Global, regional, and national time trends in incidence for migraine, from 1990 to 2019: an age-period-cohort analysis for the GBD 2019

BACKGROUND

The majority of epidemiological studies on migraine have been conducted in a specific country or region, and there is a lack of globally comparable data. We aim to report the latest information on global migraine incidence overview trends from 1990 to 2019.

METHODS

In this study, the available data were obtained from the Global Burden of Disease 2019. We present temporal trends in migraine for the world and its 204 countries and territories over the past 30 years. Meanwhile, an age-period-cohort model be used to estimate net drifts (overall annual percentage change), local drifts (annual percentage change in each age group), longitudinal age curves (expected longitudinal age-specific rate), and period (cohort) relative risks.

RESULTS

In 2019, the global incidence of migraine increased to 87.6 million (95% UI: 76.6, 98.7), with an increase of 40.1% compared to 1990. India, China, United States of America, and Indonesia had the highest number of incidences, accounting for 43.6% of incidences globally. Females experienced a higher incidence than males, the highest incidence rate was observed in the 10-14 age group. However, there was a gradual transition in the age distribution of incidence from teenagers to middle-aged populations. The net drift of incidence rate ranged from 3.45% (95% CI: 2.38, 4.54) in high-middle Socio-demographic Index (SDI) regions to -4.02% (95% CI: -4.79, -3.18) in low SDI regions, 9 of 204 countries showed increasing trends (net drifts and its 95% CI were > 0) in incidence rate. The age-period-cohort analysis results showed that the relative risk of incidence rate generally showed unfavorable trends over time and in successively birth cohorts among high-, high-middle-, and middle SDI regions, but low-middle- and low-SDI regions keep stable.

CONCLUSIONS

Migraine is still an important contributor to the global burden of neurological disorders worldwide. Temporal trends in migraine incidence are not commensurate with socioeconomic development and vary widely across countries. Both sexes and all age groups should get healthcare to address the growing migraine population, especially adolescents and females.

Effect of short-term air pollution exposure on migraine: A protocol for systematic review and meta-analysis on human observational studies

BACKGROUND

The World Health Organization (WHO) has identified air pollution as one of the greatest environmental risks to public health. High levels of ambient air pollution are known to have adverse health effects, but the relationship between exposure to air pollutants and migraine attack has not been established.

OBJECTIVES

This study aims to systematically review the effects of short-term exposure to fine and coarse particulate matter (PM), ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide on migraine attack.

METHODS

The systematic review and meta-analysis will follow the WHO handbook for guideline development. Our protocol will comply with the guidelines of the Preferred Reporting Items for Systematic Review and meta-Analysis Protocols.

ELIGIBILITY CRITERIA

Original peer-reviewed studies conducted in the general population regardless of age and sex to investigate the association between short-term exposure to ambient air pollutants and migraine will be eligible for inclusion. Only time-series, case-crossover, and panel studies will be included.

INFORMATION SOURCES

We will search the electronic databases MEDLINE, Embase, Web of Science, Global Health, Cumulative Index to Nursing and Allied Health Literature in accordance with the pre-established search strategy. We will also check the reference list of included papers and previous reviews for supplementary search.

DATA SYNTHESIS METHOD

We will perform data extraction in accordance with the predesigned table. Using random-effects meta-analysis, we will present summary statistics (RRs and corresponding 95% CIs) associated with standardized increases in each pollutant level. Heterogeneity between studies will be assessed using 80% prediction intervals (PI). Subgroup analyzes will be performed to explore sources of heterogeneity, if any. The main findings will be presented in summary of finding table, visual display and narrative synthesis. We will review the impact of each air pollutant exposure separately.

EVIDENCE APPRAISAL

We will employ the adaption of Grading of Recommendations, Assessment, Development, and Evaluations tool to assess the confidence in the body of evidence.

Disease burden of migraine and tension-type headache in non-high-income East and Southeast Asia from 1990 to 2019

BACKGROUND

The world faces severe challenges from migraine and tension-type headache (TTH), which cause grave disability to patients and place a heavy burden on their caregivers. However, headaches in specific individual regions have rarely been investigated. Therefore, we aimed to fully analyse and describe the current status and changing trends in migraine and TTH in non-high-income East and Southeast Asia to provide more detailed real-world information for policy-making.

METHODS

The migraine and TTH data used for analysis were all extracted from the Global Burden of Disease (GBD) database. We adopted three major indicators of disease burden, including prevalence, incidence, and years lived with disability (YLD), and two major metrics, including the absolute number and the age-standardized rate, in our present study for further evaluation by age and sex. The results are presented in the form of mean values and 95% uncertainty intervals (UIs). In addition, the differences between non-high-income East and Southeast Asia and other regions, as well as the potential associations between headache burden and socioeconomic background, were explored.

RESULTS

In 2019, approximately 195,702,169 migraine patients and 291,924,564 TTH patients lived in non-high-income East Asia, and 113,401,792 migraine patients and 179,938,449 TTH patients lived in non-high-income Southeast Asia. In terms of specific countries and regions, the highest age-standardized YLD rate (ASYR) of migraine was in Thailand [645 (95% UI: 64 to 1,554)]. The highest ASYR of TTH was in Indonesia [54 (95% UI: 15 to 197)]. Furthermore, people between the ages of 40 and 44, especially females, were identified as the main population that suffered from migraine and TTH. Unfortunately, we did not observe a significant association between headache burden and socioeconomic background.

CONCLUSIONS

To date, the threats from migraine and TTH in non-high-income East and Southeast Asia are still serious and ongoing, leading to prominently negative impacts on the daily life and work of local residents. Therefore, full attention and sound guidelines are urgently needed to obtain greater advantages in fighting against the burden of headache disorders in the future.

Brain Disorders and Chemical Pollutants: A Gap Junction Link?

The incidence of brain pathologies has increased during last decades. Better diagnosis (autism spectrum disorders) and longer life expectancy (Parkinson's disease, Alzheimer's disease) partly explain this increase, while emerging data suggest pollutant exposures as a possible but still underestimated cause of major brain disorders. Taking into account that the brain parenchyma is rich in gap junctions and that most pollutants inhibit their function; brain disorders might be the consequence of gap-junctional alterations due to long-term exposures to pollutants. In this article, this hypothesis is addressed through three complementary aspects: (1) the gap-junctional organization and connexin expression in brain parenchyma and their function; (2) the effect of major pollutants (pesticides, bisphenol A, phthalates, heavy metals, airborne particles, etc.) on gap-junctional and connexin functions; (3) a description of the major brain disorders categorized as neurodevelopmental (autism spectrum disorders, attention deficit hyperactivity disorders, epilepsy), neurobehavioral (migraines, major depressive disorders), neurodegenerative (Parkinson's and Alzheimer's diseases) and cancers (glioma), in which both connexin dysfunction and pollutant involvement have been described. Based on these different aspects, the possible involvement of pollutant-inhibited gap junctions in brain disorders is discussed for prenatal and postnatal exposures.