Aims: Relationship between liver enzymes such as gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), aspartate transaminase (AST) and alkaline phosphatase and risk of gestational diabetes mellitus (GDM) is a controversial issue. The aim of this systematic review and dose-response meta-analysis was to investigate the association between liver enzymes and risk of GDM in observational studies.
Methods: A comprehensive systematic literature search was conducted in MEDLINE/PubMed, SCOPUS and Web of Science databases up to September 2019. Combined odds ratios (ORs) with 95% confidence intervals (CIs) were evaluated by DerSimonian and Laird random-effects models. Dose-response analyses of these relationships were also carried out.
Results: Eight studies with 25,451 participants containing 2549 cases were included in this study. Pooled results showed a significant association between GGT levels and risk of GDM (OR 2.10, 95% CI 1.14-3.86, I2 84%). In addition, random-effects model indicated a dramatic and direct significant association between GGT and risk of GDM in nonlinear (p < 0.001) and linear (p < 0.001) dose-response analysis. Associations between ALT and AST with risk of GDM were found to be non-significant (OR 1.32, 95% CI 0.91-1.90, I2 65% and OR 0.76, 95% CI 0.52-1.10, I2 16%, respectively).
Conclusion: This systematic review and dose-response meta-analysis highlights GGT as a significant and robust predictor of the incidence of GDM in pregnant women.
Keywords: Gamma-glutamyl transferase; Gestational diabetes mellitus; Liver enzymes.