Sex-specific differences in cardiovascular risk factors and blood pressure control in hypertensive patients

Obesity- and sex-related metabolism of arginine and nitric oxide in adults

BACKGROUND

There is growing interest in the supplementation of arginine (Arg) and citrulline (Cit) in obesity due to their potential anti-obesogenic and anti-inflammatory properties. However, there is no consensus on the metabolic changes in Arg kinetics in obesity.

OBJECTIVES

This exploratory cross-sectional study aimed to investigate the association between obesity, sex, and sex-by-obesity interaction on whole-body Arg kinetics in a large group of human subjects.

METHODS

We studied 83 nonobese [BMI (kg/m2) <30] and 80 morbidly obese (BMI >30) middle-aged individuals (40% males) enrolled in the MEDIT (Metabolism of Disease with Isotope Tracers) trial. After body-composition measurement by DXA, we collected arterial(ized) blood samples for amino acid (AA) concentrations, markers of inflammation [high-sensitivity C-reactive protein (hs-CRP)], liver function, and glucose in a postabsorptive state. We administered a pulse of AA stable tracers and measured whole-body production (WBP) of Arg, Cit, ornithine (Orn), phenylalanine, and tyrosine, and calculated their clearance (disposal capacity) and metabolite interconversions [markers for NO and de novo Arg production, systemic Arg hydrolysis, and whole-body protein breakdown (wbPB)]. We measured plasma enrichments by LC-MS/MS and statistics by Fisher's exact test or analysis of (co)variance. Significance was set at P < 0.05.

RESULTS

Obese individuals were normoglycemic and characterized by low-grade inflammation (P < 0.0001) and greater wbPB (P = 0.0298). We found lower plasma Cit concentration (P < 0.0001) in the obese group but no differences in the WBP of Arg, Cit, and Orn. Furthermore, we observed overproduction of NO (P < 0.0001) in obesity but lower de novo Arg production (P = 0.0007). The WBP of Arg was lower in females for almost all Arg-related AAs, except for plasma Cit and NO production.

CONCLUSIONS

Alterations in Arg metabolism are present in morbid obesity. Further studies are needed to investigate if these changes could be related to factors such as increased Arg requirement in obesity or metabolic adaptation.

Hypertension Across a Woman's Life Cycle

PURPOSE OF REVIEW

We reviewed the effects of hypertension and the means to prevent and treat it across the spectrum of a woman's lifespan and identified gaps in sex-specific mechanisms contributing to hypertension in women that need to be addressed.

RECENT FINDINGS

Hypertension continues to be an important public health problem for women across all life stages from adolescence through pregnancy, menopause, and older age. There remain racial, ethnic, and socioeconomic differences in hypertension rates not only overall but also between the sexes. Blood pressure cutoffs during pregnancy have not been updated to reflect the 2017 ACC/AHA changes due to a lack of data. Additionally, the mechanisms behind hypertension development in menopause, including sex hormones and genetic factors, are not well understood. In the setting of increasing inactivity and obesity, along with an aging population, hypertension rates are increasing in women. Screening and management of hypertension throughout a women's lifespan are necessary to reduce the burden of cardiovascular disease, and further research to understand sex-specific hypertension mechanisms is needed.

Hypertension in Women: The Current Understanding and Future Goals

Hypertension is one of the major contributing risk factor of cardiovascular diseases. Despite enormous advances in the preventive cardiology, hypertension remains the leading cause of death and disability in women. The article aims to focus on the gender specific differences in hypertension, and existing gaps in the current understanding of high blood pressure (BP) in women. Apart from epidemiological differences, hypertension in men and women has distinct pathophysiological mechanisms, impact on cardiovascular system, awareness and control. Prevalence of hypertension is higher in men than women till menopause; following this the prevalence rises steeply in women, and exceeds that of men above 75 years of age. Women with their estrogenic environment are relatively protected from high BP as their hormonal/chromosomal profile govern expression of alternate renin angiotensin axis (RAS) pathway and anti-inflammatory, vasodilatory, anti-proliferative immune cells whereas in males, classical RAS driven inflammatory, pro-hypertensive and proliferative milieu confers higher risk of hypertension. Thus, immunotherapy can have a potential therapeutic role in the treatment of hypertension in future. Cardiovascular consequences of high BP are worse in women than men in majority of trials. Women are now getting more aware of hypertension but the control of BP still remains poorer than men, especially in older age group. There are some noteworthy pharmacokinetic and pharmacogenomics gender differences in response to various antihypertensive drugs, which can be taken into consideration while choosing a particular class of drugs in female population. Standard treatment guidelines recommend same BP targets and management strategies in both the genders, but the trials so far have not been designed in a way to draw women specific conclusions on optimal cut-offs for diagnosis and treatment of BP due to under representation of women in majority of trials. More women centered analysis in future hypertension research projects can provide better scientific insights in various clinical aspects of hypertension.

Retrospective Study of Aging and Sex-Specific Risk Factors of COVID-19 with Hypertension in China

Background

Coronavirus disease 2019 (COVID-19) has been a global threat that pushes healthcare to its limits. Hypertension is one of the most common risk factors for cardiovascular complications in COVID-19 and is strongly associated with disease severity and mortality. To date, clinical mechanisms by which hypertension leads to increased risk in COVID-19 are still unclear. Furthermore, additional factors might increase these risks, such as the consideration of age and sex, which are of interest when in search of personalized treatments for hypertensive COVID-19 patients.

Methods

We conducted a retrospective cohort study of 543 COVID-19 patients in seven provinces of China to examine the epidemiological and clinical characteristics of COVID-19 in this population and to determine risk factors of hypertensive COVID-19 patients. We also used univariable and multivariable logistic regression methods to explore the risk factors associated with hypertensive COVID-19 patients in different age and sex subgroups.

Results

Among the enrolled COVID-19 patients, the median age was 47 years (interquartile range (IQR) 34.0–57.0), and 99 patients (18.23%) were over 60 years old. With regard to comorbidities, 91 patients (16.75%) were diagnosed with hypertension, followed by diabetes, coronary disease, and cerebrovascular disease. Of the hypertensive COVID-19 patients, 51 (56.04%) were male. Multivariable analysis showed that old age, comorbid diabetes or coronary heart disease on admission, increased D-dimer, increased glucose, and decreased lymphocyte count were independent risk factors associated with hypertensive COVID-19 patients. Elevated total bilirubin (odds ratio [OR]: 1.014, 95% confidence interval [CI]: 0.23–1.05; p = 0.043) and triglycerides (OR: 1.173, 95% CI: 0.049–1.617; p = 0.007) were found to be associated with elderly hypertensive COVID-19 patients. In addition, we found that decreased lymphocytes, basophil, high-density lipoprotein, and increased fibrinogen and creatinine were related to a higher risk of disease severity in male patients. The most common abnormal clinical findings pertaining to female hypertensive COVID-19 patients were hemoglobin, total bile acid, total protein, and low-density lipoprotein.

Conclusions

Factors associated with increased risk of hypertensive COVID-19 patients were identified. Results to the different age and sex subgroups in our study will allow for better possible personalized care and also provide new insights into specific risk stratification, disease management, and treatment strategies for COVID-19 patients with hypertension in the future.

Sex Differences in Renal Function: Participation of Gonadal Hormones and Prolactin

Kidney pathophysiology is influenced by gender. Evidence suggests that kidney damage is more severe in males than in females and that sexual hormones contribute to this. Elevated prolactin concentration is common in renal impairment patients and is associated with an unfavorable prognosis. However, PRL is involved in the osmoregulatory process and promotes endothelial proliferation, dilatation, and permeability in blood vessels. Several proteinases cleavage its structure, forming vasoinhibins. These fragments have antagonistic PRL effects on endothelium and might be associated with renal endothelial dysfunction, but its role in the kidneys has not been enough investigated. Therefore, the purpose of this review is to describe the influence of sexual dimorphism and gonadal hormones on kidney damage, emphasizing the role of the hormone prolactin and its cleavage products, the vasoinhibins.

HbA1c and Aortic Calcification Index as Noninvasive Predictors of Pre-Existing Histopathological Damages in Living Donor Kidney Transplantation

We previously reported that allografts from living donors may have pre-existing histopathological damages, defined as the combination of interstitial fibrosis (ci), tubular atrophy (ct), and arteriolar hyalinosis (ah) scores of ≧1, according to the Banff classification. We examined preoperative characteristics to identify whether the degree of these damages was related to metabolic syndrome-related factors of donors. We conducted a single-center cross-sectional analysis including 183 living kidney donors. Donors were divided into two groups: chronic change (ci + ct ≧ 1 &cap; ah ≧ 1, n = 27) and control (n = 156). Preoperative characteristics, including age, sex, blood pressure, hemoglobin A1c (HbA1c), aortic calcification index (ACI), and psoas muscle index (PMI), were analyzed. Comparing the groups, the baseline estimated glomerular filtration rate was not significantly different; however, we observed a significant difference for ACI (p = 0.009). HbA1c (p = 0.016) and ACI (p = 0.006) were independent risk factors to predict pre-existing histopathological damages, whereas PMI was not. HbA1c correlated with ct scores (p = 0.035), and ACI correlated with ci (p = 0.005), ct (p = 0.021), and ah (p = 0.017). HbA1c and ACI may serve as preoperative markers for identifying pre-existing damages on the kidneys of living donors.

Registry of the Egyptian specialized hypertension clinics: patient risk profiles and geographical differences

Data regarding the prevalence and characteristics of cardiovascular (CV) risk factors among Egyptian hypertensive patients are limited. Nationwide Specialized Hypertension Clinics (SHCs) were initiated for screening, investigating, and treating hypertensive patients. This study aimed to determine the clinical characteristics and the CV risk profile of hypertensive Egyptians attending SHCs. Data from 4701 hypertensive patients were collected from the SHCs of nine university hospitals representing the different geographical regions of Egypt. Data collection started in October 2014 and ended in September 2017. Data included blood pressure (BP) measurements, clinical data, socio-demographic characteristics, anthropometric measurements, and cardiovascular risk profiles. The patients' mean age was 51.8 ± 11.5 years, 58.7% were older than 50 years, and 58.5% were females. The mean office systolic and diastolic BP values were 145.2 ± 22.4 and 88.7 ± 12.9 mmHg, respectively. Regarding CV risk factors, 58.6% were obese, 23.4% were smokers, and 25.1% had diabetes mellitus. Obesity was more prevalent in females than males (65.7% vs. 53.0%, p < 0.001, respectively), while dyslipidaemia and smoking were significantly more common in male patients. The highest levels of BP and the highest global risk were observed in the inhabitants of the Delta region, despite their younger age. In conclusion, this study revealed a high prevalence of modifiable CV risk factors among a cohort of Egyptian hypertensive patients attending SHCs. The pattern of the risk factors across the different geographic regions may be attributed to rapid urbanization. Governmental and community-based approaches are needed for better control of hypertension and its associated CV risk factors.

Testosterone and dihydrotestosterone reduce platelet activation and reactivity in older men and women

The cardiovascular effects of testosterone and dihydrotestosterone are generally attributed to their modulatory action on lipid and glucose metabolism. However, no ex vivo studies suggest that circulating androgen levels influence the activation and reactivity of blood platelets - one of the main components of the haemostasis system directly involved in atherosclerosis. The levels of testosterone, dihydrotestosterone and oestradiol in plasma from men and women aged from 60 to 65 years were measured by LC-MS; the aim was to identify any potential relationships between sex steroid levels and the markers of platelet activation (surface membrane expression of GPII/IIIa complex and P-selectin) and platelet reactivity in response to arachidonate, collagen or ADP, monitored with whole blood aggregometry and flow cytometry. The results of the ex vivo part of the study indicate that the concentrations of testosterone and its reduced form, dihydrotestosterone are significantly negatively associated with platelet activation and reactivity. These observations were confirmed in an in vitro model: testosterone and dihydrotestosterone significantly inhibited platelet aggregation triggered by arachidonate or collagen. Our findings indicate that testosterone and dihydrotestosterone are significant haemostatic steroids with inhibitory action on blood platelets in older people.

Gender-specific therapeutic approach in arterial hypertension - Challenges ahead

Hypertension was thought to be more important cardiovascular risk factor in men than in women. However, studies showed that overall incidence of hypertension-related cardiovascular diseases is higher in women comparing with men and this is particularly valid in menopause when prevalence of hypertension and its complications sharply and suddenly rises. It was also noticed that the effect of various antihypertensive groups was different in women and men. Some medications are prescribed more often in women, but it does not necessary mean that these drugs are more effective in this gender. There are several important reasons that could explain gender-induced differences in blood pressure levels, blood pressure control and antihypertensive treatment. They involve sex hormones, the renin-angiotensin-aldosterone and sympathetic nervous system, and arterial stiffness. However, taking into account many observational studies and trials, there are no consistent data regarding the impact of gender on effect of antihypertensive medications. Longitudinal study focused on gender and current antihypertensive groups would significantly help to understand the impact of gender. This might change therapeutic approach and improve cost-effectiveness in antihypertensive therapy in both genders. A full understanding of the pathophysiological characteristics of variations between genders demands additional research. This review article summarized the current knowledge regarding differences in the prevalence and awareness of arterial hypertension in women and men; alterations in pathophysiological mechanisms of hypertension between sexes; as well as the impact of sex on the effects of main antihypertensive groups of medications.

Sex and gender differences in hypertensive kidney injury

Hypertension is a complex, multifaceted disorder, affecting ~1 in 3 adults in the United States. Although hypertension occurs in both men and women, there are distinct sex differences in the way in which they develop hypertension, with women having a lower incidence of hypertension until the sixth decade of life. Despite observed sex differences in hypertension, little is known about the molecular mechanisms underlying the development of hypertension in females, primarily because of their underrepresentation in both clinical and experimental animal studies. The first goal of this review is to provide a concise overview of the participation of women in clinical trials, including a discussion of the importance of including females in basic science research, as recently mandated by the National Institutes of Health. The remaining portion of the review is dedicated to identifying clinical and experimental animal studies that concentrate on gender and sex differences in hypertensive kidney disease, ending with a proposed role for T cells in mediating sex differences in blood pressure.

Gene-specific DNA methylation profiles and LINE-1 hypomethylation are associated with myocardial infarction risk

Background

DNA methylation profiles are responsive to environmental stimuli and metabolic shifts. This makes DNA methylation a potential biomarker of environmental-related and lifestyle-driven diseases of adulthood. Therefore, we investigated if white blood cells’ (WBCs) DNA methylation profiles are associated with myocardial infarction (MI) occurrence.

Whole-genome DNA methylation was investigated by microarray analysis in 292 MI cases and 292 matched controls from the large prospective Italian European Prospective Investigation into Cancer and Nutrition (EPIC) cohort (EPICOR study). Significant signals (false discovery rate (FDR) adjusted P < 0.05) were replicated by mass spectrometry in 317 MI cases and 262 controls from the Dutch EPIC cohort (EPIC-NL). Long interspersed nuclear element-1 (LINE-1) methylation profiles were also evaluated in both groups.

Results

A differentially methylated region (DMR) within the zinc finger and BTB domain-containing protein 12 (ZBTB12) gene body and LINE-1 hypomethylation were identified in EPICOR MI cases and replicated in the EPIC-NL sample (ZBTB12-DMR meta-analysis: effect size ± se = −0.016 ± 0.003, 95 % CI = −0.021;−0.011, P = 7.54 × 10⁻¹⁰; LINE-1 methylation meta-analysis: effect size ± se = −0.161 ± 0.040, 95 % CI = −0.239;−0.082, P = 6.01 × 10⁻⁵).

Moreover, cases with shorter time to disease had more pronounced ZBTB12-DMR hypomethylation (meta-analysis, men: effect size ± se = −0.0059 ± 0.0017, P_TREND = 5.0 × 10⁻⁴; women: effect size ± se = −0.0053 ± 0.0019, P_TREND = 6.5 × 10⁻³) and LINE-1 hypomethylation (meta-analysis, men: effect size ± se = −0.0010 ± 0.0003, P_TREND = 1.6 × 10⁻³; women: effect size ± se = −0.0008 ± 0.0004, P_TREND = 0.026) than MI cases with longer time to disease.

In the EPIC-NL replication panel, DNA methylation profiles improved case-control discrimination and reclassification when compared with traditional MI risk factors only (net reclassification improvement (95 % CI) between 0.23 (0.02–0.43), P = 0.034, and 0.89 (0.64–1.14), P < 1 × 10⁻⁵).

Conclusions

Our data suggest that specific methylation profiles can be detected in WBCs, in a preclinical condition, several years before the occurrence of MI, providing an independent signature of cardiovascular risk. We showed that prediction accuracy can be improved when DNA methylation is taken into account together with traditional MI risk factors, although further confirmation on a larger sample is warranted. Our findings support the potential use of DNA methylation patterns in peripheral blood white cells as promising early biomarkers of MI.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-015-0164-3) contains supplementary material, which is available to authorized users.