The effect of oral Contraceptive pills and the natural menstrual cYCLe on arterial stiffness and hemodynamICs (CYCLIC)

Menstrual and oral contraceptive pill cycles minimally influence vascular function and associated cellular regulation in premenopausal females

Historical exclusion of females in research has been, in part, due to the perceived influence of natural menstrual (NAT) and oral contraceptive pill (OCP) cycles on vascular outcomes. NAT and OCP cycle phases may influence brachial artery (BA) endothelial function, however, findings are mixed. Minimal research has examined arterial stiffness, smooth muscle, and lower limb endothelial function. The purpose of this study was to investigate the influence of NAT and OCP cycles on cardiovascular outcomes and cellular regulation. Forty-nine premenopausal females (n = 17 NAT, n = 17 second generation OCP, n = 15 third generation OCP) participated in two randomized order visits in the low (LH, early follicular/placebo) and high (HH, midluteal/active) hormone cycle phases. BA and superficial femoral artery (SFA) endothelial function [flow-mediated dilation (FMD) test], smooth muscle function (nitroglycerine-mediated dilation test), and carotid and peripheral (pulse wave velocity) arterial stiffness were assessed. Cultured female human endothelial cells were exposed to participant serum for 24 h to examine endothelial nitric oxide synthase (eNOS) and estrogen receptor-α (ERα) protein content. BA FMD was elevated in the HH vs. LH phase, regardless of group (HH, 7.7 ± 3.5%; LH, 7.0 ± 3.3%; P = 0.02); however, allometric scaling for baseline diameter resulted in no phase effect (HH, 7.6 ± 2.6%; LH, 7.1 ± 2.6%; P = 0.052, d = 0.35). SFA FMD, BA, and SFA smooth muscle function, arterial stiffness, and eNOS and ERα protein content were unaffected. NAT and OCP phases examined have minimal influence on vascular outcomes and ERα-eNOS pathway, apart from a small effect on BA endothelial function partially explained by differences in baseline artery diameter. NEW & NOTEWORTHY Comprehensive evaluation of the cardiovascular system in naturally cycling and second and third generation OCP users indicates no major influence of hormonal phases examined on endothelial function and smooth muscle function in the arteries of the upper and lower limbs, arterial stiffness, or underlying cellular mechanisms. Study findings challenge the historical exclusion of female participants due to potentially confounding hormonal cycles; researchers are encouraged to consider the hormonal environment in future study design.

Menstrual cycle hormones and oral contraceptives: a multimethod systems physiology-based review of their impact on key aspects of female physiology

Hormonal changes around ovulation divide the menstrual cycle (MC) into the follicular and luteal phases. In addition, oral contraceptives (OCs) have active (higher hormone) and placebo phases. Although there are some MC-based effects on various physiological outcomes, we found these differences relatively subtle and difficult to attribute to specific hormones, as estrogen and progesterone fluctuate rather than operating in a complete on/off pattern as observed in cellular or preclinical models often used to substantiate human data. A broad review reveals that the differences between the follicular and luteal phases and between OC active and placebo phases are not associated with marked differences in exercise performance and appear unlikely to influence muscular hypertrophy in response to resistance exercise training. A systematic review and meta-analysis of substrate oxidation between MC phases revealed no difference between phases in the relative carbohydrate and fat oxidation at rest and during acute aerobic exercise. Vascular differences between MC phases are also relatively small or nonexistent. Although OCs can vary in composition and androgenicity, we acknowledge that much more work remains to be done in this area; however, based on what little evidence is currently available, we do not find compelling support for the notion that OC use significantly influences exercise performance, substrate oxidation, or hypertrophy. It is important to note that the study of females requires better methodological control in many areas. Previous studies lacking such rigor have contributed to premature or incorrect conclusions regarding the effects of the MC and systemic hormones on outcomes. While we acknowledge that the evidence in certain research areas is limited, the consensus view is that the impact of the MC and OC use on various aspects of physiology is small or nonexistent.

Effect of an 11-Week Resistance Training Program on Arterial Stiffness in Young Women

ABSTRACT

Morgan, B, Mirza, AM, Gimblet, CJ, Ortlip, AT, Ancalmo, J, Kalita, D, Pellinger, TK, Walter, JM, and Werner, TJ. Effect of an 11-week resistance training program on arterial stiffness in young women. J Strength Cond Res 37(2): 315-321, 2023-The current investigation was conducted to determine the effect of 2 resistance training models on indices of arterial stiffness in young, healthy women. Twenty-four women, untrained college students, aged 18-22 years were randomized into 1 of 3 groups: control (CON) group ( n = 8), high-intensity (HI) resistance exercise group ( n = 8), and high-volume (HV) resistance exercise group ( n = 8). Subjects randomized to resistance training groups were required to perform strength training exercises 3-5 days a week for 11 weeks. The exercise regimen consisted of 2-3 sets of 3-8 repetitions (80-90% of 1 repetition maximum [1RM]) for the HI group and 3-4 sets of 10-15 repetitions (50-70% of 1RM) for the HV group. All subjects were instructed to continue their normal diet and avoid cardiovascular exercise during the study. After the intervention, there was a significant increase in carotid femoral pulse wave velocity (PWV) (6.39 ± 0.73 to 8.40 ± 2.31 m·s -1 ; p < 0.05) and carotid radial PWV (9.77 ± 1.74 to 12.58 ± 2.09 m·s -1 ; p < 0.05) in the CON group alone. Both the HI and HV groups increased their maximum squat (36.6 ± 7.9 vs. 41.3 ± 31.8 percent change; p < 0.05), bench press (34.4 ± 12.6 vs. 23.4 ± 11.1 percent change; p < 0.05), and seated row (22.0 ± 12.6 vs. 21.9 ± 12.5 percent change; p < 0.05), respectively. Our findings support the use of resistance training exercise without undue impact on vascular compliance in otherwise healthy women.

Effects of peroral hormonal contraception on cardiovascular system: analysis of selected cardiovascular parameters in an adolescent cohort; a pilot project

Oral contraceptive pills (OCPs) have some strong advantages over more traditional types of contraception, including their consistently high contraceptive effect as well as multiple additional positive side effects. OCPs went through decades of intense pharmaceutical development and current formulas are well optimized - however, a handful of their negative side effects remain, including some that affect cardiovascular system, for example higher risk of hypertension, venous thromboembolism and increased arterial stiffness. The gold standard for arterial stiffness assessment is currently applanation tonometry, a method that relies on arterial pulse wave velocity measurement (PWV). Another possible method for arterial stiffness measurement is the use of the VaSera device, which measures cardio-ankle vascular index (CAVI). The aim of this study was to discover the effect of OCPs use on selected cardiovascular parameters related to arterial stiffness. We measured these cardiovascular parameters in the OCPs using group (OCP) and in the control group (CTRL) using applanation tonometer Sphygmocor and the VaSera device. Comparison of the data from both groups showed us significantly increased diastolic blood pressure (DBP) and carotid-radial pulse wave velocity (crPWV) as well as significantly lower subendocardial viability index (SVI) in the OCP. These results imply a negative effect of hormonal contraceptives on the cardiovascular system with most of the negative changes affecting the peripheral arteries. Despite this evidence supporting the hypothesis of OCPs having a negative effect on cardiovascular health, further research is necessary.

Arterial stiffness and blood pressure are similar in naturally menstruating and oral contraceptive pill using women during the higher-hormone phases

NEW FINDINGS

What is the central question of this study? Are there differences in blood pressure, arterial stiffness and indices of pressure waveforms between young oral contraceptive pill using and naturally menstruating women during lower and higher hormone phases of their cycles? What is the main finding and its importance? Blood pressure, arterial stiffness and indices of pressure waveforms are influenced similarly by exogenous and endogenous hormones. However, lower levels of exogenous hormones moderately increase blood pressure among OCP.

ABSTRACT

Elevations in blood pressure (BP) are understood as having a bidirectional relationship with stiffening of central and peripheral arteries. Arterial stiffness is mitigated by oestrogen, which aides in arterial vasorelaxation. To evaluate whether BP, stiffness, and pressure waveforms were different between young healthy naturally menstruating (non-OCP) and oral contraceptive pill using women (OCP), we measured brachial and aortic BPs, carotid-to-femoral pulse wave velocity (cfPWV), carotid β-stiffness, elastic-modulus, central augmentation index (AIx and AIx75), and forward and backward pressure waveforms (Pf and Pb) in 22 women (22 (1) yr, OCP: n = 12). To assess phasic differences, women were studied during the early follicular (EF; ≤5 days of menstruation onset) and early luteal (EL; 4 (2) days post-ovulation) phases of non-OCP and compared to the placebo pill (PP; ≤5 days of onset) and active pill (AP; ≤5 days of highest-dose AP) phases of OCP. During the lower hormone phases, OCP have significantly higher brachial SBP (119.3 (8.3) vs. 110.2 (8.3) mmHg, P = 0.02) and aortic SBP (104.10 (7.44) vs. 96.80 (6.39) mmHg, P = 0.03) as compared to non-OCP; however, during the higher hormone phases, there are no differences in measures of brachial or aortic BP, arterial stiffness, or indices of BP waveforms between OCP and non-OCP (P≥0.05). In conclusion, exogenous and endogenous hormones have similar influences on BP and arterial stiffness; however, lower levels of exogenous hormones augment both central and peripheral BPs. This article is protected by copyright. All rights reserved.

Moving beyond inclusion: Methodological considerations for the menstrual cycle and menopause in research evaluating effects of dietary nitrate on vascular function

Recent reports have acknowledged the underrepresentation of women in the field of dietary nitrate (NO₃^-) research. Undoubtedly, greater participation from women is warranted to clarify potential sex differences in the responses to dietary NO₃^- interventions. However, careful consideration for the effects of sex hormones - principally 17β-estradiol - on endogenous nitric oxide (NO) synthesis and dietary NO₃^- reductase capacity is necessary for improved interpretation and reproducibility of such investigations. From available literature, we present a narrative review describing how hormonal variations across the menstrual cycle, as well as with menopause, may impact NO biosynthesis catalyzed by NO synthase enzymes and NO₃^- reduction via the enterosalivary pathway. In doing so, we address methodological considerations related to the menstrual cycle and hormonal contraceptive use relevant for the inclusion of premenopausal women along with factors to consider when testing postmenopausal women. Adherence to such methodological practices may explicate the utility of dietary NO₃^- supplementation as a means to improve vascular function among women across the lifespan.

Sex differences in arterial wave reflection and the role of exogenous and endogenous sex hormones: results of the Berlin Aging Study II

BACKGROUND

Arterial stiffness is tightly linked to hypertension. Sex differences in hypertension and arterial stiffness have already been established, yet the role of sex hormones is not precisely defined. This study examined age and sex differences of arterial wave reflection and associations with endogenous and exogenous sex hormones in women.

METHODS

Pulse wave analysis was performed with an oscillometric device in 590 male and 400 female participants of the Berlin Aging Study II. Participants have been recruited from two age-strata, 22-35 years and 60-82 years. Data on exposures and potential confounders, including medication, have been collected at baseline visit.

RESULTS

Aumentation index (AIx) and pulse wave velocity increased with age. Mean AIx was higher in women than in men. Multivariable regression analysis showed a positive association between use of oral contraceptive pills (OCPs) and AIx controlling for confounders (age, BMI, current smoking, central blood pressure), with a significantly higher mean AIx in OCP-users compared with nonusers (mean group difference: 4.41; 95% confidence interval 1.61-7.22). Per quartile decrease in estradiol level AIx increased by 1.72 (95% confidence interval 0.43-3.00). In OCP users endogenous estradiol was largely suppressed.

CONCLUSION

The findings suggest important sex differences in measures of arterial wave reflection, with a higher mean AIx observed in women compared with men. OCPs may promote the development of hypertension by increasing AIx. Suppressed endogenous estradiol levels may be responsible for this increased wave reflection due to increased vasotonus of the small and medium arteries.

Hormonally Active Contraceptives Part I: Risks Acknowledged and Unacknowledged

Hormonal contraceptives have been on the market for over fifty years and, while their formulations have changed, the basic mechanism of action has remained the same. During this time, numerous studies have been performed documenting side effects, some of which appear over time, some within weeks or months, but all can have a serious impact on health and quality of life. An effort was made to perform a series of comprehensive literature surveys to better understand immediate and long-term side effects of these agents. The results of this literature review uncovered a number of potential side effects, some of which are acknowledged and many of which are not noted in the prescribing information for these agents. Among the unacknowledged side effects are: an increased risk of HIV transmission for depot medroxyprogesterone acetate (DMPA), and for combination contraceptives breast cancer, cervical cancer, Crohn's disease, ulcerative colitis, systemic lupus erythematosus, depression, mood disorders and suicides (especially among women twenty-five years of age and younger, in the first six months of use), multiple sclerosis, interstitial cystitis, female sexual dysfunction, osteoporotic bone fractures (especially for progesterone-only contraceptives), and fatty weight gain. Misleading prescribing information regarding cardiovascular and thrombotic risks are also noted. Women seeking birth control have a right to be informed and educated about risk avoidance through the use of effective nonhormonal methods like fertility awareness methods. In one case-that of DMPA-the increased risk of HIV acquisition has been conclusively demonstrated to be both real and unique to this drug. Considering the availability of numerous alternatives, there is no justification for the continued marketing of DMPA to the public.

SUMMARY

We reviewed the effect of hormonal contraceptives on women's health. A number of potential side effects were noted including increased risks of breast cancer, cervical cancer, inflammatory bowel  disease, lupus, multiple sclerosis, cystitis, bone fractures, depression, mood disorders and suicides,  fatty weight gain, and female sexual dysfunction.  With the long-acting injectable contraceptives there is an increased risk of getting HIV.  Misleading prescribing information regarding the risks of heart attacks, strokes and blood clotting problems were also noted. Women seeking birth control have a right to know about how to avoid these risks by using effective hormone-free Fertility Awareness Methods.

Arterial Stiffness and Hemodynamics in Young Women: The Effects of Oral Contraceptive Intake and Physical Habits

Oral contraceptive (OC) intake seems to be associated with increased central hemodynamics and arterial stiffness. Conversely, physical activity (PA) is known to induce benefits on vascular structure and function, suggesting that the negative effects of the OC pill could be counterbalanced by regular PA. The aim of this cross-sectional study was to determine (1) whether OC intake in young women is associated with higher values of hemodynamic parameters and arterial stiffness and (2) whether these negative effects could be counterbalanced by regular physical activity. Forty-nine young healthy women (21.9 years ± 2.1) were recruited and divided into 4 groups, depending on their hormonal status (OC users: OC+ or non-OC users: OC−) and their physical habits (active/inactive). Assessments of central hemodynamics (central blood pressure, Aix75) and pulse wave velocity (PWV) were performed using applanation tonometry. cBP was higher in OC+ vs. OC−, while PWV was similar between these two groups. No interaction between physical activity and hormonal status was observed for any of these variables. Nevertheless, PWV was lower in young active women compared with age-matched inactive women, suggesting that the positive effect of regular physical exercise on the cardiovascular system is already visible in the first years of women’s adulthood, whatever the hormonal status.

IGFBP-1 and IGFBP-2 are associated with a decreased pulse-wave velocity in young, healthy adults

Background and aims

In healthy, young adults we analyzed a panel of cardiovascular disease related proteins in plasma and compared them with the vascular health of the subjects. The aim was to identify proteins with a relationship to the early atherosclerotic process in healthy individuals.

Methods

We employed the proximity extension assay from OLINK proteomics to analyze 92 cardiovascular disease (CVD) related proteins on 833 subjects (men and women, ages 18–26). The women were further divided into an estrogen-using group and non-users. Protein expression was analyzed using principal component analysis (PCA). The following vascular examinations were performed: Pulse-wave velocity (PWV), augmentation index (AIX), carotid-intima media thickness (cIMT).

Results

Three principal components were obtained using PCA to analyze the protein expression. None of the obtained principal components correlated significantly with AIX or cIMT. One of the components, explaining 6% of the total variance of the data, was significantly correlated with PWV. Upon examination of the proteins with the highest factor loadings on this component independently in a multivariable model, adjusting for established CVD risk biomarkers, insulin-like growth factor-binding protein 1 (IGFBP-1) and insulin-like growth factor-binding protein 2 (IGFBP-2) were found to independently, negatively correlate with PWV. Among the established risk factors included in the multivariable model, age was significantly and adversely correlated with all vascular measurements.

Conclusions

In this population of healthy, young adults, groups of CVD related proteins correlate with PWV, but not AIX or cIMT. This group of proteins, of which IGFBP-1 and IGFBP-2 were independently, negatively correlated in a multivariable model with PWV, could have benificial effects on vascular stiffness. The robust association between age and PWV, AIX and cIMT provide insight into the impact of aging on the vasculature, which is detectable even in a population of young, healthy, non-smoking individuals of ages spanning only 8 years.

Supplementary information

The online version contains supplementary material available at 10.1186/s12872-021-01914-w.

Associations of Sex Hormones and Hormonal Status With Arterial Stiffness in a Female Sample From Reproductive Years to Menopause

OBJECTIVE

Loss of sex hormones has been suggested to underlie menopause-associated increment in cardiovascular risk. We investigated associations of sex hormones with arterial stiffness in 19-58-years-old women. We also studied associations of specific hormonal stages, including natural menstrual cycle, cycle with combined oral contraceptives (COC) and menopausal status with or without hormone therapy (HT), with arterial stiffness.

METHODS

This study includes repeated measurements of 65 healthy women representing reproductive (n=16 natural, n=10 COC-users) and menopause (n=5 perimenopausal, n=26 postmenopausal, n=8 HT-users) stages. Arterial stiffness outcomes were aortic pulse wave velocity (PWVao) and augmentation index (AIx%) assessed using Arteriograph-device. Generalized estimating equation models were constructed to investigate associations of each hormone (wide age-range models) or hormonal stage (age-group focused models) with arterial stiffness. PWVao models with cross-sectional approach, were adjusted for age, relative fitness, fat mass and mean arterial pressure, while models with longitudinal approach were adjusted for mean arterial pressure. AIx% models used the same approach for adjustments and were also adjusted for heart rate.

RESULTS

Negative and positive associations with arterial stiffness variables were observed for estradiol and follicle-stimulating hormone, respectively, until adjustment for confounding effect of age. In naturally menstruating women, AIx% was higher at ovulation (B=3.63, p<0.001) compared to the early follicular phase. In COC-users, PWVao was lower during active (B=-0.33 - -0.57, p<0.05) than inactive pills. In menopausal women, HT-users had higher PWVao (B=1.43, p=0.03) than postmenopausal non-HT-users.

CONCLUSIONS

When using wide age-range assessments covering reproductive to menopausal lifespan it is difficult to differentiate age- and hormone-mediated associations, because age-mediated influence on arterial stiffness seemed to overrule potential hormone-mediated influences. However, hormonal status associated differentially with arterial stiffness in age-group focused analyses. Thus, the role of sex hormones cannot be excluded. Further research is warranted to resolve potential hormone-mediated mechanisms affecting arterial elasticity.

Female Sex Hormone Effects on the Vasculature: Considering the Validity of Restricting Study Inclusion to Low-Hormone Phases

Many studies of vascular function limit the testing of premenopausal female participants to periods when female sex hormones, either endogenous or exogenous, are at their lowest concentration. This practice, when not part of the specific research question, may limit data surrounding the predominant physiological state of premenopausal females and pose a threat to external validity. In this Perspective, we briefly review the literature on the effect of female sex hormones on vascular function and discuss when limiting experimental testing to a certain phase of the menstrual cycle (MC) or oral contraceptive (OC) use may be appropriate. The goal of this Perspective is to open a dialog that may enhance data validity and the overall understanding of vascular function in premenopausal females.

Influence of hormonal contraceptives on peripheral vascular function and structure in premenopausal females: a review

Hormonal contraceptives are one of the most widely used prescriptions for premenopausal women worldwide. Although the risk of venous and arterial cardiovascular events (e.g., deep vein thrombosis, arterial clotting) with hormonal contraceptives, specifically oral contraceptive pills, has been established, the literature on early risk indicators, such as peripheral vascular structure and function has yet to be consolidated. The purpose of this review is to summarize literature examining the impact of different hormonal contraceptives on vascular function and structure, including consideration of phasic differences within a contraceptive cycle, and to propose future directions for research. It is evident that hormonal contraceptive use appears to impact both macrovascular and microvascular endothelial function, with phasic differences in some contraceptive types dependent on progestin type, the ratio of ethinyl estradiol-to-progestin, and route of administration. However, hormonal contraceptives do not appear to impact smooth muscle function in the macrovasculature or microvasculature, arterial stiffness, or vascular structure. Underlying mechanisms for observed impacts and areas of future research are discussed. This review provides timely consolidation of research examining hormonal contraceptives and peripheral vascular function and structure and provides guidance on considerations for hormonal contraceptive use in study design.

Importance of Sensitive Vascular Measurements for Evaluating Effects of Lifestyle in Premenopausal Women

Premenopausal women generally have a favorable cardiovascular risk profile, owing to young age and the protective effects of estrogen. Rates of hypertension and more advanced cardiovascular disease (CVD) are low in premenopausal women. A large body of epidemiological evidence has shown that lifestyle behaviors in midlife, i.e., cardiorespiratory fitness, physical activity, and healthy diet, are associated with lower risk of overt CVD and adverse cardiovascular outcomes in the future for men and women. Despite differences in future cardiovascular risk, brachial blood pressures might be similar between premenopausal women with favorable vs. unfavorable levels of lifestyle behaviors in early-to-mid-life. Here we make the case for deeper phenotyping by means of vascular function measurements, such as arterial stiffness, augmentation index, and endothelial function, to identify potential mechanistic pathways linking lifestyle behaviors in early-to-mid-adulthood with lifelong CVD risk in women. We describe considerations for vascular function measurement in premenopausal women and opportunities for investigators to fill in knowledge gaps to further our understanding of CVD risk assessment and CVD progression in premenopausal women.

Pulse wave velocity, augmentation index, and carotid intima-media thickness are each associated with different inflammatory protein signatures in young healthy adults: The lifestyle, biomarkers and atherosclerosis study

BACKGROUND AND AIMS

We aimed to identify plasma protein biomarkers related to inflammation that correlated with physiological measurements of vascular function and structure in healthy individuals.

METHODS

We used the OLINK proteomics panel, which measures 92 inflammatory proteins, in 834 young, healthy non-smokers (ages 18-26). Principal component analysis (PCA) was employed to identify patterns of proteins. The following measurements were used: pulse-wave velocity (PWV), carotid intima-media thickness (cIMT) and augmentation index (AIX). Established cardiovascular risk factors were included in multivariable models.

RESULTS

PCA showed four principal components (PC 1, PC 2, PC 3, PC 4). PC 3, comprising proteins related to hemostasis, was significantly and inversely correlated with PWV. Among the proteins with the highest factor loadings on PC 3, uPA was negatively correlated with PWV in multivariable regression models. AIX was significantly correlated with PC 2, comprising inflammatory cytokines. Among the proteins with the highest factor loadings on PC 2, interleukin-6 was significantly correlated with AIX in the multivariable model. cIMT was significantly correlated with PC 4, comprising proteins related to chemotaxis. Among the proteins with the highest factor loadings on PC 4, fractalkine was significantly correlated with cIMT in the multivariable model.

CONCLUSIONS

In young, healthy individuals, OLINK inflammatory proteins correlated with measures of vascular status. Each of the three measures PWV, AIX, and cIMT, which target different parts of the vasculature, correlated with its own specific protein signature, indicating that different subsets of inflammatory mediators affect different parts of the vasculature and are detectable already in young healthy adults.

Body fat percentage and CRP correlates with a composite score of vascular risk markers in healthy, young adults - The Lifestyle, Biomarkers, and Atherosclerosis (LBA) study

Background

Identification of early signs of atherosclerosis in young adults have the potential to guide early interventions to prevent later cardiovascular disease. We therefore analyzed measures of vascular structure and function and biomarkers of cardiovascular risk in a sample of young healthy adults.

Methods

Pulse-wave velocity (PWV), carotid-intima media thickness (cIMT) and augmentation index (AIX) were measured in 834 healthy non-smokers (ages 18.0–25.9). Emphasis was put on discriminating between individuals having a vascular structure and function associated with a higher or lower risk, and cluster analysis algorithms were employed to assign the subjects into groups based on these vascular measurements. In addition, a vascular status score (VSS) was calculated by summarizing the results according to quintiles of the vascular measurements. The associations between VSS and cardiovascular biomarkers were examined by regression analyses.

Results

The cluster analyses did not yield sufficiently distinct clustering (groups of individuals that could be categorized unequivocally as having either a vascular structure and function associated with a higher or lower CVD risk). VSS proved a better classificatory variable. The associations between VSS and biomarkers of cardiovascular risk were analyzed by univariable and multivariable regressions. Only body fat percentage and C-reactive protein (CRP) were independently associated with VSS.

Conclusions

A VSS calculation, which integrates PWV, cIMT, and AIX measurements is better suited for cardiovascular risk evaluation in young adults than cluster analyses. The independent associations of VSS with body fat percentage and CRP highlight the decisive role of adiposity and systemic inflammation in early atherosclerotic progression and suggests a subordinate role of insulin and lipid metabolism in this age span.

Sex differences in mechanisms of arterial stiffness

Arterial stiffness progressively increases with aging and is an independent predictor of cardiovascular disease (CVD) risk. Evidence supports that there are sex differences in the time course of aging-related arterial stiffness and the associated CVD risk, which increases disproportionately in postmenopausal women. The association between arterial stiffness and mortality is almost twofold higher in women versus men. The differential clinical characteristics of the development of arterial stiffness between men and women indicate the involvement of sex-specific mechanisms. This review summarizes the current literature on sex differences in vascular stiffness induced by aging, obesity, hypertension, and sex-specific risk factors as well as the impact of hormonal status, diet, and exercise on vascular stiffness in males and females. An understanding of the mechanisms driving sex differences in vascular stiffness has the potential to identify novel sex-specific therapies to lessen CVD risk, the leading cause of death in males and females. LINKED ARTICLES: This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

Effect of sex, menstrual cycle phase, and monophasic oral contraceptive pill use on local and central arterial stiffness in young adults

Arterial stiffness is associated with increased cardiovascular disease risk. Previous sex-based investigations of local and central stiffness report inconsistent findings and have not controlled for menstrual cycle phase in women. There is also evidence that sex hormones influence the vasculature, but their impact on arterial stiffness across a natural menstrual (NAT) or oral contraceptive pill (OCP) cycle has been understudied. This study sought to 1) examine potential sex differences in local and central stiffness, 2) compare stiffness profiles between NAT and OCP cycles, and 3) investigate the relationship between duration of OCP use and arterial stiffness. Sex hormone concentrations, β-stiffness index (local stiffness), and carotid-femoral pulse wave velocity [cfPWV (central stiffness)] were assessed in 53 healthy adults (22 ± 3 yr old, 20 men, 15 NAT women, and 18 OCP women). All participants were tested three times: men on the same day and time 1 wk apart, NAT women in menstrual, midfollicular and luteal phases of the menstrual cycle, and OCP women in placebo, early active and late active pill phases. β-Stiffness was higher in men than NAT and OCP women ( P < 0.001), whereas cfPWV was similar between groups ( P = 0.09). β-Stiffness and cfPWV did not differ across or between NAT and OCP cycles ( P > 0.05 for both) and were not associated with duration of OCP use (β-stiffness: r = 0.003, P = 0.99; cfPWV: r = -0.26, P = 0.30). The apparent sex differences in local, but not central, stiffness highlight the importance of assessing both indexes in comparisons between men and women. Furthermore, fluctuating sex hormone levels do not appear to influence β-stiffness or cfPWV. Therefore, these stiffness indexes may need to be assessed during only one cycle phase in women in future investigations. NEW & NOTEWORTHY We observed higher local, but not central, arterial stiffness in men than women. We also demonstrated that there are no differences in arterial stiffness between naturally cycling women and women who use monophasic oral contraceptive pills, and that the duration of oral contraceptive pill use does not influence arterial stiffness.

Carotid femoral pulse wave velocity in type 2 diabetes and hypertension: capturing arterial health effects of step counts

Objective:

Optimal medication use obscures the impact of physical activity on traditional cardiometabolic risk factors. We evaluated the relationship between step counts and carotid-femoral pulse wave velocity (cfPWV), a summative risk indicator, in patients with type 2 diabetes and/or hypertension.

Research design and methods:

Three hundred and sixty-nine participants were recruited (outpatient clinics; Montreal, Quebec; 2011–2015). Physical activity (pedometer/accelerometer), cfPWV (applanation tonometry), and risk factors (A1C, Homeostatic Model Assessment–Insulin Resistance, blood pressure, lipid profiles) were evaluated. Linear regression models were constructed to quantify the relationship of steps/day with cfPWV.

Results:

The study population comprised 191 patients with type 2 diabetes and hypertension, 39 with type 2 diabetes, and 139 with hypertension (mean ± SD: age 59.6 ± 11.2 years; BMI 31.3 ± 4.8 kg/m²; 54.2% women). Blood pressure (125/77 ± 15/9 mmHg), A1C (diabetes: 7.7 ± 1.3%; 61 mmol/mol), and low-density lipoprotein cholesterol (diabetes: 2.19 ± 0.8 mmol/l; without diabetes: 3.13 ± 1.1mmol/l) were close to target. Participants averaged 5125 ± 2722 steps/day. Mean cfPWV was 9.8 ± 2.2 m/s. Steps correlated with cfPWV, but not with other risk factors. A 1000 steps/day increment was associated with a 0.1 m/s cfPWV decrement across adjusted models and in subgroup analysis by diabetes status. In a model adjusted for age, sex, BMI, ethnicity, immigrant status, employment, education, diabetes, hypertension, medication classes, the mean cfPWV decrement was 0.11 m/s (95% confidence interval −0.2, −0.02).

Conclusions:

cfPWV is responsive to step counts in patients who are well controlled on cardioprotective medications. This ability to capture the ‘added value’ of physical activity supports the emerging role of cfPWV in arterial health monitoring.

Influence of sympathetic nerve activity on aortic hemodynamics and pulse wave velocity in women

Central (aortic) blood pressure, arterial stiffness, and sympathetic nerve activity increase with age in women. However, it is unknown if the age-related increase in sympathetic activity influences aortic hemodynamics and carotid-femoral pulse wave velocity (cfPWV), an index of central aortic stiffness. The goal of this study was to determine if aortic hemodynamics and cfPWV are directly influenced by sympathetic nerve activity by measuring aortic hemodynamics, cfPWV, and muscle sympathetic nerve activity (MSNA) in women before and during autonomic ganglionic blockade with trimethaphan camsylate. We studied 12 young premenopausal (23 ± 4 yr) and 12 older postmenopausal (57 ± 3 yr) women. These women did not differ in body mass index or mean arterial pressure (P > 0.05 for both). At baseline, postmenopausal women had higher aortic pulse pressure, augmented pressure, augmentation index adjusted for a heart rate of 75 beats/min, wasted left ventricular pressure energy, and cfPWV than young women (P < 0.05). During ganglionic blockade, postmenopausal women had a greater decrease in these variables in comparison to young women (P < 0.05). Additionally, baseline MSNA was negatively correlated with the reductions in aortic pulse pressure, augmented pressure, and wasted left ventricular pressure energy during ganglionic blockade in postmenopausal women (P < 0.05) but not young women. Baseline MSNA was not correlated with the changes in augmentation index adjusted for a heart rate of 75 beats/min or cfPWV in either group (P > 0.05 for all). Our results suggest that some aortic hemodynamic parameters are influenced by sympathetic activity to a greater extent in older postmenopausal women than in young premenopausal women.NEW & NOTEWORTHY Autonomic ganglionic blockade results in significant decreases in multiple aortic pulse wave characteristics (e.g., augmented pressure) and central pulse wave velocity in older postmenopausal women but not in young premenopausal women. Certain aortic pulse wave parameters are negatively influenced by sympathetic activity to a greater extent in older postmenopausal women.

Feasibility of a clinical trial to assess the effect of dietary calcium v. supplemental calcium on vascular and bone markers in healthy postmenopausal women

Whether supplemental Ca has similar effects to dietary Ca on vascular and bone markers is unknown. The present trial investigated the feasibility of applying dietary and supplemental interventions in a randomised-controlled trial (RCT) aiming to estimate the effect of supplemental Ca as compared with dietary Ca on vascular and bone markers in postmenopausal women. In total, thirteen participants were randomised to a Ca supplement group (CaSuppl) (750 mg Ca from CaCO3+450 mg Ca from food+20 µg vitamin D supplement) or a Ca diet group (CaDiet) (1200 mg Ca from food+10 µg vitamin D supplement). Participants were instructed on Ca consumption targets at baseline. Monthly telephone follow-ups were conducted to assess adherence to interventions (±20 % of target total Ca) using the multiple-pass 24-h recall method and reported pill count. Measurements of arterial stiffness, peripheral blood pressure and body composition were performed at baseline and after 6 and 12 months in all participants who completed the trial (n 9). Blood and serum biomarkers were measured at baseline and at 12 months. Both groups were compliant to trial interventions (±20 % of target total Ca intake; pill count ≥80 %). CaSuppl participants maintained a significantly lower average dietary Ca intake compared with CaDiet participants throughout the trial (453 (sd 187) mg/d v. 1241 (sd 319) mg/d; P<0·001). There were no significant differences in selected vascular outcomes between intervention groups over time. Our pilot trial demonstrated the feasibility of conducting a large-scale RCT to estimate the differential effects of supplemental and dietary Ca on vascular and bone health markers in healthy postmenopausal women.

Comparison of the Effect of Thiazide Diuretics and Other Antihypertensive Drugs on Central Blood Pressure: Cross-Sectional Analysis Among Nondiabetic Patients

Thiazide diuretics (TDs) are a cost-effective first-line therapy for uncomplicated hypertension; however, they are less prescribed than other options. The authors aimed to assess the noninferiority of TDs relative to different classes of antihypertensive medications in relation to central blood pressure. Cross-sectional data from the Quebec CARTaGENE project was used. Nondiabetic hypertensive participants on monotherapy for hypertension were studied. Separate adjusted models were constructed to establish noninferiority of TDs to non-TD antihypertensive medications for central blood pressure measurements. Models included a set of potential confounders. Of the 1194 hypertensive participants, 7.4% were taking TDs. We found that TDs were comparable with non-TD antihypertensive medications for central systolic blood pressure (adjusted regression coefficient, 0.45; 95% confidence interval, -1.61 to 2.50). No differences in other central measurements were noted. The results provide additional support that TDs are at least as effective as other first-line medications for treating uncomplicated hypertension.

Effect of acute high-intensity resistance exercise on optic nerve sheath diameter and ophthalmic artery blood flow pulsatility

Exertional hypertension associated with acute high-intensity resistance exercise (RE) increases both intravascular and intracranial pressure (ICP), maintaining cerebrovascular transmural pressure. Carotid intravascular pressure pulsatility remains elevated after RE. Whether ICP also remains elevated after acute RE in an attempt to maintain the vessel wall transmural pressure is unknown. Optic nerve sheath diameter (ONSD), a valid proxy of ICP, was measured in 20 participants (6 female; 24 ± 4 yr, 24.2 ± 3.9 kg m(-)(2)) at rest (baseline), following a time-control condition, and following RE (5 sets, 5 repetition maximum bench press, 5 sets 10 repetition maximum biceps curls) using ultrasound. Additionally, intracranial hemodynamic pulsatility index (PI) was assessed in the ophthalmic artery (OA) by using Doppler. Aortic pulse wave velocity (PWV) was obtained from synthesized aortic pressure waveforms obtained via a brachial oscillometric cuff and carotid pulse pressure was measured by using applanation tonometry. Aortic PWV (5.2 ± 0.5-6.0 ± 0.7 m s(-1), P < 0.05) and carotid pulse pressure (45 ± 17-59 ± 19 mm Hg, P < 0.05) were significantly elevated post RE compared with baseline. There were no significant changes in ONSD (5.09 ± 0.7-5.09 ± 0.7 mm, P > 0.05) or OA flow PI (1.35 ± 0.2-1.38 ± 0.3, P > 0.05) following acute RE. In conclusion, during recovery from acute high-intensity RE, there are increases in aortic stiffness and extracranial pressure pulsatility in the absence of changes in ICP and flow pulsatility. These findings may have implications for alterations in cerebral transmural pressure and cerebral aneurysmal wall stress following RE.