Insulin metabolism is altered in migraineurs: a new pathogenic mechanism for migraine?

Arterial hypertension in the chronic evolution of migraine: bystander or risk factor? An overview

BACKGROUND

Several risk factors are associated with the chronic evolution of migraine. Clinical and preclinical studies have provided data about the role of hypertension (HT) as one of the potential modifiable risk factors of chronic migraine (CM). This review is focused on the biological and clinical evidence supporting common mechanisms underlying HT and migraine and the potential role of HT in the transition from episodic to chronic migraine.

METHODS

We conducted a narrative review from a literature search covering the available evidence from studies investigating: i) the role of HT in the transition to CM in clinical practice; ii) the biological mechanisms potentially underpinning the association between HT and evolution to CM; iii) the role of antihypertensive medications in migraine prophylaxis.

RESULTS

HT proved to be at the base of multiple mechanisms underlying migraine and migraine chronicization. Endothelial dysfunction, blood-brain barrier alterations, calcitonin gene-related peptide signaling, and renin-angiotensin-aldosterone system dysregulation are involved in the worsening effect of HT on migraine frequency, and the role of HT in the transition to CM is supported by clinical observations.

CONCLUSIONS

The observed evidence supports HT contribution to CM evolution due to shared pathophysiologic mechanisms. While a bidirectional influence appears to be ascertained, data are still lacking about the one-way role of HT as direct risk factor for CM transition. Further research is needed to confirm a causal role of HT in this process.

Cross-trait analyses identify shared genetics between migraine, headache, and glycemic traits, and a causal relationship with fasting proinsulin

The co-occurrence of migraine and glycemic traits has long been reported in observational epidemiological studies, but it has remained unknown how they are linked genetically. We used large-scale GWAS summary statistics on migraine, headache, and nine glycemic traits in European populations to perform cross-trait analyses to estimate genetic correlation, identify shared genomic regions, loci, genes, and pathways, and test for causal relationships. Out of the nine glycemic traits, significant genetic correlation was observed for fasting insulin (FI) and glycated haemoglobin (HbA1c) with both migraine and headache, while 2-h glucose was genetically correlated only with migraine. Among 1703 linkage disequilibrium (LD) independent regions of the genome, we found pleiotropic regions between migraine and FI, fasting glucose (FG), and HbA1c, and pleiotropic regions between headache and glucose, FI, HbA1c, and fasting proinsulin. Cross-trait GWAS meta-analysis with glycemic traits, identified six novel genome-wide significant lead SNPs with migraine, and six novel lead SNPs with headache (Pmeta < 5.0 × 10-8 and Psingle-trait < 1 × 10-4), all of which were LD-independent. Genes with a nominal gene-based association (Pgene ≤ 0.05) were significantly enriched (overlapping) across the migraine, headache, and glycemic traits. Mendelian randomisation analyses produced intriguing, but inconsistent, evidence for a causal relationship between migraine and headache with multiple glycemic traits; and consistent evidence suggesting increased fasting proinsulin levels may causally decrease the risk of headache. Our findings indicate that migraine, headache, and glycemic traits share a common genetic etiology and provide genetic insights into the molecular mechanisms contributing to their comorbid relationship.

Association of Migraine and Vasomotor Symptoms

OBJECTIVE

To further examine a potential link between migraine and vasomotor symptoms as well as hypertension as a cardiovascular disease risk factor, potentially explaining the association in midlife women.

PATIENTS AND METHODS

We conducted a cross-sectional analysis from the Data Registry on Experiences of Aging, Menopause, and Sexuality using questionnaire data from women aged 45 to 60 years seen in women's clinics at a tertiary care center from May 15, 2015, through January 31, 2022. A history of migraine was self-reported; menopause symptoms were assessed with the Menopause Rating Scale. Associations between migraine and vasomotor symptoms were evaluated utilizing multivariable logistic regression models adjusting for multiple factors.

RESULTS

Of 5708 women included in the analysis, 1354 (23.7%) reported a migraine history. The total cohort had a mean age of 52.8 years, most (5184 [90.8%]) were White, and 3348 (58.7%) were postmenopausal. In adjusted analysis, women with migraine were significantly more likely to have severe/very severe hot flashes vs no hot flashes compared with women without migraine (odds ratio, 1.34; 95% CI, 1.08 to 1.66; P=.007). Migraine was associated with a diagnosis of hypertension in adjusted analysis (odds ratio, 1.31; 95% CI, 1.11 to 1.55; P=.002).

CONCLUSION

This large cross-sectional study confirms an association between migraine and vasomotor symptoms. Migraine also was associated with hypertension, potentially providing a link with cardiovascular disease risk. Given the high prevalence of migraine in women, this association may help identify those at risk for more severe menopause symptoms.

Effective holistic characterization of small molecule effects using heterogeneous biological networks

The two most common reasons for attrition in therapeutic clinical trials are efficacy and safety. We integrated heterogeneous data to create a human interactome network to comprehensively describe drug behavior in biological systems, with the goal of accurate therapeutic candidate generation. The Computational Analysis of Novel Drug Opportunities (CANDO) platform for shotgun multiscale therapeutic discovery, repurposing, and design was enhanced by integrating drug side effects, protein pathways, protein-protein interactions, protein-disease associations, and the Gene Ontology, and complemented with its existing drug/compound, protein, and indication libraries. These integrated networks were reduced to a "multiscale interactomic signature" for each compound that describe its functional behavior as vectors of real values. These signatures are then used for relating compounds to each other with the hypothesis that similar signatures yield similar behavior. Our results indicated that there is significant biological information captured within our networks (particularly via side effects) which enhance the performance of our platform, as evaluated by performing all-against-all leave-one-out drug-indication association benchmarking as well as generating novel drug candidates for colon cancer and migraine disorders corroborated via literature search. Further, drug impacts on pathways derived from computed compound-protein interaction scores served as the features for a random forest machine learning model trained to predict drug-indication associations, with applications to mental disorders and cancer metastasis highlighted. This interactomic pipeline highlights the ability of Computational Analysis of Novel Drug Opportunities to accurately relate drugs in a multitarget and multiscale context, particularly for generating putative drug candidates using the information gleaned from indirect data such as side effect profiles and protein pathway information.

Defining metabolic migraine with a distinct subgroup of patients with suboptimal inflammatory and metabolic markers

Emerging evidence suggest migraine is a response to cerebral energy deficiency or oxidative stress in the brain. Beta-hydroxybutyrate (BHB) is likely able to circumvent some of the meta-bolic abnormalities reported in migraine. Exogenous BHB was given to test this assumption and, in this post-hoc analysis, multiple metabolic biomarkers were identified to predict  clinical improvements. A randomized clinical trial, involving 41 patients with episodic migraine. Each treatment period was 12 weeks long, followed by eight weeks of washout phase / second run-in phase before entering the corresponding second treatment period. The primary endpoint was the number of migraine days in the last 4 weeks of treatment adjusted for baseline. BHB re-sponders were identified (those with at least a 3-day reduction in migraine days over placebo) and its predictors were evaluated using Akaike's Information Criterion (AIC) stepwise boot-strapped analysis and logistic regression. Responder analysis showed that metabolic markers could identify a "metabolic migraine" subgroup, which responded to BHB with a 5.7 migraine days reduction compared to the placebo. This analysis provides further support for a "metabolic migraine" subtype. Additionally, these analyses identified low-cost and easily accessible biomarkers that could guide recruitment in future research on this subgroup of patients.This study is part of the trial registration: ClinicalTrials.gov: NCT03132233, registered on 27.04.2017, https://clinicaltrials.gov/ct2/show/NCT03132233.

The potential impact of insulin resistance and metabolic syndrome on migraine headache characteristics

Background & objectives

Studying comorbidities with migraine aids in a better understanding of its pathophysiology and potential therapeutic targets. This case-control study aimed to study the impact of insulin resistance and metabolic syndrome on the characteristics of migraine headache attacks.

Methods

A case-control study was conducted on 30 migraine patients and 30 healthy controls. The following data were assessed in migraine patients: type of migraine, duration of attacks, Migraine Severity Scale (MIGSEV), and Headache Impact Test-6 (HIT-6). Both groups were assessed for waist circumference and underwent the following tests: fasting blood glucose, fasting insulin, high-density lipoprotein cholesterol level, and triglycerides, and homeostasis model assessment–insulin resistance (HOMA-IR) was applied.

Results

This study included age and sex-matched patients and controls. Migraine patients had significantly higher waist circumference, higher mean values of serum insulin, HOMA-IR and higher frequency of insulin resistance and metabolic syndrome than the control group (P-value = 0.005, 0.049, 0.01, 0.012, 0.024, respectively). Migraine patients with insulin resistance had significantly higher intensity and tolerability scores, MIGSEV total score, and HIT-6 total score compared to those without (P-value = 0.005, 0.005, 0.002, 0.018, respectively). There was a significantly positive correlation between the MIGSEV and HIT-6 scores and fasting insulin levels, and HOMA-IR value (P-value = 0.006, ≤ 0.001, 0.017, ≤ 0.001, respectively).

Conclusion

Insulin resistance and metabolic syndrome are more common in migraine patients than in healthy controls. The severity and impact of migraine attacks are higher in patients with insulin resistance than in those without.

Alterations in metabolic flux in migraine and the translational relevance

BACKGROUND

Migraine is a highly prevalent disorder with significant economical and personal burden. Despite the development of effective therapeutics, the causes which precipitate migraine attacks remain elusive. Clinical studies have highlighted altered metabolic flux and mitochondrial function in patients. In vivo animal experiments can allude to the metabolic mechanisms which may underlie migraine susceptibility. Understanding the translational relevance of these studies are important to identifying triggers, biomarkers and therapeutic targets in migraine.

MAIN BODY

Functional imaging studies have suggested that migraineurs feature metabolic syndrome, exhibiting hallmark features including upregulated oxidative phosphorylation yet depleted available free energy. Glucose hypometabolism is also evident in migraine patients and can lead to altered neuronal hyperexcitability such as the incidence of cortical spreading depression (CSD). The association between obesity and increased risk, frequency and worse prognosis of migraine also highlights lipid dysregulation in migraine pathology. Calcitonin gene related peptide (CGRP) has demonstrated an important role in sensitisation and nociception in headache, however its role in metabolic regulation in connection with migraine has not been thoroughly explored. Whether impaired metabolic function leads to increased release of peptides such as CGRP or excessive nociception leads to altered flux is yet unknown.

CONCLUSION

Migraine susceptibility may be underpinned by impaired metabolism resulting in depleted energy stores and altered neuronal function. This review discusses both clinical and in vivo studies which provide evidence of altered metabolic flux which contribute toward pathophysiology. It also reviews the translational relevance of animal studies in identifying targets of biomarker or therapeutic development.

Glucose-Related Traits and Risk of Migraine—A Potential Mechanism and Treatment Consideration

Migraine and glucose-related (glycaemic) traits (fasting glucose, fasting insulin, and type 2 diabetes) are common and complex comorbid disorders that cause major economic and social burdens on patients and their families. Studies on the relationship between migraine and glucose-related traits have yielded inconsistent results. The purpose of this review is to synthesise and discuss the information from the available literature on the relationship between fasting glucose, fasting insulin, and type 2 diabetes (T2D) with migraine. Publications on migraine and fasting glucose, migraine and fasting insulin, and migraine and T2D were identified from a PubMed and Google Scholar database search and reviewed for this article. Multiple publications have suggested that the comorbidity of migraine and glucose-related traits may have a similar complex pathogenic mechanism, including impaired glucose homeostasis, insulin resistance, reduced cerebrovascular reactivity, abnormal brain metabolism, shared genetic factors, neurotransmitters, and sex hormones. Furthermore, several studies have found a bi-directional link between migraine with insulin resistance and T2D. There is strong evidence for a biological association between migraine headache and glucose-related traits, and burgeoning evidence for shared genetic influences. Therefore, genetic research into these comorbid traits has the potential to identify new biomarkers and therapeutic targets and provide biological insight into their relationships. We encourage healthcare professionals to consider the co-occurrence of migraine with glucose-related traits in the evaluation and treatment of their patients.

Migraine, Brain Glucose Metabolism and the "Neuroenergetic" Hypothesis: A Scoping Review

Increasing evidence suggests that migraine may be the result of an impaired brain glucose metabolism. Several studies have reported brain mitochondrial dysfunction, impaired brain glucose metabolism and gray matter volume reduction in specific brain areas of migraineurs. Furthermore, peripheral insulin resistance, a condition demonstrated in several studies, may extend to the brain, leading to brain insulin resistance. This condition has been proven to downregulate insulin receptors, both in astrocytes and neurons, triggering a reduction in glucose uptake and glycogen synthesis, mainly during high metabolic demand. This scoping review examines the clinical, epidemiologic and pathophysiologic data supporting the hypothesis that abnormalities in brain glucose metabolism may generate a mismatch between the brain's energy reserve and metabolic expenditure, triggering migraine attacks. Moreover, alteration in glucose homeostasis could generate a chronic brain energy deficit promoting migraine chronification. Lastly, insulin resistance may link migraine with its comorbidities, like obesity, depression, cognitive impairment and cerebrovascular diseases. PERSPECTIVE: Although additional experimental studies are needed to support this novel "neuroenergetic" hypothesis, brain insulin resistance in migraineurs may unravel the pathophysiological mechanisms of the disease, explaining the migraine chronification and connecting migraine with comorbidities. Therefore, this hypothesis could elucidate novel potential approaches for migraine treatment.

Inflammation and endothelial dysfunction in pediatric migraine patients

BACKGROUND

Inflammation and endothelial dysfunction are the suggested underlying mechanisms in migraine. Pentraxins, C-reactive protein, erythrocyte sedimentation rate, neutrophil to lymphocyte ratio, platelet to lymphocyte ratio are good indicators of inflammation. Alterations in insulin levels and insulin sensitivity may trigger endothelial dysfunction. This study evaluates the association between migraine and serum biomarkers of inflammation and endothelial dysfunction in children.

METHODS

Children with migraine and healthy subjects were recruited. Serum samples were obtained in an attack-free period. We collected data on serum levels of complete blood cell count, C-reactive protein, erythrocyte sedimentation rate, pentraxin-3, and data from biochemical investigations. We compared these with clinical data such as age, sex, disease duration, attack frequency, attack duration, analgesic use, family history, and Pediatric Migraine Disability Assessment Questionnaire scores.

RESULTS

We assessed samples from 32 children (11 boys, 21 girls) with migraine and 19 healthy controls (8 boys, 11 girls). We found significantly higher pentraxin-3, insulin, and insulin resistance in patients with migraine (P = 0.001, P = 0.032, and P = 0.008, respectively). A positive directional correlation is found between pentraxin-3 and Pediatric Migraine Disability Assessment Questionnaire scores. The best cut-off values for pentraxin-3 is determined between 12.75 pg/mL to 15 pg/mL in migraineurs.

CONCLUSIONS

In conclusion increased pentraxin-3 levels support the suggestions that inflammation plays a role in pediatric migraine. The vascular endothelial dysfunction is observed by a rise in insulin and insulin resistance levels. Our findings support the idea that ongoing inflammation and vascular endothelial dysfunction between attacks may play a role in migraine pathogenesis in children.

Metabolic profile changes in serum of migraine patients detected using 1H-NMR spectroscopy

Background

Migraine is a common brain disorder but reliable diagnostic biomarkers in blood are still lacking. Our aim was to identify, using proton nuclear magnetic resonance (¹H-NMR) spectroscopy, metabolites in serum that are associated with lifetime and active migraine by comparing metabolic profiles of patients and controls.

Methods

Fasting serum samples from 313 migraine patients and 1512 controls from the Erasmus Rucphen Family (ERF) study were available for ¹H-NMR spectroscopy. Data was analysed using elastic net regression analysis.

Results

A total of 100 signals representing 49 different metabolites were detected in 289 cases (of which 150 active migraine patients) and 1360 controls. We were able to identify profiles consisting of 6 metabolites predictive for lifetime migraine status and 22 metabolites predictive for active migraine status. We estimated with subsequent regression models that after correction for age, sex, BMI and smoking, the association with the metabolite profile in active migraine remained. Several of the metabolites in this profile are involved in lipid, glucose and amino acid metabolism.

Conclusion

This study indicates that metabolic profiles, based on serum concentrations of several metabolites, including lipids, amino acids and metabolites of glucose metabolism, can distinguish active migraine patients from controls.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-021-01357-w.

Was it something I ate? Understanding the bidirectional interaction of migraine and appetite neural circuits

Migraine attacks can involve changes of appetite: while fasting or skipping meals are often reported triggers in susceptible individuals, hunger or food craving are reported in the premonitory phase. Over the last decade, there has been a growing interest and recognition of the importance of studying these overlapping fields of neuroscience, which has led to novel findings. The data suggest additional studies are needed to unravel key neurobiological mechanisms underlying the bidirectional interaction between migraine and appetite. Herein, we review information about the metabolic migraine phenotype and explore migraine therapeutic targets that have a strong input on appetite neuronal circuits, including the calcitonin gene-related peptide (CGRP), the pituitary adenylate cyclase-activating polypeptide (PACAP) and the orexins. Furthermore, we focus on potential therapeutic peptide targets that are involved in regulation of feeding and play a role in migraine pathophysiology, such as neuropeptide Y, insulin, glucagon and leptin. We then examine the orexigenic - anorexigenic circuit feedback loop and explore glucose metabolism disturbances. Additionally, it is proposed a different perspective on the most reported feeding-related trigger - skipping meals - as well as a link between contrasting feeding behaviors (skipping meals vs food craving). Our review aims to increase awareness of migraine through the lens of appetite neurobiology in order to improve our understanding of the earlier phase of migraine, encourage better studies and cross-disciplinary collaborations, and provide novel migraine-specific therapeutic opportunities.

Is there any association between migraine headache and polycystic ovary syndrome (PCOS)? A review article

BACKGROUND

Polycystic ovary syndrome (PCOS) and migraine headaches are considered to be common health problems that may share some risk factors. This study aimed to discuss the possible association between migraine headache and polycystic ovary syndrome.

METHODS AND RESULTS

In this narrative review, PubMed, Scopus, Web of Science, and Google Scholar were systematically searched for retrieving and summarizing published studies up to January 2021 to explore the possible interplay between migraine headache and PCOS. We discuss the possible pathways that may explain the association between migraine headaches and PCOS signs/symptoms and complications. While genetic factors have profound effects on the pathogenesis of migraine headaches, sex hormones, including estrogen and progesterone may also play an important role in inducing migraine headaches. Some disorders, such as sleep apnea, amenorrhea, and vascular disease that are more likely to occur in women with PCOS, may cause or exacerbate migraine headaches in women with PCOS.

CONCLUSIONS

Future comprehensive studies are needed to investigate the exact underlining mechanisms related to the association between PCOS and migraine headaches.

Applications of Ketogenic Diets in Patients with Headache: Clinical Recommendations

Headaches are among the most prevalent and disabling neurologic disorders and there are several unmet needs as current pharmacological options are inadequate in treating patients with chronic headache, and a growing interest focuses on nutritional approaches as non-pharmacological treatments. Among these, the largest body of evidence supports the use of the ketogenic diet (KD). Exactly 100 years ago, KD was first used to treat drug-resistant epilepsy, but subsequent applications of this diet also involved other neurological disorders. Evidence of KD effectiveness in migraine emerged in 1928, but in the last several year's different groups of researchers and clinicians began utilizing this therapeutic option to treat patients with drug-resistant migraine, cluster headache, and/or headache comorbid with metabolic syndrome. Here we describe the existing evidence supporting the potential benefits of KDs in the management of headaches, explore the potential mechanisms of action involved in the efficacy in-depth, and synthesize results of working meetings of an Italian panel of experts on this topic. The aim of the working group was to create a clinical recommendation on indications and optimal clinical practice to treat patients with headaches using KDs. The results we present here are designed to advance the knowledge and application of KDs in the treatment of headaches.

Metabolic Aspects of Migraine: Association With Obesity and Diabetes Mellitus

Migraine is a disabling neurovascular disorder, characterized by moderate to severe unilateral headaches, nausea, photophobia, and/or phonophobia, with a higher prevalence in women than in men, which can drastically affect the quality of life of migraine patients. In addition, this chronic disorder is related with metabolic comorbidities associated with the patient's lifestyle, including obesity and diabetes mellitus (DM). Beyond the personal and socioeconomic impact caused by migraine, obesity and DM, it has been suggested that these metabolic disorders seem to be related to migraine since: (i) they are a risk factor for developing cardiovascular disorders or chronic diseases; (ii) they can be influenced by genetic and environmental risk factors; and (iii) while clinical and epidemiological studies suggest that obesity is a risk factor for migraine, DM (i.e., type 1 and type 2 DM) have been reported to be either a protective or a risk factor in migraine. On this basis, and given the high worldwide prevalence of migraine, obesity, and DM, this article provides a narrative review of the current literature related to the association between the etiology and pathophysiology of migraine and these metabolic disorders, considering lifestyle aspects, as well as the possible involvement of neurotransmitters, neuropeptides, and/or sex hormones. While a link between migraine and metabolic disorders has been suggested, many studies are contradictory and the mechanisms involved in this association are not yet sufficiently established. Therefore, further research should be focused on understanding the possible mechanisms involved.

Genetics, pathophysiology, diagnosis, treatment, management, and prevention of migraine

Migraine is a neurological ailment that is characterized by severe throbbing unilateral headache and associated with nausea, photophobia, phonophobia and vomiting. A full and clear mechanism of the pathogenesis of migraine, though studied extensively, has not been established yet. The current available information indicates an intracranial network activation that culminates in the sensitization of the trigemino-vascular system, release of inflammatory markers, and initiation of meningeal-like inflammatory reaction that is sensed as headache. Genetic factors might play a significant role in deciding an individual's susceptibility to migraine. Twin studies have revealed that a single gene polymorphism can lead to migraine in individuals with a monogenic migraine disorder. In this review, we describe recent advancements in the genetics, pathophysiology, diagnosis, treatment, management, and prevention of migraine. We also discuss the potential roles of genetic and abnormal factors, including some of the metabolic triggering factors that result in migraine attacks. This review will help to accumulate current knowledge about migraine and understanding of its pathophysiology, and provides up-to-date prevention strategies.

A systematic literature review of observational studies of the bilateral association between diabetes and migraine

BACKGROUND AND AIM

To conduct a systematic literature review and synthesize data from all epidemiological studies investigating the association between diabetes and migraine in adults.

METHOD AND MATERIAL

Electronic databases, including Web of Science, PubMed and Scopus in addition to Google Scholar search engine were systematically searched up to Jun 2020 to identify studies reporting the diabetes-migraine association.

RESULTS

A total of 15 studies were selected which were published from 2012 to 2019. Five out of 15 studies assessed the presence of migraine in diabetic subjects, while nine studies assessed the presence of diabetes in migraine subjects. The cohort study reported a hazard ratio for diabetes of 1.06 (95% confidence interval (CI): 0.91-1.24) for women with migraine with aura, 1.01 (95% CI: 0.89-1.16) for women without aura, and 1.13 (95% CI: 0.98-1.3) for women with a migraine history, compared with women with no history of migraine. Due to the high degree of heterogeneity, and the lack of statistical estimates of the association in several of the reviewed studies, meta-analysis of the available data was not possible.

CONCLUSION

This study is the first review to examine the association between diabetes and migraine. Further longitudinal studies are required to clarify the migraine-diabetes association. There is also a clear need for more studies with larger sample sizes and similar methodologies in order to provide necessary information to conduct a meta-analysis.

The Role of Metabolism in Migraine Pathophysiology and Susceptibility

Migraine is a highly prevalent and disabling primary headache disorder, however its pathophysiology remains unclear, hindering successful treatment. A number of key secondary headache disorders have headaches that mimic migraine. Evidence has suggested a role of mitochondrial dysfunction and an imbalance between energetic supply and demand that may contribute towards migraine susceptibility. Targeting these deficits with nutraceutical supplementation may provide an additional adjunctive therapy. Neuroimaging techniques have demonstrated a metabolic phenotype in migraine similar to mitochondrial cytopathies, featuring reduced free energy availability and increased metabolic rate. This is reciprocated in vivo when modelling a fundamental mechanism of migraine aura, cortical spreading depression. Trials assessing nutraceuticals successful in the treatment of mitochondrial cytopathies including magnesium, coenzyme q10 and riboflavin have also been conducted in migraine. Although promising results have emerged from nutraceutical trials in patients with levels of minerals or vitamins below a critical threshold, they are confounded by lacking control groups or cohorts that are not large enough to be representative. Energetic imbalance in migraine may be relevant in driving the tissue towards maximum metabolic capacity, leaving the brain lacking in free energy. Personalised medicine considering an individual's deficiencies may provide an approach to ameliorate migraine.

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.

Mitochondrial function and oxidative stress markers in higher-frequency episodic migraine

Increasing evidence points towards the role of mitochondrial functioning, energy metabolism, and oxidative stress in migraine. However not all previous research has been conclusive and some mitochondrial function/oxidative stress markers have not yet been examined. To this end, alpha-lipoic acid (ALA), total thiols, total plasma antioxidant capacity (TAC), lipid peroxide (PerOx), oxidised LDL (oxLDL), HbA1c and lactate were determined in the serum of 32 higher frequency episodic migraineurs (5-14 migraine days/ months, 19 with aura, 28 females) in this cross-sectional study. The majority of patients had abnormally low ALA and lactate levels (87.5% and 78.1%, respectively). 46.9% of the patients had abnormally high PerOx values, while for thiols and TAC over one third of patients had abnormally low values (31.2% and 37.5%, respectively). 21.9% of patients had abnormally low HbA1c and none had an HbA1c level above 5.6%. oxLDL was normal in all but one patient. This study provides further evidence for a role of oxidative stress and altered metabolism in migraine pathophysiology, which might represent a suitable therapeutic target. ALA, being too low in almost 90% of patients, might represent a potential biomarker for migraine. Further research is needed to replicate these results, in particular a comparison with a control group.This study is part of the trial registration: ClinicalTrials.gov: NCT03132233, registered on 27.04.2017, https://clinicaltrials.gov/ct2/show/NCT03132233 .

Factors Associated with Insulin Resistance in Women with Migraine: A Cross-Sectional Study

OBJECTIVE

Studies have shown a relationship between insulin resistance (IR) and migraine that is more evident in some migraineurs. Long-term use of various drugs and increased risk of diverse side effects is an unavoidable reality in this population of patients. Thus, in this study, we aimed to investigate factors associated with IR in migraine and the impact of chronic usage of various drugs, which might play a part in development of IR.

DESIGN

Cross-sectional study.

SETTING

Gebze Fatih General Hospital, Kocaeli, Turkey.

SUBJECTS

Migraine patients (N = 150) were investigated.

METHODS

Weight, height, waist circumference, and blood pressure were measured. Fasting glucose, fasting insulin, glycated hemoglobin, and lipid profile were also measured. IR was selected as a dependent variable. The independent variables included age, cigarette smoking, alcohol consumption, family history of migraine, diabetes mellitus and hypertension, characteristics of pain, migraine triggers and subgroups, medication used during attack treatment, medication used as prophylactic treatment, and oral contraceptive treatment. Descriptive analysis and multivariate logistic regression were performed.

RESULTS

Central obesity (odds ratio [OR] = 7.131, 95% confidence interval [CI] = 2.451-20.741, P < 0.0001), metoclopramide treatment during an attack (OR = 3.645, 95% CI = 0.996-13.346, P = 0.041), family history of DM (OR = 3.109, 95% CI = 1.189-8.132, P = 0.035), nonsteroidal anti-inflammatory drug (NSAID) usage during an attack (OR = 2.578, 95% CI = 1.053-6.311, P = 0.043), and negative family history of hypertension (OR = 0.226, 95% CI = 0.085-0.602, P = 0.002) were significant factors for exhibiting IR in migraine.

CONCLUSIONS

Our study demonstrates an association between metoclopramide and NSAID treatments and IR in migraine.

Therapeutic Implications of Altered Energy Metabolism in Migraine: A State-of-the-Art Review

Currently, the management strategies aimed at the resolution of migraine are pharmacological. Most of these therapies are known to alter the serotonin balance of the brain. Furthermore, therapies blocking the calcitonin gene-related peptide (CGRP) have also proven to be quite effective in their treatments. However, apart from being expensive, these therapies do not influence premonitory and aura symptoms. This suggests an incomplete approach and an inadequate understanding of the migraine pathophysiology. Recent metabolic studies have indicated that migraine should be considered as an adaptive response to the mismatch between the cerebral energy reserves and expenditure. Therefore, understanding the underlying metabolism helps derive possible novel therapeutic modalities for migraines. In this review, we highlight the underlying metabolic abnormalities found in migraine patients. This will form the basis of our evidence-based discussion on metabolic therapeutic options for migraines.

Introducing Genes With Significant Role in Migraine: An Interactomic Approach

Introduction

Migraine is a severe kind of headache with the chance hereditary of 50%. Molecular studies can promote understanding of migraine pathophysiology. One of which is bioinformatics approach that could provide additional information related to the identified biomarkers.

Methods

In this research, migraine genes are studies in terms of interaction pattern to introduce important individuals. Through STRING database Plug-in in Cytoscape, candidate genes for migraine were retrieved and analyzed by related applications. Based on centrality and action types (expression, activation, and inhibition) genes were screened.

Results

Numbers of 33 central genes including seven hub-bottlenecks were identified which 70% of central genes were involved in expression action with each other. Activation was dominate action relative to inhibition between the central genes.

Conclusion

The finding indicates that insulin is the most important gene relative to migraine. It seems regulation of metabolism play critical role in control of migraine.

Associations Between Migraine and Type 2 Diabetes in Women: Findings From the E3N Cohort Study

Importance

Little is known about the associations between migraine and type 2 diabetes and the temporality of the association between these 2 diseases.

Objective

To evaluate the association between migraine and type 2 diabetes incidence as well as the evolution of the prevalence of active migraine before and after type 2 diabetes diagnosis.

Design, Setting, and Participants

We used data from the E3N cohort study, a French prospective population-based study initiated in 1990 on a cohort of women born between 1925 and 1950. The E3N study participants are insured by a health insurance plan that mostly covers teachers. From the eligible women in the E3N study, we included those who completed the 2002 follow-up questionnaire with information available on migraine. We then excluded prevalent cases of type 2 diabetes, leaving a final sample of women who were followed up between 2004 and 2014. All potential occurrences of type 2 diabetes were identified through a drug reimbursement database. Statistical analyses were performed in March 2018.

Exposures

Self-reported migraine occurrence.

Main Outcomes and Measures

Pharmacologically treated type 2 diabetes.

Results

From the 98 995 women in the study, 76 403 women completed the 2002 follow-up survey. Of these, 2156 were excluded because they had type 2 diabetes, leaving 74 247 women. Participants had a mean (SD) age of 61 (6) years at baseline, and all were free of type 2 diabetes. During 10 years of follow-up, 2372 incident type 2 diabetes cases occurred. A lower risk of type 2 diabetes was observed for women with active migraine compared with women with no migraine history (univariate hazard ratio, 0.80 [95% CI, 0.67-0.96], multivariable-adjusted hazard ratio, 0.70 [95% CI, 0.58-0.85]). We also observed a linear decrease in active migraine prevalence from 22% (95% CI, 16%-27%) to 11% (95% CI, 10%-12%) during the 24 years prior to diabetes diagnosis, after adjustment for potential type 2 diabetes risk factors. A plateau of migraine prevalence around 11% was then observed for 22 years after diagnosis.

Conclusions and Relevance

We observed a lower risk of developing type 2 diabetes for women with active migraine and a decrease in active migraine prevalence prior to diabetes diagnosis. Further targeted research should focus on understanding the mechanisms involved in explaining these findings.

Plasma Glucose Levels Increase During Spontaneous Attacks of Migraine With and Without Aura

OBJECTIVE

To investigate plasma glucose changes during the ictal state of migraine compared to the interictal state.

BACKGROUND

Previous studies suggest abnormal glucose metabolism in migraine patients during and outside of attacks. It is not known if plasma glucose levels change during spontaneous migraine attacks.

METHODS

Plasma glucose levels were measured during and outside of spontaneous migraine attacks with and without aura. Plasma glucose values were corrected for diurnal variation of plasma glucose by subtracting the difference between the moving average (intervals of 2 hours) and overall mean from the plasma glucose values.

RESULTS

This was a sub-study of a larger study conducted at Rigshospitalet Glostrup in the Capital Region of Denmark. Thirty-one patients (24 F, 7 M, 13 with aura, 18 without aura) were included in the study. Mean time from attack onset to blood sampling was 7.6 hours. Mean pain at the time of investigation was 6 on a 0-10 verbal rating scale. Plasma glucose was higher ictally compared to the interictal phase (interictal mean: 88.63 mg/dL, SD 11.70 mg/dL; ictal mean: 98.83 mg/dL, SD 13.16 mg/dL, difference 10.20 mg/dL, 95% CI = [4.30; 16.10]), P = .0014). The ictal increase was highest in patients investigated early during attacks and decreased linearly with time from onset of migraine (-1.57 mg/dL/hour from onset of attack, P = .020). The attack-related increase in blood glucose was not affected by pain intensity or presence of aura symptoms.

CONCLUSIONS

We demonstrated higher plasma glucose values during spontaneous migraine attacks, independent of the presence of aura symptoms and not related to pain intensity, peaking in the early phase of attacks. Additional studies are necessary to confirm our findings and explore the possible underlying mechanisms.

Association of diet and headache

The global prevalence of migraine as a primary headache has been estimated as 14.4% in both sexes. Migraine headache has been ranked as the highest contributor to disability in under 50 years old population in the world. Extensive research has been conducted in order to clarify the pathological mechanisms of migraine. Although uncertainties remains, it has been indicated that vascular dysfunction, cortical spreading depression (CSD), activation of the trigeminovascular pathway, pro-inflammatory and oxidative state may play a putative role in migraine pain generation. Knowledge about pathophysiological mechanisms of migraine should be integrated into a multimodal treatment approach to increase quality of life in patients. With respect to this, within the integrative health studies growing interest pertains to dietary interventions. Although the number of studies concerning effects of diet on headache/migraine is not yet very large, the current article will review the available evidence in this area. All publications on headache/migraine and dietary interventions up to May 2019 were included in the present review through a PubMed/MEDLINE and ScienceDirect database search. According to the current findings, Ketogenic diet and modified Atkins diet are thought to play a role in neuroprotection, improving mitochondrial function and energy metabolism, compensating serotoninergic dysfunction, decreasing calcitonin gene-related peptide (CGRP) level and suppressing neuro-inflammation. It can also be speculated that prescription of low glycemic diet may be promising in headache/migraine control through attenuating the inflammatory state. Moreover, obesity and headaches including migraine could be attributed to each other through mechanisms like inflammation, and irregular hypothalamic function. Thereby, applying dietary strategies for weight loss may also ameliorate headache/migraine. Another important dietary intervention that might be effective in headache/migraine improvement is related to balance between the intake of essential fatty acids, omega-6 and omega-3 which also affect inflammatory responses, platelet function and regulation of vascular tone. Regarding elimination diets, it appears that targeted these diets in migraine patients with food sensitivities could be effective in headache/migraine prevention. Taken together, dietary approaches that could be considered as effective strategies in headache/migraine prophylaxis include weight loss diets in obese headache patients, ketogenic and low-calorie diets, reducing omega-6 and increasing omega-3 fatty acid intakes.

The metabolic face of migraine - from pathophysiology to treatment

Migraine can be regarded as a conserved, adaptive response that occurs in genetically predisposed individuals with a mismatch between the brain's energy reserve and workload. Given the high prevalence of migraine, genotypes associated with the condition seem likely to have conferred an evolutionary advantage. Technological advances have enabled the examination of different aspects of cerebral metabolism in patients with migraine, and complementary animal research has highlighted possible metabolic mechanisms in migraine pathophysiology. An increasing amount of evidence - much of it clinical - suggests that migraine is a response to cerebral energy deficiency or oxidative stress levels that exceed antioxidant capacity and that the attack itself helps to restore brain energy homeostasis and reduces harmful oxidative stress levels. Greater understanding of metabolism in migraine offers novel therapeutic opportunities. In this Review, we describe the evidence for abnormalities in energy metabolism and mitochondrial function in migraine, with a focus on clinical data (including neuroimaging, biochemical, genetic and therapeutic studies), and consider the relationship of these abnormalities with the abnormal sensory processing and cerebral hyper-responsivity observed in migraine. We discuss experimental data to consider potential mechanisms by which metabolic abnormalities could generate attacks. Finally, we highlight potential treatments that target cerebral metabolism, such as nutraceuticals, ketone bodies and dietary interventions.

Migraine during pregnancy and in the puerperium

Pregnancy can be seen as a positive time for women migraineurs because the elevated estrogen and endogenous opioid levels raise the pain threshold and the stable hormone levels, which no longer fluctuate, eliminate a major trigger factor for the attacks. In a great majority of cases, indeed, migraine symptoms spontaneously improve throughout pregnancy. Generally, migraine without aura (MO) improves better than migraine with aura (MA), which can occur ex novo in pregnancy more frequently than MO. After childbirth, the recurrence rate of migraine attacks increases, especially during the first month; breastfeeding exerts a protective effect against the reappearance of attacks. Migraine and pregnancy share a condition of hypercoagulability; therefore, attention must be paid to the risk of cardiovascular disorders, like venous thromboembolism and ischemic or hemorrhagic strokes. Some of these diseases can be linked to preeclampsia (PE), a serious complication of pregnancy, characterized by hypertension, proteinuria, or other findings of organ failure. This condition is more common in migraineurs compared with non-migraineurs; furthermore, women whose migraines worsen during pregnancy had a 13-fold higher risk of hypertensive disorders than those in which migraine remitted or improved. Pregnancy is generally recognized to exert a beneficial effect on migraine; nonetheless, clinicians should be on the alert for possible cardiovascular complications that appear to be more frequent in this patient population.

Opening of ATP-sensitive potassium channels causes migraine attacks: a new target for the treatment of migraine

Migraine is one of the most disabling and prevalent of all disorders. To improve understanding of migraine mechanisms and to suggest a new therapeutic target, we investigated whether opening of ATP-sensitive potassium channels (KATP) would cause migraine attacks. In this randomized, double-blind, placebo-controlled, crossover study, 16 patients aged 18–49 years with one to five migraine attacks a month were randomly allocated to receive an infusion of 0.05 mg/min KATP channel opener levcromakalim and placebo on two different days (ClinicalTrials.gov number, NCT03228355). The primary endpoints were the difference in incidence of migraine attacks, headaches and the difference in area under the curve (AUC) for headache intensity scores (0–12 h) and for middle cerebral artery blood flow velocity (0–2 h) between levcromakalim and placebo. Between 24 May 2017 and 23 November 2017, 16 patients randomly received levcromakalim and placebo on two different days. Sixteen patients (100%) developed migraine attacks after levcromakalim compared with one patient (6%) after placebo (P = 0.0001); the difference of incidence is 94% [95% confidence interval (CI) 78–100%]. The incidence of headache over the 12 h observation period was higher but not significant after levcromakalim (n = 16) than after placebo (n = 7) (P = 0.016) (95% CI 16–71%). The AUC for headache intensity was significantly larger after levcromakalim compared to placebo (AUC0–12h, P < 0.0001). There was no change in mean middle cerebral artery blood flow velocity after levcromakalim compared to placebo (AUC0–2hP = 0.46). Opening of KATP channels caused migraine attacks in all patients. This suggests a crucial role of these channels in migraine pathophysiology and that KATP channel blockers could be potential targets for novel drugs for migraine.

A ketogenic diet normalizes interictal cortical but not subcortical responsivity in migraineurs

Background

A short ketogenic diet (KD) treatment can prevent migraine attacks and correct excessive cortical response. Here, we aim to prove if the KD-related changes of cortical excitability are primarily due to cerebral cortex activity or are modulated by the brainstem.

Methods

Through the stimulation of the right supraorbital division of the trigeminal nerve, we concurrently interictally recorded the nociceptive blink reflex (nBR) and the pain-related evoked potentials (PREP) in 18 migraineurs patients without aura before and after 1-month on KD, while in metabolic ketosis. nBR and PREP reflect distinct brain structures activation: the brainstem and the cerebral cortex respectively. We estimated nBR R2 component area-under-the-curve as well as PREP amplitude habituation as the slope pof the linear regression between the 1st and the 2nd block of 5 averaged responses.

Results

Following 1-month on KD, the mean number of attacks and headache duration reduced significantly. Moreover, KD significantly normalized the interictal PREP habituation (pre: + 1.8, post: − 9.1, p = 0.012), while nBR deficit of habituation did not change.

Conclusions

The positive clinical effects we observed in a population of migraineurs by a 1-month KD treatment coexists with a normalization at the cortical level, not in the brainstem, of the typical interictal deficit of habituation. These findings suggest that the cerebral cortex may be the primary site of KD-related modulation.

Trial registration

ClinicalTrials.gov NCT03775252 (retrospectively registered, December 09, 2018).

Potential Protective Mechanisms of Ketone Bodies in Migraine Prevention

An increasing amount of evidence suggests that migraines are a response to a cerebral energy deficiency or oxidative stress levels that exceed antioxidant capacity. The ketogenic diet (KD), a diet mimicking fasting that leads to the elevation of ketone bodies (KBs), is a therapeutic intervention targeting cerebral metabolism that has recently shown great promise in the prevention of migraines. KBs are an alternative fuel source for the brain, and are thus likely able to circumvent some of the abnormalities in glucose metabolism and transport found in migraines. Recent research has shown that KBs-D-β-hydroxybutyrate in particular-are more than metabolites. As signalling molecules, they have the potential to positively influence other pathways commonly believed to be part of migraine pathophysiology, namely: mitochondrial functioning, oxidative stress, cerebral excitability, inflammation and the gut microbiome. This review will describe the mechanisms by which the presence of KBs, D-BHB in particular, could influence those migraine pathophysiological mechanisms. To this end, common abnormalities in migraines are summarised with a particular focus on clinical data, including phenotypic, biochemical, genetic and therapeutic studies. Experimental animal data will be discussed to elaborate on the potential therapeutic mechanisms of elevated KBs in migraine pathophysiology, with a particular focus on the actions of D-BHB. In complex diseases such as migraines, a therapy that can target multiple possible pathogenic pathways seems advantageous. Further research is needed to establish whether the absence/restriction of dietary carbohydrates, the presence of KBs, or both, are of primary importance for the migraine protective effects of the KD.

Estrogen, migraine, and vascular risk

Migraine has a predilection for female sex and the course of symptoms is influenced by life stage (presence of menstrual cycle, pregnancy, puerperium, menopause) and use of hormone therapy, such as hormonal contraception and hormone replacement therapy. Hormonal changes figure among common migraine triggers, especially sudden estrogen drop. Moreover, estrogens can modulate neuronal excitability, through serotonin, norepinephrine, dopamine, and endorphin regulation, and they interact with the vascular endothelium of the brain. The risk of vascular disease, and ischemic stroke in particular, is increased in women with migraine with aura (MA), but the link is unclear. One hypothesis posits for a causal association: migraine may cause clinical or subclinical brain lesions following repeated episodes of cortical spreading depression (CSD) and a second hypothesis that may explain the association between migraine and vascular diseases is the presence of common risk factors and comorbidities. Estrogens can play a differential role depending on their action on healthy or damaged endothelium, their endogenous or exogenous origin, and the duration of their treatment. Moreover, platelet activity is increased in migraineurs women, and it is further stimulated by estrogens.This review article describes the course of migraine during various life stages, with a special focus on its hormonal pathogenesis and the associated risk of vascular diseases.

Macronutrient Intake in Relation to Migraine and Non-Migraine Headaches

We investigated the association of mean daily macronutrient intake with migraine and non-migraine headaches. This cross-sectional study included 8042 men and 23,728 women from the ongoing population-based NutriNet-Santé e-cohort. Headache status was assessed via an online self-report questionnaire (2013–2016). Migraine was defined using established criteria and dietary macronutrient intake was estimated via ≥3 24 h dietary records. Mean daily intake (g/day) of carbohydrates (simple, complex, and total), protein, and fat (saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, and total) were the main exposure variables. Adjusted gender-specific analysis of variance (ANOVA) models were fit. Presence of migraines was noted in 9.2% of men (mean age = 54.3 ± 13.3 years) and 25.7% of women (mean age = 49.6 ± 12.8 years). In adjusted models, we observed (1) somewhat lower protein (p < 0.02) and higher total fat (p < 0.01) intake among male migraineurs compared with males without headaches and those with non-migraine headaches; (2) somewhat higher total fat (p < 0.0001) and total carbohydrate intake (p < 0.05) among female migraineurs compared with females without headaches and those with non-migraine headaches. The findings, which provide preliminary support for modest gender-specific differences in macronutrient intake by migraine status, merit confirmation in different population-based settings, as well as longitudinally, and could help to inform future dietary interventions in headache prevention.

Bariatric Surgery Promising in Migraine Control: a Controlled Trial on Weight Loss and Its Effect on Migraine Headache

INTRODUCTION

There is evidence that substantial weight loss through bariatric surgery (BS) may result in short-term improvement of migraine severity. However, it still remains to be seen whether smaller amounts of weight loss have a similar effect on migraine headache. This study has been designed to compare the effects of weight reduction through BS and non-surgical modifications.

MATERIALS AND METHODS

Migraine characteristics were assessed at 1 month before (T0), 1 month (T1), and 6 months (T2) after BS (vertical sleeve gastrectomy (VSG) (n = 25) or behavioral therapy (BT) (n = 26) in obese women (aged 18-60 years) with migraine headache. Migraine was diagnosed using the International Classification of Headache Disorders (ICHDIIβ) criteria.

RESULTS

There was significant reduction in the visual analog scale (VAS) from the baseline to T1 and T2 in both groups. The number of migraine-free days showed a significant increase within each group (p < 0.001). The BS group had a significant reduction in attack duration (p < 0.001) while there were no changes observed within the BT group. Following the adjustment of ANCOVA models for baseline values of migraine characteristics, age, changes in weight, BMI, body fat, and fat-free mass from T0 to T2, the BS group showed statistically significant lower VAS and duration of migraine attacks and a significantly higher number of migraine-free days than the BT group at T1 and T2 (p ≤ 0.028).

CONCLUSION

Our results indicated that far before significant weight reduction after BS (VSG), there was marked alleviation in the severity and duration of migraine and a significant increase in the number of migraine-free days in obese female migraineurs. However, the effects in the BT group were not comparable with the effects in the BS group.

Is Migraine Primarily a Metaboloendocrine Disorder?

PURPOSE OF THE REVIEW

The goals of this review are to evaluate recent studies regarding comorbidity between migraine and different metabolic and endocrine disorders and to discuss the role of insulin resistance as a common pathogenetic mechanism of these diseases.

RECENT FINDINGS

Recently, several studies showed that migraine is associated with insulin resistance, a condition in which a normal amount of insulin induces a suboptimal physiological response. All the clinical studies that used the oral glucose tolerance test to examine insulin sensitivity found that, after glucose load, there is in migraine patients a significant increase of both plasmatic insulin and glucose concentrations in comparison with controls. On the contrary, no association was found between migraine and type 2 diabetes, while type 1 diabetes seems to have a protective effect in the disease. Obesity and hypertension were shown to be risk factors for both episodic and chronic migraine. Metabolic syndrome has been recently associated mainly with migraine with aura and is now considered a risk factor also for medication overuse headache. Finally, a bidirectional association between migraine and hypothyroidism has been recently demonstrated, suggesting that common genetic or autoimmune mechanisms underlie both diseases. Recent studies showed that insulin receptor signaling and the related physiological responses are altered in migraine and may have a relevant pathogenic role in the disease. Further studies are warranted in order to better elucidate mechanisms underlying insulin resistance in migraine in order to develop new therapeutic strategies for this debilitating disease.

Targeted Orexin and Hypothalamic Neuropeptides for Migraine

The hypothalamus is involved in the regulation of homeostatic mechanisms and migraine-related trigeminal nociception and as such has been hypothesized to play a central role in the migraine syndrome from the earliest stages of the attack. The hypothalamus hosts many key neuropeptide systems that have been postulated to play a role in this pathophysiology. Such neuropeptides include but are not exclusive too orexins, oxytocin, neuropeptide Y, and pituitary adenylate cyclase activating protein, which will be the focus of this review. Each of these peptides has its own unique physiological role and as such many preclinical studies have been conducted targeting these peptide systems with evidence supporting their role in migraine pathophysiology. Preclinical studies have also begun to explore potential therapeutic compounds targeting these systems with some success in all cases. Clinical efficacy of dual orexin receptor antagonists and intranasal oxytocin have been tested; however, both have yet to demonstrate clinical effect. Despite this, there were limitations in these cases and strong arguments can be made for the further development of intranasal oxytocin for migraine prophylaxis. Regarding neuropeptide Y, work has yet to begun in a clinical setting, and clinical trials for pituitary adenylate cyclase activating protein are just beginning to be established with much optimism. Regardless, it is becoming increasingly clear the prominent role that the hypothalamus and its peptide systems have in migraine pathophysiology. Much work is required to better understand this system and the early stages of the attack to develop more targeted and effective therapies aimed at reducing attack susceptibility with the potential to prevent the attack all together.

Determinants of glucose metabolism and the role of NPY in the progression of insulin resistance in chronic migraine

Background Chronic migraine has a well-documented association with increased insulin resistance and metabolic syndrome. The hypothalamus may play a role in the progression of insulin resistance in chronic migraine through the regulation of orexigenic peptides such as neuropeptide Y. Insulin resistance may lead to increased risk of future type 2 diabetes mellitus in patients with chronic migraine, which is more likely to occur if other pathogenetic defects of type 2 diabetes mellitus, such as impaired pancreatic β-cell functions and defects in intestinal glucagon-like peptide-1 secretion after meals. We studied the relationship of fasting neuropeptide Y with insulin resistance, β-cell function, and glucagon-like peptide-1 secretion in non-obese female chronic migraine patients. We also aimed to investigate glucose-stimulated insulin and glucagon-like peptide-1 secretions as early pathogenetic mechanisms responsible for the development of carbohydrate intolerance. Methods In this cross-sectional controlled study, 83 non-obese female migraine patients of reproductive age categorized as having episodic migraine or chronic migraine were included. The control group consisted of 36 healthy females. We studied glucose-stimulated insulin and glucagon-like peptide-1 secretion during a 75 g oral glucose tolerance test. We investigated the relationship of neuropeptide Y levels with insulin resistance and β-cell insulin secretion functions. Results Fasting glucose levels were significantly higher in migraine patients. Plasma glucose and insulin levels during the oral glucose tolerance test were otherwise similar in chronic migraine, episodic migraine and controls. Patients with chronic migraine were more insulin resistant than episodic migraine or controls ( p = 0.048). Glucagon-like peptide-1 levels both at fasting and two hours after glucose intake were similar in chronic migraine, episodic migraine, and controls. Neuropeptide Y levels were higher in migraineurs. In chronic migraine, neuropeptide Y was positively correlated with fasting glucagon-like peptide-1 levels (r = 0.57, p = 0.04), but there was no correlation with insulin resistance (r = 0.49, p = 0.09) or β-cell function (r = 0.50, p = 0.07). Discussion Non-obese premenopausal female patients with chronic migraine have higher insulin resistance, but normal β-cell function is to compensate for the increased insulin demand during fasting and after glucose intake. Increased fasting neuropeptide Y levels in migraine may be a factor leading to increased insulin resistance by specific alterations in energy intake and activation of the sympathoadrenal system.

Diabetes is associated with decreased migraine risk: A nationwide cohort study

Background Results from studies on diabetes and migraine risk are conflicting, which may be due to methodological limitations. Prospective studies with long follow-up could increase our understanding of the relationship between the two diseases. Method We performed a cohort study including the whole Norwegian population alive on 01.01.2004, using prescriptions registered in the Norwegian prescription database to identify individuals developing type 1 diabetes, type 2 diabetes and migraine during follow-up (10 years). We used Cox proportional hazards regression to estimate rate ratios with corresponding 95% confidence intervals for the effect of diabetes on migraine risk, adjusting for age, sex, and educational level. Result We identified 7,883 type 1 diabetes patients and 93,600 type 2 patients during the study period. Type 1 diabetes was significantly associated with a subsequent decreased migraine risk during follow-up in the age- and sex-adjusted analyses (0.74; 0.61-0.89). Type 2 diabetes was also associated with a significantly lower migraine risk (0.89; 0.83-0.95). Further adjustment for educational level yielded similar results for both diabetes. Conclusion Both type 1 and type 2 diabetes were significantly associated with a decreased risk of migraine. This suggests that diabetes or diabetes treatment may have a protective effect on the development of migraine.

Alpha-Lipoic Acid Shows Promise to Improve Migraine in Patients with Insulin Resistance: A 6-Month Exploratory Study

Alpha-lipoic acid (ALA) is known to lower insulin resistance (IR), which is common among migraineurs. To assess the effect of ALA on headache in migraineurs with IR, we performed an exploratory study on a cohort of patients with migraine, followed at our Headache Center. The 32 patients took ALA 400 mg b.i.d. for 6 months in addition to their on-going treatment. The percentage of patients with a reduction of at least 50% of the attacks was 0.53 (confidence interval [95% CI] 0.36-0.70) at 2 months, 0.56 (0.39-0.73) at 4 months, and 0.69 (0.53-0.85) at 6 months. The incidence rate ratio of attacks at 6 months versus baseline was 0.48 (0.43-0.53, P < .001), corresponding to a mean (95% CI) number of attacks of 5 (4-6) versus 11 (10-12). The number of days of treatment in the previous month was 7.7 (6.8-8.7) at baseline, 5.4 (4.6-6.2) at 2 months, 5.3 (4.5-6.1) at 4 months, and 4.3 (3.6-5.0) at 6 months. Baseline and 120-min glucose and insulin and quantitative insulin sensitivity check index (QUICKI) and the Stumvoll index did not change at 6 months versus baseline. This exploratory study shows that the administration of ALA may be associated with a reduction in the number of attacks and the days of treatment in migraineurs with IR. A randomized controlled trial is needed to test this possibility.

Pathophysiology of Migraine: A Disorder of Sensory Processing

Plaguing humans for more than two millennia, manifest on every continent studied, and with more than one billion patients having an attack in any year, migraine stands as the sixth most common cause of disability on the planet. The pathophysiology of migraine has emerged from a historical consideration of the "humors" through mid-20th century distraction of the now defunct Vascular Theory to a clear place as a neurological disorder. It could be said there are three questions: why, how, and when? Why: migraine is largely accepted to be an inherited tendency for the brain to lose control of its inputs. How: the now classical trigeminal durovascular afferent pathway has been explored in laboratory and clinic; interrogated with immunohistochemistry to functional brain imaging to offer a roadmap of the attack. When: migraine attacks emerge due to a disorder of brain sensory processing that itself likely cycles, influenced by genetics and the environment. In the first, premonitory, phase that precedes headache, brain stem and diencephalic systems modulating afferent signals, light-photophobia or sound-phonophobia, begin to dysfunction and eventually to evolve to the pain phase and with time the resolution or postdromal phase. Understanding the biology of migraine through careful bench-based research has led to major classes of therapeutics being identified: triptans, serotonin 5-HT1B/1D receptor agonists; gepants, calcitonin gene-related peptide (CGRP) receptor antagonists; ditans, 5-HT1F receptor agonists, CGRP mechanisms monoclonal antibodies; and glurants, mGlu5 modulators; with the promise of more to come. Investment in understanding migraine has been very successful and leaves us at a new dawn, able to transform its impact on a global scale, as well as understand fundamental aspects of human biology.

Inverse relationship between type 1 diabetes mellitus and migraine. Data from the Nord-Trøndelag Health Surveys 1995-1997 and 2006-2008

Aims The aim of this cross-sectional population-based study was to investigate the associations between migraine and type 1 and type 2 diabetes mellitus (DM). Methods We used data from the second (1995-1997) and third survey (2006-2008) in the Nord-Trøndelag Health Study. Analyses were made for the 26,121 participants (30-97 years of age, median 58.3 years) with known headache and DM status in both surveys, and for the 39,584 participants in the third survey (20-97 years, median 54.1 years). The diagnosis of migraine was given to those who fulfilled the questionnaire-based migraine diagnosis in the second and/or third survey. Associations were assessed using multiple logistic regression, estimating prevalence odds ratio (OR) with 95% confidence intervals (CIs). Results In the multivariate analysis of the 26,121 participants in both surveys, adjusting for age, gender, years of education, and smoking, classical type 1 DM (n = 81) was associated with a lower prevalence of any headache (OR = 0.55, 95% CI 0.34-0.88),and migraine (OR = 0.47, 95% CI 0.26-0.96) compared to those without DM (n = 24,779). Correspondingly, the merged group of classical type 1 DM and latent autoimmune diabetes of adults (LADA) (n = 153) were less likely to have migraine (OR = 0.53, 95% CI 0.31-0.91). Similarly, an inverse relationship between type 1 DM and migraine was found in analyses of 39,584 participants in the third survey. No clear association was found between headache and type 2 DM. Conclusions In this cross-sectional population-based study of mainly middle-aged participants, type 1 DM was inversely associated with headache, in particular migraine.

Neuroendocrine signaling modulates specific neural networks relevant to migraine

Migraine is a disabling brain disorder involving abnormal trigeminovascular activation and sensitization. Fasting or skipping meals is considered a migraine trigger and altered fasting glucose and insulin levels have been observed in migraineurs. Therefore peptides involved in appetite and glucose regulation including insulin, glucagon and leptin could potentially influence migraine neurobiology. We aimed to determine the effect of insulin (10U·kg^-1), glucagon (100μg·200μl^-1) and leptin (0.3, 1 and 3mg·kg^-1) signaling on trigeminovascular nociceptive processing at the level of the trigeminocervical-complex and hypothalamus. Male rats were anesthetized and prepared for craniovascular stimulation. In vivo electrophysiology was used to determine changes in trigeminocervical neuronal responses to dural electrical stimulation, and phosphorylated extracellular signal-regulated kinases 1 and 2 (pERK1/2) immunohistochemistry to determine trigeminocervical and hypothalamic neural activity; both in response to intravenous administration of insulin, glucagon, leptin or vehicle control in combination with blood glucose analysis. Blood glucose levels were significantly decreased by insulin (p<0.001) and leptin (p<0.01) whereas glucagon had the opposite effect (p<0.001). Dural-evoked neuronal firing in the trigeminocervical-complex was significantly inhibited by insulin (p<0.001), glucagon (p<0.05) and leptin (p<0.01). Trigeminocervical-complex pERK1/2 cell expression was significantly decreased by insulin and leptin (both p<0.001), and increased by glucagon (p<0.001), when compared to vehicle control. However, only leptin affected pERK1/2 expression in the hypothalamus, significantly decreasing pERK1/2 immunoreactive cell expression in the arcuate nucleus (p<0.05). These findings demonstrate that insulin, glucagon and leptin can alter the transmission of trigeminal nociceptive inputs. A potential neurobiological link between migraine and impaired metabolic homeostasis may occur through disturbed glucose regulation and a transient hypothalamic dysfunction.

Migraine and type 2 diabetes; is there any association?

BACKGROUND

Migraine headache prevalence and triggers in type2 diabetes mellitus (T2DM) were investigated in previous studies but the results are contradictory. Therefore, in this study we examined the prevalence of migraine headache in diabetic patients in comparison with non-diabetic persons and its predisposing factors in 2014.

METHODS

We enrolled 147 volunteer patients with T2DM and 150 healthy persons referred to the Yazd Diabetes Research Center and the Central Laboratory of Yazd, respectively, in 2014. The data collection instrument was a self-conducted checklist. The checklist contained demographic, anthropometric and clinical characteristics and migraine diagnostic questions according to International Classification of Headache Disorders Second Edition (ICHD-II) criteria. We compared prevalence of migraine between two groups, and also evaluated relationship between above characteristics and migraine prevalence in both groups.

RESULTS

The prevalence of migraine in participants of diabetic and non-diabetic was 27.9 and 26 %, respectively (p-value = .406). The prevalence of migraine headache among in diabetic persons was significantly correlated with family history of migraine, diabetes duration and hypoglycemia attacks. Also, the migraine prevalence was significant more prevalent in T2DM patients with duration 6-10 years (p-value = 0.031). The percentage of HbA1C, type of anti-diabetic medication, BMI value and age in diabetic patients did not show any significant association with migraine.

CONCLUSION

Although we observed no significant differences in prevalence of migraine between patients with T2DM and non-diabetic age and sex adjusted persons But, the occurrence of hypoglycemia attacks and T2DM duration were related to migraine prevalence. Decreasing hypoglycemia among long-time T2DM patients probably can decline migraine headache in this group of patients.

Cortical functional correlates of responsiveness to short-lasting preventive intervention with ketogenic diet in migraine: a multimodal evoked potentials study

BACKGROUND

Here, we aim to identify cortical electrofunctional correlates of responsiveness to short-lasting preventiveintervention with ketogenic diet (KD) in migraine.

METHODS

Eighteen interictal migraineurs underwent visual (VEPs) and median nerve somatosensory (SSEPs) evokedpotentials before and after 1 month of KD during ketogenesis. We measured VEPs N1-P1 and SSEPs N20-P25 amplitudes respectively in six and in two sequential blocks of 100 sweeps as well as habituation as theslope of the linear regression between block 1 to 6 for VEPs or between 1 to 2 for SSEPs.

RESULTS

After 1-month of KD, a significant reduction in the mean attack frequency and duration was observed (all P< 0.001). The KD did not change the 1st SSEP and VEP block of responses, but significantly inducednormalization of the interictally reduced VEPs and SSEPs (all p < 0.01) habituation during the subsequentblocks.

CONCLUSIONS

KD could restore normal EPs habituation curves during stimulus repetition without significantly changing theearly amplitude responses. Thus, we hypothesize that KD acts on habituation regulating the balancebetween excitation and inhibition at the cortical level.

Insulin Resistance and High Sensitivity C-Reactive Protein in Migraine

Background:

A relationship between migraine and vascular disorders such as hypertension, stroke, and coronary ischemia has been recently reported. Insulin resistance and endothelial dysfunction, which commonly underlies these disorders, have not been widely investigated in migraine patients. In this study, we aimed to investigate the existence of insulin resistance and endothelial dysfunction, and their relationship to vascular risk factors in patients with migraine.

Methods:

We evaluated insulin resistance and high-sensitivity C-reactive protein (hs-CRP), a marker of endothelial dysfunction, in 60 migraine patients and 25 healthy control subjects. Multiple analysis of covariance test was used to adjust for known confounding factors that can influence insulin metabolism and endothelial function, such as obesity, blood pressure, and lipid parameters.

Results:

Insulin resistance, as measured homeostasis model assessment (HOMA)-R levels, was significantly higher in the migraine group (p<0.001). After adjustment for confounding variables, the relationship between migraine and the HOMA-R levels remained significant (p<0.001). The hs-CRP levels did not differ between the migraine and control groups.

Conclusions:

Our data show that insulin resistance is present in migraine patients. Endothelial dysfunction is not found during the headache-free period. Further studies are needed to explain the role of insulin resistance in migraine pathogenesis.