Co-morbidity of migraine with somatic disease in a large population-based study

Comorbidity in Migraine with Functional Somatic Syndromes, Psychiatric Disorders and Inflammatory Diseases: A Matter of Central Sensitization?

To approach the questions as to why migraine appears to be associated with functional somatic syndromes (FSSs) and whether central sensitization may be an underlying mechanism, the present study investigated (a) comorbidity with diagnoses of three FSSs, three psychiatric disorders, and three inflammatory diseases, (b) degree of mental health problems (stress, burnout, anxiety, depression and somatization), and (c) prevalence of ten cognitive/affective and nine airway symptoms in persons with migraine in the general population. From a randomized and stratified Swedish adult sample, questionnaire data were analyzed from 151 individuals with a diagnosis of migraine and 3,255 without migraine. The results showed (a) significant comorbidity in migraine with all FSSs, psychiatric disorders and inflammatory diseases, (b) significantly elevated scores on stress, burnout, anxiety, depression, and somatization, and (c) relatively high prevalence rates on almost all symptoms. Taken together, the results motivate future study of central sensitization as a mechanism underlying migraine.

Headache Disorders May Be a Risk Factor for the Development of New Onset Hypothyroidism

OBJECTIVE

To determine whether headache disorders are a risk factor for the development of new onset hypothyroidism.

BACKGROUND

Past studies have reported associations between headache disorders and hypothyroidism, but the directionality of the association is unknown.

METHODS

This was a longitudinal retrospective cohort study using data from the Fernald Medical Monitoring Program (FMMP). Residents received physical examinations and thyroid function testing every 3 years during the 20 year program. Residents were excluded from the cohort if there was evidence of past thyroid disease or abnormal thyroid function tests at the first office visit. A diagnosis of a headache disorder was established by self-report of "frequent headaches," use of any headache-specific medication, or a physician diagnosis of a headache disorder. The primary outcome measure was new onset hypothyroidism defined as the initiation of thyroid replacement therapy or TSH ≥ 10 without thyroid medication. A Cox survival analysis with time dependent variables were used for the model. Headache disorders, age, sex, body mass index, income, smoking, narcotic use, and hypothyroidism-producing medications were independent variables in the model.

RESULTS

Data from 8412 residents enrolled in the FMMP were used in the current study. Headache disorders were present in about 26% of the residents and new onset hypothyroidism developed in ∼7%. The hazard ratio for the development of new onset hypothyroidism was 1.21 (95% CI = 1.001, 1.462) for those with headache disorders.

CONCLUSIONS

Headache disorders may be associated with an increased risk for the development of new onset hypothyroidism.

Increased risk of rheumatoid arthritis in patients with migraine: a population-based, propensity score-matched cohort study

Previous cross-sectional studies have suggested an association between migraine and rheumatoid arthritis (RA), but no longitudinal study has been performed to evaluate the temporal relationship between the two conditions. The purpose of the present population-based, propensity score-matched cohort study was to investigate whether migraineurs are at a higher risk of developing RA. A total of 58,749 subjects aged between 20 and 90 years with at least two ambulatory visits with a diagnosis of migraine were recruited in the migraine group. We fit a logistic regression model that included age, sex, comorbid conditions, and socioeconomic status as covariates to compute the propensity score. The non-migraine group consisted of 58,749 propensity score-matched, randomly sampled subjects without migraine. The RA-free survival curves were generated using the Kaplan-Meier method. Stratified Cox proportional hazard regression was used to estimate the effect of migraine on the risk of RA. During follow-up, 461 subjects in the migraine group and 220 in the non-migraine group developed RA. The incidence rate of RA was 3.18 (95% confidence interval [CI] 2.90-3.49) per 1000 person-years in the migraine group and 1.54 (95% CI 1.34-1.76) per 1000 person-years in the non-migraine group. Compared to the non-migraine group, the crude hazard ratio of RA for the migraine group was 2.15 (95% CI 1.82-2.56, P < 0.0001), and the multivariable-adjusted hazard ratio was 1.91 (95% CI 1.58-2.31, P < 0.0001). This study showed that patients with migraine had an increased risk of developing RA.

Nanobiomaterials' applications in neurodegenerative diseases

The blood-brain barrier is the interface between the blood and brain, impeding the passage of most circulating cells and molecules, protecting the latter from foreign substances, and maintaining central nervous system homeostasis. However, its restrictive nature constitutes an obstacle, preventing therapeutic drugs from entering the brain. Usually, a large systemic dose is required to achieve pharmacological therapeutic levels in the brain, leading to adverse effects in the body. As a consequence, various strategies are being developed to enhance the amount and concentration of therapeutic compounds in the brain. One such tool is nanotechnology, in which nanostructures that are 1-100 nm are designed to deliver drugs to the brain. In this review, we examine many nanotechnology-based approaches to the treatment of neurodegenerative diseases. The review begins with a brief history of nanotechnology, followed by a discussion of its definition, the properties of most reported nanomaterials, their biocompatibility, the mechanisms of cell-material interactions, and the current status of nanotechnology in treating Alzheimer's, Parkinson's diseases, and amyotrophic lateral sclerosis. Of all strategies to deliver drug to the brain that are used in nanotechnology, drug release systems are the most frequently reported.

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.

Does central sensitization help explain idiopathic overactive bladder?

The pathophysiological mechanisms underlying overactive bladder syndrome (OAB) can include dysfunction of sensory pathways of the peripheral and central nervous systems, resulting in bladder hypersensitivity. Central sensitization describes an induced state of spinal hypersensitivity that is associated with a variety of chronic pain disorders that share many attributes with OAB, albeit without the presence of pain. As such, the concept of central sensitization might be relevant to understanding the mechanisms and clinical manifestations of OAB syndrome. An understanding of the pathophysiology and clinical manifestations of central sensitization, and the evidence that supports a role of central sensitization in OAB, including the potential implications of mechanisms of central sensitization for the treatment of patients with OAB could provide a novel approach to the treatment of patients with this disease. Such an approach would be especially relevant to those patients with central sensitization-related comorbidities, and has the potential to improve the outcomes of these patients in particular.

Roads Less Traveled: Sexual Dimorphism and Mast Cell Contributions to Migraine Pathology

Migraine is a common, little understood, and debilitating disease. It is much more prominent in women than in men (~2/3 are women) but the reasons for female preponderance are not clear. Migraineurs frequently experience severe comorbidities, such as allergies, depression, irritable bowel syndrome, and others; many of the comorbidities are more common in females. Current treatments for migraine are not gender specific, and rarely are migraine and its comorbidities considered and treated by the same specialist. Thus, migraine treatments represent a huge unmet medical need, which will only be addressed with greater understanding of its underlying pathophysiology. We discuss the current knowledge about sex differences in migraine and its comorbidities, and focus on the potential role of mast cells (MCs) in both. Sex-based differences in pain recognition and drug responses, fluid balance, and the blood–brain barrier are recognized but their impact on migraine is not well studied. Furthermore, MCs are well recognized for their prominent role in allergies but much less is known about their contributions to pain pathways in general and migraine specifically. MC-neuron bidirectional communication uniquely positions these cells as potential initiators and/or perpetuators of pain. MCs can secrete nociceptor sensitizing and activating agents, such as serotonin, prostaglandins, histamine, and proteolytic enzymes that can also activate the pain-mediating transient receptor potential vanilloid channels. MCs express receptors for both estrogen and progesterone that induce degranulation upon binding. Furthermore, environmental estrogens, such as Bisphenol A, activate MCs in preclinical models but their impact on pain pathways or migraine is understudied. We hope that this discussion will encourage scientists and physicians alike to bridge the knowledge gaps linking sex, MCs, and migraine to develop better, more comprehensive treatments for migraine patients.

Migraine and Puberty: Potential Susceptible Brain Sites

Puberty is a sensitive and critical period for brain development. The relationship between developmental processes in the brain during puberty and the onset of migraine disease in relation to the potential sites of susceptibility in the brain remains largely unknown. There are few data on how such processes interact with each other in influencing the migraine onset during puberty or even later in adulthood. Focusing on the migraine brain during pubertal development may provide us with a "window of opportunity" both to better understand the mechanisms of the disease and, also more importantly, to effectively intervene.

Asthma is a risk factor for new onset chronic migraine: Results from the American migraine prevalence and prevention study

OBJECTIVES

To test the hypothesis that in persons with episodic migraine (EM), asthma is a risk factor for the onset of chronic migraine (CM).

BACKGROUND

Migraine and asthma are comorbid chronic disorders with episodic attacks thought to involve inflammatory and neurological mechanisms. Herein, we assess the influence of asthma on the clinical course of EM.

METHODS

To be eligible for this observational cohort study, AMPP Study participants had to meet criteria for EM in 2008, complete the validated six-item asthma questionnaire from the European Community Respiratory Health Survey (ECRHS) in 2008, and provide follow-up data in 2009. Using the ECRHS, we defined asthma as a binary variable (present or absent) based on an empirical cut score and developed a Respiratory Symptom Severity Score (RSSS) based on the number of positive responses (no severity = 0 positive responses, low severity = 1-2 positive responses, moderate severity = 3-4 positive responses, high severity = 5-6 positive responses). Chronic migraine was the primary outcome measure and was defined as those with ≥15 headache days per month on the 2009 AMPP Study survey. We used logistic regression in separate models to assess the influence of asthma as a binary variable (Model 1) and RSSS score categories (Model 2 using no respiratory symptoms as the reference) on CM onset after adjusting for sociodemographic factors, headache day frequency, migraine preventive medication use, and medication overuse.

RESULTS

The eligible sample for this study included 4446 individuals with EM in 2008 of whom 17% had asthma. This group had a mean age of 50.4 and was 80.8% female. In 2009, new onset CM developed in 2.9% (131/4446) of the 2008 EM cohort, including 5.4% (40/746) of the asthma subgroup and 2.5% (91/3700) of the non-asthma subgroup. In comparison to those without asthma, the adjusted odds for individuals with asthma and EM in 2008 to develop CM in 2009 were greater than two (adjusted odds ratio [aOR] 2.1; 95% CI: 1.4-3.1). Using the RSSS, the aOR for CM onset increased with the number of asthma symptoms, but only those in the high RSSS category showed a statistically significant increase in the odds of chronic migraine onset in comparison with the no RSSS reference group (aOR 3.3; 95% CI 1.7-6.2).

CONCLUSIONS

Asthma is associated with an increased risk of new onset CM 1 year later among individuals with EM, with the highest risk being among those with the greatest number of respiratory symptoms. The exact mechanisms underlying this association are unknown, but could suggest mast cell degranulation, autonomic dysfunction, or shared genetic or environmental factors.

Risk of sudden sensorineural hearing loss in patients with psoriasis: a retrospective cohort study

SIGNIFICANCE

Psoriasis, a common immune-mediated disease, affects approximately 2% of the population worldwide. Sudden sensorineural hearing loss (SSNHL) might be a manifestation of systemic vascular involvement in autoimmune disease. However, to the best of our knowledge, there is no systematic English-language examination of the risk of SSNHL in patients with psoriasis.

OBJECTIVES

We tested the hypothesis that psoriasis is a risk factor for developing SSNHL.

METHODS

Using Taiwan's National Health Insurance Research Database, we conducted a retrospective cohort study to compare patients diagnosed with psoriasis from January 1, 2001 through December 31, 2006 (n=28,817) with gender-, age-, and comorbidities-matched controls (n=28,817). We followed each patient until the end of 2011 and evaluated the incidence of SSNHL for at least 6 years after the initial psoriasis diagnosis.

RESULTS

The incidence of SSNHL was 1.51 times higher in the psoriasis cohort than in the control cohort (7.12 vs 4.73 per 10,000 person-years). Using Cox proportional hazard regressions, the adjusted hazard ratio (AHR) was 1.51 (95% confidence interval [CI] 1.18-1.93). Comorbid hypertension was an independent risk factor for SSNHL (AHR 1.49; 95% CI 1.05-2.13). However, the incidence rate ratios (IRRs) for each comorbidity subgroup in the psoriasis and control cohorts were not significantly different.

CONCLUSIONS AND RELEVANCE

Psoriasis was significantly associated with a higher risk of developing SSNHL. We suggest that physicians advise patients with psoriasis to seek medical attention if they have hearing impairments, because they may also have a higher risk of developing SSNHL.

Genetic analysis for a shared biological basis between migraine and coronary artery disease

OBJECTIVE

To apply genetic analysis of genome-wide association data to study the extent and nature of a shared biological basis between migraine and coronary artery disease (CAD).

METHODS

Four separate methods for cross-phenotype genetic analysis were applied on data from 2 large-scale genome-wide association studies of migraine (19,981 cases, 56,667 controls) and CAD (21,076 cases, 63,014 controls). The first 2 methods quantified the extent of overlapping risk variants and assessed the load of CAD risk loci in migraineurs. Genomic regions of shared risk were then identified by analysis of covariance patterns between the 2 phenotypes and by querying known genome-wide significant loci.

RESULTS

We found a significant overlap of genetic risk loci for migraine and CAD. When stratified by migraine subtype, this was limited to migraine without aura, and the overlap was protective in that patients with migraine had a lower load of CAD risk alleles than controls. Genes indicated by 16 shared risk loci point to mechanisms with potential roles in migraine pathogenesis and CAD, including endothelial dysfunction (PHACTR1) and insulin homeostasis (GIP).

CONCLUSIONS

The results suggest that shared biological processes contribute to risk of migraine and CAD, but surprisingly this commonality is restricted to migraine without aura and the impact is in opposite directions. Understanding the mechanisms underlying these processes and their opposite relationship to migraine and CAD may improve our understanding of both disorders.

Gender aspects of the relationship between migraine and cardiovascular risk factors: A cross-sectional evaluation in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Background

The relationship between cardiovascular risk factors (CVRF) and migraine is controversial and might be different in both genders. These associations were evaluated in Brazilian middle-aged men and women from the Longitudinal Study of Adult Health (ELSA-Brasil).

Methods

The cross-sectional relationship between our main outcome, which was migraine headache (definite, probable and overall), and CVRF was evaluated in the total sample and according to gender. We calculated frequencies and odds ratios (95% CI) for this relationship using binary and multinomial logistic regression analyses in crude, age-adjusted and multivariable models adjusted by potential confounders.

Results

Of 14,953 individuals who completed the data about headache and CVRF, the frequency of one-year migraine was of 29.5% (22.5% in women and 7.0% in men). In the multivariable-adjusted regression analyses, an inverse association between hypertension (OR, 0.53; 95% CI, 0.36–0.79), metabolic syndrome (OR, 0.65; 95% CI, 0.43–0.99) and definite migraine were confirmed for men, but not for women. In the opposite direction, a positive association between migraine headaches (definite, probable and overall) and dyslipidemia (overall migraine OR, 1.25; 95% CI, 1.13–1.38) was observed only for women, but not for men.

Conclusions

A gender influence on the relationship between migraine and CVRF was verified in the ELSA-Brasil.

Lifetime prevalence and underdiagnosis of migraine in a population sample of Mexican women

OBJECTIVE

The objective of this report is to evaluate migraine, migraine characteristics, and underdiagnosis of migraine in a large population sample of Mexican women.

METHODS

Participants are part of a prospective cohort of Mexican teachers. Between 2011 and 2013, 77,855 participants completed a detailed questionnaire on headache characteristics. Migraine was defined according to criteria of the International Classification of Headache Disorders (ICDH-II).

RESULTS

We found lifetime migraine prevalence was 19%, prevalence peaked at 40-44 years (20.4%) and only 45.1% participants with migraine had a previous diagnosis of the disease.

CONCLUSION

Estimated lifetime prevalence of migraine was higher than previous reports in Latin America. Migraine may be underdiagnosed and undertreated in Mexico despite its considerable burden.

Worldwide epidemiology of fibromyalgia

Studying the epidemiology of fibromyalgia (FM) is very important to understand the impact of this disorder on persons, families and society. The recent modified 2010 classification criteria of the American College of Rheumatology (ACR), without the need of tender points palpation, allows that larger and nationwide surveys may be done, worldwide. This article reviews the prevalence and incidence studies done in the general population, in several countries/continents, the prevalence of FM in special groups/settings, the association of FM with some sociodemographic characteristics of the population, and the comorbidity of FM with others disorders, especially with headaches.

Contributions of epidemiology to our understanding of migraine

BACKGROUND

During the past decade, the introduction of the second edition of the International Classification of Headache Disorders (ICHD-II) and the initiation of active campaigns to increase awareness of the high magnitude, burden, and impact of migraine have stimulated numerous studies of population-based data on the prevalence, correlates, and impact of migraine.

OBJECTIVE

This paper provides an update of the literature on the worldwide epidemiology of migraine from studies that included the ICHD-II criteria. The aims of this paper are: (1) to review evidence regarding the magnitude of migraine; (2) to summarize information on the correlates and impact of migraine; and (3) to discuss the contributions, challenges, and future directions in the epidemiology of migraine. Evidence on the magnitude of migraine is divided into the following types of data: (1) prevalence rates of ICHD-II-defined migraine and tension-type headache from international population-based studies of adults; (2) the magnitude of migraine in U.S. studies; (3) ICHD-II-based international prevalence rates of ICHD-II-defined migraine in children; and (4) incidence rates of migraine from prospective longitudinal studies.

METHODS

A comprehensive review of the literature on the prevalence of migraine subtypes and tension-type headache defined by ICHD-II criteria during the past decade was conducted and aggregate weighted rates across studies were derived.

RESULTS

Across the 19 studies of adults that employed the ICHD-II criteria, the aggregate weighted estimates of the 12-month prevalence of definite migraine are 11.5%, and probable migraine of 7%, yielding a total of 18.5%. The cross-study weighted aggregate rate of migraine with aura is 4.4%, chronic migraine is 0.5%, and of tension-type headache is 13%. There has been even greater growth in international prevalence data on migraine in children, with a total of 21 studies of children that have employed the ICDH-II criteria. The aggregate weighted rate of definite migraine in children is 10.1% and migraine with aura is 1.6%. The well-established demographic correlates of migraine including the equal sex ratio in childhood, with increasing prevalence of migraine in females across adolescence to mid-adulthood were confirmed in these studies. Despite increasing effort to increase awareness of migraine, approximately 50% of those with frequent and/or severe migraine do not receive professional treatment.

CONCLUSIONS

This review demonstrates that the descriptive epidemiology of migraine has reached its maturity. The prevalence rates and sociodemographic correlates have been stable across 50 years. These developments justify a shift in efforts to the application of the designs and methods of analytic epidemiology. Retrospective case-control studies followed by prospective cohort studies that test specific associations are likely to enhance our understanding of the predictors of incidence and progression of migraine, subtypes of migraine with differential patterns of onset and course, and specific environmental exposures that may have either causal or provocative influences on migraine etiology.

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.

Migraine before rupture of intracranial aneurysms

Background

Rupture of a saccular intracranial aneurysm (SIA) causes thunderclap headache but it remains unclear whether headache in general and migraine in particular are more prevalent in patients with unruptured SIA.

Methods

In a prospective case–control study 199 consecutive patients with SIA (103 females and 96 males, mean age: 43.2 years) received a semistructured face to face interview focusing on past headaches. All were admitted to hospital mostly because of rupture (177) or for unruptured aneurysm (22). In parallel we interviewed 194 blood donors (86 females, 108 males, mean age: 38.4 years). Diagnoses were made according to the International Headache Society criteria. Aneurysms were diagnosed by conventional cerebral angiography.

Results

During the year before rupture, 124 (62.3%) had one or more types of headache. These headaches included: migraine without aura (MO): 78 (39.2%), migraine with aura (MA): 2 (1%), probable migraine (PM): 4 (2%), tension-type headache (TTH): 39 (19.6%), cluster headache (CH): 2 (1%), posttraumatic headaches (PH): 2 (1%). 1-year prevalence of headaches in controls was 32.5% (63 patients out of 194), they included: TTH: 45 (23.1%), MO: 17(8.8%), PH: 1(0.5%). Only the prevalence of MO was significantly higher in patients with SIA (OR 6.7, 95% CI 3.8-11.9, p < 0.0001).

Conclusions

Unruptured SIA cause a marked increase in the prevalence of migraine without aura but not in the prevalence of other types of headache.

Application of density estimation algorithms in analyzing co-morbidities of migraine

In this study, we will propose a density estimation based data analysis procedure to investigate the co-morbid associations between migraine and the suspected diseases. The primary objective of this study has aimed to develop a novel analysis procedure that can discover insightful knowledge from large medical databases. The entire analysis procedure consists of two stages. During the first stage, a kernel density estimation algorithm named relaxed variable kernel density estimation (RVKDE) is invoked to identify the samples of interest. Then, in the second stage, a density estimation algorithm based on generalized Gaussian components and named G²DE is invoked to provide a summarized description of the distribution. The results obtained by applying the proposed two-staged procedure to analyze co-morbidities of migraine revealed that the proposed procedure could effectively identify a number of clusters of samples with distinctive characteristics. The results further revealed that the distinctive characteristics of the clusters extracted by the proposed procedure were in conformity with the observations reported in recently published articles. Accordingly, it is conceivable that the proposed analysis procedure can be exploited to provide valuable clues of pathogenesis and facilitate development of proper treatment strategies.

Anxiety and depression are associated with migraine and pain in general: an investigation of the interrelationships

There is a well-established comorbidity between migraine and anxiety and depression (A/D). Here, we investigate whether this relationship is specific for migraine and A/D or whether other types of pain are also consistently associated with A/D. In addition, we test whether there is a consistent association between migraine and other types of pain when comorbidity with A/D is controlled for. Data on A/D, migraine, and 6 nonheadache pain locations (back, neck, orofacial area, abdomen, joints, and chest) were analyzed in 2,981 participants from the Netherlands Study of Depression and Anxiety (NESDA). It was tested whether the prevalence of pain in each individual location, as well as the total number of pain locations, depended on A/D and migraine status. A/D was consistently associated with pain in all measured locations. Migraine was also associated with pain in all anatomical sites, but these associations weakened substantially after correction for A/D severity, suggesting that a considerable part of the comorbidity of migraine and other types of pain may be explained by A/D. These findings emphasize the importance of accounting for A/D in studies of pain comorbidity. This will contribute to a better understanding of the mechanisms underlying A/D and pain.

PERSPECTIVE

Anxiety and depression are consistently associated with pain, regardless of anatomical site. These disorders may be important factors in the co-occurrence of different pain disorders. Awareness of this comorbidity and a better understanding of the underlying mechanisms may facilitate adequate treatment of both types of conditions.

Her versus his migraine: multiple sex differences in brain function and structure

Migraine is twice as common in females as in males, but the mechanisms behind this difference are still poorly understood. We used high-field magnetic resonance imaging in male and female age-matched interictal (migraine free) migraineurs and matched healthy controls to determine alterations in brain structure. Female migraineurs had thicker posterior insula and precuneus cortices compared with male migraineurs and healthy controls of both sexes. Furthermore, evaluation of functional responses to heat within the migraine groups indicated concurrent functional differences in male and female migraineurs and a sex-specific pattern of functional connectivity of these two regions with the rest of the brain. The results support the notion of a 'sex phenotype' in migraine and indicate that brains are differentially affected by migraine in females compared with males. Furthermore, the results also support the notion that sex differences involve both brain structure as well as functional circuits, in that emotional circuitry compared with sensory processing appears involved to a greater degree in female than male migraineurs.

Migraine and risk of incident diabetes in women: a prospective study

BACKGROUND

Previous cross-sectional studies evaluating the relationship between diabetes prevalence and migraine status have found conflicting results. We examined the relationship between migraine and incident type 2 diabetes (T2D) in a cohort of adult women.

METHODS

Prospective cohort study conducted among participants in the Women's Health Study who provided information on migraine and did not have diabetes at baseline. Our four exposure groups were migraine with aura, migraine without aura, past history of migraine and no history of migraine. Cox proportional hazards models were used to determine the hazard ratio for incident T2D.

RESULTS

Among the 38,620 women included in this study, 5062 (13.1%) women had migraine, of whom 2014 (39.8%) reported migraine with aura, and 2087 (5.4%) women had a past history of migraine. During a mean of 14.6 years of follow-up, there were 3032 cases of incident T2D. After adjustment for confounders, the hazard ratio (95% confidence interval) for developing diabetes was 1.06 (0.91-1.24) for women with migraine with aura, 1.01 (0.89-1.16) for women with migraine without aura, and 1.13 (0.98-1.30) for women with a past history of migraine compared with women with no history of migraine.

CONCLUSION

Results of this prospective study in women do not support an association between migraine and incident T2D.

Prevalence, clinical features and potential therapies for fibromyalgia in primary headaches

Fibromyalgia (FM) syndrome is predominantly related to generation and persistence of central sensitization, which is an aggravating factor for chronic headaches. This review aims to examine the last 11 years of studies on FM and primary headache comorbidity, focusing on prevalence, clinical features and treatments. Chronic forms of migraine and tension-type headache show a high frequency of FM comorbidity. The symptoms characterizing headache patients presenting with FM comorbidity are high headache frequency, poor sleep quality, pericranial tenderness, anxiety and reduction of physical performances. The effects of headache-preventive drugs on factors favoring FM comorbidity were poorly evaluated. Nonpharmacological approaches such as transcranial magnetic stimulation may be an option for treatment of chronic migraine associated with FM.

Late onset and early onset aura: the same disorder

Late onset aura (LOA) is usually considered benign but raises diagnostic uncertainties. We compared individuals with LOA (>45 years of age at aura onset) with those of early onset (EOA) in clinical features, vascular risk factors and imaging, in a retrospective study design including patients with migraine aura and age >44 years at first visit. In 77 cases (51 EOA and 26 LOA), no differences were found in gender distribution, family or personal history of migraine without aura, type of aura symptoms or imaging findings. LOA patients’ were more likely to not fulfil all ICHD-II aura criteria and to lack headache. This data suggest that LOA and EOA are overall identical but there are differences in presentation that deserve a better characterization by a prospective study.

Increase in self-reported migraine prevalence in the Danish adult population: a prospective longitudinal population-based study

OBJECTIVE

It is uncertain whether migraine prevalence has increased in modern society. The aim of this study was to assess any change in migraine prevalence over an 8-year period among the adult population in Denmark.

DESIGN

Prospective longitudinal population-based study.

SETTING

30 000 twin individuals were invited to participate in two cross-sectional questionnaire surveys containing validated questions to diagnose migraine in 1994 and 2002. The twins are representative of the Danish population with regard to migraine and other somatic diseases.

PARTICIPANTS

The 1994 cohort comprised 28 571 twin individuals aged 12-41 years and the 2002 cohort 31 865 twin individuals aged 20-71 years.

OUTCOME MEASURES

Sex-, age- and subtype-specific incidence and lifetime prevalence as well as 1-year prevalence of migraine.

RESULTS

1-year prevalence in 2002 was 12.3% for migraine, 4.1% for migraine with aura and 8.2% for migraine without aura. Lifetime prevalence of migraine was 16.1% in 1994 (aged 12-41 years) and 25.2% in 2002 (aged 20-71 years). Lifetime prevalence of migraine for age 20-41 was increased from 1994 to 2002 (18.5% vs 24.5%) by 32.2% (95% CI 27.0% to 37.3%; p<0.001). The difference was primarily seen in the population older than 32 years. The increase was especially evident in migraine with aura (5.6% vs 9.4%, p<0.001) but also a significant increase in migraine without aura was found (13.0% vs 15.1%, p<0.001). Eight-year period incidence rate of migraine was 0.141 corresponding to an average annual incidence rate of 17.6 per 1000 person-years.

CONCLUSIONS

Lifetime prevalence of migraine in Denmark increased substantially from 1994 to 2002. Part of the increase may be due to increased medical consultation resulting in increased rate of physician diagnosis or awareness due to previously participation in the 1994 survey. It is pertinent to study the environmental causes of the increase and to implement preventive measures.

Comorbidities in an asthma population 8-29 years old: a study from the Norwegian Prescription Database

PURPOSE

To examine the occurrence of chronic diseases and antimicrobial treatment in an asthma population 8-29 years old, compared with the general population.

METHODS

In this cross-sectional study, the asthma population was identified from the general population (retrieved from a census covering the entire Norwegian population) using filled prescriptions on asthma drugs as a proxy measure of current asthma. The outcome was excess occurrence of specific diseases (comorbidity) among people with asthma, compared with the age-specific general population. Diseases were defined by filled prescriptions with specific diagnostic codes (International Classification of Primary Care 2nd edition [ICPC-2] or International Classification of Diseases 10th revision [ICD-10]) during a 1-year period in the Norwegian Prescription Database. Nine chronic diseases were examined: attention deficit/hyperactivity disorder, epilepsy, migraine, mental illness, cardiovascular disease, diabetes, autoimmune disorders, gastro-oesophageal reflux disease (GORD), and allergy. Additionally, antibacterials recommended for respiratory tract infections and antivirals were examined (defined by Anatomical Therapeutic Chemical codes). Standardized morbidity ratios (SMR) for each disease were calculated.

RESULTS

Fifty-nine percent of the population with asthma had at least one of nine chronic diseases examined, compared with 18% in the general population. Few individuals with asthma had more than one additional chronic disease (6% of male subjects and 8% of female subjects). SMRs were increased for all diseases except diabetes, implying higher than expected occurrence of the specific diseases in people with asthma. This pattern was observed in both age groups (8-19 and 20-29 years) and genders. Allergy and GORD had highest SMR (range 3.2-4.8), whereas the other diseases were in the range 1.2-2.5.

CONCLUSIONS

An excess occurrence of comorbidities was found in the population with asthma. A majority of people with asthma had one additional chronic disease, and few had more than one.

Association between migraine, lifestyle and socioeconomic factors: a population-based cross-sectional study

To investigate whether sex-specific associations exist between migraine, lifestyle or socioeconomic factors. We distinguished between the subtypes migraine with aura (MA) and migraine without aura (MO). In 2002, a questionnaire containing validated questions to diagnose migraine and questions on lifestyle and socioeconomic factors was sent to 46,418 twin individuals residing in Denmark. 31,865 twin individuals aged 20-71 were included. The twins are representative of the Danish population with regard to migraine and other somatic diseases and were used as such in the present study. An increased risk of migraine was significantly associated with lower level of schooling and education, retirement, unemployment, and smoking. A decreased risk of migraine was significantly associated with heavy physical exercise and intake of alcohol. Direct comparison between the subtypes showed a decreased risk of MA compared to MO in subjects with low education or weekly intake of alcohol. The risk of MA was increased compared to MO in unemployed or retired subjects. Direct comparison between sexes showed a decreased risk of migraine for men compared to women in subjects who were low educated, unemployed or studying. The risk was increased for men compared to women in subjects with heavy physical exercise, intake of alcohol, and body mass index >25. Migraine was associated with several lifestyle and socioeconomic factors. Most associations such as low education and employment status were probably due to the negative effects of having migraine while others such as smoking were risk factors for migraine.