Increased dopamine is associated with the cGMP and homocysteine pathway in female migraineurs

The association between COMT Val158Met polymorphism and migraine risk: A meta-analysis

Background The COMT Val158Met polymorphism has long been regarded as a risk factor for migraine. The possible association between COMT Val158Met polymorphism and migraine has been evaluated in several studies, but the results are not consistent. Therefore, we conduct this meta-analysis to address these issues. Methods The WEB OF SCIENCE and EMBASE databases were searched for eligible studies. The odds ratio (OR) with the corresponding 95% confidence interval (CI) was calculated to estimate the strength of the association between COMT Val158Met polymorphism and migraine. Results Five studies with 979 cases and 1870 controls were ultimately included in the present meta-analysis. The overall data showed no significant association between COMT Val158Met polymorphism and migraine in the multiplicative model (OR = 0.97, 95% CI: 0.78-1.21, p = 0.805) and dominant model (OR = 1.05, 95% CI: 0.75-1.48, p = 0.773), neither in the additive model (OR = 0.97, 95% CI: 0.77-1.23, p = 0.817) nor in the recessive model (OR = 0.88, 95% CI: 0.71-1.09, p = 0.246). In subgroup analysis, both for Caucasian and Asian populations, no statistically significant associations were observed in any genetic models. Conclusions Our meta-analysis suggested that the COMT Val158Met polymorphism was not associated with migraine risk.

A meta-analysis of biomarkers related to oxidative stress and nitric oxide pathway in migraine

Background

Oxidative and nitrosative stress are considered key events in the still unclear pathophysiology of migraine.

Methods

Studies comparing the level of biomarkers related to nitric oxide (NO) pathway/oxidative stress in the blood/urine of migraineurs vs. unaffected controls were extracted from the PubMed database. Summary estimates of mean ratios (MR) were carried out whenever a minimum of three papers were available. Nineteen studies were included in the meta-analyses, accounting for more than 1000 patients and controls, and compared with existing literature.

Results

Most studies measuring superoxide dismutase (SOD) showed lower activity in cases, although the meta-analysis in erythrocytes gave null results. On the contrary, plasma levels of thiobarbituric acid reactive substances (TBARS), an aspecific biomarker of oxidative damage, showed a meta-MR of 2.20 (95% CI: 1.65–2.93). As for NOs, no significant results were found in plasma, serum and urine. However, higher levels were shown during attacks, in patients with aura, and an effect of diet was found. The analysis of glutathione precursor homocysteine and asymmetric dimethylarginine (ADMA), an NO synthase inhibitor, gave inconclusive results.

Conclusions

The role of the oxidative pathway in migraine is still uncertain. Interesting evidence emerged for TBARS and SOD, and concerning the possible role of diet in the control of NOx levels.

Headache classification and aspects of reproductive life in young women

OBJECTIVE

To classify headaches as a function of the menstrual cycle and to contrast aspects relating to the reproductive cycle as a function of headache type.

METHOD

Participants responded to a structured questionnaire consisting of 44 questions. Detailed headache information, enabling the classification of headaches, and questions relating to the menstrual cycle were obtained.

RESULTS

The sample consisted of 422 students. Menstrual headaches were experienced by 31.8%. Migraine without aura (MO) occurred in 13.3%, migraine with aura (MA) in 7.8%, and probable migraine in 6.4%. Women with MA were significantly more likely to have reached menarche at earlier ages than women without headaches (p=0.03). Use of a hormonal contraceptive was related to the function of having MA headaches or not.

CONCLUSION

Most female college students are affected by menstrual headaches. Although the vast majority experience MO, other headaches also occur. Women with MA are equally likely to receive hormonal contraceptives as others.

Dopaminergic symptoms in migraine

Migraine pain is often preceded, accompanied and followed by dopaminergic symptoms (premonitory yawning and somnolence, accompanying nausea and vomiting, postdromal somnolence, euphoria and polyuria). After reviewing evidence from pharmacological, biochemical, genetic and animal experimental studies on the relationship between dopamine and migraine, and matching these data with patients' clinical features, we postulate that migraine attacks could be characterized by an ictal dopamine release in a subject with dopamine receptor hypersensitivity due to a chronic dopaminergic deficit synergistic to serotoninergic impairment. Our review suggests that when the attack begins, a low dopamine plasma concentration stimulates hypersensitive central presynaptic dopamine receptors thus causing prodromal symptoms such as yawning and somnolence. Increasing dopamine levels, though still insufficient to stop trigeminovascular activation, stimulate postsynaptic dopamine receptors thus inducing nausea, vomiting and hypotension. Finally, dopamine levels slowly return to baseline, giving rise to somnolence and fatigue, but, in some cases, continue to rise triggering postdromal symptoms such as euphoria and polyuria.

Migraine and erectile dysfunction: Evidence from a population-based case-control study

Background: This case-control study aimed to estimate the association between erectile dysfunction (ED) and migraines using a nationwide population-based database in Taiwan.

Methods: The data used for this matched case-control study were retrieved from the Taiwan Longitudinal Health Insurance Database 2000. We identified 5763 patients with ED as the cases and randomly selected 17,289 patients as the controls. Conditional logistic regression was used to calculate the odds ratios (OR) for prior migraine between cases and controls.

Results: After adjusting for hypertension, diabetes, hyperlipidaemia, renal disease, coronary heart disease, obesity, and alcohol abuse/alcohol dependence syndrome, conditional logistic regression revealed that among ED patients the odds of having been previously diagnosed with migraines was 1.63 (95% CI, 1.39–1.91) that of the control group. This risk was more pronounced in younger groups, with the highest risk being detected among those aged between 30 and 39 years. After adjusting for the above mentioned comorbidities, ED patients aged between 30 and 39 years were found to be at 1.98 (95% CI, 1.67–2.23) times the risk of controls for having been previously diagnosed with migraines.

Conclusion: We conclude that ED is associated with having been previously diagnosed with migraines, particularly in younger populations.