Sex differences in lipid and lipoprotein metabolism

Short Stature is Associated with Increased Risk of Dyslipidemia in Korean Adolescents and Adults

Adults with short stature have been previously reported to have increased risk of cardiovascular events and hyper-LDL-cholesterolemia. We aimed to assess the association between height and lipid profiles among Korean adolescents and adults. We analyzed data from the Korea National Health and Nutrition Examination Survey from 2007 to 2015, from 37,889 individuals (aged 12–59 years). In adolescents, total cholesterol (TC) and low density lipoprotein-cholesterol (LDL-C) levels had profound associations with height in both boys and girls, while high density lipoprotein-cholesterol (HDL-C) levels had an inverse association with height only in boys. Height was inversely associated with TC, triglycerides (TG), and LDL-C concentrations in men and women and positively correlated with HDL-C concentration in women. In boys, the odds ratios (ORs) for hypercholesterolemia, hypertriglyceridemia, hyper-LDL-cholesterolemia were higher for shorter subjects (ORs = 2.38~7.01), while only the OR of hyper-LDL-cholesterolemia was significantly higher in girls with short stature (OR = 3.12). In adults, the ORs for hypercholesterolemia, hypo-HDL-cholesterolemia, and hyper-LDL-cholesterolemia were significantly higher in short subjects than in tall subjects after controlling for covariates (ORs = 1.50~2.61). Also, short men showed significantly higher ORs for hypertriglyceridemia (OR = 1.85) than tall men. Short stature was significantly associated with adverse lipid profiles in both adolescents and adults.

The Neuroprotective Effects of Simvastatin on High Cholesterol Following Traumatic Brain Injury in Rats

BACKGROUND

High cholesterol has been correlated with a greater risk of cerebrovascular diseases. Whether pre-existing high cholesterol exacerbates traumatic brain injury (TBI), and whether treatment with the cholesterol-lowering agent simvastatin has neuroprotective effects, especially anti-neuroinflammatory effects, after TBI are not well investigated.

METHODS

Five-week-old male Sprague-Dawley rats were fed a high-fat diet for 8 weeks to induce hypercholesterolemia. Anesthetized male Sprague-Dawley rats were divided into 5 groups, including the sham-operated control, TBI control, and TBI with simvastatin treatment (4 mg/kg, 10 mg/kg, or 20 mg/kg) groups. Simvastatin was intraperitoneally injected at 0, 24, and 48 hours after TBI. Motor function was measured using an inclined plane. Neuronal apoptosis (maker Neu-N, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling), tumor necrosis factor-α expression in microglia (marker OX42) and astrocytes (marker glial fibrillary acidic protein), and Tumor necrosis factor-alpha receptor (TNFR) 1 and TNFR2 expression in neurons in the ischemic cortex were investigated using an immunofluorescence assay. All of the parameters were measured on the third day after TBI.

RESULTS

TBI significantly increased the serum levels of cholesterol. The TBI-induced motor deficit was significantly attenuated by 4, 10, and 20 mg/kg simvastatin therapy on the third day after TBI. TBI-induced neuronal TNFR1 activation and apoptosis, as well as tumor necrosis factor-α expression in astrocytes in the ischemic cortex, were significantly attenuated by simvastatin, particularly when 20 mg/kg was administered. Simultaneously, the serum cholesterol remained high despite simvastatin treatment.

CONCLUSIONS

The neuroprotection effects of simvastatin on the pre-existing hypercholesterolemia during TBI in rats may be related to its anti-neuroinflammatory effects but not to its cholesterol-lowing effects.

A Thermogenic-Like Brown Adipose Tissue Phenotype Is Dispensable for Enhanced Glucose Tolerance in Female Mice

The prevailing dogma is that thermogenic brown adipose tissue (BAT) contributes to improvements in glucose homeostasis in obesogenic animal models, though much of the evidence supporting this premise is from thermostressed rodents. Determination of whether modulation of the BAT morphology/function drives changes in glucoregulation at thermoneutrality requires further investigation. We used loss- and gain-of-function approaches including genetic manipulation of the lipolytic enzyme Pnpla2, change in environmental temperature, and lifestyle interventions to comprehensively test the premise that a thermogenic-like BAT phenotype is coupled with enhanced glucose tolerance in female mice. In contrast to this hypothesis, we found that 1) compared to mice living at thermoneutrality, enhanced activation of BAT and its thermogenic phenotype via chronic mild cold stress does not improve glucose tolerance in obese mice, 2) silencing of the Pnpla2 in interscapular BAT causes a brown-to-white phenotypic shift accompanied with inflammation but does not disrupt glucose tolerance in lean mice, and 3) exercise and low-fat diet improve glucose tolerance in obese mice but these effects do not track with a thermogenic BAT phenotype. Collectively, these findings indicate that a thermogenic-like BAT phenotype is not linked to heightened glucose tolerance in female mice.

Race-ethnic differences in the associations of maternal lipid trait genetic risk scores with longitudinal fetal growth

BACKGROUND

Fetal growth, an important predictor of cardiometabolic diseases in adults, is influenced by maternal and fetal genetic and environmental factors.

OBJECTIVE

We investigated the association between maternal lipid genetic risk score (GRS) and fetal growth among 4 US racial-ethnic populations (Whites, Blacks, Hispanics, and Asians).

METHODS

We extracted genotype data for 2008 pregnant women recruited in the National Institute of Child Health and Human Development Fetal Growth Studies-Singleton cohort with up to 6 standardized ultrasound examinations. GRS was calculated using 240 single-nucleotide polymorphisms previously associated with higher total cholesterol (GRSTChol), low-density lipoprotein cholesterol (GRSLDLc), and triglycerides (GRSTG) and lower high-density lipoprotein cholesterol (GRSHDLc).

RESULTS

At 40 weeks' gestation, a unit increase in GRSTG was associated with 11.4 g higher fetal weight (95% confidence interval [CI] 2.8-20.0 g) among normal-weight Whites, 26.3 g (95% CI 6.0-46.6 g) among obese Blacks, and 30.8 g (95% CI 6.3-55.3 g) among obese Hispanics. Higher GRSHDLc was associated with increased fetal weight across 36 to 40 weeks among normal-weight Whites and across 13 to 20 weeks among normal-weight Asians, but with decreased fetal weight across 26 to 40 weeks among normal-weight Hispanics. Higher GRSTChol was suggestively associated with increased fetal weight in males and decreased in females. Associations remained consistent after adjustment for serum lipids.

CONCLUSION

Associations between fetal weight and maternal lipid GRS appear to vary by maternal race-ethnic group, obesity status, and offspring sex. Genetic susceptibility to unfavorable lipid profiles contributes to fetal growth differences even among normal-weight women suggesting a potential future application in predicting aberrant fetal growth.

Increased aortic stiffness index in patients with type 1 diabetes without cardiovascular disease compared to controls

PURPOSE

Increased arterial stiffness is an early sign of endothelial dysfunction. Nevertheless, measures of the elastic properties of the aortic root in patients with type 1 diabetes are still lacking. The aim of this study was to compare aortic root stiffness index in type 1 diabetes and healthy controls.

METHODS

Ninety-three patients with type 1 diabetes without cardiovascular diseases were recruited and compared to 33 healthy controls. Aortic root elastic properties were estimated by measuring the systolic and diastolic diameters on M-mode acquisition.

RESULTS

None of the subjects showed alterations of either systolic or diastolic echocardiographic parameters. Patients with type 1 diabetes had a very low prevalence of chronic complications and their metabolic control was good. Significantly increased aortic stiffness index was found in type 1 diabetes compared to controls, and the same different pattern was found in men and women. The presence of type 1 diabetes and increased pulse pressure was significantly associated with aortic stiffness index in a multivariate linear analysis.

CONCLUSION

This study strongly suggests that patients with type 1 diabetes develop aortic root stiffness in the absence of cardiovascular diseases. This alteration may be part of a more generalized arterial dysfunction in type 1 diabetes.

Paradoxical role of lipocalin-2 in metabolic disorders and neurological complications

Lipocalin-2 (LCN2), also known as 24p3 and neutrophil gelatinase-associated lipocalin (NGAL), is a 25-kDa secreted protein implicated in various metabolic and inflammatory diseases. Early studies suggest the protective function of LCN2 in which it acts as a bacteriostatic agent that competes with bacteria for iron-bound siderophores. However, both detrimental and beneficial roles of LCN2 have recently been documented in metabolic and neuroinflammatory diseases. Metabolic inflammation, as observed in diabetes and obesity, has been closely associated with the upregulation of LCN2 in blood plasma and several tissues in both humans and rodents, suggesting its pro-diabetic and pro-obesogenic role. On the contrary, other studies imply an anti-diabetic and anti-obesogenic role of LCN2 whereby a deficiency in the Lcn2 gene results in the impairment of insulin sensitivity and enhances the high-fat-diet-induced expansion of fat. A similar dual role of LCN2 has also been reported in various animal models for neurological disorders. In the midst of these mixed findings, there is no experimental evidence to explain why LCN2 shows such a contrasting role in the various studies. This debate needs to be resolved (or reconciled) and an integrated view on the topic is desirable. Herein, we attempt to address this issue by reviewing the recent findings on LCN2 in metabolic disorders and assess the potential cellular or molecular mechanisms underlying the dual role of LCN2. We further discuss the possibilities and challenges of targeting LCN2 as a potential therapeutic strategy for metabolic disorders and neurological complications.

The Effect of Estrogen on Hepatic Fat Accumulation during Early Phase of Liver Regeneration after Partial Hepatectomy in Rats

Fatty liver is common in men and post-menopausal women, suggesting that estrogen may be involved in liver lipid metabolism. The aim of this study is to be clear the role of estrogen and estrogen receptor alpha (ERα) in fat accumulation during liver regeneration using the 70% partial hepatectomy (PHX) model in male, female, ovariectomized (OVX) and E₂-treated OVX (OVX-E₂) rats. Liver tissues were sampled at 0–48 hr after PHX and fat accumulation, fatty acid translocase (FAT/CD36), sterol regulatory element-binding protein (SREBP1c), peroxisome proliferator-activated receptor α (PPARα), proliferative cell nuclear antigen (PCNA) and ERα were examined by Oil Red O, qRT-PCR and immunohistochemistry, respectively. Hepatic fat accumulation was abundant in female and OVX-E₂ compared to male and OVX rats. FAT/CD36 expression was observed in female, OVX and OVX-E₂ at 0–12 hr after PHX, but not in male rats. At 0 hr, SREBP1c and PPARα were elevated in female and male rats, respectively, but were decreased after PHX in all rats. The PCNA labeling index reached a maximum at 36 hr and 48 hr in OVX-E₂ and OVX rats, respectively. ERα expression in OVX-E₂ was higher than OVX at 0–36 hr after PHX. In conclusion, these results indicated that estrogen and ERα might play an important role in fat accumulation related to FAT/CD36 during early phase of rat liver regeneration.

Evaluation of antiviral effect and toxicity of total flavonoids extracted from Robinia pseudoacacia cv. idaho

In this study, we aimed to evaluate the antiviral effect of total flavonoids extracted from Robinia pseudoacacia cv. idaho (RPTF) in vivo and its toxicity on rats with oral gavage. RPTF was prepared by percolation with 70% ethanol for 24 h and its antiviral effect on different kinds of viruses was evaluated in vitro by MTT staining. The long-term toxicity of RPTF on rats was evaluated through the detection of general behavior, body weight, food intake and related organ tissue sections of experimental animals. We found that RPTF produced significantly inhibitory effects on HSV-1 and EV-71 viruses with the therapeutic index TI values 113.8 and 46.2, respectively. Moreover, toxicity evaluation in vivo showed no significantly adverse effects in rats, indicating that RPTF was safe in use. In conclusion, we demonstrated that RPTF, natural compounds in the Chinese traditional medicine, could act as promising and effective antiviral therapeutics with relative safety in use.

Sex modulates hepatic mitochondrial adaptations to high-fat diet and physical activity

The impact of sexual dimorphism and mitophagy on hepatic mitochondrial adaptations during the treatment of steatosis with physical activity are largely unknown. Here, we tested if deficiencies in liver-specific peroxisome proliferative activated-receptor-γ coactivator-1α (PGC-1α), a transcriptional coactivator of biogenesis, and BCL-2/ADENOVIRUS EIB 19-kDa interacting protein (BNIP3), a mitophagy regulator, would impact hepatic mitochondrial adaptations (respiratory capacity, H2O2 production, mitophagy) to a high-fat diet (HFD) and HFD plus physical activity via voluntary wheel running (VWR) in both sexes. Male and female wild-type (WT), liver-specific PGC-1α heterozygote (LPGC-1α), and BNIP3 null mice were thermoneutral housed (29-31°C) and divided into three groups: sedentary-low-fat diet (LFD), 16 wk of (HFD), or 16 wk of HFD with VWR for the final 8 wk (HFD + VWR) (n = 5-7/sex/group). HFD did not impair mitochondrial respiratory capacity or coupling in any group; however, HFD + VWR significantly increased maximal respiratory capacity only in WT and PGC-1α females. Males required VWR to elicit mitochondrial adaptations that were inherently present in sedentary females including greater mitochondrial coupling control and reduced H2O2 production. Females had overall reduced markers of mitophagy, steatosis, and liver damage. Steatosis and markers of liver injury were present in sedentary male mice on the HFD and were effectively reduced with VWR despite no resolution of steatosis. Overall, reductions in PGC-1α and loss of BNIP3 only modestly impacted mitochondrial adaptations to HFD and HFD + VWR with the biggest effect seen in BNIP3 females. In conclusion, hepatic mitochondrial adaptations to HFD and treatment of HFD-induced steatosis with VWR are more dependent on sex than PGC-1α or BNIP3.

Androgens sensitise mice to glucocorticoid-induced insulin resistance and fat accumulation

AIMS/HYPOTHESIS

Chronic glucocorticoid therapy causes insulin resistance, dyslipidaemia, abnormal fat accumulation, loss of muscle mass and osteoporosis. Here we describe a hitherto unknown sexual dimorphism in the metabolic response to chronic glucocorticoid exposure in mice. This led us to investigate whether glucocorticoid-induced insulin resistance and obesity were dependent on sex hormones.

METHODS

Male and female CD1 mice were treated for 4 weeks with supraphysiological doses (~250 μg/day) of corticosterone, the main glucocorticoid in rodents, or equivalent volume of vehicle (drinking water without corticosterone). To investigate the effects of sex hormones, a separate group of mice were either orchidectomised or ovariectomised prior to corticosterone treatment, with or without dihydrotestosterone replacement. Body composition was determined before and after corticosterone treatment, and insulin tolerance was assessed after 7 and 28 days of treatment. Adipocyte morphology was assessed in white and brown adipose tissues by immunohistochemistry, and fasting serum concentrations of NEFA, triacylglycerols, total cholesterol and free glycerol were measured using colorimetric assays. Obesity- and diabetes-related hormones were measured using multiplex assays, and RNA and protein expression in adipose tissues were measured by RT-PCR and immunoblotting, respectively.

RESULTS

Chronic corticosterone treatment led to insulin resistance, fasting hyperinsulinaemia, increased adiposity and dyslipidaemia in male, but not female mice. In males, orchidectomy improved baseline insulin sensitivity and attenuated corticosterone-induced insulin resistance, but did not prevent fat accumulation. In androgen-deficient mice (orchidectomised males, and intact and ovariectomised females) treated with dihydrotestosterone, corticosterone treatment led to insulin resistance and dyslipidaemia. In brown adipose tissue, androgens were required for corticosterone-induced intracellular lipid accumulation ('whitening'), and dihydrotestosterone specifically exacerbated corticosterone-induced accumulation of white adipose tissue by increasing adipocyte hypertrophy. Androgens also suppressed circulating adiponectin concentrations, but corticosterone-induced insulin resistance did not involve additional suppression of adiponectin levels. In white adipose tissue, androgens were required for induction of the glucocorticoid target gene Gilz (also known as Tsc22d3) by corticosterone.

CONCLUSIONS/INTERPRETATION

In mice, androgens potentiate the development of insulin resistance, fat accumulation and brown adipose tissue whitening following chronic glucocorticoid treatment.

Increased systolic blood pressure associated with hypertriglyceridemia in female Sprague-Dawley rats

The effect of hyperlipidemia on the cardiovascular system is uncertain in females. The aim of the present study was to determine whether administration of a lipogenic diet alters cardiovascular parameters in female rats. Fifty female Sprague-Dawley rats were assigned into 2 groups of rats receiving a standard or a high-fat, high-sucrose diet (HFHS) for 6 weeks (n = 25 per group). Body mass, blood lipids concentrations, triglycerides clearance, blood pressures (BPs), systolic and diastolic functions, as well as vascular reactivity were assessed at the end of the diet intervention. At termination, body mass was similar between the 2 groups. Fasting blood triglycerides concentration (BTG) was greater in the HFHS group. Triglycerides clearance was impaired in the HFHS group. High-density lipoprotein (HDL) cholesterol concentration was lower in the HFHS group. The early-to-late diastolic filling velocity ratio (E/A) was lower in the HFHS group and negatively associated with BTG. The sensitivity (EC₅₀) of mesenteric arteries to phenylephrine was greater in HFHS and was negatively associated with BTG, but not HDL. Systolic BP was higher in the HFHS group and was positively associated with BTG and HDL. The association between systolic BP and BTG was independent of other lipids measured. In conclusion, hypertriglyceridemia may have increased resistance arteries responsiveness to alpha-agonist and systolic BP in female rats.

XX sex chromosome complement promotes atherosclerosis in mice

Men and women differ in circulating lipids and coronary artery disease (CAD). While sex hormones such as estrogens decrease CAD risk, hormone replacement therapy increases risk. Biological sex is determined by sex hormones and chromosomes, but effects of sex chromosomes on circulating lipids and atherosclerosis are unknown. Here, we use mouse models to separate effects of sex chromosomes and hormones on atherosclerosis, circulating lipids and intestinal fat metabolism. We assess atherosclerosis in multiple models and experimental paradigms that distinguish effects of sex chromosomes, and male or female gonads. Pro-atherogenic lipids and atherosclerosis are greater in XX than XY mice, indicating a primary effect of sex chromosomes. Small intestine expression of enzymes involved in lipid absorption and chylomicron assembly are greater in XX male and female mice with higher intestinal lipids. Together, our results show that an XX sex chromosome complement promotes the bioavailability of dietary fat to accelerate atherosclerosis.

Men and women differ in their risk of developing coronary artery disease, in part due to differences in their levels of sex hormones. Here, AlSiraj et al. show that the XX sex genotype regulates lipid metabolism and promotes atherosclerosis independently of sex hormones in mice.

Postprandial Circulating miRNAs in Response to a Dietary Fat Challenge

Postprandial lipemia has many physiopathological effects, some of which increase the risk of cardiovascular disease. MicroRNAs (miRNAs) can be found in almost all biological fluids, but their postprandial kinetics are poorly described. We aimed to profile circulating miRNAs in response to a fat challenge. In total, 641 circulating miRNAs were assessed by real-time PCR in plasmas from mice two hours after lipid gavage. Mice with intestine-specific loss of Dicer were screened to identify potential miRNAs released by the intestine. A total of 68 miRNAs were selected for further validation. Ten circulating miRNAs were finally validated as responsive to postprandial lipemia, including miR-206-3p, miR-543-3p, miR-466c-5p, miR-27b-5p, miR-409-3p, miR-340-3p, miR-1941-3p, miR-10a-3p, miR-125a-3p, and miR-468-3p. Analysis of their possible tissues of origin/target showed an enrichment of selected miRNAs in liver, intestine, brain, or skeletal muscle. miR-206, miR-27b-5p, and miR-409-3p were validated in healthy humans. Analysis of their predicted target genes revealed their potential involvement in insulin/insulin like growth factor (insulin/IGF), angiogenesis, cholecystokinin B receptor signaling pathway (CCKR), inflammation or Wnt pathways for mice, and in platelet derived growth factor (PDGF) and CCKR signaling pathways for humans. Therefore, the current study shows that certain miRNAs are released in the circulation in response to fatty meals, proposing them as potential novel therapeutic targets of lipid metabolism.

Sex, gut microbiome, and cardiovascular disease risk

Key differences exist between men and women in the determinants and manifestations of cardiovascular and cardiometabolic diseases. Recently, gut microbiome-host relations have been implicated in cardiovascular disease and associated metabolic conditions; therefore, gut microbiota may be key mediators or modulators driving the observed sexual dimorphism in disease onset and progression. While current evidence regarding pure physiological sex differences in gut microbiome composition is modest, robust research suggests that gut microbiome-dependent metabolites may interact with important biological pathways under sex hormone control, including toll-like receptor and flavin monooxygenase signaling. Here, we review key sex differences in gut microbiome interactions with four primary determinants of cardiovascular disease, impaired glucose regulation, dyslipidemia, hypertension, and obesity. Through this process, we propose important sex differences in downstream metabolic pathways that may be at the interface of the gut microbiome and cardiovascular disease.

Impact of Successful Weight Loss Maintenance on Serum Lipids and Glucose Concentrations of Previous Participants of a Weight Loss Programme in Accra, Ghana

BACKGROUND AND AIM

There is a need to investigate the long-term impact of successful weight loss maintenance on blood lipids and glucose concentrations in populations within Africa, where obesity and cardiovascular disease (CVD) rates are increasingly becoming a public health threat. The aim of this study was to compare the serum lipid and glucose concentrations of successful and unsuccessful weight loss maintainers who previously participated in the Nutriline Weight Loss Programme (NWLP) in Accra, Ghana.

METHODS

112 participants were randomly selected to participate in this cross-sectional study. Baseline and end of weight loss programme anthropometric and programmatic data were accessed via the NWLP archival database. On follow-up, anthropometric data, physical activity, dietary behaviour, serum lipid, and glucose indices were taken. Successful weight loss maintainers (SWLM) were defined as those achieving at least 5% weight loss below the baseline weight at follow-up, otherwise unsuccessful (UWLM).

RESULTS

The adjusted serum total cholesterol (TC) concentration was significantly lower for SWLM (5.17 ± 0.99 mmol/L) compared to UWLM (5.59 ± 1.06 mmol/L). Serum low-density lipoprotein (LDL), high-density lipoprotein (HDL), fasting blood glucose (FBG), and glycosylated haemoglobin (HbA1c) concentrations for SWLM versus UWLM did not differ significantly and were as follows: 3.58 ± 0.92 mmol/L versus 3.87 ± 0.99 mmol/L, 1.22 ± 0.38 mmol/L versus 1.17 ± 0.32 mmol/L, 4.48 ± 0.72 mmol/L versus 4.73 ± 1.00 mmol/L, and 5.52 ± 0.39% versus 5.59 ± 0.59%, respectively. Triglyceride (TG) concentration was significantly (P < 0.001) lower for SWLM (0.79 ± 0.28 mmol/L) compared to UWLM (1.17 ± 0.51 mmol/L). After adjusting for covariates, it was no longer significant. Additionally, there was no significant association between weight loss maintenance success and having a normal status for selected lipids and glucose parameters.

CONCLUSION

SWLM had a significantly lower serum TC compared to UWLM. In addition, a greater proportion of SWLM had normal values for TC, TG, HbA1c, and LDL out of the six parameters measured although not statistically significant.

Biological Response to Meal Ingestion: Gender Differences

In a previous study, we demonstrated that women enjoyed and tolerated lower meal loads than men. Hence, we hypothesized that with the same meal load, their postprandial response is more pronounced than in men. We performed a randomized parallel trial in 12 women and 12 men comparing the postprandial responses to a palatable comfort meal. We measured homeostatic sensations (hunger/satiety, fullness) and hedonic sensations (digestive well-being, mood) on 10 cm scales, vagal tone by heart ratio variability and the metabolomic profile before and after meal ingestion. Gender differences were analyzed by repeated measures ANCOVA. Overall (n = 24), ingestion of the probe meal induced satiation, fullness, digestive well-being and improved mood (main time-effect p ≤ 0.005 for all). Women exhibited a more intense sensory experience, specially more postprandial fullness, than men [main gender-effect F (1, 21) = 7.14; p = 0.014]; hedonic responses in women also tended to be stronger than in men. Women exhibited more pronounced effects on vagal tone [main gender-effect F (1, 21) = 5.5; p = 0.029] and a different lipoprotein response than men. In conclusion, our data indicate that gender influences the responses to meal ingestion, and these differences may explain the predisposition and higher incidence in women of meal-related functional disorders.

Effects of exercise on reverse cholesterol transport: A systemized narrative review of animal studies

AIMS

Reverse Cholesterol Transport (RCTr) is the mechanism by which excess cholesterol from peripheral tissues is transported to the liver for hepatobiliary excretion, thereby inhibiting foam cell formation and the development of atherosclerosis. Exercise affects RCTr, by influencing high-density lipoprotein cholesterol (HDL) through remodeling and by promoting hepatobiliary sterol excretion. The objectives of this systematized review of animal studies is to summarize the literature and provide an overview of the effects of chronic exercise (at least two weeks) on apolipoproteins (Apo A-I, Apo-E), Paraoxonase-1 (PON1), ATP-binding cassette transporters (ABCA1, ABCG1, ABCG4, ABCG5, ABCG8), scavenger receptor class B type I (SR-BI), cholesteryl ester transfer protein (CETP), low-density lipoprotein receptor (LDLr) and cholesterol 7 alpha-hydroxylase (CYP7A1) and Niemann-Pick C1-like 1 (NPC1L1).

MATERIALS AND METHODS

Three electronic databases (PubMed, Science Direct and Google Scholar) were searched for eligible studies conducted from the earliest available date to August 2018.

KEY FINDINGS

Most of studies investigate the effects of low to moderate intensity aerobic training on RCTr elements. The majority were on exercised rats undertaking moderate intensity aerobic training.

SIGNIFICANCE

This review highlights that moderate intensity and longer-term training has a greater effect on RCTr elements than low intensity training. There a few studies examining high intensity training which warrants further investigation.

Gender Dictates the Relationship between Serum Lipids and Leukocyte Counts in the National Health and Nutrition Examination Survey 1999⁻2004

Dyslipidemias and leukocytosis are associated with cardiovascular disease and immune disorders. Mechanistic studies have shown lipoprotein metabolism to play a significant role in the regulation of atherosclerosis development and leukocyte activation, whereas lipid-lowering treatments have been shown to exert beneficial anti-inflammatory and immunomodulatory effects in clinical trials. However, the relationship between clinical markers of lipid metabolism and leukocyte counts has not been extensively evaluated at the population level. We aimed to determine whether clinical blood lipid measures are associated with leukocyte counts in the general U.S. population represented in the National Health and Nutrition Examination Survey (NHANES) 1999–2004, and whether differences exist between men and women (n = 5647). We observed a strong positive linear trend between serum triglycerides vs. blood lymphocyte and basophil counts in both men and women, whereas a positive trend between monocytes vs. triglycerides and lymphocytes vs. total cholesterol and LDL-cholesterol (LDL-C) was only detected in women. Conversely, HDL-C was inversely associated with a greater number of leukocyte subsets in men, whereas inverse trends between HDL-C vs. lymphocytes were observed in both men and women. In multiple regression models, a 10% increase in total cholesterol, LDL-C, and triglycerides was associated with a predicted 1.6%, 0.6%, and 1.4% increase in blood lymphocyte counts in women, respectively, whereas no relationship was observed in men. In both men and women, a 10% increase in triglycerides was additionally associated with higher lymphocyte, neutrophil, and basophil counts, whereas 10% increases in HDL-cholesterol were associated with significantly lower lymphocyte, neutrophil, eosinophil, and basophil counts in men, in addition to lower lymphocyte and monocyte counts in women. These findings suggest that clinical lipid markers may be used to predict blood leukocyte distributions, and that a gender-specific relationship exists between distinct classes of serum lipids and immune cell subsets.

Sex-specific lipid molecular signatures in obesity-associated metabolic dysfunctions revealed by lipidomic characterization in ob/ob mouse

The response to overfeeding is sex dependent, and metabolic syndrome is more likely associated to obesity in men or postmenopausal women than in young fertile women. We hypothesized that obesity-induced metabolic syndrome is sex dependent due to a sex-specific regulation of the fatty acid (FA) synthesis pathways in liver and white adipose depots. We aimed to identify distinctive molecular signatures between sexes using a lipidomics approach to characterize lipid species in liver, perigonadal adipose tissue, and inguinal adipose tissue and correlate them to the physiopathological responses observed. Males had less total fat but lower subcutaneous on visceral fat ratio together with higher liver weight and higher liver and serum triglyceride (TG) levels. Males were insulin resistant compared to females. Fatty acid (FA) and TG profiles differed between sexes in both fat pads, with longer chain FAs and TGs in males compared to that in females. Remarkably, hepatic phospholipid composition was sex dependent with more abundant lipotoxic FAs in males than in females. This may contribute to the sexual dimorphism in response to obesity towards more metaflammation in males. Our work presents an exhaustive novel description of a sex-specific lipid signature in the pathophysiology of metabolic disorders associated with obesity in ob/ob mice. These data could settle the basis for future pharmacological treatment in obesity.

Toxicity Evaluation of Anacardium occidentale, the Potential Aphrodisiac Herb

Anacardium occidentale L. leaf demonstrates sexual enhancement effect. Therefore, it can be used as the potential supplement and functional ingredient. However, the ethanolic leaf extract of this plant is a modified form of traditional application and the toxicity evaluation is required. To assess cytotoxicity of the extract, RAW 264.7 cells were treated with A. occidentale leaf extract in the concentration range between 0.625 and 10 mg/mL. Our results showed that the extract showed more than 90% cell viability at the concentration of 2.5 mg/mL after 24-hour exposure. To assure the consumption safety, the acute and subchronic toxicity must be studied. Acute toxicity showed that the extract is safe even at the highest dose of 2 g/kg in both sexes of Wistar rats. No changes in behavior, physiology, gross pathology, and histology were observed. To determine the subchronic toxicity of extract, both sexes of Wistar rats were orally given the extract at doses of 20, 100, and 500 mg/kg once daily for 90 days. No changes in body weight, food, and water intake, motor coordination, behavior, and mental alertness were observed. The significant reduction of white blood cell, platelet, and cholesterol together with increase in MCHC was observed in male rats. The reductions of white blood cell and platelet together with the elevations of hemoglobin and hematocrit were also observed in female rats. However, all changes were in normal range. The current results revealed that an ethanolic extract of A. occidentale leaf was well tolerated via oral consumption up to dose of 500 mg/kg BW for 90 days and did not produce any toxicity. Our in vitro cytotoxicity test also confirmed this safety.

A Guide to Applying the Sex-Gender Perspective to Nutritional Genomics

Precision nutrition aims to make dietary recommendations of a more personalized nature possible, to optimize the prevention or delay of a disease and to improve health. Therefore, the characteristics (including sex) of an individual have to be taken into account as well as a series of omics markers. The results of nutritional genomics studies are crucial to generate the evidence needed so that precision nutrition can be applied. Although sex is one of the fundamental variables for making recommendations, at present, the nutritional genomics studies undertaken have not analyzed, systematically and with a gender perspective, the heterogeneity/homogeneity in gene-diet interactions on the different phenotypes studied, thus there is little information available on this issue and needs to be improved. Here we argue for the need to incorporate the gender perspective in nutritional genomics studies, present the general context, analyze the differences between sex and gender, as well as the limitations to measuring them and to detecting specific sex-gene or sex-phenotype associations, both at the specific gene level or in genome-wide-association studies. We analyzed the main sex-specific gene-diet interactions published to date and their main limitations and present guidelines with recommendations to be followed when undertaking new nutritional genomics studies incorporating the gender perspective.

Differential metabolomics analysis allows characterization of diversity of metabolite networks between males and females

Females and males are known to have different abilities to cope with stress and disease. This study was designed to investigate the effect of sex on properties of a complex interlinked network constructed of central biochemical metabolites. The study involved the blood collection and analysis of a large set of blood metabolic markers from a total of 236 healthy participants, which included 140 females and 96 males. Metabolic profiling yielded concentrations of 168 metabolites for each subject. A differential correlation network analysis approach was developed for this study that allowed detection and characterization of interconnection differences in metabolites in males and females. Through topological analysis of the differential network that depicted metabolite differences in the sexes, we identified metabolites with high centralities in this network. These key metabolites were identified as 10 phosphatidylcholines (PCaaC34:4, PCaaC36:6, PCaaC34:3, PCaaC42:2, PCaeC38:1, PCaeC38:2, PCaaC40:1, PCaeC34:1, PC aa C32:1 and PC aa C40:6) and 4 acylcarnitines (C3-OH, C7-DC, C3 and C0). Identification of these metabolites may help further studies of sex-specific differences in the metabolome that may underlie different responses to stress and disease in males and females.

Apolipoprotein E genotype moderates the association between dietary polyunsaturated fat and brain function: an exploration of cerebral glutamate and cognitive performance

Objective: To investigate the effect of Apolipoprotein E (APOE) genotype on the association between dietary polyunsaturated fat (PUFA), cognitive function, and cerebral glutamate. Methods: A participant sample of 122 middle-aged adults were grouped according to APOE genotype (ϵ4 carrier or ϵ4 non-carrier) and asked to record dietary intake for three consecutive days. All participants also underwent neuropsychological testing and a proton magnetic resonance spectroscopy (¹H MRS) scan to assess glutamate in the posterior cingulate cortex. Results: Multiple regression analyses revealed a significant interaction between APOE genotype and PUFA intake on memory performance, F(1,113) = 6.749, p = .016. Greater PUFA intake was associated with better memory performance in healthy middle-aged adults who were APOE ϵ4 non-carriers, but not for ϵ4 carriers. Furthermore, there was a significant interaction between APOE genotype and PUFA intake on cerebral glutamate, in that dietary PUFA was associated with greater cerebral glutamate in APOE ϵ4 carriers, but not for ϵ4 non-carriers, F(1,114) = 5.173, p = .025. Conclusions: The findings suggest that PUFA action on the brain differs according to APOE polymorphism and points towards cerebral glutamate as a potential marker of genetic risk for Alzheimer's disease (AD). Early treatment consisting of PUFA supplementation that is tailored to APOE genotype may be an important intervention for the prevention of cognitive decline.

Roles of gender and obesity in defining correlations between perfluoroalkyl substances and lipid/lipoproteins

Data from National Health and Nutrition Examination Survey (NHANES) for 2005-2014 for those aged ≥20 years fasting for ≥8 h (N = 3629) were analyzed to evaluate the role that gender and obesity play in defining correlations between selected perfluoroalkyl substances (PFAS) and total cholesterol (TC), low density lipoprotein cholesterol (LDL), high density lipoprotein cholesterol (HDL), and triglycerides. PFAS considered for analyses were: perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (PFDA), perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS), perfluoroundecanoic acid (PFUnDA), and 2-(N-methyl-perfluorooctane sulfonamido) acetic acid (Me-FOSAA). Gender and obesity stratified regression models were fitted to estimate associations between PFAS and lipid/lipoproteins with adjustments made for confounders. For obese males, but not for nonobese males, positive associations were found between TC and LDL with PFOA (β = 0.0519, p = 0.01 for TC and β = 0.0822, p = 0.03 for LDL), and PFNA (β = 0.0328, p = 0.03 for TC and β = 0.0679, p = 0.04 for LDL). For obese females, adjusted concentrations of TC increased with increase in the concentrations of PFDA (β = 0.0247, p = 0.048), PFNA (β = 0.0286, p = 0.04), and Me-PFOSAA (β = 0.0274, p = 0.02), and there was a positive association of LDL with PFOS (β = 0.0375, p = 0.04), PFDA (β = 0.0397, p = 0.047), and PFNA (β = 0.0593, p = 0.02). The findings, concerning the relationship of longer chain PFAS to serum lipids, suggest greater susceptibility to elevated TC and LDL cholesterol in the obese participants, with some differences between men and women. The key contributing modifiable risk for nonalcoholic steatosis is obesity, and, the development of nonalcoholic steatosis is recognized to be sexually dimorphic. The epidemiologic observation of a susceptible obese subgroup in our data is consistent with toxicology literature findings of disrupted cholesterol metabolism via induced steatosis following PFAS exposure. Gender differences affect serum concentration of PFAS during the reproductive years, and our data add a secondary question concerning whether they also affect the interaction between PFAS exposure and lipid handling in males and females.

Sex-Dimorphic Association of Plasma Fatty Acids with Cardiovascular Fitness in Young and Middle-Aged General Adults: Subsamples from NHANES 2003⁻2004

To explore the potential association of plasma fatty acids (FAs) and cardiovascular fitness level (CVFL), data of 449 subjects from 2003–2004 National Health and Nutrition Examination Survey (NHANES) were analyzed. Among these 249 men and 200 women, aged 20–50 years (33.4 ± 8.4 year, mean ± Standard Deviation), 79 low, 166 moderate and 204 high CVFL were categorized by age- and gender- specific percentile, respectively. Twenty-four fatty acids were quantified from fasting plasma. Higher levels of 2 very long-chain saturated FAs (VLSFAs): Arachidic acid (AR1, C20:0) and Docosanoic acid (DA1, C22:0) as well as 2 n-6 polyunsaturated FAs (PUFAs): Arachidonic acid (AA, C20:4n-6) and Docosatetraenoic acid (DTA, C22:4n-6) were observed in the subjects with low CVFL. Notably this association exists only in men. Estimated maximal oxygen consumption (VO_2max), the marker for cardiorespiratory fitness, was used for further regression analysis. After the adjustment of potential confounding factors (age, smoking, hypertension status, body mass index (BMI), insulin resistance status, and C-reactive protein (CRP), AA was the only FA correlated with low VO_2max in women; while in men AR1, DA1, AA, and DTA remain negatively associated with VO_2max. This preliminary analysis suggests a sex-dimorphic relationship between these plasma VLSFAs and n-6 PUFAs with CVFL and merits further investigation.

High-fat diet-induced hypertension is associated with a proinflammatory T cell profile in male and female Dahl salt-sensitive rats

Evidence supports a sex difference in the impact of a high-fat diet (HFD) on cardiovascular outcomes, with male experimental animals exhibiting greater increases in blood pressure (BP) than female experimental animals. The immune system has been implicated in HFD-induced increases in BP, and there is a sex difference in T-cell activation in hypertension. The goal of this study was to determine the impact of HFD on BP and aortic and renal T cell profiles in male and female Dahl salt-sensitive (DSS) rats. We hypothesized that male DSS rats would have greater increases in BP and T cell infiltration in response to a HFD compared with female DSS rats. BP was measured by tail-cuff plethysmography, and aortic and renal T cells were assessed by flow cytometric analysis in male and female DSS rats on a normal-fat diet (NFD) or HFD from 12 to 16 wk of age. Four weeks of HFD increased BP in male and female DSS rats to a similar degree. Increases in BP were accompanied by increased percentages of CD4⁺ T cells and T helper (Th)17 cells in both sexes, although male rats had more proinflammatory T cells. Percentages of renal CD3⁺ and CD4⁺ T cells as well as Th17 cells were increased in both sexes by the HFD, although the increase in CD3⁺ T cells was greater in male rats. HFD also decreased the percentage of aortic and renal regulatory T cells in both sexes, although female rats maintained more regulatory T cells than male rats regardless of diet. In conclusion, both male and female DSS rats exhibit BP sensitivity to a HFD; however, the mechanisms mediating HFD-induced increases in BP may be distinct as male rats exhibit greater increases in the percentage of proinflammatory T cells than female rats.

NEW & NOTEWORTHY Our study demonstrates that male and female Dahl salt-sensitive rats exhibit similar increases in blood pressure to a high-fat diet and an increase in aortic and renal T cells. These results are in contrast to studies showing that female rats remain normotensive and/or upregulate regulatory T cells in response to hypertensive stimuli compared with male rats. Our data suggest that a 4-wk high-fat diet has sex-specific effects on the T cell profile in Dahl salt-sensitive rats.