Sex differences in endothelial function important to vascular health and overall cardiovascular disease risk across the lifespan

Ultrasound and neuroinflammation: immune modulation via the heat shock response

Current pharmacological therapeutic approaches targeting chronic inflammation exhibit transient efficacy, often with adverse effects, limiting their widespread use - especially in the context of neuroinflammation. Effective interventions require the consideration of homeostatic function, pathway dysregulation, and pleiotropic effects when evaluating therapeutic targets. Signalling molecules have multiple functions dependent on the immune context, and this complexity results in therapeutics targeting a single signalling molecule often failing in clinical translation. Additionally, the administration of non-physiologic levels of neurotrophic or anti-inflammatory factors can alter endogenous signalling, resulting in unanticipated effects. Exacerbating these challenges, the central nervous system (CNS) is isolated by the blood brain barrier (BBB), restricting the infiltration of many pharmaceutical compounds into the brain tissue. Consequently, there has been marked interest in therapeutic techniques capable of modulating the immune response in a pleiotropic manner; ultrasound remains on this frontier. While ultrasound has been used therapeutically in peripheral tissues - accelerating healing in wounds, bone fractures, and reducing inflammation - it is only recently that it has been applied to the CNS. The transcranial application of low intensity pulsed ultrasound (LIPUS) has successfully mitigated neuroinflammation in vivo, in models of neurodegenerative disease across a broad spectrum of ultrasound parameters. To date, the underlying biological effects and signalling pathways modulated by ultrasound are poorly understood, with a diverse array of reported molecules implicated. The distributed nature of the beneficial response to LIPUS implies the involvement of an, as yet, undetermined upstream signalling pathway, homologous to the protective effect of febrile range hyperthermia in chronic inflammation. As such, we review the heat shock response (HSR), a protective signalling pathway activated by thermal and mechanical stress, as the possible upstream regulator of the anti-inflammatory effects of ultrasound.

Perivascular adipose tissue remodeling impairs vasoreactivity in thermoneutral-housed rats

Objective

Vascular pathology, characterized by impaired vasoreactivity and mitochondrial respiration, differs between the sexes. Housing rats under thermoneutral (TN) conditions causes vascular dysfunction and perturbed metabolism. We hypothesized that perivascular adipose tissue (PVAT), a vasoregulatory adipose depot with brown adipose tissue (BAT) phenotype, remodels to a white adipose (WAT) phenotype in rats housed at TN, driving diminished vasoreactivity in a sex-dependent manner.

Methods

Male and female Wistar rats were housed at either room temperature (RT) or TN. Endpoints included changes in PVAT morphology, vasoreactivity in vessels with intact PVAT or transferred to PVAT of the oppositely-housed animal, vessel stiffness, vessel mitochondrial respiration and cellular signaling.

Results

Remodeling of PVAT was observed in rats housed at TN; animals in this environment showed PVAT whitening and displayed diminished aortae vasodilation (p<0.05), different between the sexes. Juxtaposing PVAT from RT rats onto aortae from TN rats in females corrected vasodilation (p<0.05); this did not occur in males. In aortae of all animals housed at TN, mitochondrial respiration was significantly diminished in lipid substrate experiments (p<0.05), and there was significantly less expression of peNOS (p<0.001).

Conclusions

These data are consistent with TN-induced remodeling of PVAT, notably associated with sex-specific blunting of vasoreactivity, diminished mitochondrial respiration, and altered cellular signaling.

The effects of citrus flavonoids supplementation on endothelial function: A systematic review and dose-response meta-analysis of randomized clinical trials

The present systematic review and dose-response meta-analysis was conducted to synthesize existing data from randomized clinical trials (RCTs) concerning the impact of citrus flavonoids supplementation (CFS) on endothelial function. Relevant RCTs were identified through comprehensive searches of the PubMed, ISI Web of Science, and Scopus databases up to May 30, 2023. Weighted mean differences and their corresponding 95% confidence intervals (CI) were pooled utilizing a random-effects model. A total of eight eligible RCTs, comprising 596 participants, were included in the analysis. The pooled data demonstrated a statistically significant augmentation in flow-mediated vasodilation (FMD) (2.75%; 95% CI: 1.29, 4.20; I2 = 87.3%; p < 0.001) associated with CFS compared to the placebo group. Furthermore, the linear dose-response analysis indicated that each increment of 200 mg/d in CFS led to an increase of 1.09% in FMD (95% CI: 0.70, 1.48; I2 = 94.5%; p < 0.001). The findings from the nonlinear dose-response analysis also revealed a linear relationship between CFS and FMD (Pnon-linearity = 0.903, Pdose-response <0.001). Our findings suggest that CFS enhances endothelial function. However, more extensive RTCs encompassing longer intervention durations and different populations are warranted to establish more precise conclusions.

Correlation Between Blood Cadmium Levels and Platelet Characteristics, As Well As Their Impact on Susceptibility to Coronary Heart Disease: Findings from NHANES 2005-2018 Data

Investigating the correlation between blood cadmium levels, platelet characteristics, and susceptibility to coronary heart disease (CHD). Utilized NHANES 2005-2018 data with covariates such as age, sex, race, marital status, and socio-economic status. Blood cadmium served as the independent variable, while platelet count (PC) and mean platelet volume (MPV) were dependent variables. The average age of the participants was 68.77 ± 11.03 years, and 67.4% of them were male. The mean values for WBC, MPV, PC, and blood cadmium were 7.53 ± 3.36 × 103 cells/µL, 11.33 ± 0.27fL, 57.61 ± 5.34 × 103 cells/µL, and 2.58 ± 0.61 µg/L, respectively. Adjusting for other variables revealed increased MPV and PC with rising blood cadmium levels in cardiac patients, indicating a higher risk of CHD in those with elevated blood cadmium. The average age of the participants was 68.77 ± 11.03 years, and 67.4% of them were male. The mean values for WBC, MPV, PC, and blood cadmium were 7.53 ± 3.36 × 103 cells/µL, 11.33 ± 0.27fL, 57.61 ± 5.34 × 103 cells/µL, and 2.58 ± 0.61 µg/L, respectively. Adjusting for other variables revealed increased MPV and PC with rising blood cadmium levels in cardiac patients, indicating a higher risk of CHD in those with elevated blood cadmium. This study enhances understanding of how cadmium impacts platelet characteristics, contributing to increased CHD risk, providing insights for primary prevention strategies.

Large-Scale Population-Based Studies of Blood Metabolome and Brain Health

Metabolomics technologies enable the quantification of multiple metabolomic measures simultaneously, which provides novel insights into molecular aspects of human health and disease. In large-scale, population-based studies, blood is often the preferred biospecimen. Circulating metabolome may relate to brain health either by affecting or reflecting brain metabolism. Peripheral metabolites may act at or cross the blood-brain barrier and, subsequently, influence brain metabolism, or they may reflect brain metabolism if similar pathways are engaged. Peripheral metabolites may also include those penetrating the circulation from the brain, indicating, for example, brain damage. Most brain health-related metabolomics studies have been conducted in the context of neurodegenerative disorders and cognition, but some studies have also focused on neuroimaging markers of these disorders. Moreover, several metabolomics studies of neurodevelopmental disorders have been performed. Here, we provide a brief background on the types of blood metabolites commonly assessed, and we review the literature describing the relationships between human blood metabolome (n > 50 metabolites) and brain health reported in large-scale studies (n > 500 individuals).

Effect of menopausal hormonal therapy on cardiovascular risks in Korean postmenopausal women: A nationwide cohort study

OBJECTIVE

To evaluate the association between menopausal hormonal therapy (MHT) and the risk of cardiovascular disease (CVD), according to various regimens, dosages, routes of administration and starting ages of MHT.

DESIGN

A population-based cohort study using the Korean National Health Insurance Services database.

SETTING

Nationwide health insurance database.

POPULATION

Women who reported entering menopause at an age of ≥40 years with no history of CVD in the national health examination.

METHODS

The study population comprised 1 120 705 subjects enrolled between 2002 and 2019, categorised according to MHT status (MHT group, n = 319 007; non-MHT group, n = 801 698).

MAIN OUTCOME MEASURES

Incidence of CVD (a composite of myocardial infarction and stroke).

RESULTS

The incidence of CVD was 59 266 (7.4%) in the non-MHT group and 17 674 (5.5%) in the MHT group. After adjusting for confounding factors, an increased risk of CVD was observed with the administration of tibolone (hazard ratio, HR 1.143, 95% CI 1.117-1.170), oral estrogen (HR 1.246, 95% CI 1.198-1.295) or transdermal estrogen (HR 1.289, 95% CI 1.066-1.558), compared with the non-MHT group; the risk was based on an increased risk of stroke. The risk trends were consistent regardless of the age of starting MHT or the physicians' specialty. Among tibolone users, a longer period from entering menopause to taking tibolone and the use of any dosage (1.25 or 2.5 mg) were linked with a higher risk of CVD, compared with non-MHT users.

CONCLUSIONS

This nationwide cohort study demonstrated an increased risk of CVD, driven mainly by an increased risk of stroke, among tibolone and oral or transdermal estrogen users, compared with that of non-MHT users.

The menopausal transition period and cardiovascular risk

The menopausal transition period spans, on average, 2-8 years before the final menstrual period and is associated with an increase in clinical and subclinical cardiovascular risk. In this Review, we discuss the metabolic and cardiovascular changes that occur during the menopausal transition period and the role of ovarian ageing, chronological ageing and other ageing-related risk factors in mediating these changes. Disentangling the relative contributions of chronological and reproductive ageing to cardiovascular risk is challenging, but data from longitudinal studies in women transitioning from premenopause to post-menopause have provided valuable insights. We also discuss evidence on how cardiovascular risk is altered by premature or early menopause, surgical menopause, and vasomotor and other menopausal symptoms. Whether targeted interventions can slow the progression of atherosclerosis and subclinical disease during the menopausal transition, thus delaying or preventing the onset of cardiovascular events, remains to be determined. Furthermore, we consider the recommended strategies for cardiovascular risk reduction in women undergoing menopausal transition using the framework of the American Heart Association's Life's Essential 8 key measures for improving and maintaining cardiovascular health, and discuss the cardiovascular risks and benefits of menopausal hormone therapy. Finally, we also discuss novel therapies that might benefit this population in reducing cardiovascular risk.

Cardiovascular risk prediction with cardio-ankle vascular index in the malaysian cohort study

The cardio-ankle vascular index (CAVI) is an important parameter assessing arterial function. It reflects arterial stiffness from the origin of the aorta to the ankle, and the algorithm is blood pressure independent. Recent data have suggested that a high CAVI score can predict future cardiovascular disease (CVD) events; however, to date, no study has been done in Malaysia. We conducted a prospective study on 2,168 The Malaysian Cohort (TMC) CVD-free participants (971 men and 1,197 women; mean age 51.64 ± 8.38 years old) recruited from November 2011 to March 2012. This participants were followed-up until the emergence of CVD incidence and mortality (endpoint between May to September 2019; duration of 7.5 years). Eligible participants were assessed based on CAVI baseline measurement which categorised them into low (CAVI <9.0) and high (CAVI ≥ 9.0) scores. The CVD events in the group with high CAVI (6.5 %) were significantly higher than in the low CAVI (2.6 %) group (p < 0.05). CAVI with cut-off point ≥ 9.0 was a significant independent predictor for CVD event even after adjustment for male, ethnicity, age, and intermediate atherogenic index of plasma (AIP). Those who have higher CAVI have 78 % significantly higher risk of developing CVD compared to those with the low CAVI (adjusted OR [95 % CI] = 1.78 [1.04 - 3.05], p =0.035). In addition, the participants with higher CAVI have significantly lower survival probability than those who have lower CAVI values. Thus, this study indicated that the CAVI can predict CVD event independently among the TMC participants.

Postexercise cardiovascular hemodynamics assessment before and after a 30-minute standing still recovery

BACKGROUND

Although postexercise syncope usually occurs shortly after physical exercise conclusion, athletes commonly reveal symptoms of postexercise hypotension several tens of minutes after exercise completion. Currently, no studies have investigated central hemodynamic regulation during posture changes occurring several tens of minutes after exercise compared to immediately after cessation.

METHODS

This study examined changes in mean arterial pressure (MAP), heart rate (HR), systemic vascular conductance (SVC), cardiac output, and stroke volume during two sets of tilt tests performed before vs. after a 30-minute standing still recovery, respectively. Tilt tests were performed after a short-lasting supramaximal test (WNG) and long-lasting maximal incremental test (INC) in 12 young endurance-trained individuals.

RESULTS

The key findings were that, regardless of the exercise type, the 30-minute recovery augmented (P<0.01) the increase in HR and the drop in SVC during the transition from supine to upright, although the MAP drop was similar (P=0.99) after vs. before recovery. INC led to greater increases (P<0.01) in HR and drops (P<0.01) in SVC compared to WNG during postural transitions both before and after the recovery.

CONCLUSIONS

These findings suggest that, in a population that tolerates postexercise hypotension, MAP neural control is more challenged after a 30-minute standing still recovery than before, as evidenced by an augmented vasodilation capacity along with an increased HR buffering response during posture changes. Moreover, our data suggest that effective MAP control is resulting from an equally effective HR buffering response on MAP. Therefore, exercises that induce greater systemic vasodilation lead to greater HR buffering responses.

Single-Cell Transcriptional Profiling and Gene Regulatory Network Modeling in Tg2576 Mice Reveal Gender-Dependent Molecular Features Preceding Alzheimer-Like Pathologies

Alzheimer's disease (AD) onset and progression is influenced by a complex interplay of several environmental and genetic factors, one of them gender. Pronounced gender differences have been observed both in the relative risk of developing AD and in clinical disease manifestations. A molecular level understanding of these gender disparities is still missing, but could provide important clues on cellular mechanisms modulating the disease and reveal new targets for gender-oriented disease-modifying precision therapies. We therefore present here a comprehensive single-cell analysis of disease-associated molecular gender differences in transcriptomics data from the neocortex, one of the brain regions most susceptible to AD, in one of the most widely used AD mouse models, the Tg2576 model. Cortical areas are also most commonly used in studies of post-mortem AD brains. To identify disease-linked molecular processes that occur before the onset of detectable neuropathology, we focused our analyses on an age with no detectable plaques and microgliosis. Cell-type specific alterations were investigated at the level of individual genes, pathways, and gene regulatory networks. The number of differentially expressed genes (DEGs) was not large enough to build context-specific gene regulatory networks for each individual cell type, and thus, we focused on the study of cell types with dominant changes and included analyses of changes across the combination of cell types. We observed significant disease-associated gender differences in cellular processes related to synapse organization and reactive oxygen species metabolism, and identified a limited set of transcription factors, including Egr1 and Klf6, as key regulators of many of the disease-associated and gender-dependent gene expression changes in the model. Overall, our analyses revealed significant cell-type specific gene expression changes in individual genes, pathways and sub-networks, including gender-specific and gender-dimorphic changes in both upstream transcription factors and their downstream targets, in the Tg2576 AD model before the onset of overt disease. This opens a window into molecular events that could determine gender-susceptibility to AD, and uncovers tractable target candidates for potential gender-specific precision medicine for AD.

Cardiovascular aging: spotlight on mitochondria

Mitochondria are cellular organelles critical for ATP production and are particularly relevant to cardiovascular diseases including heart failure, atherosclerosis, ischemia-reperfusion injury, and cardiomyopathies. With advancing age, even in the absence of clinical disease, mitochondrial homeostasis becomes disrupted (e.g., redox balance, mitochondrial DNA damage, oxidative metabolism, and mitochondrial quality control). Mitochondrial dysregulation leads to the accumulation of damaged and dysfunctional mitochondria, producing excessive reactive oxygen species and perpetuating mitochondrial dysfunction. In addition, mitochondrial DNA, cardiolipin, and N-formyl peptides are potent activators of cell-intrinsic and -extrinsic inflammatory pathways. These age-related mitochondrial changes contribute to the development of cardiovascular diseases. This review covers the impact of aging on mitochondria and links these mechanisms to therapeutic implications for age-associated cardiovascular diseases.

Sexual function scores are associated with arterial stiffness in postmenopausal women

BACKGROUND

Female sexual dysfunction (FSD) has been suggested to be correlated with the burden of cardiovascular risk factors.

AIM

We aimed to evaluate the possible association between functional indices of vascular function and FSD scores in apparently healthy postmenopausal women.

METHODS

This cross-sectional study included 116 postmenopausal women who underwent assessment of endothelial function with measurement of flow-mediated dilation (FMD) of the branchial artery and arterial stiffness estimation with measurement of the carotid-femoral pulse wave velocity (PWV). We used the Greene Climacteric Scale to evaluate vasomotor symptomatology, the Female Sexual Function Index (FSFI) to evaluate FSD and the Beck Depression Inventory to evaluate mood disorder. Low sexual function was defined as an FSFI score <26.55.

OUTCOMES

These included FSFI and low sexual function scores as well as measures of PWV and FMD.

RESULTS

Sexual function scores were associated with measures of blood pressure (normal vs low sexual function; systolic blood pressure: 120.2 ± 15.0 mm Hg vs 113.4 ± 14.6 mm Hg; analysis of covariance P = .026; diastolic blood pressure: 75.9 ± 10.5 mm Hg vs 70.3 ± 9.9 mm Hg; analysis of covariance P = .012; both adjusted for age, body mass index, current smoking, and PWV). Systolic blood pressure, but not diastolic blood pressure, was associated with FSFI (B = 0.249, P = .041) and PWV (B = 0.392, P < .001). PWV measures were associated with FSFI (B = -0.291, P = .047) and pulse pressure (B = 0.355, P = .017). FMD measures were also associated with FSFI (B = 0.427, P = .033). All models were adjusted for age, body mass index, current smoking, insulin resistance, vasomotor symptomatology, and Beck Depression Inventory.

CLINICAL IMPLICATIONS

Our findings demonstrate that lower scores of sexual function are associated with deteriorated vascular function mainly manifested as arterial stiffening, further contributing to systolic blood pressure changes.

STRENGTHS AND LIMITATIONS

The strength of this study is the carefully selected healthy sample of postmenopausal women, with simultaneous assessment of climacteric symptomatology and mood disorders. The limitations include the small sample size, the cross-sectional design, and the recruitment of consecutive outpatients of a university menopause clinic.

CONCLUSION

Longitudinal studies and interventions to improve FSD should further assess the clinical relevance of these findings.

Sex differences in blood pressure regulation and hypertension: renal, hemodynamic, and hormonal mechanisms

The teleology of sex differences has been argued since at least as early as Aristotle's controversial Generation of Animals more than 300 years BC, which reflects the sex bias of the time to contemporary readers. Although the question "why are the sexes different" remains a topic of debate in the present day in metaphysics, the recent emphasis on sex comparison in research studies has led to the question "how are the sexes different" being addressed in health science through numerous observational studies in both health and disease susceptibility, including blood pressure regulation and hypertension. These efforts have resulted in better understanding of differences in males and females at the molecular level that partially explain their differences in vascular function and renal sodium handling and hence blood pressure and the consequential cardiovascular and kidney disease risks in hypertension. This review focuses on clinical studies comparing differences between men and women in blood pressure over the life span and response to dietary sodium and highlights experimental models investigating sexual dimorphism in the renin-angiotensin-aldosterone, vascular, sympathetic nervous, and immune systems, endothelin, the major renal sodium transporters/exchangers/channels, and the impact of sex hormones on these systems in blood pressure homeostasis. Understanding the mechanisms governing sex differences in blood pressure regulation could guide novel therapeutic approaches in a sex-specific manner to lower cardiovascular risks in hypertension and advance personalized medicine.

Gender differences in cardiovascular disease risk: Adolescence to young adulthood

BACKGROUND AND AIMS

Gender differences in cardiovascular disease (CVD) have been well documented but rarely for young adults and the extent to which gender related lifestyle differences may contribute to gender differences in CVD risk experienced by young adults have not been reported.

METHODS AND RESULTS

Data are from a long-running cohort study, the Mater-University of Queensland Study of Pregnancy (MUSP). We track gender differences in CVD related behaviours at 21 and 30 years (consumption of a Western Diet/Health-Oriented Diet, cigarette smoking, vigorous physical exercise, heavy alcohol consumption). At 30 years we compare males and females for CVD risk, and the extent to which lifestyle behaviours at 21 and 30 years contribute to CVD risk. At both 21 and 30 years of age, males more frequently consume a Western Diet and less often a Health Oriented Diet. By contrast, males are also much more likely to report engaging in vigorous physical activity. On most CVD markers, males exhibit much higher levels of risk than do females at both 21 and 30 years. At 30 years of age males have about five times the odds of being at high risk of CVD. Some lifestyle behaviours contribute to this additional risk.

CONCLUSION

Young adult males much more frequently engage in most CVD related risk behaviours and males have a higher level of CVD risk. Gender differences in CVD risk remain high even after adjustment for CVD lifestyles, though dietary factors independently contribute to CVD risk at 30 years.

Longitudinal Associations of Dietary Fructose, Sodium, and Potassium and Psychological Stress with Vascular Aging Index and Incident Cardiovascular Disease in the CARDIA Cohort

We explored how dietary behaviors (sucrose, fructose, sodium, and potassium consumption) and endured psychological stress in young adult males and females impact the vascular aging index (VAI) and CVD risk by mid-life. Data were obtained from the Coronary Artery Risk Development in Young Adults Study, an ongoing longitudinal study. The included participants (n = 2656) had undergone carotid artery ultrasound at year 20 allowing VAIs to be calculated. Demographics, dietary data, and depression scores were obtained at baseline and year 20 of follow-up. Regression analyses were used to assess the predictors of VAI. Cox regression analyses were conducted to assess the risk of CVD, stroke, and all-cause mortality. Predictors of vascular aging were found to be sex-specific. In females, depression scores at baseline were positively associated with VAI (B-weight = 0.063, p = 0.015). In males, sodium intake at year 20 positively predicted VAI (B-weight = 0.145, p = 0.003) and potassium intake inversely predicted VAI (B-weight = -0.160, p < 0.001). BMI significantly predicted CVD, stroke, and death. Fructose consumption at year 20 was a significant predictor of CVD risk while having high blood pressure at baseline was significantly associated with stroke risk. Our findings support the promotion of nutrient-specific behavior changes to prevent vascular aging in early adulthood and CVD risk in mid-life.

Sex, Endothelial Cell Functions, and Peripheral Artery Disease

Peripheral artery disease (PAD) is caused by blocked arteries due to atherosclerosis and/or thrombosis which reduce blood flow to the lower limbs. It results in major morbidity, including ischemic limb, claudication, and amputation, with patients also suffering a heightened risk of heart attack, stroke, and death. Recent studies suggest women have a higher prevalence of PAD than men, and with worse outcomes after intervention. In addition to a potential unconscious bias faced by women with PAD in the health system, with underdiagnosis, and lower rates of guideline-based therapy, fundamental biological differences between men and women may be important. In this review, we highlight sexual dimorphisms in endothelial cell functions and how they may impact PAD pathophysiology in women. Understanding sex-specific mechanisms in PAD is essential for the development of new therapies and personalized care for patients with PAD.

30-Year High Cardiovascular Risk Incidence and its Determinants: CUME Study

OBJECTIVE

Estimate the incidence of the 30-year high cardiovascular risk and its determinants among graduates of federal universities in Minas Gerais.

METHODS

This is a prospective cohort of 2,854 adults aged 20 to 59. The incidence of the outcome was calculated using the Framingham equation and its determinants were determined through multivariate Cox regression.

RESULTS

After an average of 2.62 years, the incidence of high cardiovascular risk was 8.09 and 20.1 cases per 1,000 person-years, for females and males respectively. Being male (HR: 2.34; 95% CI: 1.58 - 3.46), employment (HR: 2.13; 95% CI: 1.13 - 3.99), high consumption of processed foods (HR: 2.44; 95% CI: 1.21 - 4.90), and being physically active (HR: 0.63; 95% CI: 0.41 - 0.98) were associated with high cardiovascular risk.

CONCLUSIONS

Among highly educated adults, being male, employment, and high consumption of processed foods are predictors of high cardiovascular risk, while being physically active acts as a protective factor.

Angiotensin II type 2 receptor-mediated dilation is greater in the cutaneous microvasculature of premenopausal women compared with men

Differential activation of the renin-angiotensin system (RAS) likely contributes to sex differences in cardiovascular outcomes in premenopausal women compared with age-matched men. Women demonstrate reduced activation of the vasoconstrictor angiotensin II type 1 receptors (AT1R) compared with men, and evidence suggests that women also likely have increased sensitivity of the vasodilatory angiotensin II type 2 receptors (AT2R). However, few in vivo studies have directly examined sex differences in AT2R-mediated dilation, or the balance between AT1R- and AT2R-mediated vascular responses in humans. Using the cutaneous microcirculation as a model, we hypothesized that AT2R-mediated dilation would be greater in premenopausal women compared with men, and that AT1R-blockade would augment AT2R-mediated dilation to a greater extent in men than in women. Twelve healthy women (22 ± 3 yr) and 12 men (23 ± 5 yr) had two intradermal microdialysis fibers placed in the ventral forearm for graded infusions of compound 21 (AT2R agonist; 10-12 to 10-8 M) in a control fiber site and a site treated with 43 µM losartan (AT1R antagonist). Red blood cell flux was measured continuously by laser-Doppler flowmetry, and cutaneous vascular conductance [CVC = flux/mean arterial pressure (MAP)] was normalized to maximum [%max; 28 mM sodium nitroprusside (SNP) + 43 °C]. Women had greater AT2R-mediated dilation compared with men (women: 25 ± 4 vs. men: 15 ± 2%max, P = 0.03). Local AT1R inhibition increased AT2R-mediated dilation in men (losartan: 26 ± 4 vs. control: 15 ± 2%max, P < 0.001) but had no effect in women (losartan: 27 ± 6 vs. control: 25 ± 4%max, P > 0.05). These data suggest that premenopausal women have a greater AT2R-mediated vasodilation response than men, and that AT1R activation inhibits AT2R-mediated dilation in men, but not in women.NEW & NOTEWORTHY Premenopausal women have greater protection against cardiovascular disease than age-matched men. However, the role of vasoconstrictor angiotensin II type 1 receptors (AT1R) and vasodilatory angiotensin II type 2 receptors (AT2R) in mediating these sex differences is unclear. Here, we demonstrate that women have greater AT2R-mediated vasodilation than men and that AT1R negates AT2R-mediated dilation in men, but not in women.

Naturally menstruating women exhibit lower cardiovagal baroreflex sensitivity than oral contraceptive users during the lower hormone phase

The present study evaluated cardiovagal baroreflex sensitivity (BRS) across the menstrual/pill cycle in naturally menstruating women (NAT women) and women using oral hormonal contraceptives (OCP women). In 21 NAT women (23 ± 4 years old) and 22 OCP women (23 ± 3 years old), cardiovagal BRS and circulating concentrations of estradiol and progesterone were evaluated during the lower hormone (early follicular/placebo pill) and higher hormone (late follicular to early luteal/active pill) phases. During the lower hormone phase, cardiovagal BRS up, down and mean gain were lower in NAT women (15.6 ± 8.3, 15.2 ± 6.1 and 15.1 ± 7.1 ms/mmHg) compared with OCP women (24.7 ± 9.4, 22.9 ± 8.0 and 23.0 ± 8.0 ms/mmHg) (P = 0.003, P = 0.002 and P = 0.003, respectively), and higher oestrogen (R2  = 0.15, P = 0.024), but not progesterone (R2  = 0.06, P = 0.18), concentrations were predictive of lower BRS mean gain. During the higher hormone phase, higher progesterone concentrations were predictive of lower BRS mean gain (R2  = 0.12, P = 0.024). A multivariate regression model revealed group (NAT or OCP) to be a significant predictor of cardiovagal BRS mean gain in the lower hormone phase when hormone concentrations were adjusted for (R2  = 0.36, P = 0.0044). The multivariate regression model was not significant during the higher hormone phase (P > 0.05). In summary, cardiovagal BRS is lower in NAT compared with OCP women during the lower hormone phase of the menstrual/pill cycle and might be associated with higher oestrogen concentrations. In contrast, during the higher hormone phase of the menstrual/OCP cycle, higher progesterone concentrations were predictive of lower cardiovagal BRS. NEW FINDINGS: What is the central question of this study? Does cardiovagal baroreflex sensitivity (BRS) differ between naturally menstruating women (NAT women) and women using oral contraceptives (OCP women)? What is the main finding and its importance? The main findings are as follows: (1) NAT women exhibit lower cardiovagal BRS than OCP women during the lower hormone phase of the menstrual or pill cycle; and (2) circulating oestrogen concentrations are significant predictors of cardiovagal BRS during the lower hormone phase, with higher oestrogen concentrations predicting lower BRS. The present data advance our understanding of the effect of endogenous ovarian hormones and OCP use on cardiovascular control mechanisms.

Effects of Gender and Vitamin D on Vascular Reactivity of the Carotid Artery on a Testosterone-Induced PCOS Model

The negative cardiovascular effects of polycystic ovary syndrome (PCOS) and vitamin D deficiency (VDD) have been discussed previously; however, the sex differences between PCOS females and males are not yet known. Our aim was to investigate the effect of PCOS and VDD in the carotid artery of male and female Wistar rats. Females were treated with transdermal testosterone (Androgel) for 8 weeks, which caused PCOS. VDD and vitamin D supplementation were accomplished via diet. The carotid arteries' contraction and relaxation were examined using myography. Receptor density was investigated using immunohistochemistry. In PCOS females, angiotensin receptor density, angiotensin II-induced contraction, androgen receptor optical density, and testosterone-induced relaxation increased. The increased contractile response may increase cardiovascular vulnerability in women with PCOS. As an effect of VDD, estrogen receptor density increased in all our groups, which probably compensated for the reduced relaxation caused by VDD. Testosterone-induced relaxation was decreased as a result of VDD in males and non-PCOS females, whereas this reduction was absent in PCOS females. Male sex is associated with increased contraction ability compared with non-PCOS and PCOS females. VDD and Androgel treatment show significant gender differences in their effects on carotid artery reactivity. Both VDD and PCOS result in a dysfunctional vascular response, which can contribute to cardiovascular diseases.

Association of Cumulative Lifetime Exposure to Female Hormones With Cerebral Small Vessel Disease in Postmenopausal Women in the UK Biobank

BACKGROUND AND OBJECTIVES

Rates of cerebrovascular disease increase after menopause, which is often attributed to the absence of hormones. It remains unknown whether the cumulative exposure to hormones across a female person's premenopausal life extends the window of cerebrovascular protection to the postmenopausal period. To investigate this, we examined the relationship between lifetime hormone exposure (LHE) and cerebral small vessel disease in more than 9,000 postmenopausal women in the UK-Biobank.

METHODS

The cohort consisted of women (aged 40-69 years) who attended one of 22 research centers across the United Kingdom between 2006 and 2010. Women were excluded if they were premenopausal when scanned, had missing reproductive history data, self-reported neurologic disorders, brain cancer, cerebral vascular incidents, head or neurologic injury, and nervous system infection. Endogenous LHE (LHEEndo) was estimated by summing the number of years pregnant (LHEParity) with the duration of the reproductive period (LHECycle = age menopause - age menarche). Exogenous LHE (LHEExo) was estimated by summing the number of years on oral contraceptives and hormone replacement therapy. Cerebral small vessel disease was determined by estimating white matter hyperintensity volume (WMHV) from T2-fluid-attenuated inversion recovery brain MRI (acquired between 2014 and 2021), normalized to intracranial volume and log-transformed. Multiple linear regressions were used to assess the relationship between LHEEndo on WMHV adjusted for age, cardiovascular risk factors, sociodemographics, and LHEExo.

RESULTS

A total of 9,163 postmenopausal women (age 64.21 ± 6.81 years) were retained for analysis. Average LHEEndo was 39.77 ± 3.59 years. Women with higher LHEEndo showed smaller WMHV (adj-R 2 = 0.307, LHEEndo β = -0.007 [-0.012 to -0.002], p < 0.01). LHEParity and LHECycle were independent contributors to WMHV (adj-R 2 = 0.308, p << 0.001; LHEParity β = -0.022 [-0.042 to -0.002], p < 0.05; LHECycle β = -0.006 [-0.011 to -0.001], p < 0.05). LHEExo was not significantly related to WMHV (LHEExo β = 0.001 [-0.001 to 0.002], p > 0.05).

DISCUSSION

Women with more prolonged exposure to endogenous hormones show relatively smaller burden of cerebral small vessel disease independent of the history of oral contraceptive use or hormone replacement therapy. Our results highlight the critical role endogenous hormones play in female brain health and provide real-world evidence of the protective effects premenopausal endogenous hormone exposure plays on postmenopausal cerebrovascular health.

Vascular Endothelial Function Is Associated with eGFR Slope in Female and Non-Smoking Male Individuals with Cardiovascular Risk Factors: A Pilot Study on the Predictive Value of FMD for Renal Prognosis

AIMS

It is known that there are sex differences in vascular endothelial function and the development of chronic kidney diseases; however, it remains unclear whether sex differences influence the association between vascular endothelial function and renal prognosis.

METHODS

To clarify the relationship between vascular endothelial function and longitudinal eGFR changes in male and female patients with cardiovascular risk factors, we retrospectively evaluated 341 patients (176 males and 165 females) with cardiovascular risk factors in whom vascular function was assessed by flow-mediated dilation (FMD) and brachial-ankle pulse wave velocity (baPWV) and in whom 24-month longitudinal eGFR values were recorded after the vascular function examinations. Associations of values of FMD and baPWV with values of eGFR slope were statistically analyzed.

RESULTS

Simple regression analysis showed that the value of FMD was positively associated with eGFR slope in females (p=0.001) and non-smoking males (p=0.033) but not in smoking males. Multiple regression analysis showed that the value of FMD remains a positive contributor for eGFR slope in females (p=0.001) and non-smoking males (p=0.045) but not in smoking males. In contrast, values of baPWV had no significant association with eGFR slope regardless of sex and cigarette smoking.

CONCLUSIONS

In individuals with cardiovascular risk factors, evaluation of vascular endothelial function enables prediction of renal prognosis in females and non-smoking males.

Real-world risk of cardiovascular diseases in patients with type 2 diabetes associated with sodium-glucose cotransporter 2 inhibitors in comparison with metformin: A propensity score-matched model analysis in Japan

We aimed to compare the effects of cardiovascular disease risk in Japanese patients with type 2 diabetes on sodium-glucose cotransporter 2 inhibitors (SGLT2Is) or metformin. This retrospective, real-world cohort study was carried out using a claims database and propensity score matching; 58,402 eligible patients (29,201 per group) were included. The outcomes included nonfatal myocardial infarction, angina pectoris, nonfatal stroke, hospitalization for heart failure and composite end-points. The hazard ratio (HR) for the composite end-point was 0.79, which was lower for SGLT2Is than for metformin. For male patients (HR 0.76), patients aged <65 years (HR 0.94), patients aged ≥75 years (HR 0.78) and patients with body mass index ≥25 kg/m2 (HR 0.76), the HRs for the composite end-point were significantly lower in the SGLT2I group than in the metformin group. SGLT2Is might be superior to metformin in reducing the composite risk of cardiovascular disease in patients with type 2 diabetes.

Effects of acute aerobic exercise on arterial stiffness in transgender men

Testosterone replacement therapy (TRT) in transgender men (TM) results in side effects such as elevated triglycerides and increased arterial stiffness. Exercise may be useful to ameliorate such effects, but no studies have examined the effects of acute aerobic exercise in TM. This study aimed to investigate the effects of acute aerobic exercise on arterial stiffness in TM. Thirty-six participants were included, comprising 12 TM (duration of TRT: 57.4 ± 30.3 months), 12 males and 12 females. All participants performed acute aerobic exercise on a treadmill at 50% heart rate reserve for 30 min. Arterial stiffness as measured by brachial-ankle pulse wave velocity (baPWV) was measured before exercise (Pre), 30 min after exercise (Post30), and 60 min after exercise (Post60). Serum sex hormone levels, and serum lipid profile were determined only before exercise. Serum low-density lipoprotein cholesterol (LDL-C) levels before exercise were significantly higher in TM than in males or females (males: p < 0.01; females: p < 0.05). At all points, baPWV in TM was significantly higher than in females (p < 0.05) and significantly lower than in males (p < 0.05). However, when comparing changes in baPWV over time in each group, significant decreases in Post30 and Post60 were seen in males compared to Pre (both p < 0.05), but no significant change after aerobic exercise was seen in TM or females. These results suggest that acute aerobic exercise yield different effects in TM than in males, but is unlikely to reduce arterial stiffness in TM receiving TRT.

Widespread sex dimorphism across single-cell transcriptomes of adult African turquoise killifish tissues

The African turquoise killifish (Nothobranchius furzeri), the shortest-lived vertebrate that can be bred in captivity, is an emerging model organism for aging research. Here, we describe a multitissue, single-cell gene expression atlas of female and male blood, kidney, liver, and spleen. We annotate 22 cell types, define marker genes, and infer differentiation trajectories. We find pervasive sex-dimorphic gene expression across cell types. Sex-dimorphic genes tend to be linked to lipid metabolism, consistent with clear differences in lipid storage in female vs. male turquoise killifish livers. We use machine learning to predict sex using single-cell gene expression and identify potential markers for molecular sex identity. As a proof of principle, we show that our atlas can be used to deconvolute existing bulk RNA sequencing (RNA-seq) data to obtain accurate estimates of cell type proportions. This atlas can be a resource to the community that could be leveraged to develop cell-type-specific expression in transgenic animals.

Meta-analysis and time trend prediction of the prevalence of hypertension in Chinese college students

BACKGROUND

To understand the prevalence of hypertension among Chinese college students over the past decade (2010-2020) and predict its future trend, we aim to provide a basis for preventing and controlling hypertension among college students.

METHODS

Databases such as Chinese National Knowledge Infrastructure, Wanfang database, PubMed, and Web of Science were searched, and publications on the prevalence of hypertension among Chinese college students from 2010 to 2020 were collected. Search for publications in both Chinese and English databases using keywords "hypertension," "prevalence," "disease status," "cross-sectional survey," "epidemiology," "China," "adolescents," and "college students." Publication screening, data extraction, and quality assessment were independently conducted by 2 researchers. Meta-analysis was performed using Stata 16, and trends in the prevalence of hypertension among college students were analyzed using R 4.2.0.

RESULTS

A total of 37 publications were included in this analysis, which involved 233,603 Chinese college students. The Meta-analysis results showed significant heterogeneity among the studies (I2 = 98.9%, P < .05). Using a random-effects model, the overall prevalence of hypertension among college students was estimated to be 3.3% (95% CI = 2.9%-3.6%), with a higher prevalence among male students (6.2%, 95% CI = 5.4%-7.1%) than female students (1.1%, 95% CI = 0.9%-1.3%). The prevalence of hypertension is notably higher in northern regions than in southern regions. The prevalence of hypertension among college students showed an increasing trend from 2010 to 2020. Trend analysis predicted that the prevalence of hypertension among college students will reach 10% and 14.6% by 2030 and 2040, respectively. The risk of hypertension in male students was 4.63 times higher than that of female students (95% CI = 2.97-7.23). Compared normal weight students, overweight and obese students had 3.08 times (95% CI = 2.48-3.82) and 6.69 times (95% CI = 2.25-19.90) higher risk of hypertension, respectively.

CONCLUSION

The prevalence of hypertension in Chinese college students was about 3.3%. The prevalence of hypertension in male college students was higher than that in females, and the prevalence in northern regions was generally higher than that in southern regions. The prevalence of hypertension among Chinese college students will reach 10.0% in the next 10 years and 14.6% in the next 20 years. Male and BMI ≥ 24 were risk factors for hypertension among college students.

Paradoxical Effects of Prolonged Insufficient Sleep on Lipid Profile: A Pooled Analysis of 2 Randomized Trials

Background Insufficient sleep is associated with increased cardiovascular disease risk, but causality is unclear. We investigated the impact of prolonged mild sleep restriction (SR) on lipid and inflammatory profiles. Methods and Results Seventy-eight participants (56 women [12 postmenopausal]; age, 34.3±12.5 years; body mass index, 25.8±3.5 kg/m2) with habitual sleep duration 7 to 9 h/night (adequate sleep [AS]) underwent two 6-week conditions in a randomized crossover design: AS versus SR (AS-1.5 h/night). Total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglycerides, and inflammatory markers (CRP [C-reactive protein], interleukin 6, and tumor necrosis factor-α) were assessed. Linear models tested effects of SR on outcomes in the full sample and by sex+menopausal status (premenopausal versus postmenopausal women+men). In the full sample, SR increased high-density lipoprotein cholesterol compared with AS (β=1.2±0.5 mg/dL; P=0.03). Sex+menopausal status influenced the effects of SR on change in total cholesterol (P-interaction=0.04), LDL-C (P-interaction=0.03), and interleukin 6 (P-interaction=0.07). Total cholesterol and LDL-C decreased in SR versus AS in premenopausal women (total cholesterol: β=-4.2±1.9 mg/dL; P=0.03; LDL-C: β=-6.3±2.0 mg/dL; P=0.002). Given paradoxical effects of SR on cholesterol concentrations, we explored associations between changes in inflammation and end point lipids under each condition. Increases in interleukin 6 and tumor necrosis factor-α during SR tended to relate to lower LDL-C in premenopausal women (interleukin 6: β=-5.3±2.6 mg/dL; P=0.051; tumor necrosis factor-α: β=-32.8±14.2 mg/dL; P=0.027). Conclusions Among healthy adults, prolonged insufficient sleep does not increase atherogenic lipids. However, increased inflammation in SR tends to predict lower LDL-C in premenopausal women, resembling the "lipid paradox" in which low cholesterol associates with increased cardiovascular disease risk in proinflammatory conditions. Registration URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02835261, NCT02960776.

Contrast-Enhanced Ultrasound Feasibility in Assessing Carotid Plaque Vulnerability-Narrative Review

The risk assessment for carotid atherosclerotic lesions involves not only determining the degree of stenosis but also plaque morphology and its composition. Recently, carotid contrast-enhanced ultrasound (CEUS) has gained importance for evaluating vulnerable plaques. This review explores CEUS's utility in detecting carotid plaque surface irregularities and ulcerations as well as intraplaque neovascularization and its alignment with histology. Initial indications suggest that CEUS might have the potential to anticipate cerebrovascular incidents. Nevertheless, there is a need for extensive, multicenter prospective studies that explore the relationships between CEUS observations and patient clinical outcomes in cases of carotid atherosclerotic disease.

Sex Influence on Autophagy Markers and miRNAs in Basal and Angiotensin II-Treated Human Umbilical Vein Endothelial Cells

Cardiovascular diseases (CVD) display many sex and gender differences, and endothelial dysfunction, angiotensin II (Ang II), and autophagy represent key factors in the autophagic process Therefore, we studied whether Ang II modulates the mentioned processes in a sex-specific way in HUVECs obtained from healthy male and female newborns. In basal HUVECs, the Parkin gene and protein were higher in FHUVECs than in MHUVECs, while the Beclin-1 protein was more expressed in MHUVECs, and no other significant differences were detected. Ang II significantly increases LAMP-1 and p62 protein expression and decreases the expression of Parkin protein in comparison to basal in MHUVECs. In FHUVECs, Ang II significantly increases the expression of Beclin-1 gene and protein, and Parkin gene. The LC3 II/I ratio and LAMP-1 protein were significantly higher in MHUVECs than in FHUVECs, while Parkin protein was significantly more expressed in Ang II-treated FHUVECs than in male cells. Ang II affects the single miRNA levels: miR-126-3p and miR-133a-3p are downregulated and upregulated in MHUVECs and FHUVECs, respectively. MiR-223 is downregulated in MHUVEC and FHUVECs. Finally, miR-29b-3p and miR-133b are not affected by Ang II. Ang II effects and the relationship between miRNAs and organelles-specific autophagy is sex-dependent in HUVECs. This could lead to a better understanding of the mechanisms underlying sex differences in endothelial dysfunction, providing useful indications for innovative biomarkers and personalized therapeutic approaches.

Beyond the Scale: Investigating Adiponectin, ICAM-1, and VCAM-1 as Metabolic Markers in Obese Adolescents with Metabolic Syndrome

Background

Adiponectin acts to prevent vascular dysfunction due to obesity by inhibiting ICAM-1 and VCAM-1 expressions.

Objective

We investigate adiponectin ICAM-1, VCAM-1, and metabolic syndrome (MetS) in obese adolescents.

Methods

A cross-sectional study with healthy obese adolescents aged 13 to 18 years was conducted from October 2019 to January 2020. Statistical analysis conducted was a test of normality and homogeneity tests, ANOVA/Kruskal-Wallis, independent sample T-test/Mann-Whitney U test, and Spearman correlation and determined as significant if p value <0.05.

Results

125 obese adolescents were recruited. 42 (33.6%) were obese with MetS (we grouped as MetS) and 83 (66.4%) subjects without MetS (non-MetS group). VCAM-1 was significantly higher on boys with MetS compared to girls with MetS, and even girls with MetS had lower levels of VCAM-1 than boys with non-MetS. ICAM-1 was significantly higher in boys with low-level HDL-c (p < 0.05) and correlated weakly with HDL-c, while adiponectin levels were significantly lower in girls with central obesity and hypertriglyceridemia. Path analysis showed that triglyceride had a direct effect on ICAM-1 but not VCAM-1 in both obese boys and girls. Adiponectin had a negative direct effect on ICAM-1 and VCAM-1 in girls. However, on boys, diastole blood pressure had a negative direct effect, which might be the role of sex hormones indirectly.

Conclusion

VCAM-1 was significantly higher in boys than girls, which showed that boys had a higher risk of atherosclerosis. ICAM-1 showed no significant difference in both gender and metabolic states. Adiponectin showed a protective effect by lowering ICAM-1 and VCAM-1 directly on girls.

Vascular dysfunction in multiple sclerosis: Scoping review of current evidence for informing future research directions

BACKGROUND

The research involving vascular comorbidity in people with multiple sclerosis (MS) could be advanced through investigations applying measurements of vascular function such as pulse wave velocity or flow mediated dilation as mechanistic endpoints in the study of physical comorbidity management in MS across the lifespan. We conducted a scoping review of research on vascular function parameters and outcomes in MS and developed a research agenda for future inquiry.

METHODS

We searched PubMed from inception through February 2023 for articles involving relevant central and peripheral vascular function data or correlates of vascular function (arterial stiffness, endothelial function, blood pressure parameters, etc.) in conjunction with relevant outcomes (walking function, cognition, etc.) in MS. Studies were limited to English-language and primary research articles.

RESULTS

Our search and subsequent screening identified 10 relevant articles. Four papers focused on arterial stiffness and reported pulse wave velocity and arterial compliance in MS compared with controls. Two papers focused on endothelial function and reported flow-mediated dilation in MS compared with controls. There was evidence that arterial stiffness and endothelial function were associated with cognition and disease progression in MS, respectively. One paper reported that physical activity was associated with arterial stiffness in MS. There was one protocol paper examining the effect of a home-based exercise program on markers of subclinical atherosclerosis; however, the results are unpublished, and there was no literature beyond this surrounding the impact of lifestyle behavior (e.g., diet) or exercise interventions on vascular function.

CONCLUSION

There is emerging evidence for vascular dysfunction in MS, and this is associated with cognition and disease progression; we know very little about approaches for managing vascular dysfunction in MS. To that end, we offer an agenda for research on measurements and outcomes of vascular function in relation to MS and disease attributes, along with proposed mechanisms and lifestyle changes that could aid in managing vascular dysfunction.

Sex hormone-binding globulin levels and development of hypertension in middle-aged men and women

OBJECTIVE

To investigate the association between sex hormone-binding globulin (SHBG) levels, change in blood pressure and development of hypertension.

METHODS

In a community-based study, we examined 2816 middle-aged participants with focus on cardiometabolic risk factors in 2002-2005. A representative sample of 1954 men and women was invited to follow-up in 2012-2014 and 1327 were included in a second study visit. Mean follow-up time was 9.7 years. Blood pressure was measured according to the guidelines from the seventh Joint National Committee of Hypertension, and new cases of hypertension were recorded. SHBG was measured at baseline. The association between SHBG, blood pressure and new cases of hypertension was investigated using linear regression analyses and logistic regression analyses after excluding individuals treated with blood pressure-lowering drugs.

RESULTS

Mean SBP and DBP at follow-up was 123 and 72 mmHg, respectively, and mean increase from baseline was 5.8 and 2.9 mmHg. During the follow-up time, 167 new cases of hypertension (16.1%) were identified. One standard deviation (SD) increase in SHBG at baseline was inversely associated with the risk to develop hypertension at follow-up (OR = 0.74, 95% CI 0.58-0.95) in the fully adjusted model. Moreover, one SD increase in SHBG was associated with a decrease in mean SBP (delta = -1.5 mmHg, 95% CI - 2.2 to -0.8) and DBP (delta = - 1.0 mmHg, 95% CI - 1.5 to -0.4), after adjusting for covariates.

CONCLUSION

SHBG levels are inversely associated with development of hypertension and change in blood pressure levels independent of major risk factors.

Distinct roles of estrone and estradiol in endothelial colony-forming cells

Our current understanding of the relationship between estrogen and human endothelial colony-forming cell (hECFC) function is based almost exclusively on studies investigating estradiol action at nuclear estrogen receptors. In the current study the hypothesis was tested that the less potent estrogen receptor agonist, estrone, affects hECFC proliferation, migration, secretion, and tube formation in a way that is unique from that of estradiol. The relationship between the estrogens, estradiol and estrone, is clinically important, particularly in postmenopausal women where estradiol levels wane and estrone becomes the predominant estrogen. Cultured hECFCs from peripheral blood mononuclear cell fractions were treated with concentrations of estradiol and estrone ranging from 1 nM to 1 μM separately and in combination. Following treatment, proliferation, migration, ability to attract other hECFCs (autocrine secretion), and ability to enhance endothelial cell tube formation (tubulogenesis) were tested. Functional assays revealed unique, concentration-dependent physiological effects of estrone and estradiol. Estradiol exposure resulted in increased hECFC proliferation, migration, secretion of chemoattractant, and enhancement of tube formation as expected. As with estradiol, hECFC secretion of chemoattractant increased significantly with each increase in estrone exposure. Estrone treatment produced a biphasic, concentration-dependent relationship with proliferation and tube formation and relatively no effect on hECFC migration at any concentration. The quantitative relationship between the effects of estrone and estradiol and each hECFC function was analyzed. The extent to which estrone was similar in effect to that of estradiol was dependent on both the concentrations of estradiol and estrone and the hECFC function measured. Interestingly, when the two estrogens were present, differing ratios resulted in unique functional responses. hECFCs that were treated with combinations of estrone and estradiol with high estrone to estradiol ratios showed decreased proliferative capacity. Conversely, hECFCs that were treated with combinations that were relatively high in estradiol, showed increased proliferative capacity. Cells that were treated with estrone and estradiol in equal concentrations showed an attenuated proliferative response that was decreased compared to the proliferation that either estrone or estradiol produced when they were present alone. This co-inhibitory relationship, which has not been previously reported, challenges the prevailing understanding of estrone as solely a weak agonist at estrogen receptors. This study provides evidence that estrone signaling is distinct from that of estradiol and that further investigation of estrone's mechanism of action and the biological effect may provide important insight into understanding the dysfunction and decreased number of hECFCs, and the resulting cardiovascular disease risk observed clinically in menopausal women and women undergoing hormone replacement therapy.

Regulation of Skeletal Muscle Resistance Arteriolar Tone: Integration of Multiple Mechanisms

INTRODUCTION

Physiological system complexity represents an imposing challenge to gaining insight into how arteriolar behavior emerges. Further, mechanistic complexity in arteriolar tone regulation requires that a systematic determination of how these processes interact to alter vascular diameter be undertaken.

METHODS

The present study evaluated the reactivity of ex vivo proximal and in situ distal resistance arterioles in skeletal muscle with challenges across the full range of multiple physiologically relevant stimuli and determined the stability of responses over progressive alterations to each other parameter. The five parameters chosen for examination were (1) metabolism (adenosine concentration), (2) adrenergic activation (norepinephrine concentration), (3) myogenic activation (intravascular pressure), (4) oxygen (superfusate PO2), and (5) wall shear rate (altered intraluminal flow). Vasomotor tone of both arteriole groups following challenge with individual parameters was determined; subsequently, responses were determined following all two- and three-parameter combinations to gain deeper insight into how stimuli integrate to change arteriolar tone. A hierarchical ranking of stimulus significance for establishing arteriolar tone was performed using mathematical and statistical analyses in conjunction with machine learning methods.

RESULTS

Results were consistent across methods and indicated that metabolic and adrenergic influences were most robust and stable across all conditions. While the other parameters individually impact arteriolar tone, their impact can be readily overridden by the two dominant contributors.

CONCLUSION

These data suggest that mechanisms regulating arteriolar tone are strongly affected by acute changes to the local environment and that ongoing investigation into how microvessels integrate stimuli regulating tone will provide a more thorough understanding of arteriolar behavior emergence across physiological and pathological states.

Gender Differences in Insulin Resistance: New Knowledge and Perspectives

Insulin resistance is the main mechanism in a whole series of pathological conditions, which are not only of metabolic interest but also of a systemic type. This phenomenon means that the body's cells become less sensitive to the hormone insulin, leading to higher levels of insulin in the blood. Insulin resistance is a phenomenon that can be found in both men and women and in particular, in the latter, it is found mainly after menopause. Premenopause, hormonal fluctuations during the menstrual cycle, and the presence of estrogen can affect insulin sensitivity. Androgens, such as testosterone, are typically higher in men and can contribute to insulin resistance. In both sexes, different human body types affect the distribution and location of body fat, also influencing the development of diabetes and cardiovascular disease. Insulin resistance is also associated with some neurological and neurogenerative disorders, polycystic ovary syndrome, atherosclerosis, and some of the main neoplastic pathologies. A healthy lifestyle, including regular physical activity, a balanced diet, and self-maintenance, can help to prevent the onset of insulin resistance, regardless of gender, although the different habits between men and women greatly affect the implementation of preventative guidelines that help in fighting the manifestations of this metabolic disorder. This review may help to shed light on gender differences in metabolic diseases by placing a necessary focus on personalized medical management and by inspiring differentiated therapeutic approaches.

Short-Term L-Citrulline Supplementation Does Not Affect Blood Pressure, Pulse Wave Reflection, or Arterial Stiffness at Rest and during Isometric Exercise in Older Males

Hypertension and arterial stiffness are significant factors contributing to cardiovascular disease. L-citrulline, a nitric oxide precursor, has been proposed as a nutritional, non-pharmacological blood pressure-lowering intervention. This study aimed to investigate the impact of L-citrulline on central and peripheral blood pressure, pulse wave reflection, and central arterial stiffness at rest and during an isometric knee extension exercise protocol. Twelve older males received 6 g of L-citrulline or a placebo for six days using a double-blind crossover design. Blood hemodynamics parameters (i.e., aortic and brachial systolic and diastolic blood pressure, mean arterial pressure, pulse pressure, heart rate), pulse wave reflection (i.e., augmented pressure, augmentation index, forward/backward wave pressure), and arterial stiffness (i.e., carotid-femoral pulse wave velocity) were measured at baseline, post-supplementation, and during isometric exercise. No significant effects of L-citrulline supplementation were observed at rest or during exercise on blood pressure, pulse wave reflection, or arterial stiffness. Both central and peripheral blood pressure were increased during the exercise, which is consistent with isometric contractions. The results of the present study do not support any blood pressure-lowering effect of short-term L-citrulline at rest or during low-intensity isometric exercise compared to the pre-exercise values in older males.

Estrogen regulates myogenic tone in hippocampal arterioles by enhanced basal release of nitric oxide and endothelial SK Ca channel activity

Arteries and arterioles exhibit myogenic tone, a partially constricted state that allows further constriction or dilation in response to moment-to-moment fluctuations in blood pressure. The vascular endothelium that lines the internal surface of all blood vessels controls a wide variety of essential functions, including the contractility of the adjacent smooth muscle cells by providing a tonic vasodilatory influence. Studies conducted on large (pial) arteries on the surface of the brain have shown that estrogen lowers myogenic tone in female mice by enhancing nitric oxide (NO) release from the endothelium, however, whether this difference extends to the intracerebral microcirculation remains ambiguous. The existing incomplete picture of sex differences in cerebrovascular physiology combined with a deficiency in treatments that fully restore cognitive function after cerebrovascular accidents places heavy emphasis on the necessity to investigate myogenic tone regulation in the microcirculation from both male and female mice. We hypothesized that sex-linked hormone regulation of myogenic tone extends its influence on the microcirculation level, and sought to characterize it in isolated arterioles from the hippocampus, a major cognitive brain area. Using diameter measurements both in vivo (acute cranial window vascular diameter) and ex vivo (pressure myography experiments), we measured lower myogenic tone responses in hippocampal arterioles from female than male mice. By using a combined surgical and pharmacological approach, we found myogenic tone in ovariectomized (OVX) female mice matches that of males, as well as in endothelium-denuded arterioles. Interestingly, eNOS inhibition induced a larger constriction in female arterioles but only partially abolished the difference in tone. We identified that the remnant difference was mediated by a higher activity and expression of the small-conductance Ca 2+ -sensitive K + (SK) channels. Collectively, these data indicate that eNOS and SK channels exert greater vasodilatory influence over myogenic tone in female mice at physiological pressures.

Circadian and sex differences in post-ischemic vasodilation and reactive hyperemia in young individuals and elderly with and without type 2 diabetes

OBJECTIVE

Cardiovascular events show morning preference and sex differences, and are related to aging and type 2 diabetes. We assessed circadian variations and sex differences in vascular conductance (VC) and blood flow (BF) regulations following a brief bout of forearm ischemia.

METHODS

Young healthy individuals (H18-30) and elderly without (H50-80) and with type 2 diabetes (T2DM50-80) of both sexes were included. Forearm VC and BF, and mean arterial pressure (MAP) at baseline and following circulatory reperfusion were measured at 6 a.m. and 9 p.m.

RESULTS

In the morning compared to evening, following reperfusion, the VC and BF increments were similar in H18-30 (p>.71), but lower in H50-80 (p<.001) and T2DM50-80 (p<.01). VC and BF following circulatory reperfusion were higher in men than women in H18-30 (p<.001), but similar between sexes in the older groups (p>.23).

CONCLUSIONS

Forearm vasodilation following reperfusion is attenuated in the morning in the elderly, impairing BF towards an ischemic area. Diabetes does not affect the circadian regulation of VC and BF, but that of MAP. There are sex differences in VC and BF at baseline and after circulatory reperfusion at a young age, being greater in men, which disappear with aging without being affected by diabetes.

Protein restriction during peripubertal period impairs endothelial aortic function in adult male Wistar rats

Protein restriction during early phases of body development, such as intrauterine life can favor the development of vascular disorders. However, it is not known if peripubertal protein restriction can favor vascular dysfunction in adulthood. The present study aimed to evaluated whether a protein restriction diet during peripubertal period favors endothelial dysfunction in adulthood. Male Wistar rats from postnatal day (PND) 30 until 60 received a diet with either 23% protein (CTR group) or with 4% protein (LP group). At PND 120, the thoracic aorta reactivity to phenylephrine, acetylcholine, and sodium nitroprusside was evaluated in the presence or absence of: endothelium, indomethacin, apocynin and tempol. The maximum response (Rmax) and pD2 (-log of the concentration of the drug that causes 50% of the Rmax) were calculated. The lipid peroxidation and catalase activity were also evaluated in the aorta. The data were analyzed by ANOVA (one or two-ways and Tukey's) or independent t-test; the results were expressed as mean ± S.E.M., p < 0.05. The Rmax to phenylephrine in aortic rings with endothelium were increased in LP rats when compared with the Rmax in CTR rats. Apocynin and tempol reduced Rmax to phenylephrine in LP aortic rings but not in CTR. The aortic response to the vasodilators was similar between the groups. Aortic catalase activity was lower and lipid peroxidation was greater in LP compared to CTR rats. Therefore, protein restriction during the peripubertal period causes endothelial dysfunction in adulthood through a mechanism related to oxidative stress.

Characteristics of retinal image associated with premature ovarian insufficiency: a case- control study

PURPOSE

To establish an early clinical diagnosis model based on the retinal vascular features associated with POI, supplying a non-invasive way for accurately and early predicted the risk of POI.

METHODS

A total of 78 women with spontaneous POI and 48 healthy women were recruited from the Affiliated Shenzhen Maternity & Child Healthcare Hospital in the study. Retinal characteristics were analyzed using an automated retinal image analysis system. Binary logistic regression was used to identify POI cases and develop predictive models.

RESULTS

Compared to the normal group, the POI group had larger central retinal artery equivalent (CRAE) (P = 0.006), central retinal vein equivalent (CRVE) (P = 0.001), index of venules asymmetry (Vasym) (P = 0.000); larger bifurcation angles of arterioles (Aangle) (P = 0.001), bifurcation coefficient of venule (BCV) (P = 0.001) and more obvious arteriovenous nipping (Nipping) (P = 0.005), but lower arteriole-to-venule ratio (AVR) (P = 0.012). In the POI group, the odds ratio (OR) of Vasym was 6.72e-32 (95% C.I. 4.62e-49-9.79e-15, P = 0.000), the OR of BCV was 5.66e-20 (95% C.I. 1.93e-34-.0000, P = 5.66e-20) and the OR of Nipping was 6.65e-06 (95% C.I. 6.33e-10-.0698, P = 0.012). Moreover, the area under the ROC curve for the binary logistic regression with retinal characteristics was 0.8582, and the fitting degree of regression models was 60.48% (Prob > chi-square = 0.6048).

CONCLUSION

This study demonstrated that retinal image analysis can provide useful information for POI identification and certain characteristics may help with early clinical diagnosis of POI.

The Shear Stress-Regulated Expression of Glypican-4 in Endothelial Dysfunction In Vitro and Its Clinical Significance in Atherosclerosis

Retention of circulating lipoproteins by their interaction with extracellular matrix molecules has been suggested as an underlying mechanism for atherosclerosis. We investigated the role of glypican-4 (GPC4), a heparan sulfate (HS) proteoglycan, in the development of endothelial dysfunction and plaque progression; Expression of GPC4 and HS was investigated in human umbilical vein/artery endothelial cells (HUVECs/HUAECs) using flow cytometry, qPCR, and immunofluorescent staining. Leukocyte adhesion was determined in HUVECs in bifurcation chamber slides under dynamic flow. The association between the degree of inflammation and GPC4, HS, and syndecan-4 expressions was analyzed in human carotid plaques; GPC4 was expressed in HUVECs/HUAECs. In HUVECs, GPC4 protein expression was higher in laminar than in non-uniform shear stress regions after a 1-day or 10-day flow (p < 0.01 each). The HS expression was higher under laminar flow after a 1 day (p < 0.001). Monocytic THP-1 cell adhesion to HUVECs was facilitated by GPC4 knock-down (p < 0.001) without affecting adhesion molecule expression. GPC4 and HS expression was lower in more-inflamed than in less-inflamed plaque shoulders (p < 0.05, each), especially in vulnerable plaque sections; Reduced expression of GPC4 was associated with atherogenic conditions, suggesting the involvement of GPC4 in both early and advanced stages of atherosclerosis.

Sex as a Biological Variable in Tissue Engineering and Regenerative Medicine

Although sex differences have been noted in cellular function and behavior, therapy efficacy, and disease incidence and outcomes, the adoption of sex as a biological variable in tissue engineering and regenerative medicine remains limited. Furthering the development of personalized, precision medicine requires considering biological sex at the bench and in the clinic. This review provides the basis for considering biological sex when designing tissue-engineered constructs and regenerative therapies by contextualizing sex as a biological variable within the tissue engineering triad of cells, matrices, and signals. To achieve equity in biological sex within medicine requires a cultural shift in science and engineering research, with active engagement by researchers, clinicians, companies, policymakers, and funding agencies.

A Case of Spontaneous Coronary Artery Dissection in the Setting of Exogenous Testosterone

ABSTRACT

Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome, occurring when there is separation of the coronary artery walls by intramural hemorrhage creating a false lumen. This compresses the arterial lumen, compromising the ability of the coronary artery to perfuse the myocardial tissue. Spontaneous coronary artery dissection is usually fatal, with risk factors including pregnancy, young age, and female sex, birth control, and other hormonal therapies.In this case report, we describe the case of a 31-year-old biological female transitioning to male with exogenous testosterone who experienced a SCAD. Given the known risk factors for SCAD, such as pregnancy and exogenous hormone therapy, this case raises additional considerations regarding rare unintended consequences of testosterone therapy.

Aerobic exercise training reduces ET-1-mediated vasoconstriction and improves endothelium-dependent vasodilation in postmenopausal women

Endothelin-1 (ET-1) contributes to vascular dysfunction in postmenopausal women (PMW). Although aerobic exercise is beneficial in reducing ET-1-mediated vasoconstrictor tone in men, it is unknown whether this favorable vascular effect occurs in women. We tested the hypothesis that aerobic exercise training reduces ET-1-mediated vasoconstriction in PMW. We further hypothesized that reductions in ET-1 vasoconstrictor tone underly exercise-induced improvements in endothelium-dependent vasodilatation in PMW. Forearm blood flow (FBF) responses to intra-arterial infusion of selective ETA receptor blockade (BQ-123, 100 nmol/min for 60 min) and acetylcholine (4.0, 8.0, and 16.0 μg/100 mL tissue/min) in the absence and presence of ETA receptor blockade were determined before and after a 12-wk aerobic exercise training intervention in 18 healthy, sedentary PMW (58 ± 4 yr). Women exercised an average of 4.9 ± 0.7 day/wk for 51 ± 7 min/day at 71 ± 3% of maximal heart rate. Before exercise, BQ-123 significantly increased FBF (∼25%) in sedentary PMW; however, this effect was abolished following the exercise intervention. FBF responses to acetylcholine were also significantly higher after exercise training (from 4.2 ± 1.2 to 14.0 ± 3.8 mL/100 mL tissue/min) versus before (from 4.1 ± 1.0 to 11.4 ± 3.3 mL/100 mL tissue/min; ∼25% increase; P < 0.05). Before exercise training, coinfusion of BQ-123 with acetylcholine enhanced (∼25%; P < 0.05) the vasodilator response (from 4.4 ± 1.1 to 13.9 ± 4.2 mL/100 mL tissue/min) compared with acetylcholine alone; after exercise training, the presence of BQ-123 did not significantly affect the vasodilator response to acetylcholine. Aerobic exercise training reduces ET-1-mediated vasoconstriction in PMW. Furthermore, decreased ET-1-mediated vasoconstriction is an important mechanism underlying aerobic exercise-induced improvement in endothelium-dependent vasodilation in PMW.NEW & NOTEWORTHY Endothelin-1 (ET-1) contributes to declines in endothelial function in postmenopausal women. To our knowledge, we show for the first time that aerobic exercise reduces ET-1-mediated vasoconstriction in previously sedentary postmenopausal women. Moreover, aerobic exercise improved endothelial-dependent dilation due in part to the reductions in ET-1-mediated vasoconstriction.

Vasomotor symptoms and their links to cardiovascular disease risk

Hot flashes and night sweats, also known as vasomotor symptoms (VMS), are common and bothersome symptoms of the menopause transition. In addition to negatively impacting quality of life, VMS have been associated with multiple indicators of cardiovascular disease (CVD) risk, including an unfavorable CVD risk factor profile, increased subclinical CVD, and elevated risk of CVD events. Several facets of VMS have been associated with CVD risk, including the frequency, timing, duration, and severity of VMS. VMS may signify poor or degrading cardiovascular health among midlife women and indicate women who warrant focused CVD prevention efforts.

Topiramate treatment during the peripubertal period does not alter aortic endothelial function in female Wistar rats

AIMS

This study aimed to evaluate the short- and long-term adverse effects of blood pressure (BP), vascular endothelial function, and estrogen receptor (ERα and ERβ) modulation on endothelial function in female Wistar rats treated with topiramate (TPM), an antiepileptic drug, during the peripubertal period.

MATERIALS AND METHODS

Female Wistar rats were treated with TPM (41 mg/kg) or water (CTR group) by gavage from postnatal day (PND) 28 to 50 (peripubertal phase). At the end of the treatment, the TPM and CTR rats were divided into two groups and evaluated after 24 h or from PND 85 (adulthood). The rats were evaluated for: thoracic aorta reactivity to phenylephrine (Phenyl), acetylcholine (ACh), and sodium nitroprusside (SNP); aortic ring reactivity after ERα and ERβ antagonism; and BP.

KEY FINDINGS

It was observed that vascular response to Phenyl, ACh, and SNP was similar between TPM and CTR rats in the short- and long-term evaluations. In addition, the ER antagonism did not interfere with aortic contraction or relaxation in either TPM or CTR.

SIGNIFICANCE

Taken together, the results show that TPM treatment during the peripubertal period does not alter aortic endothelial function and its estrogen modulation via classic ER in female Wistar rats, suggesting that TPM treatment in this period is safe for the vascular system.

Brain fog in long COVID limits function and health status, independently of hospital severity and preexisting conditions

Importance

The U.S. government has named post-acute sequelae of COVID-19 (longCOVID) as influential on disability rates. We previously showed that COVID-19 carries a medical/functional burden at 1  year, and that age and other risk factors of severe COVID-19 were not associated with increased longCOVID risk. Long-term longCOVID brain fog (BF) prevalence, risk factors and associated medical/functional factors are poorly understood, especially after mild SARS-CoV-2 infection.

Methods

A retrospective observational cohort study was conducted at an urban tertiary-care hospital. Of 1,032 acute COVID-19 survivors from March 3-May 15, 2020, 633 were called, 530 responded (59.2 ± 16.3  years, 44.5% female, 51.5% non-White) about BF prevalence, other longCOVID, post-acute ED/hospital utilization, perceived health/social network, effort tolerance, disability.

Results

At approximately 1-year, 31.9% (n = 169) experienced BF. Acute COVID-19 severity, age, and premorbid cardiopulmonary comorbidities did not differ between those with/without BF at 1  year. Patients with respiratory longCOVID had 54% higher risk of BF than those without respiratory longCOVID. BF associated with sleep disturbance (63% with BF vs.29% without BF, p < 0.0001), shortness of breath (46% vs.18%, p < 0.0001), weakness (49% vs.22%, p < 0.0001), dysosmia/dysgeusia (12% vs.5%, p < 0.004), activity limitations (p < 0.001), disability/leave (11% vs.3%, p < 0.0001), worsened perceived health since acute COVID-19 (66% vs.30%, p < 0.001) and social isolation (40% vs.29%, p < 0.02), despite no differences in premorbid comorbidities and age.

Conclusions and relevance

A year after COVID-19 infection, BF persists in a third of patients. COVID-19 severity is not a predictive risk factor. BF associates with other longCOVID and independently associates with persistent debility.

Widespread sex-dimorphism across single-cell transcriptomes of adult African turquoise killifish tissues

The African turquoise killifish (Nothobranchius furzeri), the shortest-lived vertebrate that can be bred in captivity, is an emerging model organism to study vertebrate aging. Here we describe the first multi-tissue, single-cell gene expression atlas of female and male turquoise killifish tissues comprising immune and metabolic cells from the blood, kidney, liver, and spleen. We were able to annotate 22 distinct cell types, define associated marker genes, and infer differentiation trajectories. Using this dataset, we found pervasive sex-dimorphic gene expression across cell types, especially in the liver. Sex-dimorphic genes tended to be involved in processes related to lipid metabolism, and indeed, we observed clear differences in lipid storage in female vs. male turquoise killifish livers. Importantly, we use machine-learning to predict sex using single-cell gene expression in our atlas and identify potential transcriptional markers for molecular sex identity in this species. As proof-of-principle, we show that our atlas can be used to deconvolute existing liver bulk RNA-seq data in this species to obtain accurate estimates of cell type proportions across biological conditions. We believe that this single-cell atlas can be a resource to the community that could notably be leveraged to identify cell type-specific genes for cell type-specific expression in transgenic animals.

The effects of exogenous estrogen in women with SAR-CoV-2 infection: a systematic review and meta-analysis

STUDY QUESTION

Does exogenous estrogen use affect COVID-19-related mortality in women?

SUMMARY ANSWER

Menopausal hormone therapy (MHT) was associated with a lower likelihood of all-cause fatality related to COVID-19 in postmenopausal women (odds ratio (OR) 0.28, 95% CI 0.18, 0.44; 4 studies, 21 517 women) but the combined oral contraceptive pill in premenopausal women did not have a significant effect (OR 1.00, 95% CI 0.42-2.41; 2 studies, 5099 women).

WHAT IS KNOWN ALREADY

Men are much more likely to die from COVID-19 than women.

STUDY DESIGN, SIZE, DURATION

In this systematic meta-analysis, a literature search was conducted using the following search terms related toCOVID-19 and estrogen, sex hormones, hormonal replacement, menopause, or contraception. The PubMed, Scopus, Cochrane Library, and EMBASE databases were searched to identify relevant studies published between December 2019 and December 2021. We also searched MedRxiv as a preprint database and reviewed the reference lists of all included studies and clinical trial registries for ongoing clinical studies until December 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All comparative studies that compared the rates mortality and morbidity (hospitalization, intensive care unit (ICU) admission, and ventilation support) due to COVID-19 in women using exogenous estrogen to a control group of women (nonusers) were included. A review of the studies for inclusion, extraction of data, and assessment of the risk of bias was performed independently by two reviewers. The ROBINS-I tool and the RoB 2 tool were used for bias assessment of the included studies. Pooled odds ratios (ORs) with 95% CIs were calculated using Review Manager V5.4.1. The I2 statistic was used to quantify heterogeneity. The quality of the evidence was assessed using GRADE criteria.

MAIN RESULTS AND THE ROLE OF CHANCE

After searching the databases, we identified a total of 5310 studies. After removing duplicate records, ineligible studies, and ongoing studies, a total of four cohort studies and one randomized controlled trial comprising 177 809 participants were included in this review. There was a moderate certainty of evidence that MHT was associated with a lower likelihood of all-cause fatality related to COVID-19 (OR 0.28, 95% CI 0.18, 0.44; I2 = 0%; 4 studies, 21 517 women). The review indicated a low certainty of evidence for other outcomes. The mortality rate of premenopausal women in the combined oral contraceptive pill group did not differ significantly from the control group (OR 1.00, 95% CI 0.42-2.41; 2 studies, 5099 women). MHT marginally increased the rate of hospitalization and ICU admission (OR 1.37, 95% CI 1.18-1.61; 3 studies, 151 485 women), but there was no significant difference in the need for respiratory support between MHT users and nonusers (OR 0.91, 95% CI 0.52-1.59; 3 studies, 151 485 women). Overall, the tendency and magnitude of the effects of MHT in postmenopausal women with COVID-19 were consistent across the included studies.

LIMITATIONS, REASONS FOR CAUTION

The certainty of the evidence for other outcomes of this review may be limited, as all included studies were cohort studies. In addition, the dosages and durations of exogenous estrogen used by postmenopausal women varied from study to study, and combined progestogen administration may have had some effect on the outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

The findings of this study can aid in counseling postmenopausal women taking MHT when they are diagnosed with COVID, as they have a lower chance of death than those not taking MHT.

STUDY FUNDING/COMPETING INTEREST(S)

Khon Kaen University provided financial support for this review and had no involvement at any stage of the study. The authors have no conflicts of interest to declare.

REGISTRATION NUMBER

PROSPERO, CRD42021271882.