Serum retinol-binding protein 4 levels and risk of gestational diabetes mellitus: A nested case-control study in Chinese women and an updated meta-analysis

New exploration on pathogenesis and early diagnosis of gestational diabetes

Gestational diabetes mellitus (GDM) refers to varying degrees of abnormal glucose metabolism that occur during pregnancy and excludes patients previously diagnosed with diabetes. GDM is a unique among the four subtypes of diabetes classified by the international World Health Organization standards. Although GDM patients constitute a small proportion of the total number of diabetes cases, the incidence of GDM has risen significantly over the past decade, posing substantial risk to pregnant women and infants. Therefore, it warrants considerable attention. The pathogenesis of GDM is generally considered to resemble that of type II diabetes, though it may have distinct characteristics. Analyzing blood biochemical proteins in the context of GDM can help elucidate its pathogenesis, thereby facilitating more effective prevention and management strategies. This article reviews this critical clinical issue to enhance the medical community's sufficient understanding of GDM.

Impact of serum retinol-binding protein 4 levels in late pregnancy on the incidence of small/large for gestational age infants among 11,854 pregnant women: A retrospective study

BACKGROUND

There is still uncertainty regarding the association between maternal serum levels of retinol-binding protein 4 (RBP4) and pregnancy outcomes. This study aimed to determine the association between RBP4 levels and incidence of small/large for gestational age (SGA/LGA) infants among the Chinese population.

METHODS

This was a retrospective study of 11,854 pregnant women who delivered at Changzhou Maternal and Child Health Care Hospital between 2016 and 2017 and whose serum RBP4 levels were measured at the time of admission. The incidence of SGA/LGA deliveries was retrieved from the medical records of the participants.

RESULTS

Maternal RBP4 levels in the second, third and fourth quartiles (28.8-34.0, 34.1-40.0, and >40.0 mg/L, respectively) were associated with lower birthweights relative to those in the first quartile (<28.8 mg/L), with estimated average decreases of 51.30 g (95% CI: -70.51, -32.10), 86.86 g (95% CI: -106.50, -67.22) and 124.08 g (95% CI: -144.51, -103.64), respectively (P for trend <0.01). Pregnant women in the fourth quartile for RBP4 levels had a greater SGA risk (OR: 2.14, 95% CI: 1.72, 2.65) and lower LGA risk (OR: 0.53, 95% CI: 0.45, 0.63) than those in the first quartile after controlling for demographic variables, gestational age, pregnancy complications and other laboratory results. The sensitivity analysis indicated the consistency of these findings.

CONCLUSION

High RBP4 levels in late pregnancy are associated with an increased SGA risk and decreased LGA risk, indicating that serum RBP4 levels at the time of admission for delivery could be a promising predictor of SGA/LGA delivery.

Relationship between first trimester physical activity and premature rupture of membranes: a birth cohort study in Chinese women

OBJECTIVE

This study aimed to examine prospective associations of different intensity levels and types of physical activity (PA) in early pregnancy with premature rupture of membranes (PROM) among Chinese pregnant women.

METHODS

A total of 6284 pregnant women were included from the Tongji-Shuangliu Birth Cohort. Household/caregiving, occupational, sports/exercise and transportation activities during early pregnancy were investigated by the pregnancy physical activity questionnaire (PPAQ), and the diagnosis of PROM was ascertained during the whole pregnancy. Multivariate logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence interval (CI) for the associations between PA and PROM.

RESULTS

Among the 6284 pregnant women, 1246 were identified to have PROM (19.8%). Women undertaking the highest level (3 third tertile) of PA during pregnancy appeared to have a lower risk of PROM [OR = 0.68, 95%CI 0.58-0.80) when compared to those at the lowest tertile of PA. Similarly, women with increased levels of light intensity activity, moderate-vigorous intensive, household/caregiving activity and meeting exercise guidelines during pregnancy were associated with reduced risks of PROM (OR = 0.69, 95% CI 0.59-0.81, OR = 0.70, 95% CI 0.60-0.82, OR = 0.62, 95% CI 0.53-0.73 and OR = 0.82, 95% CI 0.70-0.97, respectively).

CONCLUSIONS

High levels of PA of different intensities and PA of household/caregiving activities and meeting exercise guidelines during the first trimester were associated with a lower incidence of PROM.

TRIAL REGISTRATION

The data of human participants in this study were conducted in accordance with the Helsinki Declaration. This study has been approved by the Ethics Committee of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China ([2017] No. S225). All participants provided written informed consent prior to enrollment. A statement to confirm that all methods were carried out in accordance with relevant guidelines and regulations.

Retinol-binding protein 4 (RBP4) circulating levels and gestational diabetes mellitus: a systematic review and meta-analysis

Background

Gestational diabetes mellitus (GDM) is a prevalent condition where diabetes is diagnosed during pregnancy, affecting both maternal and fetal outcomes. Retinol-binding protein 4 (RBP4) is a circulating adipokine which belongs to the lipocalin family and acts as a specific carrier protein that delivers retinol (vitamin A) from the liver to the peripheral tissues. Growing data indicate that circulating RBP4 levels may positively correlate with GDM. Thus, this systematic review and meta-analysis aimed to investigate the potential relationship between circulating RBP4 levels and GDM when measured at various stages of pregnancy.

Methods

MEDLINE, CINAHL, EMCARE, EMBASE, Scopus, and Web of Science databases were searched to identify studies comparing pregnant women with and without GDM, whose circulating RBP4 levels were measured in at least one pregnancy trimester. Findings were reported using standardized mean difference (SMD) and random-effects models were used to account for variability among studies. Furthermore, the risk of bias was assessed using the RoBANS tool.

Results

Out of the 34 studies identified, 32 were included in the meta-analysis (seven with circulating RBP4 levels measured in the first trimester, 19 at 24-28 weeks, and 14 at >28 weeks of pregnancy). RBP4 levels were statistically higher in the GDM group than in controls when measured during all these pregnancy stages, with the noted RBP4 SMD being 0.322 in the first trimester (95% CI: 0.126-0.517; p < 0.001; 946 GDM cases vs. 1701 non-GDM controls); 0.628 at 24-28 weeks of gestation (95% CI: 0.290-0.966; p < 0.001; 1776 GDM cases vs. 1942 controls); and 0.875 at >28 weeks of gestation (95% CI: 0.252-1.498; p = 0.006; 870 GDM cases vs. 1942 non-GDM controls). Significant study heterogeneity was noted for all three pregnancy timepoints.

Conclusion

The present findings indicate consistently higher circulating RBP4 levels in GDM cases compared to non-GDM controls, suggesting the potential relevance of RBP4 as a biomarker for GDM. However, the documented substantial study heterogeneity, alongside imprecision in effect estimates, underscores the need for further research and standardization of measurement methods to elucidate whether RBP4 can be utilized in clinical practice as a potential GDM biomarker.

Systematic review registration

PROSPERO (CRD42022340097: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022340097).