Dietary Cholesterol Intake and Risk of Gestational Diabetes Mellitus: A Meta-Analysis of Observational Studies

This meta-analysis aimed to understand the association between dietary cholesterol intake and the risk of gestational diabetes mellitus (GDM). We systematically searched the PubMed, Web of Science, and EMBASE databases to identify observational studies, published before September 2020, investigating the relationship between dietary cholesterol intake and risk of GDM. After evaluating the heterogeneity among studies, we used fixed- or random-effects models to calculate pooled values of relative risk (RR) and 95% confidence intervals (CIs) in order to estimate the effect of dietary cholesterol on the risk of GDM. We included a total of 9 studies (3 cohort, 4 cross-sectional, and 2 case-control) involving 30123 participants and 3237 cases. The pooled RR of GDM comparing highest versus lowest category of dietary cholesterol intake was 1.49 (95% CI, 1.18-1.88). The dose-response relationship showed that the risk of GDM increased by 32% (RR = 1.32; 95% CI, 1.20-1.45) for every increase of 100 mg per day in dietary cholesterol intake. This meta-analysis indicates that an increase in dietary cholesterol intake is associated with increased risk of GDM. Detailed cohort studies are essential to gain a better understanding of this association. Key teaching points Studies on animal models have suggested that a cholesterol-rich diet can promote systemic inflammation and insulin resistance, both of which can contribute to T2DM and GDM. Several epidemiological studies have investigated a potential relationship between dietary cholesterol intake and GDM risk, and the results are controversial. Our meta-analysis indicates that increased dietary cholesterol intake is associated with increased GDM risk. Dose-response analysis showed a linear relationship between dietary cholesterol intake and risk of GDM.