Effects of variation in retinol binding protein 4 gene and adipose specific expression of gestational diabetes in Beijing, China

A meta-analysis of the association between RBP4 rs3758539 genotype and metabolic syndrome factors

AIM

To explore the link between the RBP4 rs3758539 genotype and metabolic syndrome risk factors and whether the impact of this genetic variation displays any potential race discrepancy.

MATERIALS AND METHODS

This meta-analysis followed the PRISMA guidelines and was registered with PROSPERO (registration no. CRD42023407999). PubMed, Web of Science, Embase, Cochrane Library, Google Scholar, Airiti Library and CINAHL databases were used for the study search until October 2023. We evaluated the methodological quality using the Joanna Briggs Institute checklist and determined the correlation using a random-effects meta-analysis.

RESULTS

The results indicated that individuals with the rs3758539 GA/AA genotype had a higher risk profile, including lower high-density lipoprotein levels [correlation: -0.045, 95% confidence interval (CI): -0.080 to -0.009, p = .015, I2 = 46.9%] and higher body mass index (correlation: 0.117, 95% CI: 0.036-0.197, p = .005, I2 = 82.0%), body fat (correlation: 0.098, 95% CI: 0.004-0.191, p = .041, I2 = 64.0%), and low-density lipoprotein levels (correlation: 0.074, 95% CI: 0.010-0.139, p = .024, I2 = 0%), of developing metabolic syndrome than those with the GG genotype. The subgroup analysis maintained a significantly positive correlation between the rs3758539 GA/AA genotype and body mass index (correlation: 0.163, 95% CI: 0.031-0.289, p = .016, I2 = 88.9%) but a negative correlation with high-density lipoprotein levels (correlation: -0.047, 95% CI: -0.087 to -0.006, p = .025, I2 = 65.7%) in the Asian group only.

CONCLUSION

The current meta-analysis supports a significant link between the RBP4 rs3758539 GA/AA genotype and the metabolic syndrome.

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).

The level of serum retinol-binding protein is associated with diabetic mild cognitive impairment

BACKGROUND

Several studies have shown that retinol-binding protein (RBP) is linked to diabetes and neurodegenerative diseases. However, no studies have elucidated the relationship between RBP and diabetic cognitive disorders.

OBJECTIVE

To determine whether the change characteristics of serum RBP are associated with alterations in cognitive functioning in type 2 diabetes mellitus (T2DM).

METHODS

In this study, 252 patients with T2DM and 34 people as healthy controls were included. According to the Montreal Cognitive Assessment (MoCA), the diabetic subjects were divided into the mild cognitive impairment (MCI) group and the Non-MCI group. Demographic characteristics and clinical indicators as well as serum RBP levels were analyzed.

RESULTS

The serum RBP levels in the MCI group were lower compared with the Non-MCI group (P = 0.02). The level of RBP was higher in the diabetes without MCI group than in the healthy control (P < 0.001). Serum RBP levels were positively correlated with MoCA scores (r = 0.178, P = 0.003). Binary Logistic regression model analysis showed that low RBP [odds ratio (OR) = 0.936], old age (OR = 1.074), high fasting blood glucose (OR = 1.164), and low fasting C-peptide (OR = 0.722) may be independent risk factors for diabetic MCI. The ROC curve of serum RBP for predicting diabetic MCI showed that the area under the curve was 0.630.

CONCLUSIONS

Our study revealed an association between serum RBP and diabetic MCI. Serum RBP levels in diabetic MCI are lower and correlated with cognitive function.

Blood retinol and retinol-binding protein concentrations are associated with diabetes: a systematic review and meta-analysis of observational studies

PURPOSE

The associations between blood retinol, retinol-binding protein (RBP) concentrations and diabetes mellitus were inconsistent in literature. The objective is to investigate these associations by a systematic review and meta-analysis and provide basis for clinical intervention.

METHODS

PubMed, Web of science, and Cochrane databases were searched from the beginning to July 1, 2021. A total of 13 studies on retinol and 31 studies on RBP are included in the current meta-analysis.

RESULTS

The blood retinol concentration was significantly lower in the type I diabetes mellitus (T1DM) [standardized mean difference (SMD) (95% CI): - 0.59 (- 0.81, - 0.37), P < 0.01] and gestational diabetes mellitus (GDM) patients [SMD (95% CI): - 0.54 (- 0.87, - 0.20), P < 0.01] than in the controls. However, the difference was not significant between the type II diabetes mellitus (T2DM) patients and the controls. The RBP concentration was significantly higher in the diabetic patients than in the controls [SMD (95% CI): 0.24 (0.12, 0.35), P < 0.01]. Particularly, the RBP concentration was significantly higher in the T2DM and GDM patients.

CONCLUSION

The blood retinol concentration was negatively associated with T1DM and GDM, while the blood RBP concentration was positively associated with T2DM and GDM. Future work should use a more sensitive retinol measurement method like retinol isotope dilution method to confirm whether blood retinol concentration differs between the diabetes patients and the controls.

Adipokines in early and mid-pregnancy and subsequent risk of gestational diabetes: a longitudinal study in a multiracial cohort

INTRODUCTION

Several adipokines are implicated in the pathophysiology of gestational diabetes mellitus (GDM), however, longitudinal data in early pregnancy on many adipokines are lacking. We prospectively investigated the association of a panel of adipokines in early and mid-pregnancy with GDM risk.

RESEARCH DESIGN AND METHODS

Within the National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singletons cohort (n=2802), a panel of 10 adipokines (plasma fatty acid binding protein-4 (FABP4), chemerin, interleukin-6 (IL-6), leptin, soluble leptin receptor (sOB-R), adiponectin, omentin-1, vaspin, and retinol binding protein-4) were measured at gestational weeks (GWs) 10-14, 15-26, 23-31, and 33-39 among 107 GDM cases (ascertained on average at GW 27) and 214 non-GDM controls. Conditional logistic regression was used to estimate ORs of each adipokine and GDM, controlling for known GDM risk factors including pre-pregnancy body mass index.

RESULTS

Throughout pregnancy changes in chemerin, sOB-R, adiponectin, and high-molecular-weight adiponectin (HMW-adiponectin) concentrations from 10-14 to 15-26 GWs were significantly different among GDM cases compared with non-GDM controls. In early and mid-pregnancy, FABP4, chemerin, IL-6 and leptin were positively associated with increased GDM risk. For instance, at 10-14 GWs, the OR comparing the highest versus lowest quartile (ORQ4-Q1) of FABP4 was 3.79 (95% CI 1.63 to 8.85). In contrast, in both early and mid-pregnancy adiponectin (eg, ORQ4-Q1 0.14 (0.05, 0.34) during 10-14 GWs) and sOB-R (ORQ4-Q1 0.23 (0.11, 0.50) during 10-14 GWs) were inversely related to GDM risk. At 10-14 GWs a model that included conventional GDM risk factors and FABP4, chemerin, sOB-R, and HMW-adiponectin improved the estimated prediction (area under the curve) from 0.71 (95% CI 0.66 to 0.77) to 0.77 (95% CI 0.72 to 0.82).

CONCLUSIONS

A panel of understudied adipokines including FABP4, chemerin, and sOB-R may be implicated in the pathogenesis of GDM with significant associations detected approximately 10-18 weeks before typical GDM screening.

Heterogeneous impact of type 2 diabetes mellitus-related genetic variants on gestational glycemic traits: review and future research needs

Gestational glucose homeostasis influences mother's metabolic health, pregnancy outcomes, fetal development and offspring growth. To understand the genetic roles in pregnant glucose metabolism and genetic predisposition for gestational diabetes (GDM), we reviewed the recent literature up to Jan, 2018 and evaluated the influence of T2DM-related genetic variants on gestational glycemic traits and glucose tolerance. A total of 140 variants of 89 genes were integrated. Their associations with glycemic traits in and outside pregnancy were compared. The genetic circumstances underlying glucose metabolism exhibit a similarity between pregnant and non-pregnant populations. While, not all of the T2DM-associated genetic variants are related to pregnant glucose tolerance, such as genes involved in fasting insulin/C-peptide regulation. Some genetic variants may have distinct effects on gestational glucose homeostasis. And certain genes may be particularly involved in this process via specific mechanisms, such as HKDC1, MTNR1B, BACE2, genes encoding cell cycle regulators, adipocyte regulators, inflammatory factors and hepatic factors related to gestational glucose sensing and insulin signaling. However, it is currently difficult to evaluate these associations with quantitative synthesis due to inadequate data, different analytical methods, varied measurements for glycemic traits, controversies in diagnosis of GDM, and unknown ethnicity- and/or sex-related influences on pregnant maternal metabolism. In conclusion, different genetic associations with glycemic traits may exist between pregnant and non-pregnant conditions. Comprehensive research on specific genetic regulation in gestation is necessary.

Association of polymorphisms in STRA6 gene with gestational diabetes mellitus in a Chinese Han population

Cell and animal experiments have found that in addition to being a retinol transporter, Stimulated by Retinoic Acid 6 (STRA6) also functions as a surface signaling receptor by which retinol regulates insulin responses. Several studies revealed that the STRA6 gene may contribute to the pathogenesis of type 2 diabetes mellitus (T2DM). Gestational diabetes mellitus (GDM) and T2DM have some risk factors in common. The present study was directed to investigate whether the 3 single nucleotide polymorphism (SNPs) (rs11633768, rs351219, and rs736118) of STRA6 correlate with the development of GDM in Chinese pregnant women. We also aimed to estimate the relationship between SNPs with fasting blood glucose level, 1-hour and 2-hour blood glucose levels after 75 g oral glucose intake, fasting insulin and insulin resistance levels to better study the relationship between STRA6 and glucose metabolism.Case-control studies were conducted to compare the GDM and control groups. A total of 334 cases and 367 controls were recruited. Three tagSNPs of STRA6, rs11633768, rs351219, and rs736118, were selected. A chi-square test, logistic regression, and linear regression were used to estimate the relationship between SNPs with GDM risk and oral glucose tolerance test (OGTT), fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) levels. Regression analyses were all adjusted by maternal age, pre-pregnancy BMI, and weekly BMI growth. The Bonferroni correction was applied for multiple comparisons.After adjusting the maternal age, pre-pregnancy BMI and weekly BMI growth, STRA6 rs736118 was associated with fasting insulin level (Beta = -1.468, P = .036), and the association between rs736118 and HOMA-IR was of borderline significance (Beta = -0.290, P = .093) under the dominance model.This study found that there is a significant association between STRA6 polymorphism and GDM.

Relationships of SLC2A4, RBP4, PCK1, and PI3K Gene Polymorphisms with Gestational Diabetes Mellitus in a Chinese Population

Background

Solute carrier family 2 member 4- (SLC2A4-) retinol binding protein-4- (RBP4-) phosphoenolpyruvate carboxykinase 1 (PCK1)/phosphoinositide 3-kinase (PI3K) is an adipocyte derived “signalling pathway” that may contribute to the pathogenesis of type 2 diabetes mellitus (T2DM). We explored whether single nucleotide polymorphisms (SNPs) of these “signalling pathway” genes are associated with gestational diabetes mellitus (GDM).

Methods

Case-control studies were conducted to compare GDM and control groups. A total of 334 cases and 367 controls were recruited. Seventeen candidate SNPs of the pathway were selected. Chi-square tests, logistic regression, and linear regression were used to estimate the relationships of SNPs with GDM risk and oral glucose tolerance test (OGTT), fasting insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) levels. Model-based multifactor dimensionality reduction was used to estimate the adjusted interactions between genes. Regression and interaction analyses were adjusted by maternal age, prepregnancy BMI, and weekly BMI growth. The Bonferroni correction was applied for multiple comparisons.

Results

RBP4 rs7091052 was significantly associated with GDM risk. SLC2A4 rs5435, RBP4 rs7091052, PCK1 rs1042531 and rs2236745, and PIK3R1 (coding gene of the PI3K P85 subunit) rs34309 were associated with OGTT, fasting insulin, and HOMA-IR levels in the linear regression analysis. The gene-gene interaction analysis showed that, compared with pregnant women with other genotype combinations, women with SLC2A4 rs5435 (CC/CT), RBP4 rs7091052 (CC), PCK1 rs1042531 (TT/TG) and rs2236745 (TT), and PIK3R1 rs34309 (AA) had lower GDM risk.

Conclusion

SLC2A4, RBP4, PCK1, and PIK3R1 genes may be involved in the pathogenesis of GDM.

Molecular Biomarkers for Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a growing public health problem worldwide. The condition is associated with perinatal complications and an increased risk for future metabolic disease in both mothers and their offspring. In recent years, molecular biomarkers received considerable interest as screening tools for GDM. The purpose of this review is to provide an overview of the current status of single-nucleotide polymorphisms (SNPs), DNA methylation, and microRNAs as biomarkers for GDM. PubMed, Scopus, and Web of Science were searched for articles published between January 1990 and August 2018. The search terms included “gestational diabetes mellitus”, “blood”, “single-nucleotide polymorphism (SNP)”, “DNA methylation”, and “microRNAs”, including corresponding synonyms and associated terms for each word. This review updates current knowledge of the candidacy of these molecular biomarkers for GDM with recommendations for future research avenues.

Serum level and polymorphisms of retinol-binding protein-4 and risk for gestational diabetes mellitus: a meta-analysis

BACKGROUND

Retinol-binding protein-4 (RBP4) has been reported to be potentially involved in the pathogenesis of gestational diabetes mellitus (GDM); however, the findings are inconsistent. Our aims were to review the studies that investigated the association of serum levels and polymorphisms of RBP4 with GDM risk, and to provide recommendations for future research.

METHODS

The databases PubMed, EBSCO, ScienceDirect, and Web of Knowledge were searched up to October 2015 to find out studies evaluating the relationship between serum RBP4 level/ RBP4 polymorphisms and GDM risk. In the meta-analysis of serum RBP4 levels the key inclusion was that studies were designed as BMI-matched studies or had observed non-significant differences in BMI between cases and controls.

RESULTS

Fourteen case-control studies (647 cases and 620 controls) reporting the association between serum RBP4 level and GDM risk, and three studies (1012 cases and 1605 controls) investigating the association between RBP4 polymorphisms and GDM risk were involved. Our results showed that high serum RBP4 levels represent a risk factor for GDM (pooled standardized mean difference =0.758, 95% confidence interval [0.387, 1.128]). The results of subgroup analyses based on "gestational age at blood sampling" or "diagnostic criteria" are consistent with the overall results. However, the postpartum subgroup and "before 24 weeks" subgroup both only include one article and indicate no association between serum RBP4 level and GDM risk. The meta-analysis on the association between rs3758539 polymorphism and GDM risk shows that RBP4 rs3758539 polymorphism is not associated with the development of GDM.

CONCLUSIONS

The results of this meta-analysis support the hypothesis that RBP4 is a modest independent risk factor for GDM (i.e., nonobese patients with GDM might express RBP4 at abnormal levels). The serum RBP4 level is associated with the risk of GDM. However, the association in the first-trimester and postpartum period should be validated by further research. The association between RBP4 rs3758539 polymorphism and GDM risk was not confirmed.

Adipokine levels during the first or early second trimester of pregnancy and subsequent risk of gestational diabetes mellitus: A systematic review

OBJECTIVE

We aimed to systematically review available literature linking adipokines to gestational diabetes mellitus (GDM) for a comprehensive understanding of the roles of adipokines in the development of GDM.

METHODS

We searched PubMed/MEDLINE and EMBASE databases for published studies on adipokines and GDM through October 21, 2014. We included articles if they had a prospective study design (i.e., blood samples for adipokines measurement were collected before GDM diagnosis). Random-effects models were used to pool the weighted mean differences comparing levels of adipokines between GDM cases and non-GDM controls.

RESULTS

Of 1523 potentially relevant articles, we included 25 prospective studies relating adipokines to incident GDM. Our meta-analysis of nine prospective studies on adiponectin and eight prospective studies on leptin indicated that adiponectin levels in the first or early second trimester of pregnancy were 2.25 μg/ml lower (95% CI: 1.75-2.75), whereas leptin levels were 7.25 ng/ml higher (95% CI 3.27-11.22), among women who later developed GDM than women who did not. Prospective data were sparse and findings were inconsistent for visfatin, retinol binding protein (RBP-4), resistin, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and vaspin. We did not identify prospective studies for several novel adipokines, including chemerin, apelin, omentin, or adipocyte fatty acid-binding protein. Moreover, no published prospective studies with longitudinal assessment of adipokines and incident GDM were identified.

CONCLUSION

Adiponectin levels in the first or second trimester of pregnancy are lower among pregnant women who later develop GDM than non-GDM women, whereas leptin levels are higher. Well-designed prospective studies with longitudinal assessment of adipokines during pregnancy are needed to understand the trajectories and dynamic associations of adipokines with GDM risk.

Evaluation of Gestational Diabetes Mellitus Risk in South Indian Women Based on MTHFR (C677T) and FVL (G1691A) Mutations

We aimed to scrutinize the extent to which single amino acid substitutions in the MTHFR and factor V Leiden (FVL) genes affect the risk of gestational diabetes mellitus (GDM) in pregnant women of South Indian descendant. This case-control study was implemented once the ethical approval has been obtained. Overall, 237 women were recruited in this study: 137 had been diagnosed with GDM and the remaining 100 women were used as normal controls or non-GDM. The diagnosis of GDM was confirmed with biochemical analysis, i.e., GCT and oral glucose tolerance tests. Five milliliters of peripheral blood was collected and used for biochemical and molecular analyses. DNA was isolated, and genotyping for MTHFR (C677T) and FVL (G1691A) mutations was performed using PCR-RFLP. FVL (G1691A) locus was not polymorphic in the investigated sample. There was no significant difference in the allele and genotype frequencies of C677T polymorphism between GDM and non-GDM women (p = 0.8892).

Effect of endurance training on retinol-binding protein 4 gene expression and its protein level in adipose tissue and the liver in diabetic rats induced by a high-fat diet and streptozotocin

AIMS/INTRODUCTION

The present study was designed to investigate from which tissues the decrease in retinol-binding protein 4 (RBP4) expression could contribute to the improvement of serum RBP4 and insulin resistance (IR) after endurance training.

MATERIALS AND METHODS

Male 7-week-old Wistar rats were randomly assigned into four groups including control (C), trained (T), diabetic control (DC) and trained diabetic (TD). At 8 weeks-of-age, diabetes was induced by a high-fat diet and intraperitoneal injection of low-dose streptozotocin (STZ; 35 mg/kg). Rats in the T and TD groups carried out a 7-week exercise program on a motorized treadmill (15-20 m/min for 20 min/day for 5 weeks), whereas the C and DC remained sedentary in their cages. Tissues gene expression and protein levels of RBP4 were assessed by using real-time polymerase chain reaction and western blot, respectively, while serum RBP4 was measured using an enzyme-linked immunosorbent assay kit.

RESULTS

Exercise significantly improved IR and reduced serum concentration of RBP4 in the TD group. This reduction of serum RBP4 was accompanied by decreased RBP4 protein expression in visceral fat tissue. In contrast, exercise had no significant effect on RBP4 expression in liver and subcutaneous fat tissue in the TD group. Exercise also significantly decreased RBP4 gene expression in visceral fat tissue and muscle, whereas the effect of exercise on liver RBP4 messenger ribonucleic acid expression was not significant.

CONCLUSIONS

The present study showed that the mechanism for RBP4 reducing the effect of endurance training could involve decreased RBP4 messenger ribonucleic acid expression and its protein level in adipose tissue in STZ-induced diabetic rats.

RBP4 gene variants are associated with insulin resistance in women with previous gestational diabetes

Objective. This study aimed to examine possible genetic effects of some retinol binding protein-4 (RBP4) single nucleotide polymorphisms (SNPs) on the risk of gestational diabetes mellitus (GDM). In addition, the SNPs were examined for their possible association with insulin resistance at 6 weeks after delivery. Methods. This was a prospective study of 100 women with GDM and 100 participants with normal gestation who were evaluated at gestational week 30 and 6 weeks postpartum. Three SNPs of RBP4 (rs3758539, rs116736522, and rs34571439) were genotyped using TaqMan assay. The genotype distributions between GDM patients and normal controls were analyzed using logistic regression models. In addition, differences in clinical characteristics among subjects grouped by genotype were assessed using the analysis of covariance test. Results. The frequencies of the rare alleles were not significantly different between GDM patients and controls. However, we identified two variants rs3758539 and rs34571439 associated with insulin levels and insulin resistance in women with previous GDM. Conclusion. Noncoding SNPs of the RBP4 gene are not associated with GDM, but two SNPs showed associations with insulin resistance and insulin levels in women with prior GDM. Additional studies with increased sample size will be necessary in other GDM cohorts.

Significance of RBP4 in patients with gestational diabetes mellitus: a case-control study of Han Chinese women

The role of retinol binding protein 4 (RBP4) in insulin resistance was recently identified. Our study investigated the correlation between RBP4 levels with lipid and glucose metabolism in a case-control study of women with gestational diabetes mellitus (GDM). Between May 2008 and May 2010, 70 pregnant women (24-28 weeks gestation) were recruited, including 35 women with GDM and 35 healthy controls. Blood samples were collected prior to and after oral glucose tolerance tests (OGTT) to detect serum RBP4, insulin, glycated hemoglobin, triglyceride (TG) and total cholesterol (TC) levels; the insulin resistance index (HOMA-IR) was calculated. Serum RBP4 levels in the GDM group were significantly higher than the control group (22.9 ± 3.09 µg/ml versus 17.9 ± 3.91 µg/ml; p < 0.01). Insulin, TC and TG levels in the GDM group and the control group were all significantly higher than the control group (p < 0.05). Serum RBP4 levels in the GDM group were correlated with HOMA-IR, TG and blood glucose levels at 1 h and 2 h after glucose was administered (r = 0.49, 0.49, 0.52,0.52, respectively; p < 0.01). In conclusion, serum RBP4 levels are elevated in GDM cases than controls. In addition, RBP4 correlates with abnormalities of insulin resistance, glucose and lipid metabolism.

Elevated plasma SPARC levels are associated with insulin resistance, dyslipidemia, and inflammation in gestational diabetes mellitus

Objective

Recent studies suggested that secreted protein acidic and rich in cysteine (SPARC), a novel adipokine, is a key player in the pathology of obesity and type 2 diabetes. We aimed to determine whether concentrations of SPARC were altered in patients with gestational diabetes mellitus (GDM) compared to normal glucose tolerance (NGT) controls and to investigate the relationships between SPARC and metabolic parameters in pregnant women.

Design/Methods

Cross-sectional study of 120 pregnant women with GDM and 60 controls with NGT, in a university hospital setting. Plasma levels of SPARC, adiponectin, fibroblast growth factor 21 (FGF21), insulin and proinsulin were determined by ELISA.

Results

GDM women had higher SPARC and lower adiponectin than NGT subjects; no difference was found in FGF21. SPARC levels were the lowest in subjects in the third tertile of insulin sensitivity index (ISI_OGTT) and correlated positively with pre-pregnant BMI, insulin and 3 h glucose during 100-g OGTT, HOMA-IR, fasting proinsulin, hsCRP and white blood cells count, and negatively with ISI_OGTT, when adjusting for gestational age. Triglyceride (TG), Apolipoprotein A1, apolipoprotein B and lipoprotein (a) correlated with SPARC in partial Pearson correlation. Correlations between SPARC with adiponectin, systolic blood pressure and TG were marginally significant in partial Spearman correlation analysis. In multivariate regression analysis, SPARC was an independent negative indicator of ISI_OGTT.

Conclusions

SPARC levels are correlated significantly with inflammation and may also be correlated with dyslipidemia and represent an independent determinant of insulin resistance in late pregnancy, indicating a potential role of SPARC in the pathophysiology of GDM.