Hydrogenated fat intake during pregnancy and lactation modifies serum lipid profile and adipokine mRNA in 21-day-old rats

Trans isomeric fatty acids in human milk and their role in infant health and development

It is well known that long chain polyunsaturated fatty acids (LCPUFAs) play an important role in neurodevelopment in the perinatal life. The most important source of these fatty acids is the diet, however, they can also be formed in the human body from their shorter chain precursors, the essential fatty acids. Since the WHO recommends exclusive breastfeeding for the first six months after birth, the exclusive source of these fatty acids for breastfed infants is human milk, which can be influenced by the mother's diet. Unsaturated fatty acids can have either cis or trans configuration double bond in their chain with distinct physiological effects. Cis isomeric unsaturated fatty acids have several beneficial effects, while trans isomers are mostly detrimental, because of their similar structure to saturated fatty acids. Trans fatty acids (TFAs) can be further subdivided into industrial (iTFA) and ruminant-derived trans fatty acids (rTFA). However, the physiological effects of these two TFA subgroups may differ. In adults, dietary intake of iTFA has been linked to atherosclerosis, insulin resistance, obesity, chronic inflammation, and increased development of certain cancers, among other diseases. However, iTFAs can have a negative impact on health not only in adulthood but in childhood too. Results from previous studies have shown that iTFAs have a significant negative effect on LCPUFA levels in the blood of newborns and infants. In addition, iTFAs can affect the growth and development of infants, and animal studies suggest that they might even have lasting negative effects later in life. Since the only source of TFAs in the human body is the diet, the TFA content of breast milk may determine the TFA supply of breastfed infants and thus affect the levels of LCPUFAs important for neurodevelopment and the health of infants. In this review, we aim to provide an overview of the TFA content in human milk available in the literature and their potential effects on infant health and development.

Influence of maternal consumption of different types of fatty acids during pregnancy and lactation on lipid and glucose metabolism of the 21-day-old male offspring in rats

We evaluated the impacts of maternal consumption of different types of fatty acids during pregnancy and lactation on the lipid and glucose metabolism of 21-day-old offspring. Rats received either control (C), saturated (SFAs), trans (TFAs) or n - 3 polyunsaturated (PUFAs) normolipidic diets throughout pregnancy and lactation. 21-day old male pups constituted the groups: C21, S21, T21 and PUFA21. At 21st day, serum parameters, hepatic triacylglycerol (TAG) deposition, oral glucose tolerance test (OGTT) and liver protein expressions were investigated. We found a decrease in serum concentrations of TAG, total cholesterol and FFA as well as in hepatic TAG content and baseline glycaemia, accompanied by an increase in catalase expression in PUFA21 group. In T21 group, OGTT showed slight disturbance in glucose homeostasis. Summarily, while early exposure to TFAs-based diets seems to harm pups' glucose homeostasis, maternal consumption of n - 3 PUFAs can improve lipid metabolism, TAG hepatic accumulation and catalase protein expression in 21-day-old offspring.

Early exposure to distinct sources of lipids affects differently the development and hepatic inflammatory profiles of 21-day-old rat offspring

Introduction

Maternal diet composition of fatty acids during pregnancy and lactation seems to modify the fetal programming, epigenetic pattern and offspring phenotype.

Aim

Herein, we investigated the effects of maternal consumption of normal-fat diets with distinct lipid sources during pregnancy and lactation on the somatic development and proinflammatory status of 21-day-old rat offspring.

Materials and Methods

On the first day of pregnancy, female Wistar rats were divided into four groups as follows: soybean oil (M-SO), lard (M-L), hydrogenated vegetable fat (M-HVF) and fish oil (M-FO). Diets were maintained during pregnancy and lactation. Male offspring constituted the SO, L, HVF and FO groups. Pups were weighed and measured weekly. Lipopolysaccharide serum concentration was determined. Tumor necrosis factor alpha, interleukin (IL)-6 and IL-10 in the liver were evaluated by enzyme-linked immunosorbent assay. Liver gene expressions were determined by real-time polymerase chain reaction. Protein expressions in the liver were analyzed by Western blotting.

Results

We observed an increase in body weight and adiposity in L and HVF groups. Moreover, HVF group showed an increase in the toll-like receptor 4 mRNA levels, IL10Rα and phosphorylated form of IκB kinase (IKK; p-IKKα+β) protein expression. The FO group presented a decrease in body weight, relative weight of retroperitoneal adipose tissue, ADIPOR2 gene expression, lipopolysaccharide and p-IKKα+β and phosphorylated form of nuclear transcription factor kappa B (NFκB) p50 (p-NFκB p50) protein expression.

Conclusion

Summarily, whereas maternal intake of normal-fat diets based on L and HVF appear to affect the somatic development negatively, only early exposure to HVF impairs the pups’ proinflammatory status. In contrast, maternal diets based on FO during pregnancy and lactation have been more beneficial to the adiposity and toll-like receptor 4 signaling pathway of the 21-day-old rat offspring, particularly when compared to L or HVF diets.

Influence of trans fatty acids on glucose metabolism in soleus muscle of rats fed diets enriched in or deprived of linoleic acid

PURPOSE

Industrial trans fatty acid (TFA) intake leads to impaired glucose metabolism. However, the overall effects reported are inconsistent and vary with the dietary FA composition and TFA isomer type and levels. We investigated TFA effects on glucose uptake, incorporation and oxidation, and glycogen synthesis in incubated soleus muscle under basal conditions or after treatment with insulin and/or palmitate.

METHODS

Male Wistar rats were fed either linoleic acid (LA)-enriched (⁺LA) or LA-deprived (^-LA) diet, supplemented (⁺LA + TFA or ^-LA + TFA) or not with TFA, for 60 days. Soleus muscle glucose metabolism was assessed in the absence or presence of insulin and/or palmitic acid.

RESULTS

Under basal conditions, TFA enhanced glucose uptake and oxidation regardless of the LA status. Both TFA-supplemented groups had lower insulin response to glucose metabolism. Under insulin-stimulated conditions, TFA prevented the palmitate inhibition of muscle glucose uptake and metabolism in the ⁺LA + TFA group.

CONCLUSION

Dietary TFA enhanced glucose utilization in incubated soleus muscle under basal conditions and prevented the palmitate-induced inhibition in insulin-stimulated conditions. However, TFA reduced the insulin response to glucose uptake and metabolism. The effects mentioned above were influenced by the FA profile modifications induced by the dietary LA levels, suggesting that lipid metabolization and incorporation into plasma membrane are important determining factors of glucose metabolism and insulin sensitivity.

Total HDL cholesterol efflux capacity in healthy children - Associations with adiposity and dietary intakes of mother and child

BACKGROUND AND AIMS

High-density lipoprotein (HDL) cholesterol efflux capacity in adults may be a measure of the atheroprotective property of HDL. Little however, is known about HDL cholesterol efflux capacity in childhood. We aimed to investigate the relationship between HDL cholesterol efflux capacity and childhood anthropometrics in a longitudinal study.

METHODS AND RESULTS

Seventy-five children (mean age = 9.4 ± 0.4 years) were followed from birth until the age of 9 years. HDL cholesterol efflux capacity was determined at age 9 by incubating serum-derived HDL-supernatants with ³H-cholesterol labeled J774 macrophages and percentage efflux determined. Mothers provided dietary information by completing food frequency questionnaires in early pregnancy and then 5 years later on behalf of themselves and their children. Pearson's correlations and multiple regression analyses were conducted to confirm independent associations with HDL efflux. There was a negative correlation between HDL cholesterol efflux capacity and waist circumference at age 5 (r = -0.3, p = 0.01) and age 9 (r = -0.24, p = 0.04) and BMI at age 5 (r = -0.45, p = 0.01) and age 9 (r = -0.19, p = 0.1). Multiple regression analysis showed that BMI at age 5 remained significantly associated with reduced HDL cholesterol efflux capacity (r = -0.45, p < 0.001). HDL-C was negatively correlated with energy-adjusted fat intake (r = -0.24, p = 0.04) and positively correlated with energy-adjusted protein (r = 0.24, p = 0.04) and starch (r = 0.29, p = 0.01) intakes during pregnancy. HDL-C was not significantly correlated with children dietary intake at age 5. There were no significant correlations between maternal or children dietary intake and HDL cholesterol efflux capacity.

CONCLUSIONS

This novel analysis shows that efflux capacity is negatively associated with adiposity in early childhood independent of HDL-C.

Maternal Supplementation with Oligofructose (10%) during Pregnancy and Lactation Leads to Increased Pro-Inflammatory Status of the 21-D-Old Offspring

Previously, we showed that oligofructose (10%) supplementation during pregnancy and lactation increased endotoxemia in 21-d-old pups. The present study evaluated the effect of 10% oligofructose diet supplementation during pregnancy and lactation in the presence or absence of hydrogenated vegetable fat on the pro-inflammatory status of 21-d-old offspring. On the first day of pregnancy, female Wistar rats were divided into the following groups: control diet (C), control diet supplemented with 10% oligofructose (CF), diet enriched with hydrogenated vegetable fat (T) or diet enriched with hydrogenated vegetable fat supplemented with 10% oligofructose (TF). Diets were maintained during pregnancy and lactation. Serum TNF-α (tumor necrosis factor alpha) was assessed using a specific kit. Protein expression was determined by Western Blotting, and the relative mRNA levels were analyzed by RT-PCR (real-time polymerase chain reaction). We observed that 10% oligofructose supplementation during pregnancy and lactation increased offspring’s IL-6R (interleukin-6 receptor) mRNA levels in the liver and RET (retroperitoneal white adipose tissue) and decreased ADIPOR2 (adiponectin receptor 2) and ADIPOR1 (adiponectin receptor 1) gene expression in liver and EDL (extensor digital longus)/ SOL (soleus) muscles of CF group. Additionally, TF group presented with increased serum TNF-α, protein expression of p-NFκBp65 (phosphorylated form of nuclear factor kappa B p65 subunit) in liver and IL-6R mRNA levels in RET. These findings were accompanied by decreased levels of ADIPOR1 mRNA in the EDL and SOL muscles of the TF group. In conclusion, supplementing the dam’s diet with 10% of oligofructose during pregnancy and lactation, independent of hydrogenated vegetable fat addition, contributes to the increased pro-inflammatory status of 21-d-old offspring, possibly through the activation of the TLR4 (toll like receptor 4) pathway.

Maternal intake of fat in pregnancy and offspring metabolic health - A prospective study with 20 years of follow-up

BACKGROUND

Maternal fat intake during pregnancy in relation to offspring metabolic outcomes has been studied primarily in animal models, yet little is known about the association in humans. The aim of this study was to examine the association of total and subtype of fat consumption in pregnancy with anthropometric measures and biomarkers of adiposity and glucose metabolism in the offspring.

METHODS

A source population was 965 Danish pregnant women recruited in 1988-1989 with offspring follow-up at 20 years. Information on fat intake was collected in the 30(th) week of gestation, and we subdivided fat according to saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fat. Offspring body mass index (BMI) and waist circumference (WC) were recorded at follow-up (n = 670-678), and biomarkers were quantified in a subset (n = 443) of participants. Multivariable linear and log-binomial regression were used to calculate effect estimates and 95% CI for a 1:1%energy substitution of carbohydrates for fat.

RESULTS

The mean (standard deviation) BMI was 22.1 (3.3) and 22.8 (2.9) kg/m(2) in female and male offspring, respectively. The median (10th to 90th percentile) of maternal fat intake was 31% of energy [23,39]. We found no overall associations for maternal fat intake with female offspring anthropometry. However, for male offspring higher intake of MUFA during pregnancy was associated with higher insulin levels at 20 years (Q4 vs. Q1: %Δ: 37, 95% CI: 1, 86) accompanied by a non-significant 3.6 (95% CI: -1.1, 8.2) cm increase in WC. High maternal total fat intake (>=35% energy) was also associated with higher BMI (0.9, 95% CI: 0.2, 1.6) and WC (4.0, 95% CI: 1.6, 2.3) among male offspring.

CONCLUSIONS

A high fat diet during pregnancy may increase adiposity in adult male offspring. We surmise that maternal MUFA intake during this time included both MUFA and trans fat misclassified as MUFA, and that the associations observed may be more reflective of the latter exposure.

Trans and interesterified fat and palm oil during the pregnancy and lactation period inhibit the central anorexigenic action of insulin in adult male rat offspring

Palm oil and interesterified fat have been used to replace partially hydrogenated fats, rich in trans isomers, in processed foods. This study investigated whether the maternal consumption of normolipidic diets containing these lipids affects the insulin receptor and Akt/protein kinase B (PKB) contents in the hypothalamus and the hypophagic effect of centrally administered insulin in 3-month-old male offspring. At 90 days, the intracerebroventricular injection of insulin decreased 24-h feeding in control rats but not in the palm, interesterified or trans groups. The palm group exhibited increases in the insulin receptor content of 64 and 69 % compared to the control and trans groups, respectively. However, the quantifications of PKB did not differ significantly across groups. We conclude that the intake of trans fatty acid substitutes during the early perinatal period affects food intake regulation in response to centrally administered insulin in the young adult offspring; however, the underlying mechanisms remain unclear.

Type of fatty acids in maternal diets during pregnancy and/or lactation and metabolic consequences of the offspring

During pregnancy and/or lactation, maternal nutrition is related to the adequate development of the fetus, newborn and future adult, likely by modifications in fetal programming and epigenetic regulation. Fetal programming is characterized by adaptive responses to specific environmental conditions during early life stages, which may alter gene expression and permanently affect the structure and function of several organs and tissues, thus influencing the susceptibility to metabolic disorders. Regarding lipid metabolism during the first two trimesters of pregnancy, the maternal body accumulates fat, whereas in late pregnancy, the lipolytic activity in the maternal adipose tissue is increased. However, an excess or deficiency of certain fatty acids may lead to adverse consequences to the fetuses and newborns. Fetal exposure to trans fatty acids appears to promote early deleterious effects in the offspring's health, thereby increasing the individual risk for developing metabolic diseases throughout life. Similarly, the maternal intake of saturated fatty acids seems to trigger alterations in the liver and adipose tissue function associated with insulin resistance and diabetes. The polyunsaturated fatty acids (PUFAs), particularly long-chain PUFAs (long-chain PUFA-arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid), play an important and beneficial physiologic role in the offspring who receive this fatty acid during critical periods of development. Therefore, the maternal nutritional condition and fatty acid intake during pregnancy and/or lactation are critical factors that are strongly associated with normal fetal and postnatal development, which influence the modifications in fetal programming and in the individual risk for developing metabolic diseases throughout life.

Oligofructose supplementation during pregnancy and lactation impairs offspring development and alters the intestinal properties of 21-d-old pups

BACKGROUND

Previously, we showed that the intake of trans fatty acids during pregnancy and lactation triggers a pro-inflammatory status in the offspring. On the other hand, prebiotics can alter the intestinal environment, reducing serum lipopolysaccharides (LPS) concentrations. This study evaluated the effect of the oligofructose 10% diet supplementation in the presence or absence of hydrogenated vegetable fat during pregnancy and lactation on the development, endotoxemia and bacterial composition of 21-d-old offspring.

METHODS

On the first day of pregnancy rats were divided into four groups: control diet (C), control diet supplemented with 10% oligofructose (CF), diet enriched with hydrogenated vegetable fat, rich in TFA (T) or diet enriched with hydrogenated vegetable fat supplemented with 10% oligofructose (TF). Diets were maintained during pregnancy and lactation. At birth, 7th, 14th and 21th, pups were weighed and length was measured. Serum concentrations of LPS and free fatty acids (FFA) were performed by specific kits. Bacterial DNA present in faeces was determined by real-time PCR. Data were expressed as mean ± standard error of the mean and the statistical analysis was realized by ANOVA two-way and ANOVA for repeated measures. p < 0.05 was considered significant.

RESULTS

We observed that the oligofructose (10%) supplementation during pregnancy and lactation reduced body weight, body weight gain, length and serum FFA in the CF and TF group compared to C and T group respectively, of the 21-day-old offspring, accompanied by an increase in serum LPS and genomic DNA levels of lactobacillus spp. on faeces of the CF group in relation to C group.

CONCLUSION

In conclusion, dam's diet supplementation with 10% of oligofructose during pregnancy and lactation, independent of addition with hydrogenated vegetable fat, harms the offspring development, alters the bacterial composition and increases the serum concentrations of lipopolysaccharides in 21d-old pups.

Oligofructose supplementation (10%) during pregnancy and lactation does not change the inflammatory effect of concurrent trans fatty acid ingestion on 21-day-old offspring

Background

Previously, we demonstrated that trans fatty acid ingestion during pregnancy and lactation caused a pro-inflammatory effect on the newborn. The opposite effect was described for gestational prebiotic intake. In the present study, we examined whether supplementation of the diet of the dams with 10% of oligofructose with or without hydrogenated vegetable fat during pregnancy and lactation affected the pro-inflammatory status on the pups at age 21 days.

Methods

On the first day of pregnancy, rats were divided into four groups, each of which received one of four diets: a control diet (C group), a control diet supplemented with 10% oligofructose (CF group), a diet enriched with hydrogenated vegetable fat containing trans fatty acids (T group) or a diet enriched with hydrogenated vegetable fat containing trans fatty acids supplemented with 10% oligofructose (TF group). The pups were weighed at birth and at 7, 14 and 21 days of life and were euthanized on post-natal day 21. The serum glucose, insulin and adiponectin concentrations were analyzed. The IL-6, IL-10 and TNF-α contents of the retroperitoneal white adipose tissue, liver, soleus and extensor digital longus muscles were analyzed by ELISA. The results are presented as the means ± standard error of the mean. Statistical significance was assessed using two-way ANOVA, followed by Tukey's test and considered significant at p < 0.05

Results

The body weights of the 21-day old pups in the CF and TF groups were significant lower than those of the C (27% and 21%) and T (25% and 19%, respectively) groups. The serum levels of adiponectin in the CF, T and TF groups were lower than in the C group (41%; 34% and 31%, respectively). In the retroperitoneal adipose tissue, the IL-6 content was increased in TF group relative to the C and CF groups (74% for both), and the TNF-α content was higher in the T and TF groups than in the C group (62% and 98%, respectively). In the liver, the TNF-α (56% and 104%) and IL-10 (52% and 73%) contents were increased in the CF group relative to the C and TF groups.

Conclusions

Supplementation of the diet of the dams with 10% of oligofructose during pregnancy and lactation, independent of supplementation with hydrogenated vegetable fat, adversely affected the development of the offspring and contributed to development of a pro-inflammatory status in the pups on postnatal day 21.

Is the neck circumference an emergent predictor for inflammatory status in obese adults?

BACKGROUND

Plasminogen Activator Inhibitor 1 (PAI-1) is a prothrombotic adipokine involved in the coagulation cascade and fibrinolysis that associated with proinflammatory adipokines may increase the risk related to obesity. Anthropometric measures are commonly used in clinical practice and, currently, neck circumference (NC) has been used as a marker of cardiovascular risk that can favour inflammatory factors.

OBJECTIVE

To verify the possible correlations between prothrombotic and pro/anti-inflammatory markers with anthropometric measurements in obese.

SUBJECTS AND METHODS

  A total of 43 obese adults were enrolled. The variables include body mass, stature, body mass index (BMI), NC, chest circumference (CC), abdominal circumference (AC), hip circumference (HC), blood pressure and blood collection used to assess the level of adipokines.

RESULTS

The sample was stratified by BMI. PAI-1 levels were positively correlated with body mass (r=0.31, p=0.04), NC (r=0.43, p=0.004), CC (r=0.40, p=0.004), AC (r=0.37, p=0.01), diastolic blood pressure (r=0.35, p=0.03), leptin/adiponectin ratio (r=0.36, p=0.01) and negatively correlated with adiponectin (r=-0.34, p=0.02). In stepwise multiple linear regression analysis, NC showed to be an independent predictor to PAI-1 when adjusted for gender and BMI, according to the age (β=0.47, p=0.02 and β=0.42, p=0.02 respectively).

CONCLUSION

In conclusion, NC could be suggested as an independent predictor higher PAI-1. This association can be a new screening of persons at an enhanced cardiovascular risk and inflammation in this obese population, so useful in clinical practice.

Diet-induced effects on neuronal and glial elements in the middle-aged rat hippocampus

Consumption of a high-fat and/or high-cholesterol diet can have detrimental effects on the brain. In the present study, dietary treatment with saturated fats, trans fats, or cholesterol to middle-aged Fischer 344 rats resulted in alterations to serum triglyceride and cholesterol levels, organ weights, and hippocampal morphology. Previously, we demonstrated that a 10% hydrogenated coconut oil and 2% cholesterol diet resulted in worse performance on the 12-day water radial arm maze, increased cholesterol and triglyceride levels, and decreased dendritic microtubule associated protein 2 (MAP2) staining in the hippocampus. The diets administered herein were used to examine components from the previous diet and further examine their effects on hippocampal morphology. Specifically, neuronal morphology, dendritic integrity, fatty acid metabolism, microgliosis, and blood vessel structure in the hippocampus and/or adjacent structures were explored. Our results indicate alterations to peripheral and neural systems following each of the diets.

Hydrogenated fat intake during pregnancy and lactation caused increase in TRAF-6 and reduced AdipoR1 in white adipose tissue, but not in muscle of 21 days old offspring rats

Background

Although lipids transfer through placenta is very limited, modification in dietary fatty acids can lead to implications in fetal and postnatal development. Trans fatty acid (TFA) intake during gestation and lactation have been reported to promote dyslipidemia and increase in pro- inflammatory adipokines in offspring. The aim of this study was to evaluate whether the alterations on pro-inflammatory cytokines and dyslipidemia observed previously in 21-d-old offspring of rats fed a diet containing hydrogenated vegetable fat during gestation and lactation were related to alterations in TLR-4, TRAF-6 and adipo-R1 receptor in white adipose tissue and muscle. On the first day of gestation, rats were randomly divided into two groups: (C) received a control diet, and (T) received a diet enriched with hydrogenated vegetable fat, rich in trans fatty acids. The diets were maintained throughout gestation and lactation. Each mother was given eight male pups. On the 21st day of life the offspring were killed. Blood, soleus and extensor digital longus (EDL) muscles, and retroperitoneal (RET) white adipose tissue were collected.

Results

21-d-old of T rats had higher serum triacylglycerols, cholesterol, and insulin. The Adipo R1 protein expression was lower in RET and higher in EDL of T group than C. TLR-4 protein content in all studied tissues were similar between groups, the same was verified in TRAF-6 protein expression in soleus and EDL. However, TRAF-6 protein expression in RET was higher in T than C.

Conclusion

These results demonstrated that maternal ingestion of hydrogenated vegetable fat rich in TFAs during gestation and lactation decrease in Adipo R1 protein expression and increase in TRAF-6 protein expression in retroperitoneal adipose tissue, but not in skeletal muscle, which could contributed for hyperinsulinemia and dyslipidemia observed in their 21-d-old offspring.

Distinct effects of oleic acid and itstrans-isomer elaidic acid on the expression of myokines and adipokines in cell models

Trans-fatty acids (TFA) andcis-monounsaturated fat appear to exert detrimental and beneficial effects, respectively, on glucose metabolism and insulin sensitivity. Adipose tissue and skeletal muscle are a source of signalling proteins (adipokines and myokines), some of which have been related to the control of insulin sensitivity. Here, we investigated the possible differential effects of elaidic acid (EA;trans-9-18 : 1) – the major component in industrially produced TFA – and oleic acid (OA;cis-9-18 : 1) – itscis-isomer naturally present in food – on cellular glucose uptake and the expression of selected myokines and adipokines using cell models. Differentiated C2C12 myotubes and 3T3-L1 adipocytes were pretreated with the vehicle (control cells) or fatty acids for 24 h, after which basal and insulin-stimulated 2-deoxyglucose uptake and the expression of selected signalling proteins were measured. In C2C12 myotubes, pretreatment with OA, but not with EA, led to increased insulin-stimulated 2-deoxyglucose uptake and IL-6 expression levels, while pretreatment with EA, but not with OA, led to reduced IL-15 mRNA levels and increased TNF-α expression levels. In 3T3-L1 adipocytes, exposure to OA, but not to EA, resulted in reduced resistin gene expression and increased adiponectin gene expression. The results show evidence of distinct, direct effects of OA and EA on muscle glucose uptake and the expression of target myokines and adipokines, thus suggesting novel mechanisms by whichcis- andtrans-monounsaturated fat may differentially affect systemic functions.

Metabolism and secretory function of white adipose tissue: effect of dietary fat

Approximately 40% of the total energy consumed by western populations is represented by lipids, most of them being ingested as triacylglycerols and phospholipids. The focus of this review is to analyze the effect of the type of dietary fat on white adipose tissue metabolism and secretory function, particularly on haptoglobin, TNF-α, plasminogen activator inhibitor-1 and adiponectin secretion. Previous studies have demonstrated that the duration of the exposure to the high-fat feeding, amount of fatty acid present in the diet and the type of fatty acid may or may not have a significant effect on adipose tissue metabolism. However, the long-term or short-term high fat diets, especially rich in saturated fatty acids, probably by activation of toll-like receptors, stimulated the expression of proinflammatory adipokines and inhibited adiponectin expression. Further studies are needed to investigate the cellular mechanisms by which dietary fatty acids affect white adipose tissue metabolism and secretory functions.

Trans fat feeding results in higher serum alanine aminotransferase and increased insulin resistance compared with a standard murine high-fat diet

Diets high in trans fats are associated with an increased risk of cardiovascular disease and components of the metabolic syndrome. The influence of these toxic fatty acids on the development of nonalcoholic fatty liver disease has not been significantly examined. Therefore, we sought to compare the effect of a murine diet high in trans fat to a standard high-fat diet that is devoid of trans fats but high in saturated fats. Male AKR/J mice were fed a calorically identical trans fat diet or standard high-fat diet for 10 days, 4 wk, and 8 wk. Serum alanine aminotransferase (ALT), lipid, insulin, and leptin levels were determined and the quantitative insulin-sensitivity check index (QUICKI) was calculated as a measure of insulin resistance. Additionally, hepatic triglyceride content and gene expression of several proinflammatory genes were assessed. By 8 wk, trans fat-fed mice exhibited higher ALT values than standard high-fat-fed mice (126 +/- 16 vs. 71 +/- 7 U/l, P < 0.02) despite similar hepatic triglyceride content at each time point. Trans fat-fed mice also had increased insulin resistance compared with high-fat-fed mice at 4 and 8 wk with significantly higher insulin levels and lower QUICKI values. Additionally, hepatic interleukin-1beta (IL-1beta) gene expression was 3.6-fold higher at 4 wk (P < 0.05) and 5-fold higher at 8 wk (P < 0.05) in trans fat-fed mice compared with standard high-fat-fed mice. Trans fat feeding results in higher ALT values, increased insulin resistance, and elevated IL-1beta levels compared with standard high-fat feeding.

Hydrogenated fat diet intake during pregnancy and lactation modifies the PAI-1 gene expression in white adipose tissue of offspring in adult life

We examine whether feeding pregnant and lactating rats hydrogenated fats rich in trans fatty acids modifies the plasma lipid profiles and the expression of adipokines involved with insulin resistance and cardiovascular disease in their 90-day-old offspring. Pregnant and lactating Wistar rats were fed with either a control diet (C group) or one enriched with hydrogenated vegetable fat (T group). Upon weaning, the male pups were sorted into four groups: CC, mothers were receiving C and pups were kept on C; CT, mothers were receiving C and pups were fed with T; TT, mothers were receiving T and pups were kept on T; TC, mothers were receiving T and pups were fed with C. Pups' food intake and body weight were quantified weekly and the pups were killed at day 90 of life by decapitation. Blood and carcass as well as retroperitoneal, epididymal, and subcutaneous white adipose tissues were collected. Food intake and body weight were lower in TC and TT, and metabolic efficiency was reduced in TT. Offspring of TT and TC rats had increased white adipose tissue PAI-1 gene expression. Insulin receptor was higher in TT than other groups. Ingestion of hydrogenated vegetable fat by the mother during gestation and lactation could promote deleterious consequences, even after the withdrawal of the causal factor.