Menopause-induced changes in lipid fractions and total fatty acids in plasma

Serum Metabolic Profiles of Chinese Women With Perimenopausal Obesity Explored by the Untargeted Metabolomics Approach

By far, no study has focused on observing the metabolomic profiles in perimenopause-related obesity. This study attempted to identify the metabolic characteristics of subjects with perimenopause obesity (PO). Thirty-nine perimenopausal Chinese women, 21 with PO and 18 without obesity (PN), were recruited in this study. A conventional ultra-high-performance liquid chromatography-quadrupole time-of-flight/mass spectrometry (UHPLC-QTOF/MS) followed by principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) were used as untargeted metabolomics approaches to explore the serum metabolic profiles. Kyoto Encyclopedia of Genes and Genomes (KEGG) and MetaboAnalyst were used to identify the related metabolic pathways. A total of 46 differential metabolites, along with seven metabolic pathways relevant to PO were identified, which belonged to lipid, amino acids, carbohydrates, and organic acids. As for amino acids, we found a significant increase in l-arginine and d-ornithine in the positive ion (POS) mode and l-leucine, l-valine, l-tyrosine, and N-acetyl-l-tyrosine in the negative ion (NEG) mode and a significant decrease in l-proline in the POS mode of the PO group. We also found phosphatidylcholine (PC) (16:0/16:0), palmitic acid, and myristic acid, which are associated with the significant upregulation of lipid metabolism. Moreover, the serum indole lactic acid and indoleacetic acid were upregulated in the NEG mode. With respect to the metabolic pathways, the d-arginine and d-ornithine metabolisms and the arginine and proline metabolism pathways in POS mode were the most dominant PO-related pathways. The changes of metabolisms of lipid, amino acids, and indoleacetic acid provided a pathophysiological scenario for Chinese women with PO. We believe that the findings of this study are helpful for clinicians to take measures to prevent the women with PO from developing severe incurable obesity-related complications, such as cardiovascular disease and stroke.

Lipid profile changes during the menopausal transition

OBJECTIVES

There is evidence that the menopausal transition in women is accompanied by changes in the metabolic profile. We evaluated the lipid profile during the perimenopause to postmenopause transition and its association with menopausal status.

METHODS

This is a retrospective observational study of laboratory studies from women presenting to the gynecology unit of Hospital Quirón Salud, Madrid (2007-2018) with irregular menstruation, amenorrhea or menopausal symptoms. Inclusion criteria were one or more blood samples with determinations of fasting glucose and lipids (total cholesterol, low-density lipoprotein cholesterol [LDL-c], high-density lipoprotein cholesterol [HDL-c] and triglycerides [TGs]) from women with a menopause diagnosis recorded in the hospital database. The determinations were classified as perimenopausal or postmenopausal based on the date of last menstruation.

RESULTS

In total, 13,517 laboratory studies (3,073 perimenopausal and 10,444 postmenopausal) from 275 women were analyzed. Total cholesterol, LDL-c, and TG levels were significantly higher in postmenopausal women than in perimenopausal women, whereas HDL-c levels were significantly lower (P < 0.05 in all cases). Further adjustment by age showed differences only in LDL-c levels. Menopausal status, TG levels, and the number of pregnancies were independently related with total cholesterol and LDL-c levels. HDL-c levels were independently affected by menopausal age, TG levels, and number of pregnancies. Finally, TG concentration was independently affected by total cholesterol, LDL-c, and HDL-c levels.

CONCLUSION

Our study suggests that significant changes in LDL-c levels occur during the menopausal transition. Total cholesterol and LDL-c changes are independently affected by menopausal status and HDL-c is influenced by menopausal age.

Differential metabolomics networks analysis of menopausal status

Menopause is an endocrine-related transition that induces a number of physiological and potentially pathological changes in middle-aged and elderly women. The intention of this research was to investigate the influence of menopause on the intricate relationships between major biochemical metabolites. The study involved metabolic profiling of 186 metabolic markers measured in blood plasma collected from 120 healthy female participants. We developed a method of network analysis using differential correlation that enabled us to detect and characterize differences in metabolites and changes in inter-relationships in pre- and post-menopausal women. A topological analysis was performed on the differential network that uncovered metabolite differences in pre-and post-menopausal women. In this analysis, our method identified two key metabolites, sphingomyelins and phosphatidylcholines, which may be useful in directing further studies into menopause-specific differences in the metabolome, and how these differences may underlie the body's response to stress and disease following the transition from pre- to post-menopausal status for women.

Sex-steroids and hypolipidemic chemicals impacts on brown trout lipid and peroxisome signaling - Molecular, biochemical and morphological insights

Lipid metabolism involves complex pathways, which are regulated in a similar way across vertebrates. Hormonal and hypolipidemic deregulations cause lipid imbalance from fish to humans, but the underlying mechanisms are far from understood. This study explores the potential of using juvenile brown trout to evaluate the in vivo interferences caused by estrogenic (17α-ethinylestradiol - EE2), androgenic (testosterone - T), and hypolipidemic (clofibrate - CLF) compounds in lipidic and/or peroxisomal pathways. Studied endpoints were from blood/plasma biochemistry, plasma fatty acid profile, ultrastructure of hepatocytes and abundance of their peroxisomes to mRNA expression in the liver. Both T and CLF caused minimal effects when compared to EE2. Estrogenized fish had significantly higher hepatosomatic indexes, increased triglycerides and very-low density lipoproteins (VLDL) in plasma, compared with solvent control. Morphologically, EE2 fish showed increased lipid droplets in hepatocytes, and EE2 and T reduced volume density of peroxisomes in relation to the hepatic parenchyma. Polyunsaturated fatty acids (PUFA) in plasma, namely n-3 PUFA, increased with EE2. EE2 animals had increased mRNA levels of vitellogenin A (VtgA), estrogen receptor alpha (ERα), peroxisome proliferator-activated receptor alpha (PPARα), PPARαBa and acyl-CoA long chain synthetase 1 (Acsl1), while ERβ-1, acyl-CoA oxidase 1-3I (Acox1-3I), Acox3, PPARγ, catalase (Cat), urate oxidase (Uox), fatty acid binding protein 1 (Fabp1) and apolipoprotein AI (ApoAI) were down-regulated. In summary, in vivo EE2 exposure altered lipid metabolism and peroxisome dynamics in brown trout, namely by changing the mRNA levels of several genes. Our model can be used to study possible organism-level impacts, viz. in gonadogenesis.

Soy Improves Cardiometabolic Health and Cecal Microbiota in Female Low-Fit Rats

Phytoestrogen-rich soy is known to ameliorate menopause-associated obesity and metabolic dysfunction for reasons that are unclear. The gut microbiota have been linked with the development of obesity and metabolic dysfunction. We aimed to determine the impact of soy on cardiometabolic health, adipose tissue inflammation, and the cecal microbiota in ovariectomized (OVX) rats bred for low-running capacity (LCR), a model that has been previously shown to mimic human menopause compared to sham-operated (SHM) intact control LCR rats. In this study, soy consumption, without affecting energy intake or physical activity, significantly improved insulin sensitivity and body composition of OVX rats bred for low-running capacity. Furthermore, soy significantly improved blood lipid profile, adipose tissue inflammation, and aortic stiffness of LCR rats. Compared to a soy-free control diet, soy significantly shifted the cecal microbial community of LCR rats, resulting in a lower Firmicutes:Bacteroidetes ratio. Correlations among metabolic parameters and cecal bacterial taxa identified in this study suggest that taxa Prevotella, Dorea, and Phascolarctobacterium may be taxa of interest. Our results suggest that dietary soy ameliorates adiposity, insulin sensitivity, adipose tissue inflammation, and arterial stiffness and exerts a beneficial shift in gut microbial communities in a rat model that mimics human menopause.

Modulatory effects of caffeine on oxidative stress and anxiety-like behavior in ovariectomized rats

Menopause is accompanied by enhanced oxidative stress and behavioral changes, effects attenuated by antioxidants. The aim of this study was to evaluate the effects of caffeine on behavior and oxidative stress in an experimental model of menopause. Female rats were divided into the following groups: sham-operated (CON), sham-operated and caffeine-treated (CAF), ovariectomized (OVX), ovariectomized and caffeine-treated (OVX+CAF). Caffeine (6 mg/kg) and vehicle were administered for 21 days (subchronic) and 42 days (chronic), using 2 experimental subsets. Behavioral tests and oxidative stress parameters in the blood, whole brain, and hippocampus were assessed. The subchronic administration of caffeine decreased the lipid peroxidation and improved the antioxidant defense in the blood and brain. The GSH/GGSG ratio in the brain was improved by chronic administration, with reduced activities of antioxidant enzymes and enhanced nitric oxide and malondialdehyde levels. In particular, the lipid peroxidation in the hippocampus decreased in both experiments. The rats became hyperactive after 21 days of treatment, but no effect was observed after chronic administration. In both experimental subsets, caffeine had anxiolytic effects as tested in elevated plus maze. The administration of low doses of caffeine, for a short period of time, may be a new therapeutic approach to modulating the oxidative stress and anxiety in menopause.

Prevention of hyperphagia prevents ovariectomy-induced triacylglycerol accumulation in liver, but not plasma

Menopause is associated with higher plasma and liver triacylglycerol (TAG) and increased risk for cardiovascular disease. Lowering TAG in menopause may be beneficial; however, the mechanism underlying menopause-induced TAG accumulation is not clear. Ovariectomy is a model for menopause and is associated with metabolic alterations and hyperphagia. This study investigated the role of hyperphagia in ovariectomy-induced increases in blood and tissue TAG, as well as differences in lipid metabolism enzymes and resting metabolic measures. It was hypothesized that prevention of hyperphagia would restore blood and tissue TAG, enzyme expression, and metabolic measures to eugonadal levels. Ovariectomized rats were fed ad libitum (OVX + AL) or pair-fed (OVX + PF) relative to sham-operated rats (SHAM) to prevent hyperphagia. OVX + AL had higher TAG concentrations in liver and plasma than SHAM (60% and 50%, respectively), and prevention of hyperphagia in OVX + PF normalized TAG concentrations to SHAM levels in liver, but not plasma. OVX + AL also had 141% higher hepatic stearoyl-CoA desaturase 1 which was almost completely normalized to SHAM levels by pair-feeding, suggesting normalization of hepatic lipid storage. In contrast, skeletal muscle carnitine palmitoyl transferase 1 was 40% lower in OVX + AL than SHAM and was intermediate in OVX + PF, suggesting lower muscle fatty acid oxidation that may underlie the higher plasma TAG in OVX. No differences were seen in energy expenditure, VO2, or VCO2. Overall, this study indicates that prevention of hyperphagia resulting from ovarian hormone withdrawal normalizes hepatic TAG to eugonadal levels but has no effect on ovariectomy-induced increases in plasma TAG.

Potential benefits of berberine in the management of perimenopausal syndrome

Cardiovascular diseases are one of the leading causes of morbidity and mortality in women after menopause and 56% of all causes of death in Western European countries. Nowadays, with increasing life span, women spend approximately one-third of their life-time in postmenopausal state; therefore, the development of new strategies to improve the prevention and treatment of menopause-associated pathologies is important topic in clinical practice. The studies to assess the safety of hormone replacement therapy in women with estrogen deficiency have not been conclusive due to the relative contraindications; therefore, hormone replacement therapy is prescribed only in selected cases and for a limited time. For this reason, today women are encouraged to use naturally available compounds to prevent or to attenuate menopausal symptoms and correlated pathologies, with fewer side effects. Among these compounds, berberine, an isoquinoline alkaloid derived from plants of the generis Berberis, has been recognized as being capable of decreasing oxidative stress, LDL, triglycerides, and insulin resistance and of improving the mood. This review describes the cellular and clinical effects associated with the use of berberine, which suggest that this molecule could be an effective natural supplement to ensure a smooth peri- and postmenopausal transition.

A metabolic view on menopause and ageing

The ageing of the global population calls for a better understanding of age-related metabolic consequences. Here we report the effects of age, sex and menopause on serum metabolites in 26,065 individuals of Northern European ancestry. Age-specific metabolic fingerprints differ significantly by gender and, in females, a substantial atherogenic shift overlapping the time of menopausal transition is observed. In meta-analysis of 10,083 women, menopause status associates with amino acids glutamine, tyrosine and isoleucine, along with serum cholesterol measures and atherogenic lipoproteins. Among 3,204 women aged 40-55 years, menopause status associates additionally with glycine and total, monounsaturated, and omega-7 and -9 fatty acids. Our findings suggest that, in addition to lipid alterations, menopause may contribute to future metabolic and cardiovascular risk via influencing amino-acid concentrations, adding to the growing evidence of the importance of amino acids in metabolic disease progression. These observations shed light on the metabolic consequences of ageing, gender and menopause at the population level.

A family-based association study identified CYP17 as a candidate gene for obesity susceptibility in Caucasians

The cytochrome P450c17α gene (CYP17) encodes a key biosynthesis enzyme of estrogen, which is critical in regulating adipogenesis and adipocyte development in humans. We therefore hypothesized that CYP17 is a candidate gene for predicting obesity. In order to test this hypothesis, we performed a family-based association test to investigate the relationship between the CYP17 gene and obesity phenotypes in a large sample comprising 1873 subjects from 405 Caucasian nuclear families of European origin recruited by the Osteoporosis Research Center of Creighton University, USA. Both single SNPs and haplotypes were tested for associations with obesity-related phenotypes, including body mass index (BMI) and fat mass. We identified three SNPs to be significantly associated with BMI, including rs3740397, rs6163, and rs619824. We further characterized the linkage disequilibrium structure for CYP17 and found that the whole CYP17 gene was located in a single-linkage disequilibrium block. This block was observed to be significantly associated with BMI. A major haplotype in this block was significantly associated with both BMI and fat mass. In conclusion, we suggest that the CYP17 gene has an effect on obesity in the Caucasian population. Further independent studies will be needed to confirm our findings.

ALOX12 gene is associated with the onset of natural menopause in white women

OBJECTIVE

Natural menopause is a key physiological event in a woman's life. Timing of menopause affects risk for many postmenopausal systemic disorders and may thus influence life expectancy. Age at natural menopause (ANM) is largely determined genetically, but a list of candidate genes is far from complete. This study investigated the ALOX12 gene for its possible association with ANM.

METHODS

Six single-nucleotide polymorphisms (SNPs) of the gene (rs9904779, rs2073438, rs11571340, rs434473, rs2307214, and rs312462) were genotyped in a random sample of 210 unrelated white women. The SNPs and common haplotypes were then analyzed for their association with ANM. Smoking, alcohol consumption, and duration of breast-feeding were used as covariates.

RESULTS

Two SNPs, rs9904779 and rs434473 (encodes a replacement of asparagine by serine in the protein), were significantly associated with ANM (P = 0.022 and 0.033, respectively). The minor alleles of both SNPs seem to promote about 1.3- to 1.5-year earlier menopause and confer a 1.6 to 1.8 times higher risk for early menopause. All SNPs indicated significant or nearly significant interactions with alcohol use and duration of breast-feeding. Five common haplotypes were also associated with ANM.

CONCLUSIONS

The ALOX12 gene seems to be associated with the timing of natural menopause in white women.

Plasma free fatty acid level patterns according to cardiovascular risk status in postmenopausal women

BACKGROUND

The present study examines changes in the pattern of plasma free polyunsaturated fatty acids (PUFA) according to menopausal status and the existence of diabetes mellitus (DM) or coronary heart disease (CHD) in Korean women.

METHODS

The participants were as follows; premenopausal women (PRE, n=20) and postmenopausal women without any known chronic disease (POST, n=35), with DM (DM, n=35), or with angiographically proven CHD (CHD, n=30). Plasma free fatty acids were measured in all participants.

RESULTS

Healthy premenopausal women had a higher ratio of omega-3/omega-6 PUFA than postmenopausal women (p=0.001). As expected, the PRE group had higher docsapentaenoic acid (DPA) and docosahexaenoic acid (DHA) levels (p<0.05) and lower arachidonic acid levels (p<0.05) than the POST group. In turn, the healthy POST group had higher levels of DPA and DHA compared to the DM or CHD groups (p<0.05). There were significant shifts of increased omega-6 and decreased omega-3 among the women, according to each disease.

CONCLUSIONS

There was a significant relationship between omega-3 and omega-6 PUFA profiles and risk for CHD in women. This metabolic profile of PUFA might be an important surrogate marker in postmenopausal women.

[Psychophysiologic disturbances in early postmenopause in women after physiological and surgical menopause]

BACKGROUND/AIM

The most common secondary manifestations of menopause are clinical manifestations of estrogen deficiency. They could be early and late. The aim of this study was to compare manifestations of somatic disturbances in early postmenopause in women after physiological and surgical menopause.

METHODS

This prospective study included 60 women, age 41-55 years, divided into two groups: physiological (30 of them) and surgically induced menopause. For every subject a special evidence list, consisting of the disease history questions, physical and gynecology examination as well as dates about physiological variables (arterial tension, height, weight, and body-mass index) and laboratory examination was formed. The values of arteriol blood pressure, body height, body mass, body mass index (BMI), and lipid status were determined and gynecological examinations were performed in each patient.

RESULTS

The most frequent symptoms in both groups were vasomotor ones. Headache was the more intensive sign in the group after induced menopause. Extrasistolyc heart excursion was a common symptom in both study groups. Arterial tension, regardless of the type of menopause, was in the physiological range. The frequent organic signs of menopause, more intensive in the group after induced menopause, were genitourinary and skin atrophy. An analysis of the BMI showed that the women in both groups were obese (BMI > 25). The lipids analysis confirmed the predomination of hyperlipoproteinemia type IIa in the group with physiologic menopause and type IIb after induced menopause.

CONCLUSION

The dominant signs of menopausal syndrome were vasomotor and bone-joint symptoms, more frequent in the group after induced menopause. There were no statistically significant differences between the study groups according to the genitourinary atrophy and other signs of aging. Menopausal hormonal changes, regardless of the way of menopause developing, increase the risk for hyperlipoproteinemia. The frequency of somatic signs in early post menopause is typically higher after induced menopause. More intensive follow-up in patients after surgical removing of the ovaria is necessary in order to improve the quality of life in these patients.

Docosahexaenoic acid concentrations are higher in women than in men because of estrogenic effects

BACKGROUND

During pregnancy there is a high demand for docosahexaenoic acid (DHA), which is needed for formation of the fetal brain. Women who do not consume marine foods must synthesize DHA from fatty acid precursors in vegetable foods.

OBJECTIVE

We studied sex differences in DHA status and the role of sex hormones.

DESIGN

First, DHA status was compared between 72 male and 103 female healthy volunteers who ate the same rigidly controlled diets. Second, the effects of sex hormones were studied in 56 male-to-female transsexual subjects, who were treated with cyproterone acetate alone or randomly assigned to receive oral ethinyl estradiol or transdermal 17beta-estradiol combined with cyproterone acetate, and in 61 female-to-male transsexual subjects, who were treated with testosterone esters or randomly assigned for treatment with the aromatase inhibitor anastrozole or placebo in addition to the testosterone regimen.

RESULTS

The proportion of DHA was 15 +/- 4% (x +/- SEM; P < 0.0005) higher in the women than in the men. Among the women, those taking oral contraceptives had 10 +/- 4% (P = 0.08) higher DHA concentrations than did those not taking oral contraceptives. Administration of oral ethinyl estradiol, but not transdermal 17beta-estradiol, increased DHA by 42 +/- 8% (P < 0.0005), whereas the antiandrogen cyproterone acetate did not affect DHA. Parenteral testosterone decreased DHA by 22 +/- 4% (P < 0.0005) in female-to-male transsexual subjects. Anastrozole decreased estradiol concentrations significantly and DHA concentrations nonsignificantly (9 +/- 6%; P = 0.09).

CONCLUSION

Estrogens cause higher DHA concentrations in women than in men, probably by upregulating synthesis of DHA from vegetable precursors.