Endothelial function in migraine: a cross-sectional study

ABSTRACT: BACKGROUND: Migraine has been associated with cardiovascular disorders. Endothelial dysfunction may be a mechanism underlying this association. The present study tested the hypothesis that endothelium-dependent vasodilation, basal endothelial nitric oxide release and endothelial fibrinolytic capacity are impaired in migraine patients. METHODS: Graded doses of sodium nitroprusside (SNP, 0.2 to 0.8 microg.min 1.dL-1 forearm), substance P (0.2 to 0.8 pmol.min-1.dL-1 forearm) and NG monomethyl-L-arginine (L-NMMA, 0.1 to 0.4 micromol.min-1.dL-1 forearm) were infused into the brachial artery of 16 migraine patients with or without aura during a headache-free interval and 16 age- and sex-matched subjects without a history of migraine. Forearm blood flow (FBF) was measured by strain-gauge venous occlusion plethysmography. Local forearm release of tissue plasminogen activator (t-PA) in response to substance P infusion was assessed using the arteriovenous plasma concentration gradient. Responses to infused drugs were compared between patients and matched controls by analysis of variance. RESULTS: In both migraine patients and control subjects, SNP and substance P caused a dose-dependent increase, and L NMMA a dose-dependent decrease in FBF (P < 0.001 for all responses). In both groups, substance P caused an increase in t-PA release (P < 0.001). FBF responses and t-PA release were comparable between migraine patients and control subjects. CONCLUSIONS: The absence of differences in endothelium-dependent vasodilation, basal endothelial nitric oxide production and stimulated t-PA release between migraine patients and healthy control subjects argues against the presence of endothelial dysfunction in forearm resistance vessels of migraine patients.status: publishe

Pressure-dependence of arterial stiffness: potential clinical implications

Background: Arterial stiffness measures such as pulse wave velocity (PWV) have a known dependence on actual blood pressure, requiring consideration in cardiovascular risk assessment and management. Given the impact of ageing on arterial wall structure, the pressure-dependence of PWV may vary with age. Methods: Using a noninvasive model-based approach, combining carotid artery echo-tracking and tonometry waveforms, we obtained pressure-area curves in 23 hypertensive patients at baseline and after 3 months of antihypertensive treatment. We predicted the follow-up PWV decrease using modelled baseline curves and follow-up pressures. In addition, on the basis of these curves, we estimated PWV values for two age groups (mean ages 41 and 64 years) at predefined hypertensive (160/90 mmHg) and normotensive (120/80mmHg) pressure ranges. Results: Follow-up measurements showed a near 1 m/s decrease in carotid PWV when compared with baseline, which fully agreed with our model-prediction given the roughly 10mmHg decrease in diastolic pressure. The stiffness-blood pressure-age pattern was in close agreement with corresponding data from the 'Reference Values for Arterial Stiffness' study, linking the physical and empirical bases of our findings. Conclusion: Our study demonstrates that the innate pressure-dependence of arterial stiffness may have implications for the clinical use of arterial stiffness measurements, both in risk assessment and in treatment monitoring of individual patients. We propose a number of clinically feasible approaches to account for the blood pressure effect on PWV measurements

Altered arterial function in migraine of recent onset

OBJECTIVE: Migraine is associated with cardiovascular disorders but the underlying mechanisms are unknown. Arterial structure and function are important determinants of cardiovascular morbidity and mortality. The aim of the present study was to assess arterial properties in patients with migraine of recent onset. METHODS: In a cross-sectional study, structural and functional arterial properties were assessed using ultrasound and applanation tonometry in 50 patients with a history of migraine >1 and <6 years during a headache-free interval and 50 age- and gender-matched subjects without a history of migraine. RESULTS: Brachial artery diameter (4.82 +/- 0.93 mm vs 5.39 +/- 0.89 mm, p = 0.01) and compliance (0.30 +/- 0.17 mm(2)/kPa vs 0.37 +/- 0.19 mm(2)/kPa, p = 0.02) were decreased in migraine patients compared with controls. Femoral artery compliance was decreased in migraine patients (1.19 +/- 0.55 mm(2)/kPa vs 1.42 +/- 0.59 mm(2)/kPa, p = 0.04). Carotid arterial wall properties were similar between groups. Aortic augmentation index was increased in migraine patients (4 +/- 10% vs -1 +/- 10%, adjusted p = 0.04). Flow-mediated vasodilation of the brachial artery (normalized to peak shear rate) was decreased in patients with migraine (29 +/- 15 vs 37 +/- 15 10(-3)%. sec, p = 0.006). CONCLUSION: Functional arterial properties are altered in patients with migraine of recent onset.status: publishe

Investigation of Frankincense producing Boswellia ssp. from Somalia and quest for quality standards

BACKGROUND: Hypochlorhydric states are an important cause of iron deficiency (ID). Nevertheless, the association between therapy with proton pump inhibitors (PPIs) and ID has long been a subject of debate. This case-control study aimed to investigate the risk of ID associated with the use of PPIs using the UK Clinical Practice Research Datalink (CRPD) database. METHODS: Cases were patients aged 19 years or older with first-time diagnosis of ID between 2005 and 2015 (n = 26,806). The dates of first diagnosis of ID in cases defined the index dates. For each case, one control was matched by age, sex and general practice. A PPI "full" user (PFU) was defined as a subject who had received PPIs for a continuous duration of at least one year prior to the index date. A PPI "limited" users (PLU) was a subject who intermittently received PPI therapy. A PPI non-user (PNU) was a subject who received no PPIs prescriptions prior to the index date. The odds ratio of ID in PFU and PLU compared to PNU was estimated using conditional logistic regression. RESULTS: Among cases, 2,960 were PFU, 6,607 PLU and 17,239 PNU. Among controls, 1,091 were PFU, 5,058 PLU and 20,657 PNU. Adjusted odds ratio of ID in PFU and PLU compared to PNU was 3.60 (95%CI, [3.32 - 3.91]) and 1.51 (95% CI, [1.44 - 1.58]). Positive dose-response and time-response relationships were observed. CONCLUSIONS: Chronic PPI use increases the risk of ID. Physicians should consider this when balancing the risks and benefits of chronic PPI prescription. This article is protected by copyright. All rights reserved

Changes in mFMD_v (A) and in pFMD_v (B) with glucose loading.

<p>Glucose was ingested at time-point 0 minutes (dashed vertical line). Red line: session 1, blue line: session 2; whiskers indicate standard error. Data did not differ between sessions at any corresponding time-point (all p-values ≥ 0.176, n = 22). The p-values on top of the graphs refer to differences between pre and post glucose intake (of the mean of both sessions). Abbreviations as defined in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0115977#pone.0115977.t001" target="_blank">Table 1</a>.</p

Summary and interpretation of measured changes in local brachial artery flow velocity (v) and diameter (D) after glucose loading.

<p>Please note that scales are all conform the relative magnitudes of the effects observed in the study group. Panel A shows the steady-state working point (circle) and hyperemic changes (Δ) under the fasting condition. The hyperemic changes are not aligned with the ideal response where wall shear stress (_w ~ v/D) would be kept constant perfectly, as indicated by the grey block arrow. FMD_V would be equal to 1 in that case. The poor shear stress normalization performance (FMD_V << 1; black block arrow) under fasting conditions is corroborated by the shift in the steady-state working point with glucose loading shown in panel B (black block arrow). This analysis indicates that wall shear stress normalization under normal (fasting) conditions is already far from ideal, which does not materially change with glucose loading.</p

Summary and interpretation of measured changes in local brachial artery flow velocity (v) and diameter (D) after glucose loading.

<p>Please note that scales are all conform the relative magnitudes of the effects observed in the study group. Panel A shows the steady-state working point (circle) and hyperemic changes (Δ) under the fasting condition. The hyperemic changes are not aligned with the ideal response where wall shear stress (_w ~ v/D) would be kept constant perfectly, as indicated by the grey block arrow. FMD_V would be equal to 1 in that case. The poor shear stress normalization performance (FMD_V << 1; black block arrow) under fasting conditions is corroborated by the shift in the steady-state working point with glucose loading shown in panel B (black block arrow). This analysis indicates that wall shear stress normalization under normal (fasting) conditions is already far from ideal, which does not materially change with glucose loading.</p