Adipose Tissue Inflammation and Adrenomedullin Overexpression Contribute to Lipid Dysregulation in Diabetic Pregnancies

Gut dysbiosis contributes to SCFAs reduction-associated adipose tissue macrophage polarization in gestational diabetes mellitus

AIMS

The prevalence of gestational diabetes mellitus (GDM) has spurred investigations into various interconnected factors, among which gut dysbiosis is notably prominent. Although gut dysbiosis is strongly associated with GDM, the specific role of the gut microbiome in the pathogenesis of GDM remains unknown. This study aims to explore the pathogenesis of GDM from gut microbiota.

MATERIALS AND METHODS

In our study, we constructed two GDM mice models: one induced by a high-fat diet (HFD) and the other through fecal microbiota transplantation (FMT) from GDM patients. In vitro, we used a co-culture system of RAW264.7 and 3T3-L1 adipocytes.

KEY FINDINGS

We induced a GDM-like state in pregnant mice by FMT from GDM patients, which was consistent with the HFD model. A potential mechanism identified involves the diminished abundance of SCFA-producing microbiota, which reduces SCFAs, particularly propionic acid and butyric acid. In vitro, butyric and propionic acids were observed to alleviate LPS-induced TLR4-NF-κB activation, thereby reducing inflammation levels and inhibiting adipose insulin resistance via the PI3K/AKT signaling pathway. This reduction appears to trigger the polarization of adipose tissue macrophages toward M1 and promote insulin resistance in adipose tissue.

SIGNIFICANCE

Our study fills this knowledge gap by finding that alterations in gut microbiota have an independent impact on hyperglycemia and insulin resistance in the GDM state. In vivo and in vitro, gut dysbiosis is linked to adipose tissue inflammation and insulin resistance via the bacterial product SCFAs in the GDM state, providing new insights into the pathogenesis of GDM.

Oligopeptide-strategy of targeting at adipose tissue macrophages using ATS-9R/siCcl2 complex for ameliorating insulin resistance in GDM

Gestational diabetes mellitus (GDM) is a pregnancy-specific disease characterized by impaired glucose tolerance during pregnancy. Although diagnosis and clinical management have improved significantly, there are still areas where therapeutic approaches need further improvement. Recent evidence suggests that CCL2, a chemokine involved in immunoregulatory and inflammatory processes, is closely related to GDM. However, the potential value for clinical therapeutic applications and the mechanism of CCL2 in adipose tissue macrophages (ATMs) of GDM remain to be elucidated. Here, we found that CCL2 was enriched in macrophages of the visceral adipose tissue from GDM women and HFD-induced GDM mice. The combination of in vitro and in vivo experiments showed that Ccl2 silencing inhibited the inflammatory response of macrophage by blocking calcium transport between ER and mitochondria and reducing excessive ROS generation. Additionally, the ATS-9R/siCcl2 oligopeptide complex targeting adipose tissue was created. Under the delivery of ATS-9R peptide, Ccl2 siRNA is expressed in ATMs, which reduces inflammation in adipose tissue and, as a result, mitigates insulin resistance. All of these findings point to the possibility that the ATS-9R/siCcl2 complex, which targets adipose tissue, is able to reduce insulin resistance in GDM and the inflammatory response in macrophages. The ATS-9R/siCcl2 oligopeptide complex targeting adipose tissue seems to be a viable treatment for GDM pregnancies.

Impact of adrenomedullin on mitochondrial respiratory capacity in human adipocyte

Mitochondrial function in adipocyte is an important aspect in maintaining metabolic homeostasis. Our previous observation showed that circulating levels of adrenomedullin (ADM) and mRNA and protein for ADM in omental adipose tissue were higher in patients with gestational diabetes mellitus (GDM), and these alterations are accompanied by glucose and lipid metabolic dysregulation, but the impact of ADM on mitochondrial biogenesis and respiration in human adipocyte remain elusive. The present study demonstrated that: (1) Increasing doses of glucose and ADM inhibit human adipocyte mRNA expressions of mitochondrial DNA (mtDNA)-encoded subunits of electron transport chain, including nicotinamide adenine dinucleotide dehydrogenase (ND) 1 and 2, cytochrome (CYT) b, as well as ATPase 6; (2) ADM significantly increases human adipocyte mitochondrial reactive oxygen species generation and this increase is reversed by ADM antagonist, ADM22-52, but treatment with ADM does not significantly affect mitochondrial contents in the adipocytes; (3) Adipocyte basal and maximal oxygen consumption rate are dose-dependently suppressed by ADM, thus results in impaired mitochondrial respiratory capacity. We conclude that elevated ADM observed in diabetic pregnancy may be involved in glucose and lipid dysregulation through compromising adipocyte mitochondrial function, and blockade of ADM action may improve GDM-related glucose and adipose tissue dysfunction.

Impact of Adrenomedullin on Mitochondrial Respiratory Capacity in Human Adipocyte

For metabolic homeostasis adequate mitochondrial function in adipocytes is essential. Our previous observation showed that circulating levels of adrenomedullin (ADM) and mRNA and protein for ADM in omental adipose tissue were higher in patients with gestational diabetes mellitus (GDM) compared with normal pregnancy, and these alterations are accompanied by glucose and lipid metabolic dysregulation, but the impact of ADM on mitochondrial biogenesis and respiration in human adipocyte remain elusive. In this study we demonstrated that: (1) Increasing doses of glucose and ADM inhibit human adipocyte mRNA expressions of mitochondrial DNA (mtDNA)-encoded subunits of electron transport chain (ETC), including nicotinamide adenine dinucleotide dehydrogenase (ND) 1 and 2, cytochrome (CYT) b, as well as ATPase 6; (2) ADM significantly increases human adipocyte mitochondrial reactive oxygen species (ROS) generation and this increase is reversed by ADM antagonist, ADM22-52, but does not significantly affect adipocyte mitochondrial contents; (3) Adipocyte basal and maximal oxygen consumption rate (OCR) are dose-dependently suppressed by ADM, and results in impaired mitochondrial respiratory capacity. We conclude that elevatedADM observed in diabetic pregnancy may be involved in glucose and lipid dysregulation through compromising adipocyte mitochondrial function, and blockade of ADM actions in adipocytes may improve GDM-related metabolic complications.

Maternal and Placental DNA Methylation Changes Associated with the Pathogenesis of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is an important metabolic complication of pregnancy, which affects the future health of both the mother and the newborn. The pathogenesis of GDM is not completely clear, but what is clear is that with the development and growth of the placenta, GDM onset and blood glucose is difficult to control, while gestational diabetes patients' blood glucose drops and reaches normal after placenta delivery. This may be associated with placental secretion of insulin-like growth factor, adipokines, tumor necrosis factor-α, cytokines and insulin resistance. Therefore, endocrine secretion of placenta plays a key role in the pathogenesis of GDM. The influence of DNA methylation of these molecules and pathway-related genes on gene expression is also closely related to the pathogenesis of GDM. Here, this review attempts to clarify the pathogenesis of GDM and the related maternal and placental DNA methylation changes and how they affect metabolic pathways.

A novel model of gestational diabetes: Acute high fat high sugar diet results in insulin resistance and beta cell dysfunction during pregnancy in mice

Gestational diabetes mellitus (GDM) affects 7-18% of all pregnancies. Despite its high prevalence, there is no widely accepted animal model. To address this, we recently developed a mouse model of GDM. The goal of this work was to further characterize this animal model by assessing insulin resistance and beta cell function. Mice were randomly assigned to either control (CD) or high fat, high sugar (HFHS) diet and mated 1 week later. At day 0 (day of mating) mice were fasted and intraperitoneal insulin tolerance tests (ipITT) were performed. Mice were then euthanized and pancreata were collected for histological analysis. Euglycemic hyperinsulinemic clamp experiments were performed on day 13.5 of pregnancy to assess insulin resistance. Beta cell function was assessed by glucose stimulated insulin secretion (GSIS) assay performed on day 0, 13.5 and 17.5 of pregnancy. At day 0, insulin tolerance and beta cell numbers were not different. At day 13.5, glucose infusion and disposal rates were significantly decreased (p<0.05) in Pregnant (P) HFHS animals (p<0.05) suggesting development of insulin resistance in P HFHS dams. Placental and fetal glucose uptake was significantly increased (p<0.01) in P HFHS dams at day 13.5 of pregnancy and by day 17.5 of pregnancy fetal weights were increased (p<0.05) in P HFHS dams compared to P CD dams. Basal and secreted insulin levels were increased in HFHS fed females at day 0, however at day 13.5 and 17.5 GSIS was decreased (p<0.05) in P HFHS dams. In conclusion, this animal model results in insulin resistance and beta cell dysfunction by mid-pregnancy further validating its relevance in studying the pathophysiology GDM.

Higher serum adrenomedullin concentration is associated with an increased risk of gestational diabetes mellitus: A nested case-control study in Wuhan, China

Adrenomedullin (ADM) is thought to play a significant role in regulating insulin secretion and glucose metabolism. However, studies on the relationship between ADM and gestational diabetes mellitus (GDM) are limited. We hypothesized that a higher serum ADM concentration would be associated with an increased risk of GDM. Therefore, a nested case-control study of 65 GDM cases and 130 prepregnancy body mass index, age, parity, and gestational age of blood collection-matched controls was conducted to prospectively evaluate the association between circulating ADM concentrations in early pregnancy and the risk of GDM in pregnant women based on the Tongji Birth Cohort. Serum ADM concentrations in the GDM group were higher than those in the control group (2125.04 ± 644.97 vs 1880.76 ± 581.13 pg/mL) (P = .008). Serum ADM concentration was positively associated with the risk of developing GDM (P_trend < .05). The adjusted odds ratio (OR) comparing the highest tertile of ADM with the lowest was 2.74 (95% CI, 1.17-6.43). The risk of GDM increased by 49% (OR, 1.49; 95% CI, 1.05-2.12) for each SD increment of serum ADM. Moreover, serum ADM concentration was positively correlated with circulating total cholesterol (r = 0.204), triglycerides (r = 0.197), and systolic blood pressure (r = 0.173), but negatively correlated with circulating high-density lipoprotein cholesterol concentration (r = -0.176). Pregnant women with higher serum ADM concentrations have a markedly increased risk of developing GDM. Further studies are warranted to explore the possible thresholds of ADM that increase the risk of GDM and to confirm and elucidate the underlying mechanisms.

New Insights into Adipokines in Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is the most common metabolic disorder of pregnancy and has considerable short- and long-term consequences for the health of both the mother and the newborn. Within its pathophysiology, genetic, nutritional, epigenetic, immunological, and hormonal components have been described. Within the last two items, it is known that different hormones and cytokines secreted by adipose tissue, known collectively as adipokines, are involved in the metabolic alterations underlying GDM. Although the maternal circulating profile of adipokines in GDM has been extensively studied, and there are excellent reviews on the subject, it is in recent years that more progress has been made in the study of their expression in visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), placenta, and their concentrations in the umbilical circulation. Thus, this review compiles and organizes the most recent findings on the maternal and umbilical circulating profile and the levels of expression of adipokines in VAT, SAT, and placenta in GDM.

Adrenomedullin ameliorates palmitic acid-induced insulin resistance through PI3K/Akt pathway in adipocytes

AIMS

White adipose tissue (WAT) dysfunction has been associated with adipose tissue low-grade inflammation and oxidative stress leading to insulin resistance (IR). Adrenomedullin (ADM), an endogenous active peptide considered as an adipokine, is associated with adipocytes function.

METHODS

We evaluated the protective effects of ADM against IR in 3T3-L1 adipocytes treated by palmitic acid (PA) and in visceral white adipose tissue (vWAT) of obese rats fed with high-fat diet.

RESULTS

We found that endogenous protein expressions of ADM and its receptor in PA-treated adipocytes were markedly increased. PA significantly induced impaired insulin signaling by affecting phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) axis and glucose transporter-4 (GLUT-4) levels, whereas ADM pretreatment enhanced insulin signaling PI3K/Akt and GLUT-4 membrane protein levels, decreased pro-inflammatory cytokines tumor necrosis factor α (TNFα), interleukin-1β (IL-1β) and IL-6 levels, and improved oxidative stress accompanied with reduced reactive oxygen species (ROS) levels and increased anti-oxidant enzymes manganese superoxide dismutase 2 (SOD2), glutathione peroxidase (GPx1) and catalase (CAT) protein expressions. Furthermore, ADM treatment not only improved IR in obese rats, but also effectively restored insulin signaling, and reduced inflammation and oxidative stress in vWAT of obese rats.

CONCLUSIONS

This study demonstrates a prevention potential of ADM against obesity-related metabolic disorders, due to its protective effects against IR, inflammation and oxidative stress in adipocytes.

Lipid dysfunction and adrenomedullin expression in omental versus subcutaneous adipose tissues in diabetic pregnancies

Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy but the underlying mechanism remains obscure. The aims of this study are to examine if omental adipose tissue (OMAT) and subcutaneous AT (SCAT) differentially express proinflammatory and lipid metabolic adipokines, and if so, whether their regional differences have implications on lipid metabolism in GDM. Paired samples of OMAT and SCAT were excised from pregnant women in scheduled Cesarean sections with non-obese (NOBS), obese (OBS) and GDM. The results showed that the mRNA of monocyte chemoattractant protein (MCP)-1, macrophage marker CD68, and cytokines IL-6, IL-8, and TNF-α are increased in OMAT from GDM women compared to that in NOBS and OBS women (P<0.05). Glucose and TNF-α dose-dependently enhanced ADM and its receptor components CRLR and RAMPs in human adipocytes. Immunofluorescence showed that ADM and its receptor components are higher in OMAT from GDM women compared to non-GDM women. Further, basal lipolysis was greater in OMAT than in SCAT and ADM stimulates further glycerol release in OMAT, but not in SCAT, and these increases are reduced by ADM antagonist, ADM22-52. We therefore conclude that elevated ADM and its receptor expressions by OMAT, but not by SCAT appear to contribute to the lipid dysregulation in GDM women, and manipulation of ADM may represent one of the novel approaches in minimizing the risk of GDM-related fetal overgrowth.

Association of circulating MR-proADM with all-cause and cardiovascular mortality in the general population: Results from the KORA F4 cohort study

Background and aim

Despite its vasodilatory effect, adrenomedullin and its surrogate mid-regional pro-adrenomedullin (MR-proADM) have been found to be positively associated with all-cause and cardiovascular mortality. However, the underlying mechanisms thereof remain unclear and the associations were mostly shown in geriatric cohorts or in patients with chronic diseases. Therefore, we aimed to investigate the possible involvement of abdominal obesity, selected adipokines, and biomarkers of subclinical inflammation in the association of MR-proADM with mortality in a population based study cohort.

Methods

Prospective analysis of the KORA F4 study; median follow-up 9.1 (8.8–9.4) years. Complete data on MR-proADM and mortality was available for 1551 participants, aged 56.9±12.9 years (mean±SD). Correlation and regression analyses of MR-proADM with overall (BMI) and abdominal obesity (waist circumference), selected adipokines and biomarkers of subclinical inflammation. Cox proportional hazard models on the association of MR-proADM with all-cause and cardiovascular mortality with adjustment for cardiovascular risk factors and selected biomarkers in study subgroups (n = 603–1551).

Results

MR-proADM associated with all-cause (HR (95%CI): 2.37 (1.72–3.26) and 2.31 (1.67–3.20)) and cardiovascular mortality (4.28 (2.19–8.39) and 4.44 (2.25–8.76)) after adjustment for traditional cardiovascular risk factors including BMI or waist circumference, respectively. MR-proADM was further associated with four out of seven examined adipokines (leptin, retinol-binding protein-4, chemerin, and adiponectin) and with five out of eleven examined biomarkers of subclinical inflammation (high-sensitivity C-reactive protein, interleukin-6, myeloperoxidase, interleukin-22, and interleukin-1 receptor antagonist) after multivariable adjustment and correction for multiple testing. However, only IL-6 substantially attenuated the association of MR-proADM with all-cause mortality.

Conclusions

We found an association of MR-proADM with (abdominal) obesity, selected adipokines, and biomarkers of subclinical inflammation. However, the association of MR-proADM with mortality was independent of these parameters. Future studies should investigate the role of IL-6 and further characteristics of subclinical inflammation in the association between MR-proADM and all-cause mortality.

Brief high fat high sugar diet results in altered energy and fat metabolism during pregnancy in mice

During pregnancy several maternal adaptations occur in order to support the growing fetus which are further exacerbated by gestational diabetes mellitus (GDM). Previously we developed a mouse model of GDM, however we did not evaluate alterations to energy and fat metabolism. We have also shown that alterations in lipid metabolism are mediated by adrenomedullin (ADM) in normal and GDM pregnancies. Our objectives were: (1) evaluate energy and fat homeostasis in our GDM mouse model and (2) determine if ADM may play a role in these changes. Female mice were placed on either control (P-CD) or high fat, high sucrose diet (P-HFHS) 1 week prior to and throughout pregnancy. Mice were placed into comprehensive lab animal monitoring system (CLAMS) chambers throughout pregnancy. Visceral adipose tissue (VAT) was collected at d17.5 of pregnancy for analysis. Energy Expenditure was significantly increased (p < 0.05) in P-HFHS dams compared to all other groups. VAT ex-vivo lipolysis was increased (p < 0.05) in P-HFHS compared to P-CD dams. VAT gene expression of ADM receptors Crlr, Ramp2, and Ramp3 was increased (p < 0.05) in P-HFHS dams. ADM dose dependently increased ex vivo lipolysis. This data further validates our animal model of GDM and is usefulness in investigating the pathophysiology of GDM.

Maternal serum leptin, adiponectin, resistin and monocyte chemoattractant protein-1 levels in different types of diabetes mellitus

OBJECTIVE

Evaluation of serum concentration of leptin, adiponectin, resistin, and MCP-1 in pregnant patients with different types of diabetes mellitus (DM) considering preconception planning and method of DM correction in 11-14th and 30-34th weeks of pregnancy.

STUDY DESIGN

Longitudinal, prospective study included 130 pregnant women divided into the following comparison groups: type 1 DM (T1DM, n = 40), type 2 DM (T2DM, n = 35), GDM (n = 40), and the control group (n = 15). The ELISA method defined the levels of leptin, resistin, adiponectin, and MCP-1 concentration in serum, which was assessed in 11-14th and 30-34th weeks of pregnancy. Statistical analysis was accomplished using SPSS 23.0 and "Prism 8-GraphPad" software.

RESULTS

The leptin level in the 1st trimester was the highest in T2DM insulin group compared to the control due to gestational age, hence in the 3rd trimester in all groups its serum concentrations appeared higher than in healthy patients (p = 0.0001). In the 1st trimester leptin levels directly correlated with women's BMI, newborns' weight and macrosomia rate, in the 3rd trimester - with OGTT levels, HbA1c, gestational hypertension, and preeclampsia rates. Resistin levels in the 1st and 3rd trimesters were increased in almost all DM groups compared to the control group (p = 0.0001). The study established direct positive correlation between resistin and HbA1c, birth weight, and preeclampsia. In the 1st trimester, adiponectin demonstrated the lowest levels in T2DM insulin compared to T1DM and the control group (p = 0.0001) while in the 3rd trimester, adiponectin levels declined alongside gestational age in DM patients and all the groups compared to the control group (p < 0.05). Adiponectin negatively correlated with BMI, OGTT levels, and preeclampsia rate. MCP-1 levels in T2DM appeared higher than in T1DM patients and the control group in the 1st trimester, whereas in the 3rd trimester MCP-1 declined, correlating with BMI, preeclampsia and OGTT levels.

CONCLUSION

High rate of adverse perinatal outcomes in diabetic pregnancy might be developed due to more severe metabolic failures and further disturbances of adipokines expression.

Visceral Adipose Tissue Inflammatory Factors (TNF-Alpha, SOCS3) in Gestational Diabetes (GDM): Epigenetics as a Clue in GDM Pathophysiology

Gestational diabetes (GDM) is among the most challenging diseases in westernized countries, affecting mother and child, immediately and in later life. Obesity is a major risk factor for GDM. However, the impact visceral obesity and related epigenetics play for GDM etiopathogenesis have hardly been considered so far. Our recent findings within the prospective ‘EaCH’ cohort study of women with GDM or normal glucose tolerance (NGT), showed the role, critical factors of insulin resistance (i.e., adiponectin, insulin receptor) may have for GDM pathophysiology with epigenetically modified expression in subcutaneous (SAT) and visceral (VAT) adipose tissues. Here we investigated the expression and promoter methylation of key inflammatory candidates, tumor necrosis factor-alpha (TNF-α) and suppressor of cytokine signaling 3 (SOCS3) in maternal adipose tissues collected during caesarian section (GDM, n = 19; NGT, n = 22). The mRNA expression of TNF-α and SOCS3 was significantly increased in VAT, but not in SAT, of GDM patients vs. NGT, accompanied by specific alterations of respective promoter methylation patterns. In conclusion, we propose a critical role of VAT and visceral obesity for the pathogenesis of GDM, with epigenetic alterations of the expression of inflammatory factors as a potential factor.

Impact of adrenomedullin blockage on lipid metabolism in female mice exposed to high-fat diet

PURPOSE

Adrenomedullin (ADM) levels are elevated in gestational and type 2 diabetic patients. ADM also stimulates lipolysis in vitro. Disturbed lipid metabolism has been implicated in the pathogenesis of diabetes. Here, we explore whether blockade of ADM is beneficial for metabolic homeostasis in a diabetic mouse model.

METHODS

C57BL/6J female mice were placed on either a control or a high fat high sucrose (HFHS) diet for 8 weeks. At week 4, osmotic mini-pumps were implanted for constant infusion of either saline or ADM antagonist, ADM_22-52. Glucose tolerance tests were performed prior to infusion and 4 weeks after infusion began. Animals were then sacrificed and visceral adipose tissue collected for further analysis.

RESULTS

Mice fed HFHS displayed glucose intolerance, increased mRNA expressions in VAT for Adm and its receptor components, Crlr. HFHS fed mice also had increased basal and isoprenaline-induced glycerol release by VAT explants. ADM_22-52 did not significantly affect glucose intolerance. ADM_22-52 did suppress basal and isoprenaline-induced glycerol release by VAT explants. This alteration was associated with enhanced mRNA expression of insulin signaling factors Insr and Glut4, and adipogenic factor Pck1.

CONCLUSIONS

HFHS diet induces glucose intolerance and enhances ADM and its receptor expressions in VAT in female mice. ADM_22-52 treatment did not affect glucose intolerance in HFHS mice, but reduced both basal and isoprenaline-induced lipolysis, which is associated with enhanced expression of genes involved in adipogenesis. These results warrant further research on the effects of ADM blockade in improving lipid homeostasis in diabetic patients.

Maternal serum level of resistin is associated with risk for gestational diabetes mellitus: A meta-analysis

BACKGROUND

Resistin is most likely involved in the pathogenesis of gestational diabetes mellitus (GDM), but the existing findings are inconsistent.

AIM

To review the literature investigating the associations of the risk of GDM with serum level of resistin.

METHODS

A systematic literature search was performed using MEDLINE, EMBASE, and Web of Science (all databases). This meta-analysis included eligible studies that: (1) investigated the relationship between the risk of GDM and serum resistin; (2) included GDM cases and controls without GDM; (3) diagnosed GDM according to the oral glucose-tolerance test; (4) were performed in humans; (5) were published as full text articles in English; and (6) provided data with median and quartile range, median and minimum and maximum values, or mean and standard deviation. The pooled standardized mean difference (SMD) and 95% confidence interval (CI) were calculated to estimate the association between the risk of GDM and serum resistin. To analyze the potential influences of need for insulin in GDM patients and gestational age at blood sampling, we performed a subgroup analysis. Meta-regression with restricted maximum likelihood estimation was performed to assess the potentially important covariate exerting substantial impact on between-study heterogeneity.

RESULTS

The meta-analysis for the association between serum resistin level and GDM risk included 18 studies (22 comparisons) with 1041 cases and 1292 controls. The total results showed that the risk of GDM was associated with higher serum resistin level (SMD = 0.250, 95%CI: 0.116, 0.384). The “after 28 wk” subgroup, “no need for insulin” subgroup, and “need for insulin” subgroup indicated that higher serum resistin level was related to GDM risk (“after 28 wk” subgroup: SMD = 0.394, 95%CI: 0.108, 0.680; “no need for insulin” subgroup: SMD = 0.177, 95%CI: 0.018, 0.336; “need for insulin” subgroup: SMD = 0.403, 95%CI: 0.119, 0.687). The “before 14 wk” subgroup, “14-28 wk” subgroup, and “no information of need for insulin” subgroup showed a nonsignificant association between serum resistin level and GDM risk (“before 14 wk” subgroup: SMD = 0.087, 95%CI: -0.055, 0.230; “14-28 wk” subgroup: SMD = 0.217, 95%CI: -0.003, 0.436; “no information of need for insulin” subgroup: SMD = 0.356, 95%CI: -0.143, 0.855). The postpartum subgroup included only one study and showed that higher serum resistin level was related to GDM risk (SMD = 0.571, 95%CI: 0.054, 1.087) The meta-regression revealed that no need for insulin in GDM patients, age distribution similar between cases and controls, and ELISA all had a significant impact on between-study heterogeneity.

CONCLUSION

This meta-analysis supports that the maternal serum resistin level is associated with GDM risk.