The effect of transgender hormonal treatment on high density lipoprotein cholesterol efflux capacity

Gonadal sex vs genetic sex in experimental atherosclerosis

Epidemiological data and interventional studies with hormone replacement therapy suggest that women, at least until menopause, are at decreased cardiovascular risk compared to men. Still the molecular mechanisms beyond this difference are debated and the investigation in experimental models of atherosclerosis has been pivotal to prove that the activation of the estrogen receptor is atheroprotective, despite not enough to explain the differences reported in cardiovascular disease between male and female. This casts also for investigating the importance of the sex chromosome complement (genetic sex) beyond the contribution of sex hormones (gonadal sex) on atherosclerosis. Aim of this review is to present the dualism between gonadal sex and genetic sex with a focus on the data available from experimental models. The molecular mechanisms driving changes in lipid metabolism, immuno-inflammatory reactivity and vascular response in males and females that affect atherosclerosis progression will be discussed.

Impact of puberty, sex determinants and chronic inflammation on cardiovascular risk in young people

Worrying trends of increased cardiovascular disease (CVD) risk in children, adolescents and young people in the Modern Era have channelled research and public health strategies to tackle this growing epidemic. However, there are still controversies related to the dynamic of the impact of sex, age and puberty on this risk and on cardiovascular health outcomes later in life. In this comprehensive review of current literature, we examine the relationship between puberty, sex determinants and various traditional CVD-risk factors, as well as subclinical atherosclerosis in young people in general population. In addition, we evaluate the role of chronic inflammation, sex hormone therapy and health-risk behaviours on augmenting traditional CVD-risk factors and health outcomes, ultimately aiming to determine whether tailored management strategies for this age group are justified.

Very low HDL levels: clinical assessment and management

In individuals with very low high-density lipoprotein (HDL-C) cholesterol, such as Tangier disease, LCAT deficiency, and familial hypoalphalipoproteinemia, there is an increased risk of premature atherosclerosis. However, analyzes based on comparisons of populations with small variations in HDL-C mediated by polygenic alterations do not confirm these findings, suggesting that there is an indirect association or heterogeneity in the pathophysiological mechanisms related to the reduction of HDL-C. Trials that evaluated some of the HDL functions demonstrate a more robust degree of association between the HDL system and atherosclerotic risk, but as they were not designed to modify lipoprotein functionality, there is insufficient data to establish a causal relationship. We currently have randomized clinical trials of therapies that increase HDL-C concentration by various mechanisms, and this HDL-C elevation has not independently demonstrated a reduction in the risk of cardiovascular events. Therefore, this evidence shows that (a) measuring HDL-C as a way of estimating HDL-related atheroprotective system function is insufficient and (b) we still do not know how to increase cardiovascular protection with therapies aimed at modifying HDL metabolism. This leads us to a greater effort to understand the mechanisms of molecular action and cellular interaction of HDL, completely abandoning the traditional view focused on the plasma concentration of HDL-C. In this review, we will detail this new understanding and the new horizon for using the HDL system to mitigate residual atherosclerotic risk.

A New ABCB1 Inhibitor Enhances the Anticancer Effect of Doxorubicin in Both In Vitro and In Vivo Models of NSCLC

In tumors, the multi drug resistance phenomenon may occur through the efflux of chemotherapeutic drugs out of cancer cells, impeding their accumulation, and eventually reducing their toxicity. This process is mediated by transporters overexpressed in the plasma membranes of tumor cells, among which is the P-glycoprotein/multidrug resistance 1/ATP-binding cassette B1 (P-gp/MDR1/ABCB1). The aim of this study was to explore the effect of a new molecule, called AIF-1, on ABCB1 activity. In a cellular model of non-small cell lung cancer (NSCLC), AIF-1 significantly inhibited ABCB1 activity, which was evaluated by the fluorimetric measurement of the intracellular accumulation of calcein. AIF-1 also significantly increased the intracellular content of doxorubicin, which was evaluated by confocal microscopy and LC-MS/MS analysis. This effect translated to higher cytotoxicity of doxorubicin and reduced cellular proliferation. Finally, in a murine xenograft model, the tumor volume increased by 267% and 148% on average in mice treated with vehicle and doxorubicin alone, respectively. After the co-administration of doxorubicin with AIF-1, tumor volume increased by only 13.4%. In conclusion, these results suggest enhancement of the efficacy of the chemotherapeutic drug doxorubicin by AIF-1, laying the basis for the future development of new ABCB1 inhibitors for tumor treatment.

Anabolic-androgenic steroids: How do they work and what are the risks?

Anabolic-androgenic steroids (AAS) are a class of hormones that are widely abused for their muscle-building and strength-increasing properties in high, nontherapeutic, dosages. This review provides an up-to-date and comprehensive overview on how these hormones work and what side effects they might elicit. We discuss how AAS are absorbed into the circulation after intramuscular injection or oral ingestion and how they are subsequently transported to the tissues, where they will move into the extravascular compartment and diffuse into their target cells. Inside these cells, AAS can biotransform into different metabolites or bind to their cognate receptor: the androgen receptor. AAS and their metabolites can cause side effects such as acne vulgaris, hypertension, hepatotoxicity, dyslipidemia, testosterone deficiency, erectile dysfunction, gynecomastia, and cardiomyopathy. Where applicable, we mention treatment options and self-medication practices of AAS users to counteract these side effects. Clinicians may use this review as a guide for understanding how AAS use can impact health and to assist in patient education and, in some cases, the management of side effects.

Long-term fasting: Multi-system adaptations in humans (GENESIS) study–A single-arm interventional trial

Fasting provokes fundamental changes in the activation of metabolic and signaling pathways leading to longer and healthier lifespans in animal models. Although the involvement of different metabolites in fueling human fasting metabolism is well known, the contribution of tissues and organs to their supply remains partly unclear. Also, changes in organ volume and composition remain relatively unexplored. Thus, processes involved in remodeling tissues during fasting and food reintroduction need to be better understood. Therefore, this study will apply state-of-the-art techniques to investigate the effects of long-term fasting (LF) and food reintroduction in humans by a multi-systemic approach focusing on changes in body composition, organ and tissue volume, lipid transport and storage, sources of protein utilization, blood metabolites, and gut microbiome profiles in a single cohort. This is a prospective, single-arm, monocentric trial. One hundred subjects will be recruited and undergo 9 ± 3 day-long fasting periods (250 kcal/day). We will assess changes in the composition of organs, bones and blood lipid profiles before and after fasting, as well as high-density lipoprotein (HDL) transport and storage, untargeted metabolomics of peripheral blood mononuclear cells (PBMCs), protein persulfidation and shotgun metagenomics of the gut microbiome. The first 32 subjects, fasting for 12 days, will be examined in more detail by magnetic resonance imaging (MRI) and spectroscopy to provide quantitative information on changes in organ volume and function, followed by an additional follow-up examination after 1 and 4 months. The study protocol was approved by the ethics board of the State Medical Chamber of Baden-Württemberg on 26.07.2021 and registered at ClinicalTrials.gov (NCT05031598). The results will be disseminated through peer-reviewed publications, international conferences and social media.

Clinical trial registration

[ClinicalTrials.gov], identifier [NCT05031598].

Hormonothérapies de transition chez les personnes transgenres

Aujourd’hui encore, la prise en charge médicale des personnes transgenres pâtit d’une insuffisance d’offre de soins et de formation des soignants. La mise en œuvre d’une hormonothérapie est souvent souhaitée par les personnes transgenres et il est nécessaire qu’un médecin sache l’instaurer et la suivre tout au long de la transition. Nous abordons dans cette revue le traitement hormonal féminisant (THF) chez les femmes transgenres adultes, et le traitement hormonal masculinisant (THM) chez les hommes transgenres adultes.

Crosstalk between high-density lipoproteins and endothelial cells in health and disease: Insights into sex-dependent modulation

Atherosclerotic cardiovascular disease is the leading cause of death worldwide. Intense research in vascular biology has advanced our knowledge of molecular mechanisms of its onset and progression until complications; however, several aspects of the patho-physiology of atherosclerosis remain to be further elucidated. Endothelial cell homeostasis is fundamental to prevent atherosclerosis as the appearance of endothelial cell dysfunction is considered the first pro-atherosclerotic vascular modification. Physiologically, high density lipoproteins (HDLs) exert protective actions for vessels and in particular for ECs. Indeed, HDLs promote endothelial-dependent vasorelaxation, contribute to the regulation of vascular lipid metabolism, and have immune-modulatory, anti-inflammatory and anti-oxidative properties. Sex- and gender-dependent differences are increasingly recognized as important, although not fully elucidated, factors in cardiovascular health and disease patho-physiology. In this review, we highlight the importance of sex hormones and sex-specific gene expression in the regulation of HDL and EC cross-talk and their contribution to cardiovascular disease.

HDL Cholesterol Efflux and Serum Cholesterol Loading Capacity Alterations Associate to Macrophage Cholesterol Accumulation in FH Patients with Achilles Tendon Xanthoma

Achilles tendon xanthoma (ATX) formation involves macrophage cholesterol accumulation within the tendon, similar to that occurring in atheroma. Macrophage cholesterol homeostasis depends on serum lipoprotein functions, namely the high-density lipoprotein (HDL) capacity to promote cell cholesterol efflux (cholesterol efflux capacity, CEC) and the serum cholesterol loading capacity (CLC). We explored the HDL-CEC and serum CLC, comparing 16 FH patients with ATX to 29 FH patients without ATX. HDL-CEC through the main efflux mechanisms mediated by the transporters ATP binding cassette G1 (ABCG1) and A1 (ABCA1) and the aqueous diffusion (AD) process was determined by a cell-based radioisotopic technique and serum CLC fluorimetrically. Between the two groups, no significant differences were found in terms of plasma lipid profile. A trend toward reduction of cholesterol efflux via AD and a significant increase in ABCA1-mediated HDL-CEC (+18.6%) was observed in ATX compared to no ATX patients. In ATX-presenting patients, ABCG1-mediated HDL-CEC was lower (−11%) and serum CLC was higher (+14%) compared to patients without ATX. Considering all the patients together, ABCG1 HDL-CEC and serum CLC correlated with ATX thickness inversely (p = 0.013) and directly (p < 0.0001), respectively. In conclusion, lipoprotein dysfunctions seem to be involved in ATX physiopathology and progression in FH patients.

Effects of PCSK9 inhibitors on HDL cholesterol efflux and serum cholesterol loading capacity in familial hypercholesterolemia subjects: a multi-lipid-center real-world evaluation

Proprotein convertase subtilisin/kexin type 9 (PCSK9), beyond regulating LDL cholesterol (LDL-c) plasma levels, exerts several pleiotropic effects by modulating lipid metabolism in extrahepatic cells such as macrophages. Macrophage cholesterol homeostasis depends on serum lipoprotein functions, including the HDL capacity to promote cell cholesterol efflux (CEC) and the serum capacity to promote cell cholesterol loading (CLC). The aim of this observational study was to investigate the effect of PCSK9 inhibitors (PCSK9-i) treatment on HDL-CEC and serum CLC in patients with familial hypercholesterolemia (FH). 31 genetically confirmed FH patients were recruited. Blood was collected and serum isolated at baseline and after 6 months of PCSK9-i treatment. HDL-CEC was evaluated through the main pathways with a radioisotopic cell-based assay. Serum CLC was assessed fluorimetrically in human THP-1 monocyte-derived macrophages. After treatment with PCSK9-i, total cholesterol and LDL-c significantly decreased (−41.6%, p < 0.0001 and −56.7%, p < 0.0001, respectively). Total HDL-CEC was not different between patients before and after treatment. Conversely, despite no changes in HDL-c levels between the groups, ABCG1 HDL-CEC significantly increased after treatment (+22.2%, p < 0.0001) as well as HDL-CEC by aqueous diffusion (+7.8%, p = 0.0008). Only a trend towards reduction of ABCA1 HDL-CEC was observed after treatment. PCSK9-i significantly decreased serum CLC (−6.6%, p = 0.0272). This effect was only partly related to the reduction of LDL-c levels. In conclusion, PCSK9-i treatment significantly increased HDL-CEC through ABCG1 and aqueous diffusion pathways and reduced the serum CLC in FH patients. The favorable effect of PCSK9-i on functional lipid profile could contribute to the cardiovascular benefit of these drugs in FH patients.

The ENIGI (European Network for the Investigation of Gender Incongruence) Study: Overview of Acquired Endocrine Knowledge and Future Perspectives

Literature on the efficacy and safety of gender-affirming hormonal treatment (GAHT) in transgender people is limited. For this reason, in 2010 the European Network for the Investigation of Gender Incongruence (ENIGI) study was born. The aim of this review is to summarize evidence emerging from this prospective multicentric study and to identify future perspectives. GAHT was effective in inducing desired body changes in both trans AMAB and AFAB people (assigned male and female at birth, respectively). Evidence from the ENIGI study confirmed the overall safety of GAHT in the short/mid-term. In trans AMAB people, an increase in prolactin levels was demonstrated, whereas the most common side effects in trans AFAB people were acne development, erythrocytosis, and unfavorable changes in lipid profile. The main future perspectives should include the evaluation of the efficacy and safety of non-standardized hormonal treatment in non-binary trans people. Furthermore, long-term safety data on mortality rates, oncological risk, and cardiovascular, cerebrovascular and thromboembolic events are lacking. With this aim, we decided to extend the observation of the ENIGI study to 10 years in order to study all these aspects in depth and to answer these questions.

The Role of High-Density Lipoprotein Cholesterol in 2022

PURPOSE OF THE REVIEW

High-density lipoproteins (HDL) are responsible for the transport in plasma of a large fraction of circulating lipids, in part from tissue mobilization. The evaluation of HDL-associated cholesterol (HDL-C) has provided a standard method for assessing cardiovascular (CV) risk, as supported by many contributions on the mechanism of this arterial benefit. The present review article will attempt to investigate novel findings on the role and mechanism of HDL in CV risk determination.

RECENT FINDINGS

The most recent research has been aimed to the understanding of how a raised functional capacity of HDL, rather than elevated levels per se, may be responsible for the postulated CV protection. Markedly elevated HDL-C levels appear instead to be associated to a raised coronary risk, indicative of a U-shaped relationship. While HDL-C reduction is definitely related to a raised CV risk, HDL-C elevations may be linked to non-vascular diseases, such as age-related macular disease. The description of anti-inflammatory, anti-oxidative and anti-infectious properties has indicated potential newer areas for diagnostic and therapeutic approaches. In the last two decades inconclusive data have arisen from clinical trials attempting to increase HDL-C pharmacologically or by way of recombinant protein infusions (most frequently with the mutant A-I _Milano); prevention of stent occlusion or heart failure treatment have shown instead significant promise. Targeted clinical studies are still ongoing.

Prevalence and Predictors of Cardiovascular Disease and Risk Factors in Transgender Persons in the United States

BACKGROUND

The cardiovascular health of transgender and gender diverse (TGD) persons, a growing population in the United States, has become a subject of heightened interest. We sought to assess the prevalence and predictors of cardiovascular disease (CVD) in transgender men, transgender women, and gender nonconforming persons in the United States.

METHODS

A cohort of individuals self-identified as TGD (ie, transgender or gender nonconforming) in the United States was identified using the 2018 Centers for Disease Control's Behavioral Risk Factor Surveillance Survey.

RESULTS

Among the 1019 TGD individuals studied, 378 (37.1%) identified their transition status as male-to-female, 394 (38.7%) as female-to-male, and the remaining 247 (24.2%) as gender nonconforming. A total of 138 (13.5%) had reported CVD, while 881 (86.5%) did not. The prevalence of CVD in TGD individuals identified as male-to-female, female-to-male, and gender nonconforming were noted to be similar (14.6% vs. 13.5% vs. 12.1%; P = 0.69). TGD persons with CVD were older with lower annual income. They also had higher rates of smoking, lower rates of regular exercise, and higher rates of smoking and chronic medical comorbidities. Independent predictors of CVD in TGD persons included older age, diabetes, chronic kidney disease, chronic obstructive pulmonary disease, and depressive disorder.

CONCLUSIONS

In this contemporary cross-sectional nationally representative survey, CVD was prevalent in nearly 14% of TGD persons. Further studies examining interventions to reduce CV risk and enhance access to medical care in the TGD population are warranted.

Sex hormones drive changes in lipoprotein metabolism

Women have a reduced cardiovascular disease (CVD) risk compared with men, which could be partially driven by sex hormones influencing lipid levels post puberty. The interrelationship between sex hormones and lipids was explored in pre-pubertal children, young post-pubertal cis-men/women, and transgender individuals on cross-sex-hormone treatment (trans-men/women) using serum metabolomics assessing 149 lipids. High-density lipoproteins (HDL, typically atheroprotective) were significantly increased and very-low- and low-density lipoproteins (typically atherogenic) were significantly decreased in post-pubertal cis-women compared with cis-men. These differences were not observed pre-puberty and were induced appropriately by cross-sex-hormone treatment in transgender individuals, supporting that sex hormones regulate lipid metabolism in vivo. Only atheroprotective apolipoprotein (Apo)A1 expressing lipoproteins (HDL) were differentially expressed between all hormonally unique comparisons. Thus, estradiol drives a typically atheroprotective lipid profile through upregulation of HDL/ApoA1, which could contribute to the sexual dimorphism observed in CVD risk post puberty. Together, this could inform sex-specific therapeutic strategies for CVD management.