Circulating apelin levels are associated with cardiometabolic risk factors in women with previous gestational diabetes

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.

The Apelinergic System in Pregnancy

The apelinergic system is a highly conserved pleiotropic system. It comprises the apelin receptor apelin peptide jejunum (APJ) and its two peptide ligands, Elabela/Toddler (ELA) and apelin, which have different spatiotemporal localizations. This system has been implicated in the regulation of the adipoinsular axis, in cardiovascular and central nervous systems, in carcinogenesis, and in pregnancy in humans. During pregnancy, the apelinergic system is essential for embryo cardiogenesis and vasculogenesis and for placental development and function. It may also play a role in the initiation of labor. The apelinergic system seems to be involved in the development of placenta-related pregnancy complications, such as preeclampsia (PE) and intrauterine growth restriction, but an improvement in PE-like symptoms and birth weight has been described in murine models after the exogenous administration of apelin or ELA. Although the expression of ELA, apelin, and APJ is altered in human PE placenta, data related to their circulating levels are inconsistent. This article reviews current knowledge about the roles of the apelinergic system in pregnancy and its pathophysiological roles in placenta-related complications in pregnancy. We also discuss the challenges in translating the actors of the apelinergic system into a marker or target for therapeutic interventions in obstetrics.

Apelin levels in pregnant women with and without gestational diabetes mellitus: a collaborative systematic review and meta-analysis

Aims: This systematic review and meta-analysis investigated maternal apelin levels in pregnant women with and without GDM. Secondary outcomes were glucose- and lipid-related results.Methods: Databases including PubMed, Embase, Cochrane Library, LILACS, CNKI, and Wang Fang were searched. The methodological quality of included studies was evaluated with the Newcastle-Ottawa Scale. Mean differences (MDs) or standardized MDs (SMDs) with their 95% confidence intervals (CIs) were evaluated. Random effect model analyses were carried out and heterogeneity with the I² and Tau² statistics.Results: Fourteen observational studies (sample size: 1033 women with GDM and 1053 for control women) with a low or moderate risk of bias were included in the analysis. During the second half of pregnancy, maternal apelin estimate was significantly higher in women with GDM (SMD = 0.64; 95% CI: 0.03 to 1.25), as well as insulin (SMD = 1.41% CI: 0.84 to 1.99), glucose (SMD = 1.56; 95% CI 1.20 to 1.91), glycated hemoglobin (SMD = 1.11, 95% CI: 0.69 to 1.54), HOMA-IR (MD = 2.25; 95%CI: 1.51 to 2.98), BMI (MD = 0.80 kg/m², 95%CI: 0.52 to 1.08), total cholesterol (SMD = 0.42, 0.12 to 0.73), LDL-cholesterol (SMD = 0.63, 95%CI: 0.23 to 1.02), and triglycerides (SMD = 0.40, 95%CI: 0.19 to 0.61) as compared to control women. There was heterogeneity between studies as evidence by high I² values. Meta-regression analysis indicated statistically significant regression coefficients for age of women, glucose and total cholesterol.Conclusions: GDM was associated with increased circulating apelin, insulin, glucose, glycated hemoglobin, total cholesterol, LDL-cholesterol levels, and HOMA-IR index.

Low serum apelin levels are associated with mild cognitive impairment in Type 2 diabetic patients

BACKGROUND

Apelin is a new adipokine that is secreted by adipocytes, and is associated with insulin resistance (IR), inflammation, and obesity. This study was designed to investigate the role of apelin in type 2 diabetes mellitus (T2DM) patients with mild cognitive impairment (MCI).

METHODS

A total of 235 patients with T2DM were included. The cognitive function of patients was evaluated using Montreal Cognitive Assessment (MoCA) tool, then patients were divided into MCI group and non-MCI group according to the MoCA score. Blood sample was analyzed for the level of apelin by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The MCI group (n = 73) presented lower serum apelin levels compared with the patients with normal cognitive function (P < 0.001). Apelin levels showed significantly negative correlation with diabetes duration, triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C, creatinine and high sensitivity C-reactive protein (hs-CRP), and positive correlation with high-density lipoprotein cholesterol (HDL-C) and brain-derived neurotrophic factor (BDNF). Multivariable logistic regression analysis indicated that serum apelin (OR = 0.304, 95%CI: 0.104-0.886, P = 0.029), as well as education levels, diabetes duration, cardiovascular disease, serum HbA1c, HDL-C, creatinine, and BDNF, were independent risk factors of MCI in patients with T2DM.

CONCLUSIONS

Serum apelin level is reduced in T2DM patients with MCI. Apelin might has protective effect against cognitive impairment and serve as a serum biomarker of T2DM.

Is Apelin a new biomarker in patients with polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS) is associated with multiple risk factors for cardiovascular diseases, including insulin resistance, diabetes mellitus type 2, obesity, hypertension, and dyslipidaemia. Many studies have assessed the role of adipokines in the etiopathogenesis of PCOS, however, no single biomarker has been recognized to be in causal relation to the syndrome. Apelin has been identified as a new adipokine linked to obesity and insulin resistance. Some studies demonstrated that the apelin / apelin receptor could play a pivotal role in the pathogenesis of polycystic ovary syndrome, however the other yielded controversial results. Underlying mechanisms of possible involvement of apelin/apelin receptor complex are discussed.

Cardiovascular risk factors in women with previous gestational diabetes mellitus: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to synthesize evidence on conventional cardiovascular disease (CVD) risk factors among women with previous Gestational Diabetes Mellitus (GDM). The review protocol is registered with PROSPERO (CRD42019118149). PubMed, CINAHL, SCOPUS, and EMBASE databases were searched. Studies reporting on CVD risk factors in women with previous GDM compared to women without previous GDM were selected. A total of 139 studies were eligible, of which 93 were included in the meta-analysis. Women with previous GDM have significantly higher systolic blood pressure (2.47 mmHg 95% CI 1.74 to 3.40, n = 48, 50,118 participants) diastolic blood pressure (1.89 mmHg 95% CI 1.32 to 2.46, n = 48, 49,495 participants), BMI (1.54 kg/m² 95% CI 1.32 to 2.46, n = 78, 255,308 participants), total cholesterol (0.26 SMD 95% CI 0.15 to 0.37, n = 48, 38,561 participants), LDL cholesterol (0.19 SMD 95% CI 0.08 to 0.30, n = 44, 16,980 participants), triglycerides (0.56 SMD 95% CI 0.42 to 0.70, n = 46, 13,175 participants), glucose (0.69 SMD 95% CI 0.56 to 0.81, n = 55, 127,900 participants), insulin (0.41 SMD 95% CI 0.23 to 0.59, n = 32, 8881 participants) and significantly lower HDL cholesterol (-0.28 SMD 95% CI -0.39 to -0.16, n = 56, 35,882 participants), compared to women without previous GDM. The increased blood pressure, total cholesterol, triglycerides and glucose are seen as early as <1 year post-partum.Women with previous GDM have a higher risk of CVD based on significant increases in conventional risk factors. Some risk factors are seen as early as <1 year post-partum. Women with GDM may benefit from early screening to identify modifiable CVD risk factors.

The Role of the Adipokines in the Most Common Gestational Complications

Adipocytokines are hormonally active molecules that are believed to play a key role in the regulation of crucial biological processes in the human body. Numerous experimental studies established significant alterations in the adipokine secretion patterns throughout pregnancy. The exact etiology of various gestational complications, such as gestational diabetes, preeclampsia, and fetal growth abnormalities, needs to be fully elucidated. The discovery of adipokines raised questions about their potential contribution to the molecular pathophysiology of those diseases. Multiple studies analyzed their local mRNA expression and circulating protein levels. However, most studies report conflicting results. Several adipokines such as leptin, resistin, irisin, apelin, chemerin, and omentin were proposed as potential novel early markers of heterogeneous gestational complications. The inclusion of the adipokines in the standard predictive multifactorial models could improve their prognostic values. Nonetheless, their independent diagnostic value is mostly insufficient to be implemented into standard clinical practice. Routine assessments of adipokine levels during pregnancy are not recommended in the management of both normal and complicated pregnancies. Based on the animal models (e.g., apelin and its receptors in the rodent preeclampsia models), future implementation of adipokines and their receptors as new therapeutic targets appears promising but requires further validation in humans.

Emerging roles of APLN and APELA in the physiology and pathology of the female reproductive system

APLN, APELA and their common receptor APLNR (composing the apelinergic axis) have been described in various species with extensive body distribution and multiple physiological functions. Recent studies have witnessed emerging intracellular cascades triggered by APLN and APELA which play crucial roles in female reproductive organs, including hypothalamus-pituitary-gonadal axis, ovary, oviduct, uterus and placenta. However, a comprehensive summary of APLN and APELA roles in physiology and pathology of female reproductive system has not been reported to date. In this review, we aim to concentrate on the general characteristics of APLN and APELA, as well as their specific physiological roles in female reproductive system. Meanwhile, the pathological contexts of apelinergic axis dysregulation in the obstetrics and gynecology are also summarized here, suggesting its potential prospect as a diagnostic biomarker and/or therapeutic intervention in the polycystic ovary syndrome, ovarian cancer, preeclampsia and gestational diabetes mellitus.

Circulating apelin, chemerin and omentin levels in patients with gestational diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

The available data on the significance of circulating apelin, chemerin and omentin in women with gestational diabetes mellitus (GDM) are inconsistent. This analysis includes a systematic review of the evidence associating the serum concentrations of these adipokines with GDM.

METHODS

Publications through December 2019 were retrieved from PubMed, Embase, the Cochrane Library, and Web of Science. Subgroup analysis and meta-regression were conducted to evaluate sources of heterogeneity.

RESULTS

Analysis of 20 studies, including 1493 GDM patients and 1488 normal pregnant women did not find significant differences in circulating apelin and chemerin levels (apelin standardized mean difference [SMD] = 0.43, 95% confidence interval (CI): - 0.40 to 1.26, P = 0.31; chemerin SMD = 0.77, 95% CI - 0.07 to 1.61, P = 0.07). Circulating omentin was significantly lower in women with GDM than in healthy controls (SMD = - 0.72, 95% CI - 1.26 to - 0.19, P = 0.007). Publication bias was not found; sensitivity analysis confirmed the robustness of the pooled results.

CONCLUSIONS

Circulating omentin was decreased in GDM patients, but apelin and chemerin levels were not changed. The results suggest that omentin has potential as a novel biomarker for the prediction and early diagnosis of GDM.

Serum levels of adipokines in gestational diabetes: a systematic review

OBJECTIVE

To determine the difference of serum levels of 10 adipokines (apelin, chemerin, fatty acid-binding protein-4, fibroblast growth factor-21, monocyte chemoattractant protein-1, nesfatin-1, omentin-1, resistin, vaspin, and visfatin) among women with gestational diabetes and healthy pregnant controls.

MATERIALS AND METHODS

Literature search was conducted using the Medline (1966-2018), Scopus (2004-2018), Cochrane Central Register of Controlled Trials (CENTRAL) (1999-2018), Clinicaltrials.gov (2008-2018) and Google Scholar (2004-2018) databases, along with the reference list of the included studies.

RESULTS

Ninety-one studies were included in the present review, with a total number of 11,074 pregnant women. A meta-analysis was not conducted due to the high inter-study heterogeneity. Current evidence suggests that fatty acid-binding protein-4 levels are significantly increased in pregnancies complicated with gestational diabetes, while no association of serum apelin and monocyte chemoattractant protein-1 with the disease can be supported. Data regarding the rest adipokines are conflicting, since the available studies did not unanimously indicate a significant change of their levels in gestational diabetes.

CONCLUSIONS

The findings of the present systematic review suggest the promising role of fatty acid-binding protein-4 in the prediction of gestational diabetes, while inconsistent evidence exists regarding the rest novel adipokines. Future cohorts are needed to assess their predictive efficacy and fully elucidate their contribution in the disease.

Differential effect of metformin and/or glyburide on apelin serum levels in patients with type 2 diabetes mellitus: Concepts and clinical practice

Type 2 diabetes mellitus (T2DM) is a metabolic disorder associated with abundant adipocytokine changes which may play an important role in the progression of insulin resistance and micro- and macro-vascular complications. Therefore, the objective of this study was to assess the differential effect of metformin alone or in combination with glyburide on apelin serum levels in patients with T2DM. In this case–control study, fifty patients with T2DM in the age range of 45–65 years and twenty-five healthy controls matched for age and body weight were recruited from single endocrinology center, subdivided according to the diabetic pharmacotherapy into: Group I: healthy controls (n = 25), Group II: T2DM patients on metformin (n = 15), Group III: T2DM patients on glyburide (n = 17), and Group IV: T2DM patients on metformin plus glyburide (n = 28). Biochemical and anthropometric variables in relation to apelin serum levels were estimated. Apelin serum levels were low in normal healthy controls compared to T2DM patients (P < 0.01). The differential effect of diabetic pharmacotherapy on apelin serum level was statistically significant (P < 0.01) compared to the controls, but insignificant when compared among used drugs (P > 0.05). Apelin level was high in T2DM compared to the controls; both metformin and glyburide might play a role in this elevation.

An overview on biological functions and emerging therapeutic roles of apelin in diabetes mellitus

Type 2 diabetes mellitus is a common type of diabetes and considered as multifactorial disease. Apelin is an adipokine which secreted from white adipose tissue and involved in various functions such as insulin sensitivity and food intake. Many studies showed that apelin has a crucial role in diabetes and its concentration will change in relation with insulin resistance. In this review, we will discuss the roles of apelin in energy metabolism and pathogenesis of diabetes and explain why apelin can be a good candidate adipokine to promoting insulin sensitivity.

Gestational Diabetes Mellitus and Future Cardiovascular Risk: An Update

The prevalence of gestational diabetes mellitus is increasing in parallel with the rising prevalence of type 2 diabetes and obesity around the world. Current evidence strongly suggests that women who have had gestational diabetes mellitus are at greater risk of cardiovascular disease later in life. Given the growing prevalence of gestational diabetes mellitus, it is important to identify appropriate reliable markers of cardiovascular disease and specific treatment strategies capable of containing obesity, diabetes, and metabolic syndrome in order to reduce the burden of cardiovascular disease in the women affected.

Association of gestational diabetes mellitus (GDM) with subclinical atherosclerosis: a systemic review and meta-analysis

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with an elevated risk of adverse health outcomes such as type 2 diabetes and cardiovascular diseases. Carotid intima-media thickness (cIMT) is increasingly used as a noninvasive marker for subclinical atherosclerosis. Whether there is a direct correlation between GDM and elevated cIMT is still controversial.

METHODS

PubMed, Embase and reference lists of relevant papers were reviewed. Studies assessing the relationship between GDM and cIMT were included. Weighted Mean Difference (WMD) of cIMT was calculated using random-effect models.

RESULTS

Fifteen studies with a total of 2247 subjects were included in our analysis, giving a pooled WMD of 0.05 (95% confidence interval [CI] 0.03 -0.07). Furthermore, meta regression and subgroup analysis found that the association between GDM and larger cIMT already existed during pregnancy, and this relation was stronger in obese GDM patients.

CONCLUSIONS

GDM in and after pregnancy is associated with subclinical atherosclerosis. Weight control may be helpful to prevent cardiovascular diseases for GDM patients.

Serum oxidative stress, visfatin and apelin in healthy women and those with premenstrual syndrome

The aim of this study was to investigate whether there is a relationship between premenstrual syndrome and oxidative stress, visfatin and apelin. The study included 40 women with premenstrual syndrome and 40 healthy women. In all subjects, serum visfatin, apelin and oxidative stress parameters were studied in venous blood samples. The oxidative stress parameters were higher in the premenstrual syndrome group than among the controls, but this difference did not reach statistical significance (p > 0.05). It was found that total antioxidant capacity was similar in both groups. For the insulin-serotonin cycle markers, no significant difference was found between groups in terms of visfatin level (p = 0.893), although apelin was found to be significantly higher in the premenstrual syndrome group when compared with the controls (p < 0.001). According to our results, apelin can be used as an ancillary laboratory test in the diagnosis of premenstrual syndrome.