results Out of a total of 849 articles, sixteen studies were eligible. Our findings indicated higher NLR (WMD = 0.48, 95% CI: 0.25, 0.71) and PLR (WMD = 8.22, 95% CI: -0.50, 16.94) values in pregnancies diagnosed with GDM compared with non-GDM control pregnancies. However, the difference in PLR value did not reach a statistically significant level (Z = 1.85, p = 0.065). In meta-regression analysis, we found no significant influence of total sample size [for NLR (B= -0.0, p = 0.13), for PLR (B= -0.02, p = 0.55)] and publication year [for NLR (B= -0.02, p = 0.61), for PLR (B = 0.89, p = 0.75)] on association between NLR and PLR with GDM. Conclusion The current meta-analysis is the first, to our knowledge, to show that NLR value is significantly associated with GDM. However, PLR showed no significant association with GDM.