Endothelium-dependent vasodilatation in migraine patients

Migraine-Associated Common Genetic Variants Confer Greater Risk of Posterior vs. Anterior Circulation Ischemic Stroke☆

OBJECTIVE

To examine potential genetic relationships between migraine and the two distinct phenotypes posterior circulation ischemic stroke (PCiS) and anterior circulation ischemic stroke (ACiS), we generated migraine polygenic risk scores (PRSs) and compared these between PCiS and ACiS, and separately vs. non-stroke control subjects.

METHODS

Acute ischemic stroke cases were classified as PCiS or ACiS based on lesion location on diffusion-weighted MRI. Exclusion criteria were lesions in both vascular territories or uncertain territory; supratentorial PCiS with ipsilateral fetal posterior cerebral artery; and cases with atrial fibrillation. We generated migraine PRS for three migraine phenotypes (any migraine; migraine without aura; migraine with aura) using publicly available GWAS data and compared mean PRSs separately for PCiS and ACiS vs. non-stroke control subjects, and between each stroke phenotype.

RESULTS

Our primary analyses included 464 PCiS and 1079 ACiS patients with genetic European ancestry. Compared to non-stroke control subjects (n=15396), PRSs of any migraine were associated with increased risk of PCiS (p=0.01-0.03) and decreased risk of ACiS (p=0.010-0.039). Migraine without aura PRSs were significantly associated with PCiS (p=0.008-0.028), but not with ACiS. When comparing PCiS vs. ACiS directly, migraine PRSs were higher in PCiS vs. ACiS for any migraine (p=0.001-0.010) and migraine without aura (p=0.032-0.048). Migraine with aura PRS did not show a differential association in our analyses.

CONCLUSIONS

Our results suggest a stronger genetic overlap between unspecified migraine and migraine without aura with PCiS compared to ACiS. Possible shared mechanisms include dysregulation of cerebral vessel endothelial function.

Cerebral Hemodynamics, Right-to-Left Shunt and White Matter Hyperintensities in Patients with Migraine with Aura, Young Stroke Patients and Controls

Background: Migraine with aura (MA) patients present an increased risk of cerebrovascular events. However, whether these patients present an increased white matter hyperintensities (WMHs) load compared to the general population is still under debate. Our study aimed to evaluate the relationship between cerebral hemodynamics, right-to-left shunt (RLS) and WMHs in MA patients, young patients with cryptogenic stroke or motor transient ischemic attack (TIA) and controls. Methods: We enrolled 30 MA patients, 20 young (<60 years) patients with cryptogenic stroke/motor TIA, and 10 controls. All the subjects underwent a transcranial Doppler bubble test to detect RLS and cerebral hemodynamics assessed by the breath holding index (BHI) for the middle (MCA) and posterior (PCA) cerebral arteries. Vascular risk factors were collected. The WMHs load on FLAIR MRI sequences was quantitatively assessed. Results: The stroke/TIA patients presented a higher prevalence of RLS (100%) compared with the other groups (p < 0.001). The MA patients presented a higher BHI compared with the other groups in the PCA (p = 0.010) and higher RLS prevalence (60%) than controls (30%) (p < 0.001). The WMHs load did not differ across groups. BHI and RLS were not correlated to the WMHs load in the groups. Conclusions: A preserved or more reactive cerebral hemodynamics and the presence of a RLS are likely not involved in the genesis of WMHs in MA patients. A higher BHI may counteract the risk related to their higher prevalence of RLS. These results need to be confirmed by further studies to be able to effectively identify the protective role of cerebral hemodynamics in the increased RLS frequency in MA patients.

Pathophysiological Bases of Comorbidity in Migraine

Despite that it is commonly accepted that migraine is a disorder of the nervous system with a prominent genetic basis, it is comorbid with a plethora of medical conditions. Several studies have found bidirectional comorbidity between migraine and different disorders including neurological, psychiatric, cardio- and cerebrovascular, gastrointestinal, metaboloendocrine, and immunological conditions. Each of these has its own genetic load and shares some common characteristics with migraine. The bidirectional mechanisms that are likely to underlie this extensive comorbidity between migraine and other diseases are manifold. Comorbid pathologies can induce and promote thalamocortical network dysexcitability, multi-organ transient or persistent pro-inflammatory state, and disproportionate energetic needs in a variable combination, which in turn may be causative mechanisms of the activation of an ample defensive system with includes the trigeminovascular system in conjunction with the neuroendocrine hypothalamic system. This strategy is designed to maintain brain homeostasis by regulating homeostatic needs, such as normal subcortico-cortical excitability, energy balance, osmoregulation, and emotional response. In this light, the treatment of migraine should always involves a multidisciplinary approach, aimed at identifying and, if necessary, eliminating possible risk and comorbidity factors.

Pentraxin 3 (PTX3): A Molecular Marker of Endothelial Dysfunction in Chronic Migraine

Even though endothelial dysfunction is known to play a role in migraine pathophysiology, studies regarding levels of endothelial biomarkers in migraine have controversial results. Our aim was to evaluate the role of pentraxin 3 (PTX3) and soluble tumour necrosis factor-like weak inducer of apoptosis (sTWEAK) as potential biomarkers of endothelial dysfunction in chronic migraine (CM). We performed a case-control study including 102 CM patients and 28 control subjects and measured serum levels of markers of endothelial dysfunction (PTX3 and sTWEAK) and inflammation [high-sensitivity C-reactive protein (hs-CRP)] as well as brachial artery flow-mediated dilation (FMD) during interictal periods. Interictal serum levels of PTX3 and sTWEAK were higher in CM patients than in controls (1350.6 ± 54.8 versus 476.1 ± 49.4 pg/mL, p < 0.001 and 255.7 ± 21.1 versus 26.4 ± 2.6 pg/mL, p < 0.0001; respectively). FMD was diminished in CM patients compared to controls (9.6 ± 0.6 versus 15.2 ± 0.9%, p < 0.001). Both PTX3 and sTWEAK were negatively correlated with FMD (r = −0.508, p < 0.001 and r = −0.188, p = 0.033; respectively). After adjustment of confounders, PTX3 remained significantly correlated to FMD (r = −0.250, p = 0.013). Diagnosis of CM was 68.4 times more likely in an individual with levels of PTX3 ≥ 832.5 pg/mL, suggesting that PTX3 could be a novel biomarker of endothelial dysfunction in CM.

Endothelial and Autonomic Functions in Patients with Migraine

OBJECTIVE

It has been shown that patients with migraine have endothelial dysfunction. Migraine patients with aura, especially, have more clinical manifestations of autonomic nervous system dysfunction. We aimed to evaluate the endothelial and autonomic functions in migraine patients during both migraine headache attack and headache-free periods.

DESIGN

This was a cross-sectional, randomized study.

SUBJECTS AND METHODS

A total of 130 participants (67 male and 63 female patients, minimum age = 19 years, maximum age = 71 years, mean age = 38.8 ± 12.2 years) were enrolled into the study. For the statistical evaluation of data, we classified the participants of the study as follows: group 1: headache (+) aura (+); group 2: headache (+) aura (-); group 3: headache (-) aura (+); group 4: headache (-) aura (-). Noninvasive evaluation of endothelial function was performed by flow-mediated dilation (FMD) and pulse wave analysis methods. Heart rate variability measurements were used for noninvasive evaluation of autonomic functions.

RESULTS

Group 1 had a higher FMD ratio than the control group, group 3, or group 4 (P < 0.001, P < 0.001, and P = 0.003, respectively). Group 4 had lower FMD ratio levels than the other migraine groups and or the control group (P < 0.001). Group 3 had the highest high-frequency (HF) power levels among all migraine groups (P < 0.001). Group 2 had higher low-frequency/HF ratio values than other migraineurs (P < 0.001).

CONCLUSIONS

We concluded that endothelial dysfunction and headache are closely related. Additionally, higher parasympathetic tonus might be associated with the presence of aura.

Migraine and Markers of Carotid Atherosclerosis in Middle-Aged Women: A Cross-Sectional Study

OBJECTIVE

This study evaluated the association between migraine and the markers of carotid artery disease.

BACKGROUND

Migraine increases the risk of cardiovascular events, but its relationship with vascular dysfunction is unclear.

METHODS

In this cross-sectional study, middle-aged women with no known cardiovascular diseases underwent clinical, neurological, and laboratory evaluations; pulse wave velocity (PWV) assessment; and carotid artery ultrasonography. We divided the participants based on the presence of migraine and, further, based on the type of migraine. Associations between migraine and carotid thickening (intima-media thickness >0.9 mm), carotid plaques, or arterial stiffening (PWV >10 m/s) were evaluated using a multiple regression analysis.

RESULTS

The study comprised 112/277 (40%) women with migraine, of whom 46/277 (17%) reported having an aura. Compared to the non-migraineurs, the migraine with aura group had an increased risk of diffuse carotid thickening (3/46 [6.8%] vs 2/165 [1.3%], adjusted OR = 7.12, 95% CI 1.05-48.49). Migraine without aura was associated with a low risk of carotid plaques (3/66 [4.7%] vs 26/165 [16.7%], adjusted OR = 0.28, 95% CI 0.08-0.99) and arterial stiffening (21/66 [34.4%] vs 82/165 [51.2%], adjusted OR = 0.39, 95% CI 0.19-0.79). There were no correlations between migraine characteristics and arterial stiffness or carotid thickness measurements.

CONCLUSION

Migraine with aura is associated with an increased risk of carotid thickening, and migraine without aura is associated with a low risk of carotid plaques and arterial stiffening.

A thicker intima-media carotid wall was found in a cohort of children with recent onset migraine

AIM

Migraine affects approximately 10-20% of the general population, including children and adolescents, and an association between migraine and increased risks for cardiovascular disease and stroke have been reported in adult patients. This study aimed to address the lack of data on children with migraine.

METHODS

This study comprised 30 children and adolescents (16 male) with migraine. We evaluated their biochemical profile, glucose homeostasis, vascular function by flow-mediated dilatation and arterial structure by carotid intima-media thickness (cIMT). A group of 32 age, sex and auxologically matched children (17 male) served as controls.

RESULTS

The group of children with migraine had a normal biochemical profile and glucose homeostasis, but presented with significantly thicker cIMT than the control group (0.48 ± 0.07 mm versus 0.45 ± 0.04, p < 0.05).

CONCLUSION

We observed a significantly thicker cIMT in children with migraine compared with the controls. The brief time interval between the onset of the disease and the time of the study makes it unlikely that repetitive migraine attacks could be responsible for the thickening of the cIMT. Thus, it may be speculated that primitive vascular function abnormalities were wholly or partly responsible for the development of migraine in this paediatric cohort.

Migraine and endothelial function: The HUNT3 Study

Background

Reduced endothelial function is associated with elevated risk of cardiovascular disease, but evidence on the association between migraine and endothelial function is conflicting. The aim of this population-based study was to examine the relationship between flow-mediated dilatation (FMD) and migraine with aura, migraine without aura and tension-type headache.

Methods

In the third Nord-Trøndelag Healthy Study (HUNT3) FMD was measured by ultrasound during reactive hyperaemia of the brachial artery in a sample of 4739 healthy adult participants, 3929 of whom answered headache questions. The cross-sectional association between different headache diagnoses and FMD was evaluated by logistic regression, using a categorical approach.

Results

Mean FMD did not differ between the headache groups and headache-free controls. In multi-adjusted analyses, no consistent association was found between FMD quintiles and headache groups.

Conclusions

There was no relationship between FMD and migraine or other headache diagnoses in this large cross-sectional study of otherwise healthy respondents including freedom from pulmonary and cardiovascular diseases.

Migraine and subclinical atherosclerosis in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Introduction

The relationship between migraine and coronary heart disease (CHD) remains controversial. We aimed to investigate the association of subclinical atherosclerosis and migraine with or without aura compared to a non-migraine subgroup (reference) in a large Brazilian multicentric cohort study, the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

Methods

Migraine diagnostic was based on International Headache Society criteria, and aura symptoms were validated by a medical doctor in a sub-sample of the ELSA-Brasil, who also underwent coronary artery calcium score (CAC) and carotid intima-media thickness (C-IMT) evaluations. Subclinical atherosclerosis indexes (CAC and C-IMT) were analyzed as dependent variables and migraine (all, with aura, without aura) as an independent variable in the linear and multinomial logistic regression models adjusted for possible confounders.

Results

Of 3217 ELSA participants free from CVD at baseline, we found a migraine frequency of 11.9% (5.1% with aura and 6.8% without aura). Overall, migraineurs were mostly women, younger and had lower frequency of CV risk factors, such as hypertension, diabetes and low HDL-cholesterol, compared to non-migraineurs. The strongest inverse correlation between migraine and subclinical atherosclerosis was verified with CAC score. However, all associations lost their significance after multivariate adjustment.

Conclusions

In this cross-sectional evaluation of the ELSA study, migraine was not associated with subclinical atherosclerosis, regardless of aura symptoms.

The Migraine-Stroke Connection

Migraine and stroke are common neurovascular disorders which share underlying physiological processes. Increased risks of ischemic stroke, hemorrhagic stroke, and subclinical ischemic lesions have been consistently found in migraineurs. Three possible associations are suggested. One is that underlying pathophysiology of migraine can lead to ischemic stroke. Second, common comorbidities between migraine and stroke can be present. Lastly, some syndromes can manifest with both migraine-like headache and cerebrovascular disease. Future studies should be targeted on bidirectional influence of migraine on different stroke mechanisms and optimal prevention of stroke in migraine patients.

Interictal cerebral and systemic endothelial dysfunction in patients with migraine: a case-control study

BACKGROUND

Although systemic endothelial function is unimpaired in migraine, it is unknown whether cerebral endothelial function impairment exists in migraineurs.

MATERIALS AND METHODS

We conducted a prospective study to assess endothelial function in migraineurs (n=45) and healthy volunteers (n=44). Cerebral endothelial function was assessed by Breath Holding Index (BHI) on transcranial Doppler in bilateral middle cerebral artery (MCA at 30-60 mm), posterior cerebral artery (PCA at 60-80 mm) and basilar artery (BA at 80-120 mm) using bilateral monitoring probes fixed on headband. Brachial artery flow-mediated dilation (FMD) was used as measure of systemic endothelial function.

RESULTS

There was no difference in baseline mean velocities of MCA, PCA, BA among migraineurs and controls. Mean BHI was significantly lower in PCA (p<0.001) and BA (p<0.001) in patients with migraine with no difference in MCA (p=0.909, 0.450). Cerebral endothelial dysfunction (BHI<1.15) was present in 62.2% of migraineurs in the right PCA (p<0.001), 57.8% in left PCA (p<0.001) and 77.8% in BA (BHI <0.83, p<0.001). There was no difference in BHI among migraineurs without and with aura (n=15). Cerebral and systemic endothelial function had no correlation in migraineurs. Increasing BMI was identified as a predictor of impaired BHI in the BA in migraineurs (p=0.020). Age, sex, presence of aura, lateralisation of headache, headache frequency, time to last attack and impaired FMD were not associated with impaired PCA and BA BHI in migraineurs.

CONCLUSIONS

Migraineurs may have isolated cerebral endothelial dysfunction restricted to the posterior circulation in the absence of systemic endothelial dysfunction.

Endothelial function in migraine with aura - a systematic review

BACKGROUND

An increased risk of ischemic stroke is repeatedly reported in young subjects with migraine with aura (MA). Such may be caused by changes in endothelial function. The present review evaluates current evidence on endothelial function in MA patients.

METHODS

A systematic search of electronic databases (Medline, Embase, Cochrane library) was performed, and a search in associated reference lists of identified studies was done.

RESULTS

In total, 27 studies met inclusion criteria for this review. Six studies assessed endothelial function by flow-mediated dilation; four reported no differences compared with healthy subjects, one study reported an increase and one study a decrease in migraineurs. Peripheral arterial tonometry was applied in one study where no changes were detected between groups. Likewise, applying venous occlusion plethysmography elicited comparable responses. Arterial function was investigated in six studies; increased augmentation index and decreased arterial distensibility were reported in migraineurs, whereas findings regarding pulse wave velocity were dissimilar. However, when investigating levels of endothelial progenitor cells, two studies reported reduced levels in migraineurs, and several studies on endothelial markers in the areas of inflammation, oxidative stress, and coagulation found increased endothelial activation in migraineurs, particularly in MA. One study, assessing cerebral endothelial function using transcranial Doppler sonography, reported lower cerebrovascular reactivity to L-arginine in the posterior cerebral arteries in migraineurs.

CONCLUSION

Endothelial dysfunction appears not to be of importance in MA patients. However, the studies were few with a wide variety of techniques applied in small groups of patients. Endothelial biomarkers were increased in patients indicating a possible subtle change in the endothelium. Further investigations on larger groups of patients combining testing of endothelial dysfunction as well as biomarkers are warranted to identify whether or not endothelial changes may play a role in the increased risk of stroke in young MA patients.

Markers of endothelial function in migraine patients: Results from a bi-center prospective study

Background

Numerous studies suggest an increased vascular risk in patients with migraine, in particular in those with aura. A possible link between both conditions might be a dysfunction of the vascular endothelium. This observational study analyzed the endothelial markers angiopoietin-1, angiopoietin-2, Tie-2, sFlt-1 and NT-proBNP for the first time in migraineurs, patients with other primary headache disorders and healthy controls.

Methods

Patients with episodic migraine with and without aura, episodic cluster headache, tension-type headache and healthy controls were included. Blood samples were obtained during migraine attacks and headache-free periods in migraineurs, in and out of bout in cluster headache and during headache-free periods in tension-type headache and healthy individuals to analyze markers of endothelial function.

Results

No significant difference in endothelial markers between migraine, other headache disorders and healthy controls was detected. There was no significant difference between migraine attacks and headache-free intervals. Additionally, no distinction could be found between migraine with and without aura.

Discussion

The endothelial markers analyzed do not display a characteristic pattern in different headache disorders especially migraine compared to healthy controls. The novel findings of our study indicate that factors other than endothelial dysfunction seem to be responsible for the at least statistical association of migraine with vascular disease.

Circulating endothelial microparticles in female migraineurs with aura

BACKGROUND AND PURPOSE

Endothelial microparticles (EMPs) are vesicles that are released from activated endothelial cells and serve as a surrogate for endothelial dysfunction (ED). ED may be involved in migraine pathophysiology and contribute to the increased risk of ischemic stroke, particularly in female migraineurs with aura (MA). We sought to determine whether EMPs are elevated in women with MA.

METHODS

In this case-control study, EMPs were detected by analysing surface markers using fluorescence-activated cell sorting (FACS). Surface markers were measured covering the main cell lines relevant in cardiovascular disease like endothelial cells, platelets, monocytes and leucocytes. Microparticles (MPs) were identified in correlation to calibration by 1 -µm calibrator beads (Beckman Coulter). Arterial stiffness was assessed using fingertip tonometry and the heart rate-adjusted augmentation index (AI).

RESULTS

We included 29 patients with MA and 29 matched controls. MA patients had significantly higher EMPs (CD62E(+)AnnexinV(+): 5142/µl vs 1535/µl; p < 0.001; CD144(+)AnnexinV(+): 6683/µl vs 3107/µl; p < 0.001), monocytic (CD14(+)AnnexinV(+) 6378 vs 3161; p < 0.001), and platelet MPs (CD62P(+)CD42b(+)AnnexinV(+) 5450 vs 3204; p < 0.001). Activated EMPs (CD62E(+)AnnexinV(+)) correlated with heart-rate adjusted AI (r = 0.46; p < 001).

CONCLUSION

EMP levels are significantly elevated in women with MA and correlated with increased AI. Our findings suggest that endothelial activation is present in women with MA. This might contribute to higher stroke risk in MA.

Biomarkers associated with migraine and their potential role in migraine management

OBJECTIVE

The focus of this review is to review potential diagnostic and therapeutic biomarkers associated with migraine.

BACKGROUND

Migraine headache is a common disease that affects millions of individuals worldwide. Although well-accepted diagnostic criteria exist for migraine, it is still a complex disorder that remains both underdiagnosed and misdiagnosed. The causes of migraine are likely a mix of genetic, epigenetic, and environmental factors that, together with the individual's life history, translate into the observed clinical heterogeneity. Inherent clinical heterogeneity is an obstacle in developing more effective treatments. The lack of appropriate biomarkers is also an impediment to developing more effective therapeutic/preventive approaches. Ultimately, biomarkers may facilitate the goal of individualized medicine by enabling clinicians to more accurately diagnose and treat migraine and other types of headache.

METHODS

A comprehensive review was conducted of PubMed citations containing the key word "marker" OR "biomarker" combined with "migraine" OR "headache." Other key words included "serum," "saliva," "cerebrospinal fluid," "genes," "blood," and "inflammation." The only restriction was English-language publication. The abstracts of all articles meeting these criteria were reviewed, and full text was retrieved and examined for relevant references.

RESULTS

Data from human studies have begun to identify genetic mutations/polymorphisms and altered levels of specific proinflammatory and neuromodulatory molecules that strongly correlate with migraine as well as symptom severity. Results from a smaller number of studies have identified parameters, such as the neuropeptide calcitonin gene-related peptide (CGRP), which are significantly associated with response to specific treatments for acute migraine attacks and prophylaxis. Epigenetic mechanisms may also be involved in the development of migraine, and understanding environmentally induced genetic changes associated with this disease may eventually guide the development of therapies capable of reversing these pathophysiological changes in gene function.

CONCLUSIONS

The understanding of the etiology of migraine is incomplete. Although the identification and validation of biomarkers has greatly advanced diagnostic precision and measures of therapeutic efficacy in other diseases, there are no currently accepted biomarkers for chronic or episodic migraine. However, the continued investigation and identification of genetic, epigenetic, and molecular biomarkers is likely to facilitate the goal of individualizing medicine by enabling clinicians to more accurately diagnose and treat migraine and other headache disorders.

[Migraine and vascular risk]

Migraine with aura is well known to be associated with an increased risk of ischemic stroke. This risk dramatically increases in smokers and uses of oral contraceptives. Brain MRI studies suggest that migraine is associated with silent brain infarcts. Migraine is also established as a risk factor for significantly more cerebral white matter lesions. Recent data suggest that migraine is also associated with coronary artery disease. Data concerning an increase risk of mortality in migraine are controversial. The pathophysiology of the increased risk of ischemic events is unclear. Migrainous infarcts seem to be very rare. Migraine is associated with an increased risk of cervical artery dissection. Classical vascular risk factors are more common in migraineurs. Triptans are not associated with an increased risk of ischemic events. Another explanation is a probable endothelial dysfunction and a lower level of endothelial progenitor cells in migraine. A prothrombotic state in migraine is also another possible explanation due to genetic polymorphisms. Appropriate management for primary vascular prevention in migraineurs is not different from that proposed for the general population. Oral contraceptives should be avoided in migraineurs with aura, especially if they smoke.

Migraine-related ischemic stroke?

INTRODUCTION

Migraine, especially migraine with aura, has been described to be associated with an increased risk for ischemic stroke. An increased incidence of silent lesions in the posterior circulation has also been described.

METHOD

Six cases with migraine and stroke in close relation over time were retrospectively reviewed.

RESULTS

All patients had previously known MA or MO and suffered from a stroke within the first 24-hour period after an acute migraine attack. None of the patients fulfilled the IHS criteria for migrainous infarction. Four out of these six patients had a patent foramen ovale (PFO) or an atrial septal defect (ASD).

DISCUSSION

None of these cases can be categorized as migrainous infarctions according to IHS. However, the migraine attack might have been involved in the mechanisms for the development of the infarctions.

Migraine is not associated with enhanced atherosclerosis

AIM

Migraine, in particular with aura, has been associated with an increased risk for ischemic stroke and coronary heart disease. The underlying mechanism is unknown. In a cross-sectional case control study we investigated whether an enhanced risk of atherosclerosis in migraineurs explains this increased cardiovascular risk.

METHODS

Subjects were participants from the population-based Erasmus Rucphen Family study. Atherosclerosis was assessed in 360 migraineurs (209 without aura and 151 with aura) and 617 subjects without migraine or severe headache. Atherosclerosis was quantified by intima media thickness, pulse wave velocity and ankle-brachial index.

RESULTS

Migraineurs, especially with aura, were found more likely to smoke, have diabetes or a modestly decreased HDL-cholesterol. No differences were found for the atherosclerosis parameters.

CONCLUSION

In this large population-based study, migraineurs have no increased risk of atherosclerosis. Therefore, enhanced atherosclerosis is an unlikely explanation for the increased cardiovascular risk seen in migraineurs.

Reduced endothelial function in the skin in Southeast Asians compared to Caucasians

BACKGROUND

The reaction of vascular endothelial cells to occlusion and heat in Southeast Asian Indians (SAI) compared to Caucasians (C) has not been studied, although genetic differences are found in endothelial cells between the races.

MATERIAL/METHODS

Ten C and Ten SAI (<35 years old) male and female subjects participated. There was no difference in the demographics of the subjects except that the SAI group had been in the United States for 6 months; C was natives to the US. Endothelial function was assessed by the response of the circulation (BF) to local heating and the response to vascular occlusion. The effects of local heat on circulation in the skin on the forearm was assessed by applying heat for 6 minutes at temperatures, 38, 40 and 42°C on 3 separate days. On different days, vascular occlusion was applied for 4 minutes to the same arm and skin blood flow was measured for 2 minutes after occlusion; skin temperature was either 31°C or 42°C.

RESULTS

When occlusion was applied at a skin temperature of 31°C, the BF response to occlusion was significantly lower in the SAI cohort compared to C (peak BF C = 617 ± 88.2 flux, SAE = 284 ± 73 flux). The same effect was seen at skin temperatures of 42°C. The circulatory response to heat was also significantly less in SAI compared to C at each temperature examined (p<0.05)(for temperatures of 38, 40 and 42°C, peak blood flow for C was 374.7 ± 81.2, 551.9 ± 91.3 and 725.9 ± 107 flux respectively and 248.5 ± 86.2, 361.4 ± 104.3 and 455.3 ± 109.7 flux respectively for SAI. (p<0.05).

CONCLUSIONS

Thus there seems to be big differences in these 2 populations in endothelial response to these stressors. The difference may be due to genetic variations between the 2 groups of subjects.

Peripheral endothelial function and arterial stiffness in women with migraine with aura: a case-control study

BACKGROUND

Vascular dysfunction may be involved in migraine pathophysiology and contribute to the increased risk of ischemic stroke in migraine, particularly in women with migraine with aura (MA). However, data on endothelial function in MA are controversial. Here, we investigated whether systemic endothelial function and arterial stiffness are altered in women with MA, using a novel peripheral arterial tonometry device for the first time.

METHODS

Twenty-nine female MA patients without comorbidities and 30 healthy women were included, and carotid intima-media thickness was assessed by a standardized procedure. Endothelial function was assessed using peripheral arterial tonometry. Reactive hyperaemic response of digital pulse amplitude was measured following 5 minutes of forearm occlusion of the brachial artery. Arterial stiffness was assessed by fingertip tonometry derived and heart-rate-adjusted augmentation index.

RESULTS

No differences were found in peripheral arterial tonometry ratio (2.3 ± 0.6 vs 2.2 ± 0.8; p = 0.58) and left carotid intima-media thickness (in µm: 484 ± 119 vs 508 ± 60; p = 0.37). Women with MA had higher heart-rate-averaged augmentation index [median (interquartile range, IQR) of 5 (IQR 0.5 to 18) vs -5 (IQR -16.8 to 8.3), p = 0.005] and heart-rate-adjusted augmentation index [1 (IQR -6 to 12.5) vs -8 (IQR -20.3 to 2.5), p = 0.008] than healthy controls.

CONCLUSION

Peripheral endothelial function is not impaired in women with MA, but they have greater arterial stiffness. This may contribute to the increased stroke risk in women with MA.

Associations between cerebral and systemic endothelial function in migraine patients: a post-hoc study

Background

There is a growing interest in the role of the endothelium in migraine. Recently, our group showed differences in endothelial function between the anterior and posterior cerebral circulation in healthy subjects, reduced vasodilatatory capacity of the posterior cerebral circulation and unimpaired systemic endothelial function in migraine patients without comorbidities. However, the relationship between cerebral and systemic endothelial function and the anterior and posterior cerebral endothelial function in migraine patients is still not clear.

Methods

We compared cerebral and systemic endothelial function through post-hoc linear regression analysis of cerebrovascular reactivity (CVR) to L-arginine between the middle cerebral artery (MCA) and flow-mediated vasodilatation (FMD) of the right brachial artery and the posterior cerebral artery (PCA) and FMD in migraine patients without comorbidities and in healthy subjects. The anterior and posterior cerebral endothelial function was also compared using post-hoc linear regression analysis between CVR to L-arginine in the MCA and the PCA.

Results

No significant correlation was found between CVR to L-arginine in the MCA and FMD and in the PCA and FMD in migraine patients with aura (p = 0.880 vs. p = 0.682), without aura (p = 0.153 vs. p = 0.179) and in healthy subjects (p = 0.869 vs. p = 0.662). On the other hand, we found a significant correlation between CVR to L-arginine in the MCA and PCA in migraine patients with aura (p = 0.004), without aura (p = 0.001) and in healthy subjects (p = 0.002). Detailed analysis of the linear regression between all migraine patients and healthy subjects did not show any difference in the regression coefficient (slope) (p = 0.382). However, a significant difference in curve elevation (intercept) was found (p = 0.002).

Conclusions

Our study suggests that the endothelial function in the cerebral and systemic circulation might be different in migraine patients without comorbidities, while that of the anterior and posterior cerebral circulation might be coupled. These results could improve understanding of endothelial function in migraine patients without comorbidities.