Relation of endothelial function to cardiovascular risk in women with sedentary occupations and without known cardiovascular disease

Association between Life's Essential 8 and rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) exhibits a robust association with cardiovascular disease. Our study aims to elucidate the correlation between RA prevalence and Life's Essential 8 (LE8), a recently updated measure of cardiovascular health (CVH).

METHODS AND RESULTS

We conducted a population-based cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES) spanning from 2007 to 2018. Utilizing multivariable logistic and restricted cubic spline models, we explored the relationship between LE8 and RA. Our analysis included 17,263 participants. We found that higher LE8 scores were closely associated with reduced odds of RA (odds ratio for each 10-point increase, 0.91 (95% CI, 0.75-0.87)). Furthermore, we observed a nonlinear association between LE8 and RA after adjusting for potential confounders. Specifically, higher scores for sleep health, nicotine exposure, body mass index, and blood pressure within the LE8 components were significantly correlated with a lower risk of RA. Additionally, the inverse relationship between LE8 scores and RA was notably stronger among young and female individuals.

CONCLUSION

Our findings suggest a negative correlation between LE8 and RA prevalence, indicating that adherence to the lifestyle defined by LE8 may confer protective effects against RA.

Gender differences in vascular aging and in coronary artery disease pathophysiology

Women have a clinical advantage over men in relation to atherosclerotic cardiovascular disease (CVD) (morbidity and mortality). This advantage disappears once women become older, and in their seventh decade, the risk to develop CVD equals men at that age. There have been several theories about this gender difference that were related to hormones, and the different morphology and physiology that characterize the cardiovascular system in women. In this review, the different mechanisms will be reviewed and discussed.

Is endothelial function impaired among women with placenta-mediated fetal growth restriction? Evidence from a prospective cohort study using peripheral artery tonometry

INTRODUCTION

Women with pregnancies complicated by IUGR are at increased risk for future cardiovascular disease. Nevertheless, it is unknown whether endothelial function of women with pregnancies complicated by IUGR is already impaired during pregnancy. Hence, we evaluated maternal endothelial function in pregnancies complicated by IUGR due to placental dysfunction.

METHODS

Prospective cohort study assessing systemic endothelial function of women with singleton pregnancies and estimated fetal weight (EFW) below 10th percentile and abnormal umbilical artery flow (n = 15). Control group included women with singleton pregnancies and normal EFW (n = 22). Endothelial function was assessed using EndoPAT™ device which evaluates the change in peripheral vascular tone in reaction to temporal ischemia, a process called reactive hyperemia. The ratio of the readings before and after ischemia is used to assess endothelial function and called reactive hyperemia index (RHI). Low RHI values indicate endothelial dysfunction.

RESULTS

The median gestational age at endoPAT examination was comparable between the IUGR and control groups (32; IQR 31,33; p = 0.18). The median RHI was significantly lower in the IUGR group compared to the control group (1.3 vs 1.5, p = 0.02). Median gestational age at delivery and mean neonatal birth weight were lower in the IUGR group compared to the control group (36.7 (35.6,37.2) vs 37.7 (35.3, 39.3), p = 0.04 and 1647 ± 414 g vs 2785 ± 587 g, p < 0.001).

DISCUSSION-

Pregnant women with IUGR due to placental dysfunction are characterized by impaired systemic endothelial function.

Effects of Preoperative WBC Count on Post-CABG Surgery Clinical Outcome

OBJECTIVE

White blood cells (WBCs) play a major role in inflammation, with effects on the vascular wall, the microvascular blood flow, and endothelial cells and endothelial function. Previous studies have shown that a high WBC count may increase the risk of cardiovascular complication rate and mortality after coronary artery bypass graft (CABG) surgery. The aim of the study was to evaluate the association between preoperative WBC count and the post-CABG clinical outcome.

METHODS

A retrospective study that was based on 239 patients who underwent CABG surgery in our medical center. Statistical analysis estimated the effect of WBC count in postoperative clinical outcomes, including atrial fibrillation, length of stay, readmission rate, and death.

RESULTS

The preoperative WBC count was associated with longer hospitalization length (B = 0.392, P < 0.01). A preoperative WBC count >8150/μL predicted a longer stay (Z = 2.090, P = 0.03). A low lymphocyte count was associated with atrial fibrillation (B = -0.543, P = 0.03). Female patients were older (Z = 2.920, P < 0.01), had impaired renal function (Z = -3.340, P < 0.01), and had a higher rate of postoperative atrial fibrillation (df 2 = 3.780, P = 0.05) and readmission (df 2 = 5.320, P = 0.02).

CONCLUSIONS

Preoperative WBC count may have an effect on the postoperative clinical outcome in patients undergoing CABG. Surgeons should pay more attention to patients' WBC count and sex and plan surgery and postoperative management accordingly.

Gender differences in cardiovascular risk of patients with rheumatoid arthritis

BACKGROUND

Rheumatoid Arthritis (RA) is a chronic inflammatory disease, affecting women more than men, with a more aggressive course in women.

DESIGN

A prospective study that recruited 58 patients (46 women aged 56 ± 12 years) with active long-standing RA disease (>12 months). Our goals were to measure their endothelial function, part of the cardiovascular risk assessment.

METHODS

The Brachial Artery method measured endothelial function (the flow mediated percent change [FMD percentage] of the brachial artery diameter). A senior Rheumatologist clinically evaluated all subjects. Mann Whitney rank sum test estimated gender differences among the RA patients.

RESULTS

Median FMD% change for men was -6.07%, while median FMD% change for women was 0.44% (Z = 2.38, P = 0.01). Baseline Brachial artery diameter was larger in men (Z = 2.52, P = 0.01); however, tender joints count and BMI were greater in women (Z=-2.24, P = 0.01; Z=-3.99, P = 0.001), respectively.

CONCLUSIONS

Women with RA have significantly better endothelial function than men with RA. It means that even though RA is 3-fold more prevalent in women, women are more protected from atherosclerotic coronary artery disease and cardiac events.

Exercise Improves Vascular Function, but does this Translate to the Brain?

The number of adults with Alzheimer’s disease (AD) or related dementia is expected to increase exponentially. Interventions aimed to reduce the risk and progression of AD and dementia are critical to the prevention and treatment of this devastating disease. Aging and cardiovascular disease risk factors are associated with reduced vascular function, which can have important clinical implications, including brain health. The age-associated increase in blood pressure and impairment in vascular function may be attenuated or even reversed through lifestyle behaviors. Greater volumes of habitual exercise and higher cardiorespiratory fitness are associated with beneficial effects on vascular health and cognition. Exercise and cardiorespiratory fitness may be most important during midlife, as physical activity and cardiorespiratory fitness during the middle-aged years are associated with future cognitive function. The extent to which exercise, and more specifically aerobic exercise, influences the cerebral circulation is not well established. In this review, we present our working hypothesis showing how cerebrovascular function may be a mediating factor underlying the association between exercise and cognition, as well as discuss recent studies evaluating the effect of exercise interventions on the cerebral circulation.

The association of cardiorespiratory fitness with endothelial or smooth muscle vasodilator function

BACKGROUND

Maximal oxygen consumption (VO2max) is strongly associated with peripheral vasodilator function as determined by exercise-induced vasodilation. However, findings with regard to its relation with non-exercise-stimulated vasodilation are unclear. The purpose of this study was to systematically review published literature reporting associations between VO2max and endothelial function (EF) or smooth muscle function (SMF).

DESIGN AND METHODS

We conducted a systematic search of MEDLINE, Cochrane and Web of Science, since their inceptions until April 2014 for articles reporting the association between (a) VO2max during incremental exercise and (b) endothelium-dependent or -independent vasodilator function, by means of correlation and/or regression analysis.

RESULTS

Fifty-six articles exploring 88 associations between VO2max and vascular EF or SMF were included, involving a total of 4159 healthy and diseased subjects. VO2max was determined by incremental cycle ergometer (64%), treadmill (33%) and cycle ergometer/treadmill (3%) exercise. Vasodilator function variables were assessed in the upper limb (86%), lower limb (10%) and both upper and lower limbs (3%). Most of the evaluated bivariate associations involved EF stimuli such as flow-mediated dilation (FMD) (n = 29) or blood flow occlusion (BFO) (n = 18). VO2max was significantly associated with FMD and BFO in 59% and 67% of bivariate associations and 46% and 33% of age-independent associations, respectively. Explored bivariate associations regarding SMF involved sodium nitroprusside (SNP) iontophoresis (n = 7) and nitrate-mediated dilation (NMD) (n = 4). VO2max was associated with NMD in 50% of bivariate associations and 50% of age-independent associations. VO2max was not associated with SNP iontophoresis. Results were similar for associations including only healthy subjects.

CONCLUSIONS

The association between VO2max and EF or SMF is moderately frequent and independent of health status, despite very few studies having assessed vasodilator function in the lower limb.

The effect of exercise intensity on endothelial function in physically inactive lean and obese adults

Purpose

To examine the effects of exercise intensity on acute changes in endothelial function in lean and obese adults.

Methods

Sixteen lean (BMI <25, age 23±3 yr) and 10 obese (BMI >30, age 26±6 yr) physically inactive adults were studied during 3 randomized admissions [control (C, no exercise), moderate-intensity exercise (M, @ lactate threshold (LT)) and high-intensity exercise (H, midway between LT and VO₂peak) (30 min)]. Endothelial function was assessed by flow-mediated dilation (FMD) at baseline and 1, 2, and 4 h post-exercise.

Results

RM ANCOVA revealed significant main effects for group, time, and group x condition interaction (p<0.05). A diurnal increase in FMD was observed in lean but not obese subjects. Lean subjects exhibited greater increases in FMD than obese subjects (p = 0.0005). In the obese group a trend was observed for increases in FMD at 2- and 4-hr after M (p = 0.08). For lean subjects, FMD was significantly elevated at all time points after H. The increase in FMD after H in lean subjects (3.2±0.5%) was greater than after both C (1.7±0.4%, p = 0.015) and M (1.4±0.4%, p = 0.002). FMD responses of lean and obese subjects significantly differed after C and H, but not after M.

Conclusion

In lean young adults, high-intensity exercise acutely enhances endothelial function, while moderate-intensity exercise has no significant effect above that seen in the absence of exercise. The FMD response of obese adults is blunted compared to lean adults. Diurnal variation should be considered when examining the effects of acute exercise on FMD.

Impaired retinal vasodilator responses in prediabetes and type 2 diabetes

PURPOSE

In diabetes, endothelial dysfunction and subsequent structural damage to blood vessels can lead to heart attacks, retinopathy and strokes. However, it is unclear whether prediabetic subjects exhibit microvascular dysfunction indicating early stages of arteriosclerosis and vascular risk. The purpose of this study was to examine whether retinal reactivity may be impaired early in the hyperglycaemic continuum and may be associated with markers of inflammation.

METHODS

Individuals with prediabetes (n = 22), type 2 diabetes (n = 25) and healthy age and body composition matched controls (n = 19) were studied. We used the Dynamic Vessel Analyzer to assess retinal vasoreactivity (percentage change in vessel diameter) during a flickering light stimulation. Fasting highly sensitive c-reactive protein (hs-CRP), a marker of inflammation, was measured in blood plasma.

RESULTS

Prediabetic and diabetic individuals had attenuated peak vasodilator and relative amplitude changes in retinal vein diameters to the flickering light stimulus compared with healthy controls (peak dilation: prediabetic subjects 3.3 ± 1.8%, diabetic subjects 3.3 ± 2.1% and controls 5.6 ± 2.6%, p = 0.001; relative amplitude: prediabetic subjects 4.3 ± 2.2%, diabetic subjects 5.0 ± 2.6% and control subjects 7.2 ± 3.2%, p = 0.003). Similar findings were observed in retinal arteries. Levels of hs-CRP were not associated with either retinal vessel response parameters.

CONCLUSION

Retinal reactivity was impaired in prediabetic and type 2 diabetic individuals in parallel with reduced insulin sensitivity but not associated with levels of hs-CRP. Retinal vasoreactivity measurements may be a sensitive tool to assess early vascular risk.

Oxidative stress and endothelial dysfunction: therapeutic implications

In a previous issue of Annals of Medicine, we presented evidence in support of the concept that an abnormally increased production of reactive oxygen species plays a central role in the genesis and progression of cardiovascular disease. While a number of preclinical lines of evidence support this concept, and despite the results of many studies suggesting a beneficial impact of antioxidant drugs on endothelial function, large clinical trials have failed to demonstrate a benefit of antioxidants on cardiovascular outcomes. Studies exploring the possibility that classical antioxidants such as vitamin C, vitamin E, selenium, or folic acid may improve the prognosis of patients with cardiac disease have substantially reported neutral-and occasionally negative-results. In contrast, medications such as statins, ACE inhibitors, certain β-blockers, or angiotensin I receptor blockers, which possess indirect 'ancillary' antioxidant properties, have been associated with beneficial effects in both preclinical studies and large clinical trials. The reasons for the failure of the 'direct' approach to antioxidant therapy, and for the success of the therapy with these drugs, are discussed in the present review.

Noninvasive vascular function measurement in the community: cross-sectional relations and comparison of methods

BACKGROUND

Several methods of noninvasive vascular function testing have been suggested for cardiovascular risk screening in the community. A direct comparison of the different methods and their relation to classical cardiovascular risk factors in a large cohort is missing.

METHODS AND RESULTS

In 5000 individuals (mean age, 55.5 ± 10.9 years; age range, 35 to 74 years; women, 49.2%) of the population-based Gutenberg Heart Study, we performed simultaneous measurement of flow-mediated dilation (FMD) and peripheral arterial volume pulse determined by infrared photo (reflection index) and pneumatic plethysmography (PAT) and explored their associations. All function measures were recorded at baseline and after reactive hyperemia induced by 5-minute brachial artery occlusion. Correlations between different measures of vascular function were statistically significant but moderate. The strongest association for hyperemic response variables was observed for PAT ratio and FMD (Spearman r = 0.17; age- and sex-adjusted partial correlation, 0.068). Classical risk factors explained between 15.8% (baseline reflection index) and 58.4% (brachial artery diameter) of the baseline values but only accounted for 3.2% (reflection index), 15.4% (FMD), and 13.9% (PAT ratio) of the variability of reflective hyperemic response. Regression models varied in their relations to classical risk factors for the individual vascular function measures. Consistently associated with different vascular function methods were age, sex, body mass index, and indicators of hypertension. Peripheral tonometry also showed a relation to fasting glucose concentrations.

CONCLUSIONS

Noninvasive measures of conduit artery and peripheral arterial function are modestly correlated, differ in their relation to classical cardiovascular risk factors, and may thus reflect different pathologies.

An essential role for diet in exercise-mediated protection against dyslipidemia, inflammation and atherosclerosis in ApoE⁻/⁻ mice

BACKGROUND

Diet and exercise promote cardiovascular health but their relative contributions to atherosclerosis are not fully known. The transition from a sedentary to active lifestyle requires increased caloric intake to achieve energy balance. Using atherosclerosis-prone ApoE-null mice we sought to determine whether the benefits of exercise for arterial disease are dependent on the food source of the additional calories.

METHODS AND RESULTS

Mice were fed a high-fat diet (HF) for 4.5 months to initiate atherosclerosis after which time half were continued on HF while the other half were switched to a high protein/fish oil diet (HP). Half of each group underwent voluntary running. Food intake, running distance, body weight, lipids, inflammation markers, and atherosclerotic plaque were quantified. Two-way ANOVA tests were used to assess differences and interactions between groups. Exercised mice ran approximately 6-km per day with no difference between groups. Both groups increased food intake during exercise and there was a significant main effect of exercise F((1,44) = 9.86, p<0.01) without interaction. Diet or exercise produced significant independent effects on body weight (diet: F(1,52) = 6.85, p = 0.012; exercise: F(1,52) = 9.52, p<0.01) with no significant interaction. The combination of HP diet and exercise produced a greater decrease in total cholesterol (F(1, 46) = 7.9, p<0.01) and LDL (F(1, 46) = 7.33, p<0.01) with a large effect on the size of the interaction. HP diet and exercise independently reduced TGL and VLDL (p<0.05 and 0.001 respectively). Interleukin 6 and C-reactive protein were highest in the HF-sedentary group and were significantly reduced by exercise only in this group. Plaque accumulation in the aortic arch, a marker of cardiovascular events was reduced by the HP diet and the effect was significantly potentiated by exercise only in this group resulting in significant plaque regression (F1, 49 = 4.77, p<0.05).

CONCLUSION

In this model exercise is beneficial to combat dyslipidemia and protect from atherosclerosis only when combined with diet.

Endothelium-dependent vasodilation is associated with exercise capacity in smokers and non-smokers

Smoking is an established cardiovascular risk factor that impairs endothelial function and reduces exercise capacity. Peripheral vascular endothelial function correlates with exercise capacity, but whether this association prevails in smokers is unknown. The purpose of this investigation was to examine the association between endothelial function and exercise capacity in chronic smokers and non-smoking controls. Brachial artery flow-mediated dilation (FMD, endothelium-dependent) following 5 minutes of upper arm occlusion was compared in 26 smokers (age 58 +/- 2 years; 15 female; BMI (body mass index) = 28 +/- 1) and 39 non-smokers (age 58 +/- 2 years; 24 female; BMI = 28 +/- 1) using ultrasound. Exercise treadmill time (ETT) was recorded from a standard Bruce protocol during symptom limited stress testing. There was found to be a significant positive association between FMD and ETT in smokers (r = 0.60, p < 0.05) and non-smokers (r = 0.28, p < 0.05). FMD was significantly lower in smokers versus non-smokers (8.9 +/- 0.9 vs 12.6 +/- 0.7%, p < 0.05). ETT was significantly lower in smokers (425 +/- 35 seconds) versus non-smokers (522 +/- 25 seconds, p < 0.05). After adjusting for FMD, there were no longer group differences in ETT. When patients were matched according to FMD, there were no differences in ETT between smokers and non-smokers. In conclusion, peripheral endothelial dysfunction is a correlate of low exercise capacity in smokers and non-smokers alike. Future research is needed to examine if improving endothelial function will lead to concomitant increases in exercise capacity in chronic smokers.

Coronary artery disease: Are men and women created equal?

BACKGROUND

Ischemic heart disease in women is a difficult issue in cardiovascular medicine, mainly because of our lack of understanding of the early-stage mechanisms and symptoms. A better and earlier understanding of the pathophysiology of coronary artery disease (CAD) in women will enable us to detect ischemic heart disease earlier and prevent adverse clinical outcomes.

OBJECTIVES

The aims of this article were to describe the phenomenon of ischemic heart disease in women, increase awareness of the difference between men and women in relation to ischemic heart disease, improve our understanding of the mechanisms that cause this difference, and identify new approaches for better and earlier detection and treatment of CAD in women.

METHODS

We conducted a search of the PubMed database for double-blind studies on the mechanistic pathways of CAD in women published in English within the past 10 years and epidemiologic studies published since 1970. Search terms included women and coronary artery disease and ischemic heart disease in women.

RESULTS

The literature search revealed 30 peer-reviewed articles pertaining to this issue. The incidence of CAD was markedly lower in women <60 years of age than in older women. After 60 years of age, the rate of CAD increased and reached the rate seen among men by the 8th decade of life. The gender difference in atherosclerosis in the coronary tree was particularly large in patients <55 years of age and remained large at older ages. The gender difference in the coronary bed was strikingly larger than in other vascular beds. Intensive risk-factor modification had a similar effect on plaque progression in both men and women. Coronary endothelial dysfunction appeared to be related to cardiovascular morbidity and mortality in women as well as in men, and because endothelial dysfunction could be modified, it appeared that the prognosis could be improved by appropriate management. A strong association was found between body mass index (BMI) and metabolic status, but only the metabolic syndrome was associated with CAD. Physical activity was independently associated with fewer risk factors, less CAD, and fewer adverse events in women; however, obesity was not associated with these outcomes.

CONCLUSIONS

Results of the identified studies suggest that reduction of risk factors is a common approach to fighting heart disease in both sexes. It appears that for women, weight and BMI are not as important as previously thought, but physical exercise and fitness are very important and can change risk factors and clinical outcomes more than any other known intervention. Data suggest that global inflammation may play an important role in women and may predict cardiovascular outcome in women much better than the traditional risk factors that have been used and proved for men.

Relationships between Obesity, Cardiorespiratory Fitness, and Cardiovascular Function

Background. Obesity and low cardiorespiratory fitness (CRF) have been shown to independently increase the risk of CVD mortality. The aim of this study was to investigate the relationship between CRF, body fatness and markers of arterial function. Method and Results. Obese (9 male, 18 female; BMI 35.3 ± 0.9 kg·m(-2)) and lean (8 male, 18 female; BMI 22.5 ± 0.3 kg·m(-2)) volunteers were assessed for body composition (DXA), cardiorespiratory fitness (predicted V˙O2max), blood pressure (BP), endothelial vasodilatator function (FMD), and arterial compliance (AC) (via radial artery tonometry). The obese group had more whole body fat and abdominal fat (43.5 ± 1.2% versus 27.2 ± 1.6%; P < .001 and 48.6 ± 0.9% versus 28.9 ± 1.8%; P < .001, resp.), and lower FMD (3.2 ± 0.4% versus 5.7 ± 0.7%; P < .01) than the lean subjects, but there was no difference in AC. AC in large arteries was positively associated with CRF (R = 0.5; P < .01) but not with fatness. Conclusion. These results indicate distinct influences of obesity and CRF on blood vessel health. FMD was impaired with obesity, which may contribute to arterial and metabolic dysfunction. Low CRF was associated with reduced elasticity in large arteries, which could result in augmentation of aortic afterload.

Chronic intermittent fasting improves the survival following large myocardial ischemia by activation of BDNF/VEGF/PI3K signaling pathway

Chronic heart failure (CHF) is the major cause of death in the developed countries. Calorie restriction is known to improve the recovery in these patients; however, the exact mechanism behind this protective effect is unknown. Here we demonstrate the activation of cell survival PI3kinase/Akt and VEGF pathway as the mechanism behind the protection induced by intermittent fasting in a rat model of established chronic myocardial ischemia (MI). Chronic MI was induced in rats by occlusion of the left coronary artery. Two weeks later, the rats were randomly assigned to a normal feeding group (MI-NF) and an alternate-day feeding group (MI-IF). After 6 weeks of observation, we evaluated the effect of intermittent fasting on cellular and ventricular remodeling and long-term survival after CHF. Compared with the normally fed group, intermittent fasting markedly improved the survival of rats with CHF (88.5% versus 23% survival, P<0.05). The heart weight body weight ratio was significantly less in the MI-IF group compared to the MI-NF group (3.4+/-0.17 versus 3.9+/-0.18, P<0.05). Isolated heart perfusion studies exhibited well preserved cardiac functions in the MI-IF group compared to the MI-NF group (P<0.05). Molecular studies revealed the upregulation of angiogenic factors such asHIF-1-alpha (3010+/-350% versus 650+/-151%), BDNF (523+/-32% versus 110+/-12%), and VEGF (450+/-21% versus 170+/-30%) in the fasted hearts. Immunohistochemical studies confirmed increased capillary density (P<0.001) in the border area of the ischemic myocardium and synthesis VEGF by cardiomyocytes. Moreover fasting also upregulated the expression of other anti-apoptotic factors such as Akt and Bcl-2 and reduced the TUNEL positive apoptotic nuclei in the border zone. Chronic intermittent fasting markedly improves the long-term survival after CHF by activation through its pro-angiogenic, anti-apoptotic and anti-remodeling effects.