The dietary supplements effect on metabolic markers in non-pharmacologically managed gestational diabetes mellitus patients: a systematic review and meta-analysis and meta-regression of randomized controlled trials.

Background: Although several randomized clinical trials have tested the effect of prenatal dietary supplements on plasma glucose and lipid levels in non-pharmacologically managed gestational diabetes mellitus patients (GDM), a rigorous meta-analytic compendium lacks in the context. Therefore, this study aims to address this evidence gap.

Method: Eligible trials retrieved from searches in the PubMed, Embase, and Scopus databases were appraised using the Revised Cochrane risk-of-bias tool for randomized trials (RoB 2). The weighted mean differences (WMD) between dietary supplements and placebo were estimated using random-effect meta-analysis models for plasma glycemic and lipid markers. Meta-regression analysis ensued for effect modifier identification. The statistical significance estimation happened at  < 0.05 (95% confidence interval).

Results: This review included 19 trials (mostly Iranian and of low risk of bias primarily) of > 8000 GDM patients. Meta-analysis showed favorable effects of dietary supplementation on fasting plasma glucose (WMD: -5.42 mg/dL, p < 0.001), homeostasis model assessment indexes- insulin resistance (HOMA-IR; WMD: -1.02, p < 0.001), quantitative insulin sensitivity check index (WMD: 0.01, p < 0.001), total cholesterol (TC; WMD: -7.70 mg/dL,  = 0.006), triglycerides (WMD: -10.23 mg/dL,  = 0.0083), TC/high-density lipoprotein (WMD: -0.31 mg/dL,  < 0.001), low-density lipoprotein (WMD: -5.79 mg/dL;  < 0.001) and very-low-density lipoprotein (WMD: -5.67 mg/dL,  < 0.001) levels. However, the HOMA- ß-cell function didn't increase (WMD: -17.91,  < 0.001). Baseline maternal age ( = 0.28,  = 0.014) and GDM diagnostic criteria ( = 0.90,  = 0.012) were effect moderators of HOMA-IR and body mass index (BMI) ( = 6.07,  = 0.022) and supplement type (solo versus combined) ( = 14.99,  = 0.006) were effect moderators of triglyceride levels.

Conclusion: Altogether, antenatal dietary supplements achieved control over plasma glycemic and lipid profiles in non-pharmacologically treated GDM patients. Maternal age and GDM diagnostic criteria moderated HOMA-IR levels. BMI and supplement-type moderated triglyceride levels.

Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-023-01369-0.