The effect of gestational diabetes mellitus on carotid artery intima-media thickness in and after pregnancy: a systematic review and meta-analysis

Aims: The association between gestational diabetes mellitus (GDM) and common carotid artery (CCA) intima-media thickness (IMT) is still controversial. This systematic review and meta-analysis was performed to assess the correlation between GDM and CCA-IMT in and after pregnancy. Methods: PubMed and EMBASE databases were systematically reviewed on April 2023. Studies measuring CCA-IMT in both pregnant women with GDM and women with previous history of GDM (pGDM) vs. healthy controls were included. The subtotal and overall standardized mean differences (SMDs) of CCA-IMT were calculated using the random-effect model. Results: Nineteen studies with a total of 302 GDM and 861 pGDM women were analyzed. The average value of CCA-IMT measured in GDM/pGDM (0.59 ± 0.12 mm) was slightly increased in comparison to the accepted reference limits of IMT according to age classes. Substantial heterogeneity was detected for the studies involving both GDM and pGDM women, with an overall statistic I2 of 86.0% (p < 0.001). Large SMDs were obtained for the studies conducted on both GDM and pGDM women, with an overall SMD of 0.89 (95%CI 0.63–1.15, p < 0.001). Egger's test for a regression intercept gave a p-value of 0.37, indicating no publication bias. On meta-regression analysis, all potential confounders (number of patients, age at pregnancy, body mass index, measuring time, follow-up duration and GDM criteria) were not significantly associated with effect modification. Conclusions: GDM in and after pregnancy is independently associated with subclinical atherosclerosis. The association between GDM and carotid remodeling is potentially mediated by the longstanding underlying risk.