Sex Differences in the Transmission of Migraine

Sex Differences in Migraine: A Twin Study

Migraine is a neurological disorder with a prominent sex difference such that two thirds of sufferers are female. The mechanisms behind the preponderance of migraine in women have yet to be elucidated. With data on 51,872 participants from the Swedish Twin Registry, we report results from two distinct analyses intended to clarify the degree to which genetic and environmental factors contribute to sex differences in migraine. First, we fit a sex-limitation model to determine if quantitative genetic differences (i.e., is migraine equally heritable across men and women) and/or qualitative genetic differences (i.e., are different genes involved in migraine across men and women) were present. Next, we used a multilevel logistic regression model to compare the prevalence of migraine in individuals from opposite-sex and same-sex twin pairs to determine whether differences in the prenatal hormone environment contribute to migraine risk. In the final analytic sample, women were found to have a significantly higher rate of migraine without aura relative to men (17.6% vs. 5.5%). The results from an ADE sex-limitation model indicate that migraine is equally heritable in men and women, with a broad sense heritability of 0.45, (95% CI = 0.40-0.50), while results from a reduced AE sex-limitation model provide subtle evidence for differences in the genes underlying migraine across men and women. The logistic regression analysis revealed a significant increase in migraine risk for females with a male co-twin relative to females with a female co-twin (OR = 1.51, 95% CI = 1.26-1.81). These results suggest that the prominent sex difference in migraine prevalence is not entirely accounted for by genetic factors, while demonstrating that masculinization of the prenatal environment may increase migraine risk for females. This effect points to a potential prenatal neuroendocrine factor in the development of migraine.

Using the tools of genetic epidemiology to understand sex differences in neuropsychiatric disorders

Many neuropsychiatric disorders exhibit differences in prevalence, age of onset, symptoms or course of illness between males and females. For the most part, the origins of these differences are not well understood. In this article, we provide an overview of sex differences in psychiatric disorders including autism spectrum disorder (ASD), attention deficit/hyperactivity disorder (ADHD), anxiety, depression, alcohol and substance abuse, schizophrenia, eating disorders and risk of suicide. We discuss both genetic and nongenetic mechanisms that have been hypothesized to underlie these differences, including ascertainment bias, environmental stressors, X‐ or Y‐linked risk loci, and differential liability thresholds in males and females. We then review the use of twin, family and genome‐wide association approaches to study potential genetic mechanisms of sex differences and the extent to which these designs have been employed in studies of psychiatric disorders. We describe the utility of genetic epidemiologic study designs, including classical twin and family studies, large‐scale studies of population registries, derived recurrence risks, and molecular genetic analyses of genome‐wide variation that may enhance our understanding sex differences in neuropsychiatric disorders.

Linking migraine frequency with family history of migraine

Background

Migraine is a complex genetic disorder that is brought about by multiple genetic and environmental factors. We aimed to assess whether migraine frequency is associated with genetic susceptibility.

Methods

We investigated in 2829 migraine patients (14% males) whether ‘migraine frequency’ (measured as the number of migraine days per month) was related to ‘genetic load’ (measured as the number of parents affected with migraine) using a validated web-based questionnaire. In addition, we investigated associations with age-at-onset, migraine subtype, use of acute headache medication, and comorbid depression.

Results

We found an association between the number of migraine days per month and family history of migraine for males (p = 0.03), but not for females (p = 0.97). This association was confirmed in a linear regression analysis. Also, a lower age-at-onset (p < 0.001), having migraine with aura (p = 0.03), and a high number of medication days (p = 0.006) were associated with a stronger family history of migraine, whereas lifetime depression (p = 0.13) was not.

Discussion

Migraine frequency, as measured by the number of migraine days per month, seems associated with a genetic predisposition only in males. A stronger family history of migraine was also associated with a lower age-at-onset, a higher number of medication days, and migraine with aura. Our findings suggest that specific clinical features of migraine seem more determined by genetic factors.

Sex differences in the epidemiology, clinical features, and pathophysiology of migraine

Migraine is two to three times more prevalent in women than men, and women report a longer attack duration, increased risk of headache recurrence, greater disability, and a longer period of time required to recover. Conditions recognised to be comorbid with migraine include asthma, anxiety, depression, and other chronic pain conditions, and these comorbidities add to the amount of disability in both sexes. Migraine-specifically migraine with aura-has been identified as a risk factor for vascular disorders, particularly in women, but because of the scarcity of data, the comparative risk in men has yet to be established. There is evidence implicating the role of female sex hormones as a major factor in determining migraine risk and characteristics, which accounts for sex differences, but there is also evidence to support underlying genetic variance. Although migraine is often recognised in women, it is underdiagnosed in men, resulting in suboptimal management and less participation of men in clinical trials.

The effect of poor sleep quality on mood outcome differs between men and women: A longitudinal study of bipolar disorder

BACKGROUND

Sleep disturbance is bi-directionally related to mood de-stabilization in bipolar disorder (BD), and sleep quality differs in men and women. We aimed to determine whether perception of poor sleep quality would have a different effect on mood outcome in men versus women.

METHODS

We assessed association between sleep quality (Pittsburgh Sleep Quality Index (PSQI)) at study intake and mood outcome over 2 years in subjects from the Prechter Longitudinal Study of Bipolar Disorder (N=216; 29.6% males). The main outcome measure was the severity, variability, and frequency of mood episodes measured by self-report over 2 years of follow-up. Multivariable linear regression models stratified by sex examined the relationship between PSQI with mood outcomes, while age, stressful life events, mood state and neuroticism at baseline were controlled.

RESULTS

In women, poor sleep quality at baseline predicted increased severity (B=0.28, p<0.001) and frequency of episodes (B=0.32, p<0.001) of depression, and poor sleep quality was a stronger predictor than baseline depression; poor sleep quality predicted increased severity (B=0.19, p<0.05) and variability (B=0.20, p<0.05) of mania, and frequency of mixed episodes (B=0.27, p<0.01). In men, baseline depression and neuroticism were stronger predictors of mood outcome compared to poor sleep quality.

LIMITATIONS

We measured perception of sleep quality, but not objective changes in sleep.

CONCLUSIONS

In a longitudinal study of BD, women reported poorer perceived sleep quality than men, and poor sleep quality predicted worse mood outcome in BD. Clinicians should be sensitive to addressing sleep complaints in women with BD early in treatment to improve outcome in BD.

Sex-related differences in migraine

This paper reviews sex-related differences in migraine epidemiology, symptoms, natural history and co-morbid disorders. Migraine is more than twice as common in females as in males, and women experience more frequent, longer lasting and more painful attacks, have more disability and a risk of transition from episodic to chronic migraine greater than men, but the mechanisms behind these differences are still poorly understood. The role of sex hormones, genes, and the differences in brain function and structure are discussed. Finally, we evaluate the many gender-related questions about treatment of migraine in women. In future research data should be analyzed separately for men and women to ensure that differences between the sexes could be identified.

Pharmacoinformatics elucidation of potential drug targets against migraine to target ion channel protein KCNK18

Migraine, a complex debilitating neurological disorder is strongly associated with potassium channel subfamily K member 18 (KCNK18). Research has emphasized that high levels of KCNK18 may be responsible for improper functioning of neurotransmitters, resulting in neurological disorders like migraine. In the present study, a hybrid approach of molecular docking and virtual screening were followed by pharmacophore identification and structure modeling. Screening was performed using a two-dimensional similarity search against recommended migraine drugs, keeping in view the physicochemical properties of drugs. LigandScout tool was used for exploring pharmacophore properties and designing novel molecules. Here, we report the screening of four novel compounds that have showed maximum binding affinity against KCNK18, obtained through the ZINC database, and Drug and Drug-Like libraries. Docking studies revealed that Asp-46, Ile-324, Ile-44, Gly-118, Leu-338, Val-113, and Phe-41 are critical residues for receptor–ligand interaction. A virtual screening approach coupled with docking energies and druglikeness rules illustrated that ergotamine and PB-414901692 are potential inhibitor compounds for targeting KCNK18. We propose that selected compounds may be more potent than the previously listed drug analogs based on the binding energy values. Further analysis of these inhibitors through site-directed mutagenesis could be helpful for exploring the details of ligand-binding pockets. Overall, the findings of this study may be helpful for designing novel therapeutic targets to cure migraine.

Gender differences, clinical correlates, and longitudinal outcome of bipolar disorder with comorbid migraine

OBJECTIVE

Migraine is a common comorbidity of bipolar disorder and is more prevalent in women than men. We hypothesized comorbid migraine would be associated with features of illness and psychosocial risk factors that would differ by gender and impact outcome.

METHOD

A retrospective analysis was conducted to assess association between self-reported, physician-diagnosed migraine, clinical variables of interest, and mood outcome in subjects with DSM-IV bipolar disorder (N = 412) and healthy controls (N = 157) from the Prechter Longitudinal Study of Bipolar Disorder, 2005-2010. Informed consent was obtained from all participants.

RESULTS

Migraine was more common in subjects with bipolar disorder (31%) than in healthy controls (6%) and had elevated risk in bipolar disorder women compared to men (OR = 3.5; 95% CI, 2.1-5.8). In men, migraine was associated with bipolar II disorder (OR = 9.9; 95% CI, 2.3-41.9) and mixed symptoms (OR = 3.5; 95% CI, 1.0-11.9). In comparison to absence of migraine, presence of migraine was associated with an earlier age at onset of bipolar disorder by 2 years, more severe depression (β = .13, P = .03), and more frequent depression longitudinally (β = .13, P = .03). Migraine was correlated with childhood emotional abuse (P = .01), sexual abuse (P = 4 × 10⁻³), emotional neglect (P = .01), and high neuroticism (P = 2 × 10⁻³). Protective factors included high extraversion (P = .02) and high family adaptability at the trend level (P = .08).

CONCLUSIONS

Migraine is a common comorbidity with bipolar disorder and may impact long-term outcome of bipolar disorder, particularly depression. Clinicians should be alert for migraine comorbidity in women and in men with bipolar II disorder. Effective treatment of migraine may impact mood outcome in bipolar disorder as well as headache outcome. Joint pathophysiologic mechanisms between migraine and bipolar disorder may be important pathways for future study of treatments for both disorders.

Interaction between γ-aminobutyric acid A receptor genes: new evidence in migraine susceptibility

Migraine is a common neurological episodic disorder with a female-to-male prevalence 3- to 4-fold higher, suggesting a possible X-linked genetic component. Our aims were to assess the role of common variants of gamma-aminobutyric acid A receptor (GABA_AR) genes, located in the X-chromosome, in migraine susceptibility and the possible interaction between them. An association study with 188 unrelated cases and 286 migraine-free controls age- and ethnic matched was performed. Twenty-three tagging SNPs were selected in three genes (GABRE, GABRA3 and GABRQ). Allelic, genotypic and haplotypic frequencies were compared between cases and controls. We also focused on gene-gene interactions. The AT genotype of rs3810651 of GABRQ gene was associated with an increased risk for migraine (OR: 4.07; 95% CI: 1.71-9.73, p=0.002), while the CT genotype of rs3902802 (OR: 0.41; 95% CI: 0.21-0.78, p=0.006) and GA genotype of rs2131190 of GABRA3 gene (OR: 0.53; 95% CI: 0.32-0.88, p=0.013) seem to be protective factors. All associations were found in the female group and maintained significance after Bonferroni correction. We also found three nominal associations in the allelic analyses although there were no significant results in the haplotypic analyses. Strikingly, we found strong interactions between six SNPs encoding for different subunits of GABA_AR, all significant after permutation correction. To our knowledge, we show for the first time, the putative involvement of polymorphisms in GABA_AR genes in migraine susceptibility and more importantly we unraveled a role for novel gene-gene interactions opening new perspectives for the development of more effective treatments.

Sex-related differences in epidemiological and clinic-based headache studies

This manuscript discusses sex-related differences in headache prevalence, the symptoms and natural history of migraine, associated disability, and co-morbid disorders. The role of sex hormones is discussed with reference to the effects of hormonal events across the reproductive years and the specific effects of the menstrual cycle on migraine. Differences between the sexes were identified across all parameters reviewed. Future research should ensure that data are analyzed separately for men and women to ensure that differences between the sexes are identified.

Assessing risk factors for migraine: differences in gender transmission

Aim

Our aim was to assess which specific factors are contributing to an increased risk of migraine in a group of 131 Portuguese families.

Methods

We studied 319 first-degree relatives, using a multilevel approach to account for the dependency among members from the same family. We included in the model relative’s gender, the proband’s gender and age-at-onset, to evaluate if any of these variables were associated with relative’s affection status. We also included in the model proband’s migraine subtype. We further assessed female and male transmissions within the proband nuclear family.

Results

Relatives’ gender was found to be a risk factor for migraine (Odds Ratio = 2.86; 95% CI = 1.75–4.67), with females at a higher risk. When splitting probands according to their migraine subtype, we found that none of the variables studied contributed to relatives of MA-probands affection-status. Our results also show a significant difference between proband’s transmission and the gender of the parents and offspring.

Conclusions

With this study, we showed that gender is truly a risk factor for migraine and that a gender-biased transmission is also observed. This reinforce the importance of identifying genes associated with migraine that are modulated by genes located in the sex chromosomes and the study of mitochondrial DNA or X-chromosome and hormonal-related effects associated with migraine susceptibility.

Comorbidity of migraine and mood episodes in a nationally representative population-based sample

OBJECTIVE

To examine the lifetime comorbidity of migraine with different combinations of mood episodes: (1) manic episodes alone; (2) depressive episodes alone; (3) manic and depressive episodes; (4) controls with no lifetime history of mood episodes, as well as sociodemographic and clinical correlates of migraine for each migraine-mood episode combination.

BACKGROUND

Migraine has been found to be comorbid with bipolar disorder and major depressive disorder in clinical and population-based samples. However, variability in findings across studies suggests that examining mood episodes separately may be fruitful in determining which of these mood episodes are specifically associated with migraine.

METHODS

Using a cross-sectional, population-based sample from the Canadian Community Health Survey 1.2 (n = 36,984), sociodemographic and clinical correlates of migraine were examined in each combination of mood episodes as well as controls. Logistic regression analyses controlling for age, sex, and education level compared the lifetime prevalence of migraine (1) between controls and each combination of mood episodes, and then (2) among the different combinations of mood episodes.

RESULTS

Migraine comorbidity in all combinations of mood episodes was associated with lower socioeconomic status, earlier onset of affective illness, more anxiety, suicidality and use of mental health resources. Compared with controls, the adjusted odds ratio of having migraine was 2.0 (95% confidence interval [CI] 1.4-2.8) for manic episodes alone, 1.9 (95% CI 1.6-2.1) for depressive episodes alone, and 3.0 (95% CI 2.3-3.9) for subjects with both manic and depressive episodes. Compared with those with manic episodes alone and depressive episodes alone, the odds of having migraine were significantly increased in subjects with both manic and depressive episodes (odds ratio 1.5 vs. manic episodes alone; 1.8 vs. depressive episodes alone). In addition, migraine comorbidity was associated with different correlates depending on the specific combination of mood episodes; in subjects with both manic and depressive episodes, migraine comorbidity was associated with an earlier onset of mental illness, while in subjects with either manic or depressive episodes alone, migraine comorbidity was associated with increased suicidality and anxiety.

CONCLUSIONS

Migraine comorbidity appears to delineate a subset of individuals with earlier onset of affective illness and more psychiatric complications, suggesting that migraine assessment in mood disorder patients may be useful as an indicator of potential clinical severity. Differences in the prevalence of migraine as well as sociodemographic and clinical correlates associated with specific combinations of mood episodes underscore the importance of examining this comorbidity by specific type of mood episode.

Headache following intracranial neuroendovascular procedures

AIMS

Predicting who will develop post-procedure headache (PPH) following intracranial endovascular procedures (IEPs) would be clinically useful and potentially could assist in reducing the excessive diagnostic testing so often obtained in these patients. Although limited safety data exist, the use of triptans or dihydroergotamine (DHE) often raise concern when used with pre/post-coiled aneurysms. We sought to determine risk factors for PPH following IEP, to evaluate the utility of diagnostic testing in patients with post-coil acute headache (HA), and to record whether triptans and DHE have been used safely in this clinical setting.

METHODS

We conducted a retrospective chart review of adult patients undergoing IEPs. Bivariate analyses were conducted to compare patients who did and did not develop PPH.

RESULTS

We reviewed records pertaining to 372 patients, of whom 263 underwent intracranial coil embolizations, 21 acrylic glue embolizations, and 88 stent placements. PPH occurred in 72% of coil patients, 33% of glue patients, and 14% of stent patients. Significant risk factors for post-coil HA were female gender, any pre-coil HA history, smoking, and anxiety/depression. A pre-stent history of HA exceeding 1 year's duration, and smoking were risk factors for post-stent HA. A pre-glue history of HA exceeding 1 year was the only risk factor for post-glue HA. In the small subgroup available for study, treatment with triptans or DHE was not associated with adverse events in pre/post-coiled aneurysms. Diagnostic testing was low yield.

CONCLUSIONS

Occurrence of PPH was common after IEPs and especially so with coiling and in women, smokers, and those with anxiety/depression, and was often of longer duration than allowed by current International Classification of Headache Disorders-II criteria. The yield of diagnostic testing was low, and in a small subgroup treatment with triptans or DHE did not cause adverse events in pre/post-coiled aneurysms. Prospective studies are needed to confirm these findings.

Migraine as a sex-conditioned inherited disorder: evidences from China and the world

Migraine is a complex and heterogeneous disorder. Although several genetic models has been proposed including autosomal-dominant/autosomal recessive, sex-linked, sex-limited, mitochondrial, and multi-gene, none of these models can well-explain the transmission of the disease. We hypothesied that migraine is a sex-conditioned inherited disorder (autosomal dominant in females and autosomal recessive in males). This hypothesis is supported by the evidence such as the locations of genes associated with familial hemiplegic migraine, possibly "typical" migraine as well (dominantly on chromosome 19p, 1q, and 2q), male:female ratio of prevalence (1:2-1:4), the mostly youth-onset, the provocation by the contraceptives, the induction by menstruation, and the self-limitation after menopause. Female sex-hormones appear to be the key contributor to a higher prevalence of migraine in female. Socio-environmental factors may also play an important role.