Non-alcoholic fatty liver disease through the female lifespan: the role of sex hormones

Menopause and metabolic dysfunction-associated steatotic liver disease

Nonalcoholic fatty liver disease, recently proposed to be renamed metabolic dysfunction-associated steatotic liver disease, is a highly prevalent disease (25-30 % of the global general population) whose prevalence increases after menopause. Apart from the rates of simple steatosis, the severity of the disease (e.g., hepatic fibrosis) increases after menopause. Menopause is associated with higher abdominal adiposity and dysmetabolism of carbohydrate and lipid metabolism, which may contribute to the development and severity of metabolic dysfunction-associated steatotic liver disease and the higher cardiovascular risk observed after menopause. The association between menopause and metabolic dysfunction-associated steatotic liver disease renders menopausal hormone therapy an appealing way to reverse hepatic disease in parallel with the benefits of menopausal hormone therapy in other tissues. In this regard, most animal studies have shown a beneficial effect of estrogens on metabolic dysfunction-associated steatotic liver disease. Still, clinical studies are few, and their data are conflicting. The effect of menopausal hormone therapy on metabolic dysfunction-associated steatotic liver disease may be distinct among estrogen monotherapies and the combinations of estrogens and progestogens. It may also depend on the type of progestogen and the route of administration. However, more studies specifically designed for these aims are needed to draw secure conclusions. This review summarizes the data related to the association between menopause and metabolic dysfunction-associated steatotic liver disease, as well as between menopausal hormone therapy and metabolic dysfunction-associated steatotic liver disease, with a special focus on clinical studies.

Body composition analysis: A snapshot across the perimenopause

During the perimenopause, estrogen concentrations gradually decrease, and this is associated with changes to women's energy expenditure and intake. These changes result in weight gain and altered body fat distribution, with increased abdominal fat deposition and cardiometabolic risk via insulin resistance. Body composition analysis is a useful clinical tool in outpatient settings, as it is simple, not expensive and provides information on body mass index, skeletal mass, fat mass, fat percentage and basal metabolic rate. This review discusses body composition analysis as part of a health assessment for healthy women during the perimenopause and investigates the associations between body composition and cardiometabolic profile.

Understanding of and clinical approach to cardiometabolic transition at the menopause

Cardiovascular disease (CVD) represents the leading cause of death and accounts for almost 50% of all deaths in women worldwide. The menopausal transition is associated with central body fat accumulation, a decrease in energy expenditure, weight gain, insulin resistance and a pro-atherogenic lipid profile. Moreover, menopause is independently associated with an adverse effect on functional and structural indices of subclinical atherosclerosis. Women with premature ovarian insufficiency have heightened CVD risk compared to women of natural age at menopause. Furthermore, women with severe menopausal symptoms may have a more adverse cardiometabolic profile than those without symptoms. We reviewed the latest evidence on the cardiovascular management of perimenopausal or postmenopausal women. Clinicians should aim for cardiovascular risk stratification, followed by dietary and lifestyle advice as required based on individual needs. The medical management of cardiometabolic risk factors at midlife should always be individualized, focusing on hypertension, diabetes and dyslipidemia. Menopausal hormone therapy, when prescribed for the management of bothersome menopausal symptoms or for the prevention of osteoporosis, has also a beneficial effect on cardiometabolic risk factors. This narrative review aims to summarize the cardiometabolic alternations occurring during the menopausal transition and to outline the appropriate prevention strategies to prevent future cardiovascular adverse outcomes.

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.

Endocrine aspects of metabolic dysfunction-associated steatotic liver disease (MASLD): Beyond insulin resistance

While the association of metabolic dysfunction-associated steatotic liver disease (MASLD) with obesity and insulin resistance is widely appreciated, there are a host of complex interactions between the liver and other endocrine axes. While it can be difficult to definitively distinguish direct causal relationships and those attributable to increased adipocyte mass, there is substantial evidence of the direct and indirect effects of endocrine dysregulation on the severity of MASLD, with strong evidence that low levels of growth hormone, sex hormones, and thyroid hormone promote the development and progression of disease. The impact of steroid hormones, e.g. cortisol and dehydroepiandrosterone, and adipokines is much more divergent. Thoughtful assessment, based on individual risk factors and findings, and management of non-insulin endocrine axes is essential in the evaluation and management of MASLD. Multiple therapeutic options have emerged that leverage various endocrine axes to reduce the fibroinflammatory cascade in MASH.

Molecular Action of Tamoxifen in the Ovaries of Rats with Mammary Neoplasia

Tamoxifen (TAM) is a drug commonly used in patients with breast cancer. The anticancer effect of TAM occurs via its ability to antagonize estrogen-dependent growth of mammary epithelial cells. Previously, we demonstrated that TAM prevented the chemotherapy-induced loss of ovarian follicular reserves in both cancer-free rats and rats with cancer. Such follicular loss is a main cause of infertility in young women treated for cancer. The current study was undertaken to discover the molecules and intracellular pathways involved in the action of TAM in the ovaries of rats with mammary tumors. To meet this goal we used transcriptomic (RNA-Seq) and proteomic (2D-DIGE/MS) approaches. TAM inhibited the expression of genes and lncRNAs involved in ovarian steroidogenesis. Moreover, TAM altered the expression of genes related to primordial follicle activation or arrest. In addition, proteomic screening indicated the importance of basic metabolic processes in the ovarian actions of TAM. Although simple extrapolation of these data to humans is not possible, the results of this study emphasize the need to explore the ability of TAM to affect ovarian function in women undergoing cancer treatment.

Sarcopenia, sarcopenic obesity and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), sarcopenia and sarcopenic obesity (SO) are highly prevalent conditions that may coexist, especially in the aging population, without any approved pharmacologic treatment for all of them. There are multiple pathophysiologic mechanisms suggested to explain an association between NAFLD and sarcopenia or SO, including alterations in the adipokines, cytokines, hepatokines and myokines, which may interplay with other factors, such as aging, diet and physical inactivity. In clinical terms, most observational studies support an association between NAFLD and sarcopenia or SO; importantly, there are few cohort studies indicating higher mortality in patients with NAFLD and sarcopenia. Their association also bears some treatment considerations: for example, pioglitazone or vitamin E, suggested as off label treatment for selected patients with nonalcoholic steatohepatitis, may be recommended in the coexistence of sarcopenia or SO, since limited evidence did not show adverse effects of them on sarcopenia and abdominal obesity. In this review, evidence linking sarcopenia and SO with NAFLD is summarized, with a special focus on clinical data. A synopsis of the major pathophysiological links between NAFLD and sarcopenia/SO is initially presented, followed by selected clinical studies and, finally, treatment considerations in patients with NAFLD and sarcopenia or SO are discussed.

Unraveling the Role of Hepatic PGC1α in Breast Cancer Invasion: A New Target for Therapeutic Intervention?

Breast cancer (BC) is the most common cancer among women worldwide and the main cause of cancer deaths in women. Metabolic components are key risk factors for the development of non-alcoholic fatty liver disease (NAFLD), which may promote BC. Studies have reported that increasing PGC1α levels increases mitochondrial biogenesis, thereby increasing cell proliferation and metastasis. Moreover, the PGC1α/ERRα axis is a crucial regulator of cellular metabolism in various tissues, including BC. However, it remains unclear whether NAFLD is closely associated with the risk of BC. Therefore, the present study aimed to determine whether hepatic PGC1α promotes BC cell invasion via ERRα. Various assays, including ELISA, western blotting, and immunoprecipitation, have been employed to explore these mechanisms. According to the KM plot and TCGA data, elevated PGC1α expression was highly associated with a shorter overall survival time in patients with BC. High concentrations of palmitic acid (PA) promoted PGC1α expression, lipogenesis, and inflammatory processes in hepatocytes. Conditioned medium obtained from PA-treated hepatocytes significantly increased BC cell proliferation. Similarly, recombinant PGC1α in E0771 and MCF7 cells promoted cell proliferation, migration, and invasion in vitro. However, silencing PGC1α in both BC cell lines resulted in a decrease in this trend. As determined by immunoprecipitation assay, PCG1a interacted with ERRα, thereby facilitating the proliferation of BC cells. This outcome recognizes the importance of further investigations in exploring the full potential of hepatic PGC1α as a prognostic marker for BC development.