Plasma Levels of Free Fatty Acids in Women with Gestational Diabetes and Its Intrinsic and Extrinsic Determinants: Systematic Review and Meta-Analysis

Advances in free fatty acid profiles in gestational diabetes mellitus

The morbidity of gestational diabetes mellitus (GDM) is increasing and is associated with adverse perinatal outcomes and long-term maternal and infant health. The exact mechanism underlying changes in plasma free fatty acid (FFA) profiles in patients with GDM is unknown. However, it is believed that changes in diet and lipid metabolism may play a role. Fatty acids contain many specific FFAs, and the type of FFA has different impacts on physiological processes; hence, determining changes in FFAs in individual plasma is essential. Alterations in FFA concentration or profile may facilitate insulin resistance. Additionally, some FFAs show potential to predict GDM in early pregnancy and are strongly associated with the growth and development of the fetus and occurrence of macrosomia. Here, we aimed to review changes in FFAs in women with GDM and discuss the relationship of FFAs with GDM incidence and adverse outcomes.

A Study of the Metabolic Pathways Affected by Gestational Diabetes Mellitus: Comparison with Type 2 Diabetes

BACKGROUND

Gestational diabetes mellitus (GDM) remains incompletely understood and increases the risk of developing Diabetes mellitus type 2 (DM2). Metabolomics provides insights etiology and pathogenesis of disease and discovery biomarkers for accurate detection. Nuclear magnetic resonance (NMR) spectroscopy is a key platform defining metabolic signatures in intact serum/plasma. In the present study, we used NMR-based analysis of macromolecules free-serum to accurately characterize the altered metabolic pathways of GDM and assessing their similarities to DM2. Our findings could contribute to the understanding of the pathophysiology of GDM and help in the identification of metabolomic markers of the disease.

METHODS

Sixty-two women with GDM matched with seventy-seven women without GDM (control group). ¹H NMR serum spectra were acquired on an 11.7 T Bruker Avance DRX NMR spectrometer.

RESULTS

We identified 55 metabolites in both groups, 25 of which were significantly altered in the GDM group. GDM group showed elevated levels of ketone bodies, 2-hydroxybutyrate and of some metabolic intermediates of branched-chain amino acids (BCAAs) and significantly lower levels of metabolites of one-carbon metabolism, energy production, purine metabolism, certain amino acids, 3-methyl-2-oxovalerate, ornithine, 2-aminobutyrate, taurine and trimethylamine N-oxide.

CONCLUSION

Metabolic pathways affected in GDM were beta-oxidation, ketone bodies metabolism, one-carbon metabolism, arginine and ornithine metabolism likewise in DM2, whereas BCAAs catabolism and aromatic amino acids metabolism were affected, but otherwise than in DM2.

Unique Metabolic Profiles Associate with Gestational Diabetes and Ethnicity in Low- and High-Risk Women Living in the UK

BACKGROUND

Gestational diabetes mellitus (GDM) is the most common global pregnancy complication; however, prevalence varies substantially between ethnicities, with South Asians (SAs) experiencing up to 3 times the risk of the disease compared with white Europeans (WEs). Factors driving this discrepancy are unclear, although the metabolome is of great interest as GDM is known to be characterized by metabolic dysregulation.

OBJECTIVES

The primary aim was to characterize and compare the metabolic profiles of GDM in SA and WE women (at <28 wk of gestation) from the Born in Bradford (BIB) prospective birth cohort in the United Kingdom.

METHODS

In total, 146 fasting serum metabolites, from 2,668 pregnant WE and 2,671 pregnant SA women (average BMI 26.2 kg/m2, average age 27.3 y) were analyzed using partial least squares discriminatory analyses to characterize GDM status. Linear associations between metabolite values and post-oral glucose tolerance test measures of dysglycemia (fasting glucose and 2 h postglucose) were also examined.

RESULTS

Seven metabolites associated with GDM status in both ethnicities (variable importance in projection ≥1), whereas 6 additional metabolites associated with GDM only in WE women. Unique metabolic profiles were observed in healthy-weight women who later developed GDM, with distinct metabolite patterns identified by ethnicity and BMI status. Of the metabolite values analyzed in relation to dysglycemia, lactate, histidine, apolipoprotein A1, HDL cholesterol, and HDL2 cholesterol associated with decreased glucose concentration, whereas DHA and the diameter of very low-density lipoprotein particles (nm) associated with increased glucose concertation in WE women, and in SAs, albumin alone associated with decreased glucose concentration.

CONCLUSIONS

This study shows that the metabolic risk profile for GDM differs between WE and SA women enrolled in BiB in the United Kingdom. This suggests that etiology of the disease differs between ethnic groups and that ethnic-appropriate prevention strategies may be beneficial.

Adiponectin ameliorates placental injury in gestational diabetes mice by correcting fatty acid oxidation/peroxide imbalance-induced ferroptosis via restoration of CPT-1 activity

PURPOSE

In gestational diabetes (GDM), abnormalities occur not only in glucose metabolism, but also in lipid metabolism. Adiponectin (ADPN) plays an important role in the regulation of lipid metabolism. In this paper, the role and mechanism of ADPN in GDM are discussed.

METHODS

GDM model was formed in pregnant mice induced by high-fat diet and streptozotocin, and blood glucose level was detected after ADPN treatment. The levels of TG, TC, HDL-C, and LDL-C in blood lipid of mice were detected by biochemical apparatus. HE staining was used to detect the placenta damage in mice. The expression of oxidative stress-related indexes in placental tissues was also detected by ELISA. Placental iron deposition was detected by Prussian blue staining. Redox capacity of placental tissue was detected by ELISA. Western blot was used to detect the expression of ferroptosis-related proteins in placental tissues. The expression of ADPN in placenta and peripheral blood was detected by ELISA, and the expression of ADPNR, downstream CPT-1, and GLUT4 of placenta were detected by RT-qPCR and western blot. Subsequently, trophoblast cells were induced by palmitic acid and glucose, and the cell activity was detected by CCK-8. The results in animal experiments were verified in cell experiments by RT-qPCR, western blot, and fluorescence labeling of iron ions. Finally, ADPN and CPT-1 inhibitor PM were given to trophoblast cells to further explore the mechanism.

RESULTS

ADPN inhibited blood glucose and lipid levels in GDM mice. ADPN inhibited oxidation/peroxide imbalance-induced ferroptosis in placental tissues of GDM mice. ADPN inhibited the expression of CPT-1 and GLUT4 in placental tissues of GDM mice. This result was also confirmed in cell experiments, and this process may be achieved by regulating CPT-1.

CONCLUSIONS

ADPN ameliorated placental injury in GDM by correcting fatty acid oxidation/peroxide imbalance-induced ferroptosis via restoration of CPT-1 activity.

A low-carbohydrate dietary pattern characterised by high animal fat and protein during the first trimester is associated with an increased risk of gestational diabetes mellitus in Chinese women: a prospective cohort study

We aimed to examine the association between low-carbohydrate diet (LCD) scores during the first trimester and gestational diabetes mellitus (GDM) risk in a Chinese population. A total of 1455 women were included in 2017. Dietary information during the first trimester was collected by 24-h dietary recalls for 3 d. The overall, animal and plant LCD scores, which indicated adherence to different low-carbohydrate dietary patterns, were calculated. GDM was diagnosed based on the results of a 75-g, 2-h oral glucose tolerance test at 24-28 weeks gestation. Log-binomial models were used to estimate relative risks (RR) and 95 % CI. The results showed that the multivariable-adjusted RR of GDM from the lowest to the highest quartiles of the overall LCD score were 1·00 (reference), 1·15 (95 % CI 0·92, 1·42), 1·30 (95 % CI 1·06, 1·60) and 1·24 (95 % CI 1·01, 1·52) (P = 0·026 for trend). Multivariable-adjusted RR (95 % CI) of GDM from the lowest to the highest quartiles of the animal LCD score were 1·00 (reference), 1·20 (95 % CI 0·96, 1·50), 1·41 (95 % CI 1·14, 1·73) and 1·29 (95 % CI 1·04, 1·59) (P = 0·002 for trend). After additional adjustment for gestational weight gain before GDM diagnosis, the association of the overall LCD score with GDM risk was non-significant, while the association of animal LCD score with GDM risk remained significant. In conclusion, a low-carbohydrate dietary pattern characterised by high animal fat and protein during the first trimester is associated with an increased risk of GDM in Chinese women.

Increased Fetal Cardiovascular Disease Risk: Potential Synergy Between Gestational Diabetes Mellitus and Maternal Hypercholesterolemia

Cardiovascular diseases (CVD) remain a major cause of death worldwide. Evidence suggests that the risk for CVD can increase at the fetal stages due to maternal metabolic diseases, such as gestational diabetes mellitus (GDM) and maternal supraphysiological hypercholesterolemia (MSPH). GDM is a hyperglycemic, inflammatory, and insulin-resistant state that increases plasma levels of free fatty acids and triglycerides, impairs endothelial vascular tone regulation, and due to the increased nutrient transport, exposes the fetus to the altered metabolic conditions of the mother. MSPH involves increased levels of cholesterol (mainly as low-density lipoprotein cholesterol) which also causes endothelial dysfunction and alters nutrient transport to the fetus. Despite that an association has already been established between MSPH and increased CVD risk, however, little is known about the cellular processes underlying this relationship. Our knowledge is further obscured when the simultaneous presentation of MSPH and GDM takes place. In this context, GDM and MSPH may substantially increase fetal CVD risk due to synergistic impairment of placental nutrient transport and endothelial dysfunction. More studies on the separate and/or cumulative role of both processes are warranted to suggest specific treatment options.

Gestational diabetes mellitus decreased umbilical cord blood polyunsaturated fatty acids: a meta-analysis of observational studies

BACKGROUND

Polyunsaturated fatty acid (PUFA) is important for the development of the fetal brain, and the retina. Gestational diabetes mellitus (GDM) may influence maternal and fetal fatty acid metabolism, in turn affecting fetal growth and development. In several studies, maternal and fetal PUFA metabolic differences have been reported between mothers with and without GDM, but not in other studies. Thus, the aim of this meta-analysis (registration number: CRD42020220448) was to compare levels of linoleic acid (LA), α-linolenic acid (ALA), arachidonic acid (AA), docosahexaenoic acid (DHA), and total n-3 and n-6 PUFA between mothers with and without GMD and their fetuses.

METHODS

We performed a meta-analysis of observational studies on maternal and fetal fatty acid metabolism, published until May 2021. In addition, we performed subgroup analysis depending on the analyzed tissues (plasma/serum, erythrocyte membrane, or placenta) and the expression modes of fatty acids (concentration or percentage).

RESULTS

We included 24 observational studies involving 4335 maternal datasets and 12 studies involving 1675 fetal datasets in the meta-analysis. Levels of AA, DHA, and n-6 and n-3 PUFA were lower in the cord blood of mothers with GDM than in controls (P  <  0.05). Compared to that in controls, in erythrocyte membranes, the percentages of AA, DHA, and n-6 and n-3 PUFA in total fatty acid were lower in mothers with GDM (P  <  0.05), but in plasma/serum, the percentages of AA, DHA, and n-6 PUFA in total fatty acid were higher in mothers with GDM (P  <  0.05).

CONCLUSIONS

GDM appears to influence the transfer of PUFAs from mothers to fetuses. The percentage of PUFAs in maternal plasma/serum was higher, and that in erythrocyte membranes was lower in mothers with GDM compared to those with normal glucose tolerance.

Early pregnancy plasma fatty acid profiles of women later diagnosed with gestational diabetes

INTRODUCTION

Fatty acid (FA) concentrations have previously been associated with gestational diabetes mellitus (GDM). However, few studies on GDM have examined FA profiles in early pregnancy or before diagnosis. This study aimed to compare early pregnancy plasma FA profiles of women with and without GDM diagnoses as well as their reported dietary consumption.

RESEARCH DESIGN AND METHODS

The subjects comprised 853 women from the prospective study: Pregnant Women in Iceland II (PREWICE II), attending their 11-14 weeks ultrasound appointment in 2017-2018. During the visit, blood samples were collected for plasma FA analysis, and dietary habits were assessed using a short food frequency questionnaire. Information on GDM diagnoses was then later extracted from medical records. Differences in FA profile between GDM cases and non-cases were evaluated using the Mann-Whitney U test.

RESULTS

GDM was diagnosed in 127 women (14.9%). Concentrations of saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids (PUFA) n-6, PUFA n-3 and total FA were higher in the women who later developed GDM compared with those who did not (p≤0.05). The medians for total FA were 2898 μg/mL for the women with GDM and 2681 μg/mL for those without GDM. Mean adjusted difference for total FA between the groups was 133 μg/mL (95% CI 33 to 233). Similar results were observed in prepregnancy normal-weight women and overweight women/women with obesity. Overall diet quality in early pregnancy appeared to be lower among the women later diagnosed with GDM.

CONCLUSION

We found that plasma FA profiles in early pregnancy were different for women later diagnosed with GDM compared with those who were not, independent of the women's body mass index.