Association of insulin resistance and autonomic tone in patients with pregnancy-induced hypertension

The Effects of L-Carnitine Supplementation on Blood Pressure in Adults: A Systematic Review and Dose-response Meta-analysis

PURPOSE

Hypertension stands as a prominent risk factor for cardiovascular disease, making it of utmost importance to address. Studies have shown that L-carnitine supplementation may lower blood pressure (BP) parameters in different populations. Therefore, we have conducted a systematic review and dose-response meta-analysis of published Randomized Controlled Trials (RCTs), including the most recent articles on the effect of L-carnitine supplementation on BP.

METHODS

PubMed, ISI Web of Science, Cochrane databases, and Scopus were used to collect RCT studies published up to October 2022 without limitations in language. Inclusion criteria were adult participants and recipients of L-carnitine in oral supplemental forms. The funnel plot test, Begg's test, and Egger's test were used to examine publication bias.

FINDINGS

After the search strategy, 22 RCTs (n = 1412) with 24 effect sizes fulfilled the criteria. It was found L-Carnitine supplementation did not have a significant effect on systolic blood pressure (SBP) (mm Hg) (weighted mean difference [WMD] = -1.22 mm Hg, 95% CI: -3.79, 1.35; P = 0.352; I2 = 85.0%, P < 0.001), and diastolic blood pressure (mm Hg) (WMD = -0.50 mm Hg, 95% CI: -1.49, 0.48; P = 0.318; I2 = 43.4%, P = 0.021) in the pooled analysis. Subgroup analyses have shown that L-carnitine supplementation had no lowering effect on SBP in any subgroup. However, there was a significant reduction in diastolic blood pressure in participants with a baseline body mass index >30 kg/m2 (WMD = -1.59 mm Hg; 95% CI: -3.11, -0.06; P = 0.041; I2 = 41.3%, P = 0.164). There was a significant nonlinear relationship between the duration of L-carnitine intervention and changes in SBP (coefficients = -6.83, P = 0.045).

IMPLICATIONS

L-carnitine supplementation in adults did not significantly affect BP. But anyway, more studies should be done in this field on different individuals.

The association between maternal HbA1c and adverse outcomes in gestational diabetes

BACKGROUND

The role of HbA1c in women with gestational diabetes mellitus (GDM) is still unclear, particularly in the Asian population.

AIM

To investigate the association between HbA1c levels and adverse outcomes considering maternal age, pre-pregnancy body mass index (BMI), and gestational weight gain (GWG) in women with GDM.

METHOD

A retrospective study included 2048 women with GDM and singleton live births. Using logistic regression, the associations between HbA1c and adverse pregnancy outcomes were assessed.

RESULT

Compared to women with HbA1c ≤ 5.0%, HbA1c was significantly associated with macrosomia (aOR 2.63,95%CI1.61,4.31), pregnancy-induced hypertension (PIH, aOR 2.56,95%CI1.57,4.19), preterm birth (aOR 1.64,95%CI 1.05,2.55), and primary Cesarean section (primary C-section, aOR1.49,95%CI1.09,2.03) in GDM women with HbA1c ≥5.5% while significantly associated with PIH (aOR 1.91,95%CI1.24,2.94) in women with HbA1c 5.1-5.4%. The associations between HbA1c and adverse outcomes varied with maternal age, pre-pregnancy BMI, and GWG. In women aged ≤29 years, there's significant association between HbA1c and primary C-section when HbA1c was 5.1-5.4% and ≥5.5%. In women aged 29-34 years and HbA1c ≥5.5%, HbA1c was significantly associated with macrosomia. In women aged ≥35 years, there's significant association between HbA1c and preterm birth when HbA1c was 5.1-5.4% and macrosomia and PIH when HbA1c ≥5.5%. In pre-pregnant normal-weight women, HbA1c was significantly associated with macrosomia, preterm birth, primary C-section, and PIH when HbA1c ≥5.5% while HbA1c was significantly associated with PIH when HbA1c was 5.1-5.4% . In pre-pregnant underweight women with HbA1c 5.1-5.4%, HbA1c was significantly associated with primary C-section. HbA1c was significantly associated with macrosomia among women with inadequate GWG or excess GWG and HbA1c≥5.5%. In women with adequate GWG, there's significant association between HbA1c and PIH when HbA1c was 5.1-5.4% and ≥5.5% .

CONCLUSION

Conclusively, HbA1c at the time of diagnosis is significantly associated with macrosomia, preterm birth, PIH, and primary C-section in Chinese women with GDM.

Association between Retinol-Binding Protein 4 Levels and Preeclampsia: A Systematic Review and Meta-Analysis

Retinol-binding protein 4 (RBP4) is claimed to be associated with the development of preeclampsia, yet the reports are inconclusive. This systematic review and meta-analysis aimed to assess the association between RBP4 levels and preeclampsia. The PubMed, Google Scholar and ScienceDirect databases were searched for studies that investigated RBP4 levels in preeclampsia patients and compared them with normal controls. The meta-analysis was conducted by calculating the standardized mean difference (SMD) of RBP4 between cases and controls. The meta package with the R software was used to perform all statistical analysis. A total of 13 studies, comprising 569 cases and 1411 controls, met the inclusion criteria and were thus included in the meta-analysis. According to the random effect model, the SMD of RBP4 was significantly higher in women with preeclampsia compared with normal controls [SMD of RBP4: 0.55 ng/mL; 95% CI (0.06; 1.05); p = 0.028; I² = 89%]. Likewise, the stratified meta-analysis showed the same pattern in the studies which measured RBP4 levels in the third trimester, as well as in the studies that investigated severe preeclampsia. Meta-regression did not identify any factor that significantly affected the overall estimate. There was no evidence of reporting bias (Egger's test; t = 0.43; p = 0.587). This meta-analysis with high heterogeneity showed that higher levels of RBP4 were associated with preeclampsia risk. More longitudinal studies spanning the three trimester periods are needed to clarify the association of RBP4 and its dynamics in preeclampsia cases throughout pregnancy.

The Relationship between Angiogenic Factors and Energy Metabolism in Preeclampsia

Antiangiogenic factors are currently used for the prediction of preeclampsia. The present study aimed to evaluate the relationship between antiangiogenic factors and lipid and carbohydrate metabolism in maternal plasma and placenta. We analyzed 56 pregnant women, 30 healthy and 26 with preeclampsia (including early and late onset). We compared antiangiogenic factors soluble Fms-like Tyrosine Kinase-1 (sfLt-1), placental growth factor (PlGF), and soluble endoglin (sEng)), lipid and carbohydrate metabolism in maternal plasma, and lipid metabolism in the placenta from assays of fatty acid oxidation, fatty acid esterification, and triglyceride levels in all groups. Antiangiogenic factors sFlt-1, sFlt-1/PlGF ratio, and sEng showed a positive correlation with triglyceride, free fatty acid, and C-peptide maternal serum levels. However, there was no relationship between angiogenic factors and placental lipid metabolism parameters. Free fatty acids were predictive of elevated sFlt-1 and sEng, while C-peptide was predictive of an elevated sFlt1/PlGF ratio. The findings in this study generate a model to predict elevated antiangiogenic factor values and the relationship between them with different products of lipid and carbohydrate metabolism in maternal serum and placenta in preeclampsia.

Association of pre-pregnancy subclinical insulin resistance with cardiac dysfunction in healthy nulliparous women

OBJECTIVES

To investigate the association between pre-pregnancy subclinical insulin resistance and cardiovascular dysfunction in healthy nulliparous women, and with hypertension in subsequent pregnancy.

STUDY DESIGN

Secondary analysis of a single center prospective observational study conducted November 2011-June 2014. Healthy nulliparous women underwent detailed cardiovascular and metabolic assessment. Insulin resistance was determined by homeostasis model assessment (HOMA-IR). Associations of HOMA-IR with metabolic and cardiovascular measurements were assessed with Spearman correlations. Charts were reviewed in women who conceived singleton pregnancies.

MAIN OUTCOME MEASURES

Metabolic measurements included serum glucose, insulin, creatinine, CRP, and lipids. HOMA-IR was calculated using fasting serum insulin and glucose. Indices of cardiovascular stiffness were determined from pulse wave velocity and response to volume challenge. Pregnancy outcomes included delivery mode and gestational age, birthweight, and hypertension.

RESULTS

HOMA-IR was positively associated with BMI (r = 0.462, p < 0.001), body fat percentile (r = 0.463, p < 0.001), CRP (r = 0.364, p = 0.003), and negatively associated with serum HDL (r = -0.38, p = 0.002) and creatinine (r = -0.242, p = 0.049). HOMA-IR was positively associated with blood pressure (r = 0.347, p = 0.004), resting heart rate (r = 0.433, p = <0.001), response to volume challenge (r = 0.325, p < 0.01). Increased HOMA-IR was associated with a faster cardiac ejection time in response to volume challenge (r = -0.415, p < 0.001), which is a marker of decreased cardiac compliance to volume increase, or cardiac stiffness.

CONCLUSION

HOMA-IR is associated with pre-pregnancy cardiac stiffness. Cholesterol was not associated with cardiovascular dysfunction. A non-significant trend was observed between HOMA-IR and hypertension in subsequent pregnancy.

Assessment of plasma cell-free DNA and ST2 as parameters in gestational hypertension and preeclampsia

The objective of this study was to evaluate the differences and predictive efficacy of circulating cell-free DNA (cfDNA) and human suppression of tumorigenesis 2 (ST2) among women with uncomplicated pregnancies and patients with gestational hypertension (GH) or preeclampsia (PE). This study included patients with GH (n = 41), patients with PE (n = 62), and women with uncomplicated pregnancies (n = 148). The cfDNA concentration was determined by qPCR, and the ST2 levels were measured by ELISA. A receiver operating characteristic curve was employed to measure the diagnostic performance of cfDNA and ST2. Our results showed that ST2 but not cfDNA was increased in the middle and third trimesters of normal pregnancy; ST2 and cfDNA were increased in GH and PE patients compared to women with uncomplicated pregnancies. More importantly, plasma cfDNA and ST2 served as diagnostic biomarkers for GH and PE, and the AUCs were 0.883 and 0.734 for GH and 0.838 and 0.816 for PE, respectively. Moreover, their combination significantly elevated the diagnostic efficiency for GH and PE, with AUCs of 0.906 and 0.916, respectively. Plasma cfDNA and ST2 could be used as parameters for GH and PE.

Acetylcholine ameliorated TNF-α-induced primary trophoblast malfunction via muscarinic receptors†

Oxidative stress and apoptosis of trophoblasts are involved in preeclampsia (PE). Numerous studies have shown that acetylcholine (ACh), the principal vagal neurotransmitter, plays a crucial role in attenuating oxidative stress, inflammation, and apoptosis in a variety of human diseases. However, the role of ACh in PE management remains unclear. Here, we aimed to determine the effects of ACh on TNF-α-treated human primary trophoblast cells. Western blotting, CCK-8, DHE, TUNEL immunofluorescence staining, transwell assays, and wound-healing assays were performed to evaluate the role of ACh in vitro. We found that both TNF-α expression and the apoptotic index were higher in placentas from preeclamptic women than in normal placentas. TNF-α enhanced oxidative stress and increased the number of TUNEL-positive nuclei, Bax/Bcl-2 ratio, and the cleaved caspase-3/caspase-3 ratio while decreasing cell viability in primary human trophoblast cells. TNF-α promoted cell migration and invasion. PDTC, a selective NF-κB inhibitor, significantly blunted TNF-α-induced effects. ACh treatment attenuated oxidative stress and apoptosis while further promoting migration and invasion of TNF-α-treated primary trophoblast cells. The effects of ACh could be reversed by the muscarinic receptor antagonist atropine. Overall, our findings indicate that ACh significantly ameliorates TNF-α-induced oxidative stress and apoptosis of human primary trophoblast cells via muscarinic receptors. This is the first time that the improvement of vagal activity served as a therapeutic strategy for PE-like trophoblasts, suggesting its potential value in clinical practice.

L-Carnitine's Effect on the Biomarkers of Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

A systematic review and meta-analysis of randomized controlled trials (RCTs) was carried out to assess L-carnitine supplements’ influence on the biomarkers of metabolic syndrome (MetSyn). PubMed, EMBASE, Cochrane library, and CINAHL were used to collect RCT studies published prior to February 2020. RCT studies were included if they had at least one of the following biomarker outcome measurements: waist circumference (WC), blood pressure (BP), fasting blood sugar (FBS), triglyceride (TG), or high density lipoprotein-cholesterol (HDLc). Nine of twenty studies with adequate methodological quality were included in this meta-analysis. The dose of L-carnitine supplementation administered varied between 0.75 and 3 g/day for durations of 8–24 weeks. L-carnitine supplementation significantly reduced WC and systolic BP (SBP), with no significant effects on FBS, TG, and HDLc. We found that L-carnitine supplementation at a dose of more than 1 g/d significantly reduced FBS and TG and increased HDLc. In conclusion, L-carnitine supplementation is correlated with a significant reduction of WC and BP. A dose of 1–3 g/d could improve the biomarkers of MetSyn by reducing FBS and TG and increasing HDLc.

Effect of preeclampsia and preeclampsia severity on insulin, HOMA-IR, and betatrophin levels in non-diabetic pregnant women

BACKGROUND

The aim of the study was to evaluate the effect of preeclampsia and its severity on insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), and betatrophin levels in non-diabetic pregnant women.

METHODS

Our study comprised 102 pregnant women who were divided into the following three groups: (1) control, (2) severe preeclampsia, and (3) mild preeclampsia. The women were screened with the single-stage 75-g oral glucose tolerance test (OGTT), and the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria were used for diagnosis. Those women with type 2 diabetes (T2D) mellitus or gestational diabetes mellitus (GDM) were excluded from the study.

RESULTS

Maternal demographic characteristics were similar among the groups. Fasting plasma glucose and postprandial 2-h plasma glucose levels were significantly increased in the severe-preeclampsia group compared to that in the other groups. Fasting insulin levels were 14.3 ± 8.7uU/mL in the severe-preeclampsia group, 19.1 ± 6.0uU/mL in the mild-preeclampsia group, and 20.5 ± 12.5uU/mL in the control group and significantly lower in the severe-preeclampsia group than in the mild-preeclampsia and control groups. The serum betatrophin level was 7.8 ± 2.6 ng/mL in the severe-preeclampsia group, 6.1 ± 1.8 ng/mL in the mild-preeclampsia group, and 5.8 ± 1.3 ng/mL in the control group and significantly increased in the severe-preeclampsia group compared to other groups. HOMA-IR was similar among the groups. Maternal serum insulin levels were negatively (r = -0,255; P = 0.010) and serum betatrophin levels were positively (r = 0.368; P ≤ 0.001) correlated with preeclampsia severity.

CONCLUSION

Our results indicated that severe preeclampsia effect maternal serum glucose, insulin and betatrophin levels. Histhopatholical and immunohistochemical demostrations on pancreatic cells in new preeclampsia rat models will expand the information on the current situation.

Heart rate variability in hypertensive pregnancy disorders: A systematic review

BACKGROUND

Hypertensive pregnancy disorders (HPD) are associated with dysfunction of the autonomic nervous system. Cardiac autonomic functions can be assessed by heart rate variability (HRV) measurements.

OBJECTIVE

To study whether HRV detects differences in the function of the autonomic nervous system between pregnant women with HPD compared to normotensive pregnant women and between women with a history of a pregnancy complicated by HPD compared to women with a history of an uncomplicated pregnancy.

METHODS

A systematic search was performed in Medline, EMBASE, and CENTRAL to identify studies comparing HRV between pregnant women with HPD or women with a history of HPD to women with (a history of) normotensive pregnancies.

RESULTS

The search identified 523 articles of which 24 were included in this review, including 850 women with (a history of) HPD and 1205 normotensive controls. The included studies showed a large heterogenicity. A decrease in overall HRV was found in preeclampsia (PE), compared to normotensive pregnant controls. A trend is seen towards increased low frequency/high frequency-ratio in women with PE compared to normotensive pregnant controls.

CONCLUSION

Our systematic review supports the hypothesis a sympathetic overdrive is found in HPD which is associated with a parasympathetic withdrawal. However, the included studies in our review showed a large diversity in the methods applied and their results.

Down-regulation of Cx43 expression on PIH-HUVEC cells attenuates monocyte-endothelial adhesion

INTRODUCTION

Pregnancy-induced hypertension (PIH) is the most common serious complication of pregnancy, resulting in significant maternal and fetal morbidity and mortality. Vasospasm is the main pathogenesis of PIH, which leads to the hemodynamic changes and the injury of vascular endothelial cells. However, the underlying mechanism is still unclear. Monocyte-endothelial adhesion is always considered to be one of the most important indicators of vascular endothelial cell injury. Connexin43 (Cx43) plays an important part in monocyte-endothelial adhesion. Thus, we explored effects of Cx43 on cell adhesion in PIH-induced vascular endothelial cells injury.

METHODS

We obtained human umbilical vein endothelial cells (HUVECs) from patients with or without PIH. Different methods, such as inhibitors: oleamide and Gap26, or specific siRNA were used to alter Cx43 channels function or protein expression in normal or PIH-HUVECs. U937-HUVECs adhesion, adhesion molecules expression, such as VCAM-1 and ICAM-1, and the activity of PI3K/AKT/NF-κB signaling pathway were determined.

RESULTS

Monocyte-endothelial adhesion on PIH-HUVECs was much more obvious than that on normal HUVECs. Inhibition of Cx43 protein expression could attenuate cell adhesion significantly, however, function of Cx43 channels had no effects on it. Alternation of Cx43 protein expression on PIH-HUVECs mediated VCAM-1 and ICAM-1 expression via regulating the activity of PI3K/AKT/NF-κB signaling pathway.

CONCLUSIONS

We firstly reported Cx43 protein expression on PIH-HUVECs was much higher than that on normal HUVECs. Elevation of Cx43 protein expression within the vasculature resulted in PI3K/AKT/NF-κB signaling pathway activation and VCAM-1 and ICAM-1 over-expression, which ultimately lead to monocyte-endothelial adhesion increase.

Correlation of gestational hypertension with abnormal lipid metabolism, insulin resistance and D-dimer and their clinical significance

Correlation of gestational hypertension with abnormal lipid metabolism, insulin resistance and D-dimer were investigated. Seventy-three patients with gestational hypertension in Jinhua People's Hospital were selected as the observation group and 70 healthy gestational subjects were selected as the control group. The indexes of lipid metabolism, insulin resistance index [homeostasis model assessment (HOMA)] and the level of D-dimer in the two groups were compared and the correlation of gestational hypertension with the changes in lipid metabolism, insulin resistance and D-dimer was analyzed. The level of HDL-C (high-density lipoprotein cholesterol) in the observation group was significantly lower than that in the control group (P<0.05), while the levels of other indexes were all significantly higher than those in the control group (P<0.05). HOMA index and D-dimer in the observation group were both significantly higher than those in the control group (P<0.05). TG was positively correlated with gestational hypertension (r=0.8767, P<0.01). The correlation analysis of HOMA and gestational hypertension showed positive correlation (r=0.8819, P<0.01). In addition, D-dimer was positively correlated with gestational hypertension (r=0.8933, P<0.01). Lipid metabolism indexes are abnormal in patients with gestational hypertension as well as for insulin resistance index and D-dimer. Besides, the above-mentioned indexes are all correlated with the patients with gestational hypertension. Therefore, more observations should be made on lipid metabolism indexes, insulin resistance and D-dimer in the future treatment of gestational hypertension.