Role of adipocytokines in the pathophysiology of migraine: A cross-sectional study

A causal effects of gut microbiota in the development of migraine

BACKGROUND

The causal association between the gut microbiome and the development of migraine and its subtypes remains unclear.

METHODS

The single nucleotide polymorphisms concerning gut microbiome were retrieved from the gene-wide association study (GWAS) of the MiBioGen consortium. The summary statistics datasets of migraine, migraine with aura (MA), and migraine without aura (MO) were obtained from the GWAS meta-analysis of the International Headache Genetics Consortium (IHGC) and FinnGen consortium. Inverse variance weighting (IVW) was used as the primary method, complemented by sensitivity analyses for pleiotropy and increasing robustness.

RESULTS

In IHGC datasets, ten, five, and nine bacterial taxa were found to have a causal association with migraine, MA, and MO, respectively, (IVW, all P < 0.05). Genus.Coprococcus3 and genus.Anaerotruncus were validated in FinnGen datasets. Nine, twelve, and seven bacterial entities were identified for migraine, MA, and MO, respectively. The causal association still exists in family.Bifidobacteriaceae and order.Bifidobacteriales for migraine and MO after FDR correction. The heterogeneity and pleiotropy analyses confirmed the robustness of IVW results.

CONCLUSION

Our study demonstrates that gut microbiomes may exert causal effects on migraine, MA, and MO. We provide novel evidence for the dysfunction of the gut-brain axis on migraine. Future study is required to verify the relationship between gut microbiome and the risk of migraine and its subtypes and illustrate the underlying mechanism between them.

A Bidirectional View of Migraine and Diet Relationship

Migraine is a common headache with a large negative impact on health. Several endogenous and exogenous factors can influence the severity and frequency of migraine, for example, lifestyle factors including dietary factors. Consequently, lifestyle modifications and dietary considerations have been reported beneficial to moderate clinical features of migraine. Much effort has been invested in determining the lifestyle factors (eg, stress, exercise, sleep, and diet) that trigger migraine to develop recommendations and guidelines for prevention. Diet has also been investigated with a major focus on the content of the diet and to a lesser extent on the amount, pattern, and quality of diet. Identification of dietary factors in migraine has led to nutritional interventions with a major focus on elimination of triggers, and weight control strategies. Several so-called migraine diets have consequently been proposed, for example, the ketogenic diet. Some theories have considered epigenetic diets or functional food to help in altering components of migraine pathogenesis; however, these theories are less investigated. In contrast, evidence is being accumulated to support that some mechanisms underlying migraine may alter dietary choices, for example type, amount, or patterns. Since a causative relationship is not yet established in migraine-diet relationship as to which comes first, this concept is equally valuable and interesting to investigate. Only limited epidemiological data are available to demonstrate that dietary choices are different among patients with migraine compared with individuals without migraine. Differences are reflected on quality, composition, pattern, and the amount of consumption of dietary components. This view emphasizes a potential bidirectional relationship between migraine and diet rather than a one-way influence of one on the other. This targeted review presents examples from current literature on the effects of diet on migraine features and effects of migraine on dietary choices to draw a perspective for future studies.

Medication overuse headache in 787 patients admitted for inpatient treatment over a period of 32 years

BACKGROUND

Definitions of medication overuse headache have changed over time.

OBJECTIVE

To evaluate the clinical characteristics of medication overuse headache patients admitted for inpatient withdrawal therapy over a period of 32 years.

METHODS

We included all patients with medication overuse headache treated from 1 January 1984 to 31 December 2015. We obtained all data from the medical reports and defined three periods, P1 (1984-1993), P2 (1994-2003), and P3 (2004-2015). The p-value adjusted for multiple comparisons was set to 0.005.

RESULTS

Within 32 years, a total of 787 patients accounted for 904 admissions for MOH. From P1 to P3, the proportion of patients with preexisting migraine increased from 44.3% to 53.3% (chi² = 9.0, p = 0.01) and that with preexisting tension-type headache decreased from 47.9% to 34.6% (chi² = 9.3, p < 0.01). The median time since onset of headache and medication overuse headache decreased from 20 to 15 years (p < 0.001) and from 3 to 2 years (p < 0.001). The median cumulative number of single doses decreased from 120 to 90 per month (p = 0.002). Overuse of triptans, non-opioid analgesics, and opioids increased, whereas overuse of ergotamines decreased over time (p < 0.001 for all tests). The use of prophylactic medication before admission increased from 8.3% to 29.9% (chi² = 89.5, p < 0.001).

CONCLUSION

This retrospective study in a large number of patients with medication overuse headache admitted for inpatient withdrawal therapy over a period of 32 years shows a trend towards changes in the preexisting headache type, a decrease in the time since onset of headache and medication overuse headache, a decrease in the number of drug doses used per month, changes in the type of drugs overused, and an increase in, but still low rate, of prophylactic medication prior to admission.

Circulating Biomarkers in Migraine: New Opportunities for Precision Medicine

Background:

Migraine is the most common neurological disorder and the second most disabling human condition, whose pathogenesis is favored by a combination of genetic, epigenetic, and environmental factors. In recent years, several efforts have been made to identify reliable biomarker(s) useful to monitor disease activity and/or ascertain the response to a specific treatment.

Objective:

To review the current evidence on the potential biological markers associated with migraine.

Methods:

A structured search of peer-reviewed research literature was performed by searching major publications databases up to December 2017.

Results:

Several circulating biomarkers have been proposed as diagnostic or therapeutic tools in migraine, mostly related to migraine’s inflammatory pathophysiological aspects. Nonetheless, their detection is still a challenge for the scientific community, reflecting, at least in part, disease complexity and clinical diagnostic limitations. At the present time, calcitonin generelated peptide (CGRP) represents probably the most promising candidate as a diagnostic and/or therapeutic biomarker, as its plasma levels are elevated during migraine attack and decrease during successful treatment. Other molecules (including some neuropeptides, cytokines, adipokines, or vascular activation markers) despite promising, do not possess the sufficient prerequisites to be considered as migraine biomarkers.

Conclusion:

The characterization of migraine-specific biomarkers would be fundamental in a perspective of precision medicine, enabling risk assessment and tailored treatments. However, speculating on the clinical validity of migraine biomarkers may be premature and controlled clinical trials are presently needed to investigate both the diagnostic and therapeutic value of these biomarkers in migraine.

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.

The role of leptin as a biomarker in the relationship between periodontitis and chronic migraine

AIM

To evaluate the prevalence of periodontitis (CP) and its contribution to serum leptin levels in chronic migraine (CM).

MATERIAL AND METHODS

In this case-control study, we included 150 subjects divided into healthy controls (n = 58) and CM patients (n = 92). Demographic, neurological, clinical data as well as full-mouth periodontal records were obtained. Serum leptin levels were measured by ELISA technique.

RESULTS

Both the prevalence of CP and mean serum leptin levels were significantly higher in patients with CM in comparison with controls (57.6% versus 36.2%, p = .01 and 16.4 versus 7.2 ng/ml, p < .0001, respectively). Patients from the CM group who had CP showed significantly higher leptin concentrations than CM patients without CP (19.8 versus 11.8 ng/ml, p < .0001). Multivariable linear regression analysis showed that CP was an independent contributor to raised leptin levels in CM patients (R²  = 0.270, p = 0.013).

CONCLUSIONS

CP is prevalent in CM patients and when present it contributes to elevated serum leptin levels, independently of other confounding factors. Therefore, it seems that CP via leptin could be involved in the process of migraine chronification.