Inflammation and large arteries: Potential mechanisms for inflammation-induced arterial stiffness

Do Photopletysmographic Parameters of Arterial Stiffness Differ Depending on the Presence of Arterial Hypertension and/or Atherosclerosis?

BACKGROUND

Hypertension and atherosclerotic cardiovascular diseases (ASCVD) increase cardiovascular risk and worsen patients' prognoses. One early predictor of increased risk is a change in arterial stiffness. This study aimed to evaluate arterial stiffness parameters using the non-invasive photoplethysmography (PPG) method in Polish patients with arterial hypertension (AH) and/or atherosclerosis (AS).

METHODS

The study group consisted of 333 patients (Caucasians, both sexes, aged 30-85 years old). Patients were analyzed in four groups depending on AH and AS (Group I: patients without AH or AS, Group II: AH patients, Group III: AS patients, and Group IV: AH/AS patients) and, in addition, according to sex and history of SARS-CoV-2 infection. Arterial stiffness parameters, i.e., reflection index (RI), peak-to-peak time (PPT), and stiffness index (SI) were automatically calculated with PPG based on the analysis of the pulse wave contour.

RESULTS

Mean values of RI and SI were higher in men than women (p < 0.001 each). Diastolic blood pressure (DBP) also differed between sexes (p = 0.010). Mean SI values differed between the study groups (p = 0.038) with the highest SI found in AS/AH patients and the lowest-in patients without AH or AS. The mean SI values were significantly lower in women compared to men in both Group I and Group II (p = 0.006 and p < 0.001, respectively). The mean values of RI were also greater in men than in women in Group I and Group II (p < 0.001 for each group). Regarding COVID-19 history, only HR values differed between patients with and without COVID-19 in AH patients (p = 0.012). In AH patients, men had higher values of RI and SI compared to women (p < 0.001 and p < 0.001). On the other hand, AS women with COVID-19 had significantly greater mean values of SI (9.66 m/s ± 1.61) than men with COVID-19 (7.98 m/s ± 1.09) (p = 0.045).

CONCLUSIONS

The present study confirmed that sex had a significant impact on arterial stiffness parameters. Both AH and AS affected arterial stiffness. Heart rate was greater in hypertensive patients after COVID-19 compared to hypertensive patients without COVID-19.

Arterial Stiffness as a Cardiovascular Risk Factor for the Development of Preeclampsia and Pharmacopreventive Options

Arterial stiffness (AS) describes the rigidity of the arterial walls. Epidemiological studies have shown that increased AS is an independent predictive marker of cardiovascular (CV) morbidity and mortality in both pregnant and non-pregnant women. Preeclampsia (PE), a form of pregnancy-induced hypertension, affects approximately 5% of pregnancies worldwide. Preeclamptic women have a higher risk of CV disease (CVD), mainly because PE damages the heart's ability to relax between contractions. Different pharmacological approaches for the prevention of PE have been tested in clinical trials (e.g. aspirin, enoxaparin, metformin, pravastatin, and sildenafil citrate). In current clinical practice, only low-dose aspirin is used for PE pharmacoprevention. However, low-dose aspirin does not prevent term PE, which is the most common form of PE. Compromised vascular integrity precedes the onset of PE and therefore, AS assessment may constitute a promising predictive marker of PE. Several non-invasive techniques have been developed to assess AS. Compared with normotensive pregnancies, both carotid-femoral pulse wave velocity (cfPWV) and augmentation index (AIx) are increased in PE. In view of simplicity, reliability, and reproducibility, there is an interest in oscillometric AS measurements in pregnancies complicated by PE.

The Association between Inflammation and Pulse Wave Velocity in Dyslipidemia: An Evidence-Based Review

Dyslipidemia is associated with increased arterial stiffness (AS) which may lead to hypertension. Among the methods to assess AS are carotid-femoral and brachial-ankle pulse wave velocity. Dyslipidemia is also known to trigger inflammation. C-reactive protein (CRP) is one of the commonest inflammatory markers measured in the clinical setting. However, the association between inflammation and pulse wave velocity (PWV) in people with dyslipidemia is less studied. Therefore, this review investigated the association between inflammation (as measured by CRP) and PWV in dyslipidemia patients. The search of the literature was conducted via PubMed and Scopus database. The keywords used were "aortic stiffness" OR "arterial stiffness" OR "pulse wave velocity" OR "vascular stiffness" OR "carotid femoral pulse wave velocity" OR "pulse wave analysis" AND "inflammation" OR "c reactive protein" OR "c-reactive protein" OR "high sensitivity c reactive protein" AND "dyslipidemia" OR "hyperlipidemia" OR "hypercholesterolemia" OR "hyperlipoproteinemia" OR "hypertriglyceridemia". The following criteria were used: (1) only full-length original articles published in English language, (2) articles that reported the association between arterial stiffness measured as carotid-femoral PWV (cfPWV) or brachial-ankle PWV (baPWV) and CRP or high-sensitivity CRP, and (3) study involving human subjects. The search identified 957 articles published between 1980 and February 2020. Only eight articles fulfilled the inclusion criteria and were used for data extraction. Five of the studies were cross-sectional studies while another three studies were interventional studies. Seven out of eight papers found a significant positive association between AS and CRP, and the correlation ranged from mild to moderate association (Pearson r = 0.33 to r = 0.624). In conclusion, inflammation is associated with increased PWV in patients with dyslipidemia. This supports the involvement of inflammation in the development of AS in dyslipidemia.

Arterial Stiffness Parameters Correlate with Estimated Cardiovascular Risk in Humans: A Clinical Study

Arterial stiffness is said to be a novel predictor of cardiovascular events. This study investigated the correlation between arterial stiffness parameters and the estimated cardiovascular disease risk (RISK) in a Polish cohort of patients divided by age, sex, and body-mass index (BMI). The cross-sectional study enrolled 295 patients who met the inclusion criteria. Subjects were divided into three age groups, four weight groups, and by gender. The stiffness of the vessels was assessed by the measurement of the stiffness index (SI) and reflection index (RI). An individual 10-year RISK was calculated for each patient using the Heart Risk Calculator algorithm by the American Heart Association. A correlation between the SI and estimated RISK was observed (rS 0.42, p < 0.05). The strongest relationship was presented for women, the age group 40-54, and individuals with normal weight. The correlation between RI and calculated RISK was observed (rS 0.19, p < 0.05), the highest correlation was noticed for people aged 40-54 and obese. In conclusion, both SI and RI are correlated with estimated cardiovascular risk, however SI seems to be more useful than RI to predict the individual risk of future cardiovascular events. Both of these can be measured using non-invasive techniques, which demonstrates their potential utility in clinical practice.

The Role of Renin-Angiotensin-Aldosterone System and Its New Components in Arterial Stiffness and Vascular Aging

Many cardiovascular diseases present renin-angiotensin-aldosterone system (RAAS) hyperactivity as an important pathophysiological mechanism to be target in the therapeutic approaches. Moreover, arterial stiffness is currently considered as a new independent risk factor for cardiovascular disease in different clinical conditions, including hypertension and chronic kidney disease. In fact, excessive stimulation of angiotensin type 1 (AT1) receptors, as well as mineralocorticoid receptors, results in cellular growth, oxidative stress and vascular inflammation, which may lead to arterial stiffness and accelerate the process of vascular aging. In the last decades, a vasoprotective axis of the RAAS has been discovered, and now it is well established that new components with antioxidant and anti-inflammatory properties play important roles promoting vasodilation, natriuresis and reducing collagen deposition, thus attenuating arterial stiffness and improving endothelial function. In this review, we will focus on these pathophysiological mechanisms and the relevance of RAAS inhibition by different strategies to increase arterial compliance and to decelerate vascular aging.

Carotid Intima-Media Thickness Is Associated with Increased Androgens in Adolescents and Young Adults with Classical Congenital Adrenal Hyperplasia

BACKGROUND/AIMS

Youth with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency develop cardiovascular disease (CVD) risk factors of obesity and hypertension. Carotid intima-media thickness (CIMT), a marker of CVD risk, is increased in CAH young adults. We examined CIMT and its relationship with androgens and obesity in adolescents/young adults with CAH.

METHODS

Twenty CAH subjects (age 16 ± 3.3 years, 50% female) and 20 matched controls were studied cross-sectionally. Eight additional obese patients with CAH were included in within-group comparisons. CIMT by high-resolution ultrasound, androgens, anthropometry, bone age (BA), and metabolic/inflammatory markers were assessed.

RESULTS

Within the CAH group, CIMT correlated with 17-hydroxyprogesterone (r = 0.48, p < 0.05) and androstenedione (r = 0.46, p < 0.05), and was greater in obese subjects. CIMT was greater in CAH males than females, but similar among CAH females with advanced BA, CAH males with normal BA, and control males. There was no difference in CIMT between CAH and controls, although high-density lipoprotein was inversely correlated with CIMT in both groups.

CONCLUSION

CIMT is associated with increased androgens in CAH adolescents and young adults, with loss of sex differences in CAH females with excess androgen exposure. Our findings highlight the importance of hormonal control for CVD prevention in CAH.

Cardiovascular risk factors and events in women with androgen excess

Androgen excess (AE) was approximated to be present in 7% of the adult population of women. Polycystic ovary syndrome (PCOS) is the most prevalent among them, followed by idiopathic hirsutism (IH), congenital adrenal hyperplasia (CAH), hyperandrogenic insulin-resistant acanthosis nigricans (HAIRAN) syndrome, and androgen-secreting neoplasms (ASNs). Increased cardiovascular risk was implicated in women with AE. Serum testosterone independently increases risk for cardiovascular disease (CVD), and correlates even with indices of subclinical atherosclerosis in various populations of postmenopausal women. Hyperandrogenism in PCOS is closely related to the aggravation of abdominal obesity, and together with insulin resistance forming the metabolic core for the development of CVD. However, phenotypic variability of PCOS generates significant influence on the cardiometabolic risks. Numerous risk factors in PCOS lead to 5-7 times higher risk for CVD and over 2-fold higher risk for coronary heart disease and stroke. However, issue on the cardiometabolic risk in postmenopausal women with hyperandrogenic history is still challenging. There is a significant overlapping in the CVD characteristics of women with PCOS and variants of CAH. Relevant clinical data on the prevalence and cardiometabolic risk and events in women with IH, HAIRAN syndrome or ASNs are scarce. The effects of various oral contraceptives (OCs) and antiandrogenic compounds on metabolic profile are varying, and could be related to the selected populations and different therapy regiments mainly conducted in women with PCOS. It is assumed relation of OCs containing antiandrogenic progestins to the increased risk of cardiovascular and thromboembolic events.

"Inflammation and arterial stiffness in humans"

Arterial stiffness is an established marker of cardiovascular morbidity and mortality and a potential therapeutic target. While hypertension and aging are established factors contributing to arterial stiffness, the role of inflammation in stiffening of the arteries is less well understood. We summarize existing literature regarding inflammation and arterial stiffness, including a discussion of the potential mechanisms by which inflammation may lead to arterial stiffening and studies assessing: (1) The association between subclinical inflammation and arterial stiffness in the general population; (2) The presence of increased arterial stiffness in primary inflammatory diseases; (3) The effect of anti-inflammatory therapy on arterial stiffness in primary inflammatory disease including the effect of statins; (4) Experimental evidence of immunization-induced arterial stiffening in normal adults. We discuss potential opportunities to assess the impact of anti-inflammatory interventions on arterial stiffness in subjects without primary inflammatory conditions. We also review the effect of inflammation on wave reflections.

Arterial stiffness is increased in asymptomatic nondiabetic postmenopausal women with a polycystic ovary syndrome phenotype

OBJECTIVE

The metabolic dysfunction accompanying the polycystic ovary syndrome (PCOS) may increase the risk of hypertension and cardiovascular disease (CVD). Although menopause per se may be an additional risk factor of CVD, the association between PCOS in postmenopausal women and cardiovascular risk has not been adequately investigated. We aimed to evaluate the effect of PCOS on markers of subclinical atherosclerosis in nondiabetic postmenopausal women.

METHODS

This cross-sectional study included 286 postmenopausal women with intact ovaries. PCOS phenotype was defined if three of the following were present: insulin resistance, current hyperandrogenism or history of clinical androgen excess, history of infertility, central obesity and history of irregular menses. Traditional CVD risk factors, as well as indices of arterial structure (intima-media thickness, atheromatous plaques presence) and function [flow-mediated dilation, pulse wave velocity (PWV), augmentation index] were compared between women with a PCOS phenotype and the rest of the sample, who served as controls.

RESULTS

Women with the PCOS phenotype (N=43) had higher SBP and triglycerides and lower high-density lipoprotein (HDL)-cholesterol than controls. Mean values of PWV differed significantly between PCOS cases and controls (9.46±1.74 vs. 8.60±1.51 m/s, P=0.001, univariate). Multivariate regression analysis showed that the PCOS phenotype, age and SBP were the only independent predictors of PWV.

CONCLUSION

Arterial stiffness is increased in asymptomatic, nondiabetic women with a putative PCOS phenotype, independently of age, BMI or blood pressure. This might present one mechanism through which PCOS increases the risk of CVD and hypertension later in life.