Serum saturated fatty acid decreases plasma adiponectin and increases leptin throughout pregnancy independently of BMI

Serum fatty acid profiles associated with metabolic risk in women with polycystic ovary syndrome

PURPOSE

Dyslipidemia is a feature of polycystic ovary syndrome (PCOS) that may augment metabolic disturbances. Serum fatty acids are important biomedical indicators of dyslipidemia. The aim of this study was to determine the distinct serum fatty acids in various PCOS subtypes and their association with metabolic risk in women with PCOS.

METHODS

Fatty acids in the serum of 202 women with PCOS were measured using gas chromatography-mass spectrometry. Fatty acids were compared between PCOS subtypes and correlated with glycemic parameters, adipokines, homocysteine, sex hormones, and sex hormone-binding globulin (SHBG).

RESULTS

The levels of total monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) in the reproductive subtype of PCOS were lower than those in the metabolic subtype. Docosahexaenoic acid, a PUFA, was associated with higher SHBG after correction for multiple comparisons. Eighteen species of fatty acids emerged as potential biomarkers associated with the metabolic risk factors measured, independent of body mass index (BMI). Among them, myristic acid (C14:0), palmitoleic acid (C16:1), oleic acid (C18:1n-9C), cis-vaccenic acid (C18:1n-7), and homo-gamma-linolenic acid (C20:3n-6) were the strongest lipid species that were consistently associated with metabolic risk factors, particularly insulin-related parameters in women with PCOS. As for adipokines, 16 fatty acids were positively associated with serum leptin. Among them, C16:1 and C20:3n-6were significantly associated with leptin levels.

CONCLUSION

Our data demonstrated that a distinct fatty acid profile comprising high C14:0, C16:1, C18:1n-9C, C18:1n-7, and C20:3n-6levels is associated with metabolic risk in women with PCOS, independent of BMI.

High-fat diets containing different types of fatty acids modulate gut-brain axis in obese mice

Background

Excessive consumption of high-fat diets is associated with disordered metabolic responses, which may lead to chronic diseases. High-fat diets containing different types of fatty acids lead to distinct alterations in metabolic responses of gut-brain axis.

Methods

In our study, normal male C57BL/6J mice were fed to multiple high fatty acid diets (long-chain and medium-chain saturated fatty acid, LCSFA and MCSFA group; n-3 and n-6 polyunsaturated fatty acid, n-3 and n-6 PUFA group; monounsaturated fatty acid, MUFA group; trans fatty acid, TFA group) and a basic diet (control, CON group) for 19 weeks. To investigate the effects of high-fat diets on metabolic responses of gut-brain axis in obese mice, blood lipids were detected by fast gas chromatography, and related proteins in brain and intestine were detected using Western blotting, ELISA, and immunochemistry analysis.

Results

All high-fat diets regardless of their fatty acid composition induced obesity, lipid disorders, intestinal barrier dysfunction, and changes in gut-brain axis related factors except basal diet in mice. For example, the protein expression of zonula occludens-1 (ZO-1) in ileum in the n-3 PUFA group was higher than that in the MCSFA group (P < 0.05). The expressions of insulin in hippocampus and leptin in ileum in the MCSFA group significantly increased, compared with other groups (all Ps < 0.05).

Conclusion

The high MCSFA diet had the most effect on metabolic disorders in gut-brain axis, but the high n-3 PUFA diet had the least effect on changes in metabolism.

Sources of Variation in Food-Related Metabolites during Pregnancy

The extent to which variation in food-related metabolites are attributable to non-dietary factors remains unclear, which may explain inconsistent food-metabolite associations observed in population studies. This study examined the association between non-dietary factors and the serum concentrations of food-related biomarkers and quantified the amount of variability in metabolite concentrations explained by non-dietary factors. Pregnant women (n = 600) from two Canadian birth cohorts completed a validated semi-quantitative food frequency questionnaire, and serum metabolites were measured by multisegment injection-capillary electrophoresis-mass spectrometry. Hierarchical linear modelling and principal component partial R-square (PC-PR2) were used for data analysis. For proline betaine and DHA (mainly exogenous), citrus foods and fish/fish oil intake, respectively, explained the highest proportion of variability relative to non-dietary factors. The unique contribution of dietary factors was similar (15:0, 17:0, hippuric acid, TMAO) or lower (14:0, tryptophan betaine, 3-methylhistidine, carnitine) compared to non-dietary factors (i.e., ethnicity, maternal age, gestational age, pre-pregnancy BMI, physical activity, and smoking) for metabolites that can either be produced endogenously, biotransformed by gut microbiota, and/or derived from multiple food sources. The results emphasize the importance of adjusting for non-dietary factors in future analyses to improve the accuracy and precision of the measures of food intake and their associations with health and disease.

Longitudinal changes in circulating concentrations of inflammatory markers throughout pregnancy: are there associations with diet and weight status?

The natural inflammation occurring during pregnancy can, under certain conditions, be associated with adverse pregnancy outcomes. This study aimed to: 1) quantify changes in circulating concentrations of leptin, adiponectin, interleukin-6 (IL-6) and C-reactive protein (CRP) across trimesters of pregnancy, according to pre-pregnancy body mass index (ppBMI); and 2) examine the trimester-specific associations between the inflammatory markers' concentrations, a Mediterranean diet score (MDS) and the dietary inflammatory index (DII). We measured leptin, adiponectin and IL-6 by ELISA, and CRP by high-sensitivity immunonephelometry, in blood samples from 79 pregnant women (age: 32.1 ± 3.7 years; ppBMI: 25.7 ± 5.8 kg/m2). Three web-based 24h recalls were completed at each trimester and used to compute the MDS and the DII. CRP concentrations remained stable across trimesters, whereas concentrations of leptin and IL-6 increased, and adiponectin concentrations decreased (p<0.001). Changes in leptin and adiponectin concentrations also differed according to ppBMI categories (p<0.05). As for the dietary scores, the only significant association was observed in the second trimester between leptin concentrations and the MDS (r=-0.26, p<0.05). In conclusion, ppBMI and the progression of pregnancy itself probably supplant the potential associations between diet and the inflammation occurring during that period. Novelty: • Circulating leptin and IL-6 concentrations increased across trimesters whereas CRP was stable, and adiponectin decreased. • Variations in circulating leptin and adiponectin concentrations differed by ppBMI categories. • Very few associations were observed between dietary scores and inflammatory markers.

The Influence of Nutrition on Adiponectin-A Narrative Review

The adipose tissue is an active endocrine organ which synthesizes and secretes a variety of adipokines, including adiponectin with its anti-inflammatory properties. Its expression is influenced by numerous factors such as age, sex, body weight and adipose tissue content. However, dietary factors, i.e., diet structure and the percentage of individual nutrients and products, are very important modulators. Beneficial dietary habits are the Mediterranean diet, DASH diet, diet based on plant products and diet with reduced energy value. Moreover, the share of individual products and nutrients which increase the concentration of adiponectin is worth noting. This group may include monounsaturated fatty acids, polyunsaturated omega-3 fatty acids, dietary fiber, polyphenols, alcohol and milk products. Conversely, dietary ingredients which have a negative effect on the concentration of adiponectin are typical components of the Western diet: saturated fatty acids, trans fatty acids, monosaccharides and disaccharides, and red meat. Furthermore, a diet characterized by a high glycemic index such as a high-carbohydrate low-fat diet also seems to be unfavorable. Due to the fact that available knowledge should be systematized, this study aimed to summarize the most recent research on the influence of dietary factors on the concentration of adiponectin.

Diet containing stearic acid increases food reward-related behaviors in mice compared with oleic acid

Obesity is currently a worldwide phenomenon. The consumption of calorie-rich foods is responsible for most obesity cases, but not all humans exposed to high-calorie diets develop obesity. According to recent studies, exposure to fat-rich diets may be the actual cause of obesity. Dietary long-chain fatty acids affect brain function and are linked to food intake and motivation-related behaviors. Recently, many studies have shown that different types of fatty acids play different roles in animals. In our study, the effects of stearic acid (a saturated fatty acid) and oleic acid (a monounsaturated fatty acid) in diets on hedonic feeding behaviors were investigated, and changes of feeding-related protein levels in the brain were detected to explore the possible mechanism underlying the effects of these fatty acids. As a result, mice fed a diet containing stearic acid, compared to a diet containing oleic acid, exhibited increased food intake, hedonic eating, and an operant response to sucrose and locomotor activity. Furthermore, stearic acid corresponded to a higher level of leptin in serum than oleic acid. In addition, the stearic acid treated group had lower protein levels of p-JAK2 and p-STAT3 in the VTA and a higher dopamine concentration in the NAc than the oleic acid-treated group. Meanwhile, the protein level of TH in the NAc was higher and the protein level of the DA transporter in the VTA was lower in the stearic acid-fed group than in the oleic acid-fed group. In conclusion, these findings indicated that a diet containing stearic acid can increase hedonic feeding behavior and affect mesolimbic dopamine system signals in mice. Moreover, the lowering of serum leptin and leptin signaling in the VTA may contribute to this effect.

Uterine perivascular adipose tissue is a novel mediator of uterine artery blood flow and reactivity in rat pregnancy

KEY POINTS

In vivo, uterine perivascular adipose tissue (PVAT) potentiates uterine artery blood flow in pregnant rats, although not in non-pregnant rats. In isolated preparations, uterine PVAT has pro-contractile and anti-dilatory effects on uterine arteries. Pregnancy induces changes in uterine arteries that makes them responsive to uterine PVAT signalling.

ABSTRACT

An increase in uterine artery blood flow (UtBF) is a common and necessary feature of a healthy pregnancy. In the present study, we tested the hypothesis that adipose tissue surrounding uterine arteries (uterine perivascular adipose tissue; PVAT) is a novel local mediator of UtBF and uterine artery tone during pregnancy. In vivo experiments in anaesthetized Sprague-Dawley rats showed that pregnant animals (gestational day 16, term = 22--23 days) had a three-fold higher UtBF compared to non-pregnant animals. Surgical removal of uterine PVAT reduced UtBF only in pregnant rats. In a series of ex vivo bioassays, we demonstrated that uterine PVAT had pro-contractile and anti-dilatory effects on rat uterine arteries. In the presence of PVAT-conditioned media, isolated uterine arteries from both pregnant and non-pregnant rats had reduced vasodilatory responses. In non-pregnant rats, these responses were mediated at the level of uterine vascular smooth muscle, whereas, in pregnant rats, PVAT-media reduced endothelium-dependent relaxation. Pregnancy increased adipocyte size in ovarian adipose tissue but had no effect on uterine PVAT adipocyte morphology. In addition, pregnancy down-regulated the gene expression of metabolic adipokines in uterine but not in aortic PVAT. In conclusion, this is the first study to demonstrate that uterine PVAT plays a regulatory role in UtBF, at least in part, as a result of its actions on uterine artery tone. We propose that the interaction between the uterine vascular wall and its adjacent adipose tissue may provide new insights for interventions in pregnancies with adipose tissue dysfunction and abnormal UtBF.

A prospective and longitudinal study of plasma phospholipid saturated fatty acid profile in relation to cardiometabolic biomarkers and the risk of gestational diabetes

Background

Data on saturated fatty acids (SFAs) in relation to metabolic function and glucose homeostasis remain controversial. Such data are lacking among pregnant women.

Objective

We prospectively investigated objectively measured individual and subclasses of plasma phospholipid SFAs throughout pregnancy in relation to cardiometabolic markers and gestational diabetes mellitus (GDM) risk.

Design

Within the National Institute of Child Health and Human Development Fetal Growth Studies-Singleton Cohort of 2802 singleton pregnancies, 107 GDM cases were ascertained via medical record review and matched to 214 non-GDM controls on age, race/ethnicity, and gestational week (GW) at blood collection. Individual plasma phospholipid SFA concentrations were repeatedly measured throughout pregnancy at GWs 10-14, 15-26, 23-31, and 33-39 and also grouped into subclasses of even- or odd-chain SFAs.

Results

From GW 10, even-chain SFA concentrations were significantly higher among women who later developed GDM, whereas odd-chain SFAs were significantly lower among GDM cases compared with controls. At GWs 10-14, the SFA palmitic acid (16:0) was positively associated with impaired insulin resistance and cardiometabolic markers and the risk of GDM [adjusted OR comparing the highest with the lowest quartile (aORQ4-Q1): 4.76; 95% CI: 1.72, 13.10; P-trend = 0.001]. In contrast, odd-chain SFAs were inversely related to the previously mentioned markers and GDM risk [aORQ4-Q1 for pentadecanoic acid (15:0): 0.32; 95% CI: 0.11, 0.92; P-trend = 0.025; for heptadecanoic acid (17:0): 0.20; 95% CI: 0.07, 0.58; P-trend = 0.003]. Women with high (median or greater) even-chain SFA concentrations and low (less than median) odd-chain SFAs had a 9.43-fold (95%: CI 3.26-, 27.30-fold) increased risk compared with women with low even-chain and high odd-chain SFA concentrations. Similar results were observed at GWs 15-26.

Conclusions

The study provided one of the first lines of evidence suggesting that circulating concentrations of SFAs varying by SFA chain length, as early as GWs 10-14, were significantly and differentially associated with subsequent risk of GDM. Our findings highlight the importance of assessing objectively measured, individual, and subclasses of SFAs to investigate their distinct biological and pathophysiologic roles in glucose homeostasis and cardiometabolic outcomes. This study was registered at www.clinicaltrials.gov as NCT00912132.

Maternal lipids and leptin concentrations are associated with large-for-gestational-age births: a prospective cohort study

The change in maternal lipid, leptin and adiponectin concentrations during pregnancy and infant birth weight (BW) is still poorly characterized. Thus, the aim of the study was to evaluate the association of maternal lipids, leptin and adiponectin throughout pregnancy with large-for-gestational-age (LGA) births and BW z-score. A prospective cohort of 199 mothers was followed during pregnancy in Rio de Janeiro, Brazil. The statistical analyses comprised multiple logistic and linear regression. Women delivered 36 LGA and 11 small-for-gestational-age newborns. HDL-c rate of change throughout pregnancy was negatively associated with BW z-score (β = −1.99; p = 0.003) and the delivery of a LGA newborn (OR = 0.02; p = 0.043). Pregnancy baseline concentration of log leptin was positively associated (OR = 3.92; p = 0.025) with LGA births. LDL-c rate of change throughout pregnancy was positively associated with BW z-score (β = 0.31; p = 0.004). Log triglycerides and log adiponectin were not significantly associated with BW z-score or LGA birth. In conclusion, a higher log leptin pregnancy baseline concentration and a lower HDL-c rate of change during pregnancy were associated with higher odds of having a LGA newborn. These maternal biomarkers are important to foetal growth and could be used in prenatal care as an additional strategy to screen women at risk of inadequate BW.

Low-Grade Metabolically-Induced Inflammation Mediators Interleukin-6, Adiponectin, and TNF-α Serum Levels in Obese Pregnant Patients in the Perinatal Period

Background

Obesity is a major clinical problem. The number of obese pregnant women is rising rapidly. The consequences of obesity are significant and affect every aspect of perinatal care for both the mother and the developing fetus. Adipose tissue may be responsible for chronic subclinical inflammation in obesity, being a source of inflammatory mediators. The study was designed to evaluate the analysis of the serum concentration of inflammatory mediators, including interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and adiponectin, in obese pregnant women at full-term pregnancies.

Material/Methods

The study included 40 women with body mass index (BMI) less than 30 and 24 pregnant women with BMI equal to or greater than 30, admitted to the Perinatology and Obstetrics Department of the University Hospital in Cracow in the first stage of labor. Blood samples were taken from patients to detect the serum concentration of cytokines. Ultrasound was used to evaluate the development of the fetus, including estimated fetal weight, Doppler flows, and the amount of amniotic fluid. We also included the history of chronic diseases and other complications of the pregnancy. A p-value <0.05 was considered significant.

Results

The level of adiponectin in obese patients as compared to controls was significantly lower. There was no statistically significant difference in either group when TNF-α and IL-6 were measured. The results of the survey are consistent with previous reports.

Conclusions

The exact role of inflammation in pregnancy is not well understood. Determining the exact functions of the different cytokines in physiological pregnancy and pregnancy complicated by obesity requires further study.