The interplay between metabolic dysregulations and non-alcoholic fatty liver disease in women after menopause

Metabolic Risk in Patients with a Diminished Ovarian Reserve and Premature Ovarian Insufficiency

Objective: Diminished ovarian reserve (DOR) and premature ovarian insufficiency (POI) represent conditions of different severity, characterized by an earlier-than-expected decrease in ovarian activity. The present study aims to compare metabolic disturbances between women with DOR and patients with POI from a different origin. Materials and methods: A total of 226 women (28 healthy women; 77 individuals with DOR, and 121 patients with POI/36 with Turner syndrome [TS] and 85 with non-TS POI/) have been studied retrospectively. Data concerning anthropometric indices, and metabolic parameters were collected. Results: Patients with DOR, non-TS POI, and TS had increased blood pressure and liver enzymes, pronounced insulin resistance, and worse lipid profiles than controls (p < 0.008 for all). TS patients had significantly higher ASAT, GGT, and TSH levels compared to non-TS POI and DOR individuals. The prevalence of type 2 diabetes tended to be higher in TS women compared to other groups. The prevalence of previously diagnosed polycystic ovarian syndrome was lower in the non-TS POI patients than in the DOR patients (p = 0.005). Conclusions: patients with decreased ovarian function suffer from insulin resistance, abnormal lipid profile, and subtle hepatic disturbances, irrespective of the severity of the condition and the presence of chromosomal aberrations.

Adipose-derived extracellular vesicles - a novel cross-talk mechanism in insulin resistance, non-alcoholic fatty liver disease, and polycystic ovary syndrome

Obesity is the best described risk factor for the development of non-alcoholic fatty liver disease (NAFLD)/metabolic dysfunction associated steatotic liver disease (MASLD) and polycystic ovary syndrome (PCOS) while the major pathogenic mechanism linking these entities is insulin resistance (IR). IR is primarily caused by increased secretion of proinflammatory cytokines, adipokines, and lipids from visceral adipose tissue. Increased fatty acid mobilization results in ectopic fat deposition in the liver which causes endoplasmic reticulum stress, mitochondrial dysfunction, and oxidative stress resulting in increased cytokine production and subsequent inflammation. Similarly, IR with hyperinsulinemia cause hyperandrogenism, the hallmark of PCOS, and inflammation in the ovaries. Proinflammatory cytokines from both liver and ovaries aggravate IR thus providing a complex interaction between adipose tissue, liver, and ovaries in inducing metabolic abnormalities in obese subjects. Although many pathogenic mechanisms of IR, NAFLD/MASLD, and PCOS are known, there is still no effective therapy for these entities suggesting the need for further evaluation of their pathogenesis. Extracellular vesicles (EVs) represent a novel cross-talk mechanism between organs and include membrane-bound vesicles containing proteins, lipids, and nucleic acids that may change the phenotype and function of target cells. Adipose tissue releases EVs that promote IR, the development of all stages of NAFLD/MASLD and PCOS, while mesenchymal stem cell-derived AVs may alleviate metabolic abnormalities and may represent a novel therapeutic device in NAFLD/MASLD, and PCOS. The purpose of this review is to summarize the current knowledge on the role of adipose tissue-derived EVs in the pathogenesis of IR, NAFLD/MASLD, and PCOS.

Hypogonadism and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), recently proposed to be renamed to metabolic dysfunction-associated steatotic liver disease (MASLD), is a major global public health concern, affecting approximately 25-30% of the adult population and possibly leading to cirrhosis, hepatocellular carcinoma, and liver transplantation. The liver is involved in the actions of sex steroids via their hepatic metabolism and production of the sex hormone-binding globulin (SHBG). Liver disease, including NAFLD, is associated with reproductive dysfunction in men and women, and the prevalence of NAFLD in patients with hypogonadism is considerable. A wide spectrum of possible pathophysiological mechanisms linking NAFLD and male/female hypogonadism has been investigated. As therapies targeting NAFLD may impact hypogonadism in men and women, and vice versa, treatments of the latter may affect NAFLD, and an insight into their pathophysiological pathways is imperative. This paper aims to elucidate the complex association between NAFLD and hypogonadism in men and women and discuss the therapeutic options and their impact on both conditions.

What Do Higher Alanine Aminotransferase Levels Mean in Premature Ovarian Insufficiency?

The objective of this study was to investigate the relationship between alanine aminotransferase and related biochemical parameters and potential risk factors in women with premature ovarian insufficiency (POI). This is a retrospective cohort study with 126 POI patients (including subclinical POI, n= 27) and 130 healthy controls who visited our clinic between April 2021 to November 2022. Associations were investigated by multiple linear regression, Person correlation analysis, the Kruskal-Wallis test, Mann-Whitney U test, and the independent t-test. When compared to controls, analysis of POI patients showed that body mass index (BMI), uric acid (UA) and urea, alanine aminotransferase (ALT), aspartate aminotransferase (AST), monocyte/lymphocyte ratio, monocyte count (MONO), neutrophil count (NEUT), follicle-stimulating hormone (FSH), luteinizing hormone, and neutrophil/lymphocyte ratio (NLR) were significantly higher, while estradiol (E2), the lymphocyte count and the AST/ALT ratio were lower (P < 0.05). According to linear correlation, it was clear that BMI, FSH, white blood cell count (WBC), NEUT, MONO, UA, AST, and NLR were positively associated with ALT (r = 0.215, 0.388, 0.195, 0.187, 0.184, 0.605, 0.819, and 0.189, respectively, all P < 0.05) while E2 was negatively associated with ALT (r = -0.278, P < 0.05). In addition, multiple linear regression revealed a significant, independent, and positive correlation between AST, FSH, and ALT (B =1.403 and 0.069, respectively, P < 0.05). Analysis revealed that the levels of ALT were significantly higher in POI patients. In addition, BMI, FSH, UA, AST, MONO, NLR, NEUT, and WBC were positively associated with ALT in POI patients. E2 was negatively associated with ALT. Multiple linear regression revealed an independent and positive correlation between AST, FSH, and ALT. In addition, there was also a risk of liver function damage in women with POI and subclinical POI. If patients were diagnosed with POI, early examination and corresponding intervention will be required to effectively prevent the further development of liver disease.

Sex and Age Differences in the Association Between Metabolic Dysfunction-Associated Fatty Liver Disease and Heart Failure: A Prospective Cohort Study

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a risk factor for heart failure (HF) occurrence, but it remains unclear whether the association between MAFLD and HF differs in different sexes and ages.

METHODS

A total of 96 576 participants of Kailuan Study were included. MAFLD was defined as presence of hepatic steatosis and metabolic dysfunction and classified as mild and significant by ultrasound. Hazard ratios (HRs) were calculated by Cox regression models.

RESULTS

After a median follow-up of 14.0 years, 2939 participants developed HF. Adjusting for confounding factors, mild-MAFLD (HR, 1.27 [95% CI, 1.16-1.39]) and significant-MAFLD (HR, 1.45 [95% CI, 1.31-1.63]) were associated with a higher risk of HF in all participants, and the risk differed by sex (Pinteraction<0.05) and age (Pinteraction<0.001). Compared with non-MAFLD participants, in women, significant-MAFLD was associated with an 84% (HR, 1.84 [95% CI, 1.43-2.37]) increased risk of HF; however, in men, the risk was 36% (HR, 1.36 [95% CI, 1.20-1.53]). In participants under 45 years, mild-MAFLD and significant-MAFLD had a 55% (HR, 1.55 [95% CI, 1.07-2.25]) and 172% (HR, 2.72 [95% CI, 1.87-3.97]) increased risk of HF; however, in participants over 65 years, even significant-MAFLD did not associate with a higher risk of HF (HR, 1.11 [95% CI, 0.92-1.34]). Afterwards, we stratified all participants by both sex and age and found that the risk of MAFLD-associated HF decreased with age in men (Pinteraction<0.05) and women (Pinteraction<0.05), but the sex difference in this risk was only present in participants younger than 45 years (Pinteraction<0.05).

CONCLUSIONS

MAFLD greatly increased the risk of HF in women, especially young women. With increasing age, MAFLD-related risk of HF decreased and the difference between men and women disappeared.

Micro-scale vertebral features in postmenopausal women with alcohol-associated and metabolic-associated fatty liver disease: ex vivo bone quality analyses

PURPOSE

Although epidemiological studies indicate increased fracture risk in women with alcohol-associated liver disease (AALD) and metabolic-associated fatty liver disease (MAFLD), data about their micro-scale bone features are still limited. We aimed to characterize bone quality changes in the anterior mid-transverse part of the first lumbar vertebral body collected from 32 adult postmenopausal females. Based on pathohistological assessment of the liver tissue, individuals were divided into AALD (n = 13), MAFLD (n = 9), and control group (n = 10).

METHODS

We analyzed trabecular and cortical micro-architecture (using micro-computed tomography), bone mechanical properties (using Vickers microhardness tester), osteocyte lacunar network and bone marrow adiposity morphology (using optic microscopy). Data were adjusted to elude the covariant effects of advanced age and body mass index on our results.

RESULTS

Our data indicated a minor trend toward deteriorated bone quality in MAFLD women, presented in impaired trabecular and cortical micro-architectural integrity, which could be associated with bone marrow adiposity alterations noted in these women. Additionally, we observed a significant decline in micro-architectural, mechanical, and osteocyte lacunar features in lumbar vertebrae collected from the AALD group. Lastly, our data indicated that vertebral bone deterioration was more prominent in the AALD group than in the MAFLD group.

CONCLUSION

Our data suggested that MAFLD and AALD are factors that could play a part in compromised vertebral strength of postmenopausal women. Also, our data contribute to understanding the multifactorial nature of bone fragility in these patients and highlight the necessity for developing more effective patient-specific diagnostic, preventive, and therapeutic strategies.

17β-Estradiol (E2) Upregulates the ERα/SIRT1/PGC-1α Signaling Pathway and Protects Mitochondrial Function to Prevent Bilateral Oophorectomy (OVX)-Induced Nonalcoholic Fatty Liver Disease (NAFLD)

Premature menopause is associated with an increased prevalence of nonalcoholic fatty liver disease (NAFLD). Menopausal hormone therapy (MHT) has been widely used in clinical practice and has the potential to protect mitochondrial function and alleviate NAFLD. After bilateral oophorectomy (OVX), female rats without 17β-estradiol (E2) intervention developed NAFLD, whereas E2 supplementation was effective in preventing NAFLD in female rats. The altered pathways and cellular events from both comparison pairs, namely, the OVX vs. sham group and the OVX vs. E2 group, were assessed using transcriptomic analysis. KEGG pathways enriched by both transcriptomic and metabolomic analyses strongly suggest that oxidative phosphorylation is a vital pathway that changes during the development of NAFLD and remains unchanged when E2 is applied. Liver tissue from the OVX-induced NAFLD group exhibited increased lipid peroxidation, impaired mitochondria, and downregulated ERα/SIRT1/PGC-1α expression. An in vitro study indicated that the protective effect of E2 treatment on hepatic steatosis could be abolished when ERα or SIRT1 was selectively inhibited. This damage was accompanied by reduced mitochondrial complex activity and increased lipid peroxidation. The current research indicates that E2 upregulates the ERα/SIRT1/PGC-1α signaling pathway and protects mitochondrial function to prevent OVX-induced NAFLD.

Identification of Diagnostic Biomarkers for Compensatory Liver Cirrhosis Based on Gut Microbiota and Urine Metabolomics Analyses

Liver cirrhosis is one of the most prevalent chronic liver disorders with high mortality. We aimed to explore changed gut microbiome and urine metabolome in compensatory liver cirrhosis (CLC) patients, thus providing novel diagnostic biomarkers for CLC. Forty fecal samples from healthy volunteers (control: 19) and CLC patients (patient: 21) were undertaken 16S rDNA sequencing. Chromatography-mass spectrometry was performed on 40 urine samples (20 controls and 20 patients). Microbiome and metabolome data were separately analyzed using corresponding bioinformatics approaches. The diagnostic model was constructed using the least absolute shrinkage and selection operator regression. The optimal diagnostic model was determined by five-fold cross-validation. Pearson correlation analysis was applied to clarify the relations among the diagnostic markers. 16S rDNA sequencing analyses showed changed overall alpha diversity and beta diversity in patient samples compared with those of controls. Similarly, we identified 841 changed metabolites. Pathway analysis revealed that the differential metabolites were mainly associated with pathways, such as tryptophan metabolism, purine metabolism, and steroid hormone biosynthesis. A 9-maker diagnostic model for CLC was determined, including 7 microorganisms and 2 metabolites. In this model, there were multiple correlations between microorganisms and metabolites. Subdoligranulum, Agathobacter, norank_f_Eubacterium_coprostanoligenes_group, Butyricicoccus, Lachnospiraceae_UCG_004, and L-2,3-Dihydrodipicolinate were elevated in CLC patients, whereas Blautia, Monoglobus, and 5-Acetamidovalerate were reduced. A novel diagnostic model for CLC was constructed and verified to be reliable, which provides new strategies for the diagnosis and treatment of CLC.

Review of mendelian randomization studies on age at natural menopause

Menopause marks the end of the reproductive phase of life. Based on epidemiological studies, abnormal age at natural menopause (ANM) is thought to contribute to a number of adverse outcomes, such as osteoporosis, cardiovascular disease, and cancer. However, the causality of these associations remains unclear. A powerful epidemiological method known as Mendelian randomization (MR) can be used to clarify the causality between ANM and other diseases or traits. The present review describes MR studies that included ANM as an exposure, outcome and mediator. The findings of MR analyses on ANM have revealed that higher body mass index, poor educational level, early age at menarche, early age at first live birth, early age at first sexual intercourse, and autoimmune thyroid disease appear to be involved in early ANM etiology. The etiology of late ANM appears to be influenced by higher free thyroxine 4 and methylene tetrahydrofolate reductase gene mutations. Furthermore, early ANM has been found to be causally associated with an increased risk of osteoporosis, fracture, type 2 diabetes mellitus, glycosylated hemoglobin, and the homeostasis model of insulin resistance level. In addition, late ANM has been found to be causally associated with an increased systolic blood pressure, higher risk of breast cancer, endometrial cancer, endometrioid ovarian carcinoma, lung cancer, longevity, airflow obstruction, and lower risk of Parkinson's disease. ANM is also a mediator for breast cancer caused by birth weight and childhood body size. However, due to the different instrumental variables used, some results of studies are inconsistent. Future studies with more valid genetic variants are needed for traits with discrepancies between MRs or between MR and other types of epidemiological studies.

Plasma metabolomic characterization of premature ovarian insufficiency

BACKGROUND

Premature ovarian insufficiency (POI) patients are predisposed to metabolic disturbances, including in lipid metabolism and glucose metabolism, and metabolic disorders appear to be a prerequisite of the typical long-term complications of POI, such as cardiovascular diseases or osteoporosis. However, the metabolic changes underlying the development of POI and its subsequent complications are incompletely understood, and there are few studies characterizing the disturbed metabolome in POI patients. The aim of this study was to characterize the plasma metabolome in POI by using ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) metabolomics and to evaluate whether these disturbances identified in the plasma metabolome relate to ovarian reserve and have diagnostic value in POI.

METHODS

This observational study recruited 30 POI patients and 30 age- and body mass index (BMI)-matched controls in the Center for Reproductive Medicine, Department of Gynecology and Obstetrics, Nanfang Hospital, Southern Medical University, from January 2018 to October 2020. Fasting venous blood was collected at 9:00 am on days 2-4 of the menstrual cycle and centrifuged for analysis. An untargeted quantitative metabolomic analysis was performed using UHPLC-MS/MS.

RESULTS

Our study identified 48 upregulated and 21 downregulated positive metabolites, and 13 upregulated and 48 downregulated negative metabolites in the plasma of POI patients. The differentially regulated metabolites were involved in pathways such as caffeine metabolism and ubiquinone and other terpenoid-quinone biosynthesis. Six metabolites with an AUC value > 0.8, including arachidonoyl amide, 3-hydroxy-3-methylbutanoic acid, dihexyl nonanedioate, 18-HETE, cystine, and PG (16:0/18:1), were correlated with ovarian reserve and thus have the potential to be diagnostic biomarkers of POI.

CONCLUSION

This UHPLC-MS/MS untargeted metabolomics study revealed differentially expressed metabolites in the plasma of patients with POI. The differential metabolites may not only be involved in the aetiology of POI but also contribute to its major complications. These findings offer a panoramic view of the plasma metabolite changes caused by POI, which may provide useful diagnostic and therapeutic clues for POI disease.

The Effect of Menopause and Menopausal Hormone Therapy on the Risk of Peripheral Artery Disease

Peripheral artery disease (PAD), defined as lower extremity arterial disease, constitutes an underestimated aspect of the menopause-associated risk of atherosclerotic cardiovascular disease (ASCVD). Accumulation of ASCVD risk factors, such as atherogenic dyslipidaemia, diabetes, and arterial hypertension, after the transition to menopause may contribute to atherosclerotic plaque formation in peripheral arteries. However, inconsistency exists among studies as to whether transition to menopause increases the risk of PAD, although early menopause (<45 years) or premature ovarian insufficiency may accelerate peripheral atherosclerotic plaque formation. Menopausal hormone therapy may decrease the risk of PAD if administered early (i.e., within the first 5-6 years after last menstruation), whereas it has no effect in women with established ASCVD.

Interleukin-15 are associated with insulin resistance in postmenopausal women with metabolic syndrome

OBJECTIVE

To determine if higher levels of circulating interleukin (IL)-15 are positively associated with improvement in insulin resistance in postmenopausal women (PW) with metabolic syndrome (MS).

METHODS

According to the median value of IL-15 at baseline, PW older than or equal to 45 years were divided into two groups: higher (n = 43) and lower (n = 42) IL-15. There was a 9-month follow-up period with clinical assessments at baseline and at 9 months (criteria of metabolic syndrome, body fat, and insulin resistance). Insulin resistance (IR) was calculated according to the Homeostasis Model Assessment-estimated insulin resistance (HOMA-IR). For IL-1β, IL-6, IL-10, IL-13, IL-33, IL-15, and TNF-α was determined using immunoassay Magnetic Bead Panel.

RESULTS

There was an interaction between the time and group only for insulin (p = .008) and HOMA-IR (p = .024). After adjusting for confounding variables (clinical and ILs), the HOMA-IR (p = .006) and insulin (p = .003) were lower in the higher-IL-15 group [HOMA-IR: 2.2 (95% CI: 1.9-2.5) and insulin: 9.1 µIU/mL (95% CI: 7.9-10.3)] when compared to the lower-IL-15 group [HOMA-IR: 3.1 (95% CI: 2.6-3.6) and insulin: 12.9 (95% CI: 11.1-14.9)] after 9 months of follow-up.

CONCLUSION

Higher levels of circulating IL-15 are positively associated with improvements in IR in PW with MS.

Chitosan reduces inflammation and protects against oxidative stress in a hyperlipidemic rat model: relevance to nonalcoholic fatty liver disease

BACKGROUND

An altered lipid profile may lead to the development of inflammation and NAFLD (Non-alcoholic fatty liver disease). Although statins have a positive effect on blood lipid levels their long-term use is known to cause adverse effects, in this backdrop there is an interest in natural compounds which may affect lipid metabolism and prevent NAFLD. We have examined the effect of Chitosan on rats subjected to a high-fat diet.

METHODS AND RESULTS

Male Wistar middle aged rats (12-16 months) were treated with high-fat diet orally for two months for creating a NAFLD model. Rats were also supplemented with Chitosan (2% chitosan daily) for 2 months. We assessed the activity of antioxidant enzymes, the histopathological profile of the liver. Inflammatory cytokines and adiponectin levels were also measured in serum. HFD induced significant changes in liver tissue and inflammatory markers (Il-6, TNF- alpha, NF-KB). Chitosan treatment protected rats from HFD induced alterations.

CONCLUSIONS

The findings suggest that Chitosan can effectively improve liver lipid metabolism by normalizing cholesterol, triglyceride, lowering NF-KB expression, and protecting the liver from oxidative stress by improving hepatic function. Chitosan also regulates genes related to lipidemic stress i,e leptin and adiponectin.

Mechanisms of Estrogen Influence on Skeletal Muscle: Mass, Regeneration, and Mitochondrial Function

Human menopause is widely associated with impaired skeletal muscle quality and significant metabolic dysfunction. These observations pose significant challenges to the quality of life and mobility of the aging population, and are of relevance when considering the significantly greater losses in muscle mass and force-generating capacity of muscle from post-menopausal females relative to age-matched males. In this regard, the influence of estrogen on skeletal muscle has become evident across human, animal, and cell-based studies. Beneficial effects of estrogen have become apparent in mitigation of muscle injury and enhanced post-damage repair via various mechanisms, including prophylactic effects on muscle satellite cell number and function, as well as membrane stability and potential antioxidant influences following injury, exercise, and/or mitochondrial stress. In addition to estrogen replacement in otherwise deficient states, exercise has been found to serve as a means of augmenting and/or mimicking the effects of estrogen on skeletal muscle function in recent literature. Detailed mechanisms behind the estrogenic effect on muscle mass, strength, as well as the injury response are beginning to be elucidated and point to estrogen-mediated molecular cross talk amongst signalling pathways, such as apoptotic signaling, contractile protein modifications, including myosin regulatory light chain phosphorylation, and the maintenance of muscle satellite cells. This review discusses current understandings and highlights new insights regarding the role of estrogen in skeletal muscle, with particular regard to muscle mass, mitochondrial function, the response to muscle damage, and the potential implications for human physiology and mobility.

Long or Irregular Menstrual Cycles and Risk of Prevalent and Incident Nonalcoholic Fatty Liver Disease

CONTEXT

The association of menstrual cycle length and irregularity with the risk of non-alcoholic fatty liver disease (NAFLD) is unknown.

OBJECTIVE

We examined this association in large cross-sectional and cohort studies.

METHODS

The cross-sectional study included 72 092 women younger than 40 years who underwent routine health examinations; the longitudinal analysis included the subset of 51 118 women without NAFLD at baseline. Long or irregular cycles were defined as menstrual cycles of 40 days or longer or too irregular to estimate. Abdominal ultrasonography was performed to identify NAFLD. Multivariable Cox proportional hazard regression analyses were performed to estimate hazard ratios (HRs) and 95% CIs for incident NAFLD according to menstrual cycle regularity and length, with 26- to 30-day cycles as the reference.

RESULTS

At baseline, 27.7% had long or irregular menstrual cycles and 7.1% had prevalent NAFLD. Long or irregular menstrual cycles were positively associated with prevalent NAFLD. During a median follow-up of 4.4 years, incident NAFLD occurred in 8.9% of women. After adjustment for age, body mass index, insulin resistance, and other confounders, the multivariable-adjusted HR for NAFLD comparing long or irregular menstrual cycles to the reference group was 1.22 (95% CI, 1.14-1.31); this association strengthened in the time-dependent analysis with an HR of 1.49 (95% CI, 1.38-1.60).

CONCLUSION

Long or irregular menstrual cycles were associated with increased risk of both prevalent and incident NAFLD in young, premenopausal women. Women with long or irregular menstrual cycles may benefit from lifestyle modification advice to reduce the risk of NAFLD and associated cardiometabolic diseases.

Menopause-associated risk of cardiovascular disease

Cardiovascular disease (CVD) is of major concern in women entering menopause. The changing hormonal milieu predisposes them to increased CVD risk, due to a constellation of risk factors, such as visceral obesity, atherogenic dyslipidemia, dysregulation in glucose homeostasis, non-alcoholic fatty liver disease and arterial hypertension. However, an independent association of menopause per se with increased risk of CVD events has only been proven for early menopause (<45 years). Menopausal hormone therapy (MHT) ameliorates most of the CVD risk factors mentioned above. Transdermal estrogens are the preferable regimen, since they do not increase triglyceride concentrations and they are not associated with increased risk of venous thromboembolic events (VTE). Although administration of MHT should be considered on an individual basis, MHT may reduce CVD morbidity and mortality, if commenced during the early postmenopausal period (<60 years or within ten years since the last menstrual period). In women with premature ovarian insufficiency (POI), MHT should be administered at least until the average age of menopause (50-52 years). MHT is contraindicated in women with a history of VTE and is not currently recommended for the sole purpose of CVD prevention. The risk of breast cancer associated with MHT is generally low and is mainly conferred by the progestogen. Micronized progesterone and dydrogesterone are associated with lower risk compared to other progestogens.

Non-Alcoholic Fatty Liver Disease and the Risk of Diabetes Mellitus by Menopausal Status: A Nationwide Cohort Study

Background: Non-alcoholic fatty liver disease (NAFLD) is regarded as a risk factor for type 2 diabetes mellitus (DM). Menopausal status also influences T2DM risk, where estrogen is presumed to play a protective role by decreasing insulin resistance. As such, we investigated the association between NAFLD and DM risk according to menopausal status. Objectives: We sought to examine the association between NAFLD and DM incidence in pre- and post-menopausal women. Methods: A total of 842,772 pre-menopausal and 1,074,767 post-menopausal women who underwent health examinations between 2009 and 2014 were included from the Korean National Health Insurance Service database. Multivariate Cox proportional hazard analyses were performed to evaluate the association between the risk of DM according to menopausal status and NAFLD, defined by a fatty liver index >60. Results: During the mean follow-up period (7.8 years), DM was diagnosed in 33,461 (4.0%) of pre-menopausal women and 121,102 (9.4%) post-menopausal women. A stronger association between NAFLD and the risk of DM was found in pre-menopausal women (multivariable-adjusted hazard ratio [aHR], 3.60; 95% confidence interval [CI], 3.48−3.71) than in post-menopausal women (aHR, 2.24; 95% CI, 2.21−2.28) (P-interaction < 0.01). Subgroup analyses among women aged 45 to 55 years also showed a stronger association in pre-menopausal (aHR, 3.35; 95% CI, 3.21−3.49) than in post-menopausal women (aHR, 2.83; 95% CI, 2.68−2.98) (P-interaction < 0.01). Conclusions: The association between NAFLD and DM was stronger in pre-menopausal women than in post-menopausal women. This might be due to the protective effect of estrogen, which is possibly in higher production in the peripheral fat tissue of post-menopausal women with NAFLD.

Remnant cholesterol/high-density lipoprotein cholesterol ratio is a new powerful tool for identifying non-alcoholic fatty liver disease

BACKGROUND

Remnant cholesterol/high-density lipoprotein cholesterol (RC/HDL-C) ratio has been shown to be a good predictor of metabolic disease risk, but no studies have further investigated the role of RC/HDL-C ratio in non-alcoholic fatty liver disease (NAFLD) patients.

METHODS

The participants were 14,251 adults who underwent a physical examination, all of whom underwent abdominal ultrasonography to determine whether they had NAFLD. Receiver operating characteristic curve analysis and multivariate logistic regression models were used to assess the association between the RC/HDL-C ratio and the risk of NAFLD.

RESULTS

Multivariate logistic regression analysis showed that after fully adjusting the confounding factors, the higher RC/HDL-C ratio was independently positively correlated with the risk of NAFLD. Interaction tests suggested that the effect of RC/HDL-C ratio on NAFLD was significantly affected by sex. Additionally, receiver operating characteristic curve analysis showed that the area under the curve of RC/HDL-C ratio for identifying NAFLD was 0.82, which was significantly higher than that of other conventional lipid parameters.

CONCLUSIONS

This study indicates for the first time that the higher RC/HDL-C ratio in the general population may be closely related to the increased risk of NAFLD.

The advantages of physical exercise as a preventive strategy against NAFLD in postmenopausal women

BACKGROUND

The prevalence and severity of nonalcoholic fatty liver disease (NAFLD) increase in women after menopause. This narrative review discusses the causes and consequences of NAFLD in postmenopausal women and describes how physical activity can contribute to its prevention.

METHODS

The authors followed the narrative review method to perform a critical and objective analysis of the current knowledge on the topic. The Medical Subject Heading keywords 'physical exercise', 'menopause', 'hormone replacement therapy', 'estradiol' and 'NAFLD' were used to establish a conceptual framework. The databases used to collect relevant references included Medline and specialized high-impact journals.

RESULTS

Higher visceral adiposity, higher rate of lipolysis in adipose tissue after oestrogen drop and changes in the expression of housekeeping proteins involved in hepatic lipid management are observed in women after menopause, contributing to NAFLD. Excessive liver steatosis leads to hepatic insulin resistance, oxidative stress and inflammation, accelerating NAFLD progression. Physical activity brings beneficial effects against several postmenopausal-associated complications, including NAFLD progression. Aerobic and resistance exercises partially counteract alterations induced by metabolic syndrome in sedentary postmenopausal women, impacting NAFLD progression and severity.

CONCLUSIONS

With the increased global obesity epidemic in developing countries, NAFLD is becoming a severe problem with increased prevalence in women after menopause. Evidence shows that physical activity may delay NAFLD development and severity in postmenopausal women, although the prescription of age-appropriate physical activity programmes is advisable to assure the health benefits.