Multiple sclerosis and environmental risk factors: a case-control study in Iran

Prevalence and disease disability in immigrants with multiple sclerosis in Malmö, southern Sweden

BACKGROUND

Multiple sclerosis (MS) is the most common chronic demyelinating disease of the central nervous system and the major non-traumatic cause of permanent disability in young adults. Several migration studies have been performed over the years suggesting a pattern of higher disease disability in certain ethnic groups. To our knowledge, differences in disease progression in immigrants have not been studied in Sweden before. Thus, the aims of our study were to estimate the prevalence of multiple sclerosis among first-generation immigrants in the City of Malmö and to compare differences in disease severity with the native population.

METHODS

All persons with multiple sclerosis living in Malmö on prevalence day 31 Dec 2010 were included. Cases were classified according to the country of birth into Scandinavians, Western and non-Western.

RESULTS

The crude prevalence was 100/100,000 (95% CI, 80-124) among first-generation immigrants, 154/100,000 (95% CI, 137-173) among individuals with Scandinavian background, 123/100,000 (95% CI, 94-162) in the Western group and 76/100,000 (95% CI, 53-108) in the non-Western group. The mean Multiple Sclerosis Severity Score (MSSS) value among Scandinavians was 4.2 (SD 3.5), whereas the figures in the immigrant group were 4.6 (SD 3.3) and 5.2 (SD 3.7) among Westerns respectively non-Westerns, which differences were not statistically significant. When adjusting for gender, age at onset and initial disease course, the mean MSSS difference between the non-Western and the Scandinavian individuals was 1.7 (95% CI 0.18-3.3, p = 0.030). There were no differences on time to diagnosis or the time from diagnosis to treatment initiation between the three groups.

CONCLUSIONS

We found a lower prevalence among Western and non-Western first-generation immigrants compared to the Scandinavian population and a more severe disease in non-Western immigrants than in Scandinavians.

Childhood and adolescence factors and multiple sclerosis: results from the German National Cohort (NAKO)

BACKGROUND

Multiple Sclerosis (MS) represents the most common inflammatory neurological disease causing disability in early adulthood. Childhood and adolescence factors might be of relevance in the development of MS. We aimed to investigate the association between various factors (e.g., prematurity, breastfeeding, daycare attendance, weight history) and MS risk.

METHODS

Data from the baseline assessment of the German National Cohort (NAKO) were used to calculate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for the association between childhood and adolescence factors and risk of MS. Analyses stratified by sex were conducted.

RESULTS

Among a total of 204,273 participants, 858 reported an MS diagnosis. Male sex was associated with a decreased MS risk (HR 0.48; 95% CI 0.41-0.56), while overweight (HR 2.03; 95% CI 1.41-2.94) and obesity (HR 1.89; 95% CI 1.02-3.48) at 18 years of age compared to normal weight were associated with increased MS risk. Having been breastfed for ≤ 4 months was associated with a decreased MS risk in men (HR 0.59; 95% CI 0.40-0.86) compared to no breastfeeding. No association with MS risk was observed for the remaining factors.

CONCLUSIONS

Apart from overweight and obesity at the age of 18 years, we did not observe considerable associations with MS risk. The proportion of cases that can be explained by childhood and adolescence factors examined in this study was low. Further investigations of the association between the onset of overweight and obesity in childhood and adolescence and its interaction with physical activity and MS risk seem worthwhile.

Exclusive breastfeeding may be a protective factor in individuals with familial multiple sclerosis. A population registry-based case-control study

BACKGROUND

Multiple sclerosis (MS) is an immune-mediated disease that affects the central nervous system, which most likely results from the interplay between environmental and genetic factors. The aim of our study was to assess the effect of breastfeeding on the risk of developing familial multiple sclerosis (fMS) in persons with positive MS history, being the first such investigation performed in fMS cohort.

METHODS

A case-control study based on the Belgrade population MS Registry was conducted. Cases for the sporadic MS (sMS) control group were randomly selected from the Registry, and matched with individuals with fMS at a ratio of 1:1. Spouses of the persons with fMS were included as a healthy control (HC) group. A specific questionnaire that was previously validated was used to obtain the data. To evaluate risk factors associated with breastfeeding for fMS occurrence compared with sMS and HC, multinomial regression analysis was performed to compute the relative risk ratios (RRR) along with 95% confidence intervals (95% CI). The analysis was afterwards repeated, stratified by sex. Both models were adjusted for potential confounding factors.

RESULTS

A total of 393 participants were included in our case-control study, 131 per group. There were more individuals who were exclusively breastfed longer than six months in the sMS group compared to fMS group (RRR 2.01, 95% CI 1.22-3.32). After stratification by sex, exclusive breastfeeding was shown to be a protective factor for fMS only in male population, for individuals breastfed ≥4 months. The results of both the main and stratified analysis remained robust after adjustment.

CONCLUSION

Our study findings indicate that breastfeeding reduces the risk of MS in infants with family history of the disease, although this protective effect may be limited to the male population. Further investigation into the differences in risk factors between fMS and sMS is warranted to gain a more comprehensive understanding of the disease.

The association between multiple sclerosis and migraine: A meta-analysis

BACKGROUND

Multiple sclerosis (MS) is a chronic progressive condition marked by the deterioration of myelin and impairment of neurological function. The global prevalence of MS is approximately 2.2 million. Migraines are common in MS patients, with inconclusive data on their relationship. Our systematic review aimed to assess the prevalence and odds of migraine in pwMS and investigate the potential factors that may influence these associations.

METHOD

Through an extensive search and meticulous study selection, we identified pertinent literature investigating the occurrence and odds of migraines among pwMS. Additionally, we explored the comparative risk of migraines in MS patients compared to healthy controls. Data were extracted, including publication details, diagnostic criteria, and migraine prevalence in MS patients.

RESULTS

A total of 35 studies were included, involving 279,620 pwMS and 279,603 healthy controls. The overall prevalence of migraine in pwMS was 0.24 (95% CI: 0.21-0.28). Subgroup analyses and meta-regression were conducted to investigate the potential impact of various factors on the relationship between migraine and MS. These factors included age, duration of MS, study design, and the Expanded Disability Status Scale (EDSS), migraine diagnosis method, study design, publication year of the study, country and continent of the study population. The results of these analyses revealed no significant influence of these factors on the relationship between migraine and MS. The meta-analysis indicated that pwMS had significantly increased odds of having migraine compared to healthy controls (OR = 1.96, 95% CI: 1.20-3.20). Sensitivity analyses supported the robustness of the findings.

CONCLUSIONS

Our study highlights that approximately 24% of pwMS experience migraine. The method of diagnosis significantly affects the reported prevalence, with questionnaires yielding higher rates. Furthermore, pwMS have a 1.96-fold increased odds of having migraine compared to healthy individuals. These findings emphasize the importance of further research and interventions to address the significant burden of migraine in the MS population.

Environmental Influences on Risk and Disease Course in Pediatric Multiple Sclerosis

Pediatric multiple sclerosis (MS) accounts for 3%-10% of all patients diagnosed with MS. Complex interplay between environmental factors impacts the risk for MS and may also affect disease course. Many of these environmental factors are shared with adult-onset MS. However, children with MS are in closer temporal proximity to the biological onset of MS and have less confounding environmental exposures than their adult counterparts. Environmental factors that contribute to MS risk include: geographical latitude, viral exposures, obesity, vitamin deficiencies, smoking, air pollution, perinatal factors, gut microbiome, and diet. More recently, research efforts have shifted to studying the impact of these risk determinants on the clinical course of MS. In this article we will examine relevant environmental risk determinants of pediatric MS and review the current knowledge on how these factors may contribute to pediatric MS disease evolution.

Relationship between medical history and multiple sclerosis: A-case-control study

This project sought to explore the potential association between medical history and the development of multiple sclerosis (MS) by conducting a retrospective study. This population-based case-control study included 200 MS cases and 2 control groups of 200 patients and healthy individuals each. Data was collected through face-to-face interviews, medical file reviews, and an electronic checklist. Multivariable analysis was used to calculate odds ratios and 95% confidence intervals to estimate the risk of each medical history on MS occurrences. Of 600 participants, 381 (63.5%) individuals were female. The mean age of the participants was 36.5 ± 11.9 years. The adjusted risks of MS were 4.40; 95% CI: 1.73 to 11.1 for measles and 4.75; 95% CI: 2.05 to 11 for amoxicillin consumption. The adjusted MS odds for autoimmune disease including 4.63; 95% CI: 0.35 to 60.6 for psoriasis and 7.15; 95% CI: 1.87 to 27.2 for myasthenia gravis. On the other hand, the calculated adjusted odds of MS occurrence were 0.14; 95% CI: 0.03 to 0.69 for seizure and 0.17; 95% CI: 0.02 to 1.49 for epilepsy. This study suggested that individuals with autoimmune diseases should be monitored more closely, as they may be at an increased risk of developing other autoimmune conditions, particularly MS.

Current and future trends in multiple sclerosis management: Near East perspective

BACKGROUND

Multiple sclerosis (MS) prevalence is rising in the Middle East. Most MS medications are available in the region, but not all, possibly affecting neurologists' prescribing habits.

OBJECTIVES

To provide an overview of the current practices of Near East (NE) healthcare practitioners by probing their prescribing decisions, to report the COVID-19 impacts on neurologists' prescribing habits, and to explore the future relevance of current medication used in MS management among other newcomers.

METHODS

A cross-sectional study was carried out using an online survey from April 27, 2022, to July 5, 2022. The questionnaire was designed with the input of five neurologists representing five NE countries (Iran, Iraq, Lebanon, Jordan & Palestine). They identified several factors that play a crucial role in the optimal care of MS patients. The link was shared among neurologists using snowball sampling.

RESULTS

The survey included 98 neurologists. Effectiveness and safety balance was the most important factor considered when selecting the MS treatment. Among patients with MS, the most challenging factor for the patients was thought to be related to family planning, followed by affordability and tolerability of side effects. In the treatment of mild to moderate relapsing remitting multiple sclerosis (RRMS) in men, Interferon beta 1a SC, Fingolimod, and Glatiramer acetate were the most commonly recommended treatments. Dimethyl fumarate substituted fingolimod in female patients. Interferon beta 1a SC was the safest treatment for mild to moderate RRMS. Interferon beta 1a SC was preferred over other treatments for patients with mild to moderate MS and planning for pregnancy (56.6%) or breastfeeding (60.2%). Fingolimod was not a choice for these patients. Neurologists seemed to discuss the top three treatments of Natalizumab, Ocrelizumab, and Cladribine with patients with highly active MS. When asked to position future disease-modifying therapies five years from today, more than 45% of physicians expressed a lack of information on Bruton's tyrosine kinase (BTK) inhibitors.

CONCLUSIONS

Most neurologists in the NE region followed Middle East North Africa Committee for Treatment and Research in Multiple Sclerosis (MENACTRIMS) recommendations for prescribing treatment. The treatment choice also depended on the availability of disease-modifying therapies (DMTs) in the region. Regarding the use of upcoming DMTs, there is a clear need for real-world data, long-term extension studies, and comparative studies to support their efficacy and safety profiles in treating patients with MS.

Predictors of severity and outcome of multiple sclerosis relapses

BACKGROUND

Multiple Sclerosis (MS) is a demyelinating disease of the central nervous system (CNS). The most common type of MS is the relapsing-remitting MS (RRMS) where relapses are the main component of the disease course. However, the relationship between the characteristics of the relapses on one hand and their severity and outcome on the other hand has not been fully characterized.

OBJECTIVES

To explore the characteristics of relapses among a cohort of Egyptian MS patients and their relation to the severity and outcome of the disease.

SUBJECTS AND METHODS

We analyzed 300 attacks from 223 patients in a retrospective study to identify demographic, clinical and paraclinical (laboratory and radiological) factors affecting: 1- Severity of relapses (the difference between the EDSS at the day of maximum worsening and the EDSS before the onset of the attack). 2- Outcome of relapses (the difference between the EDSS at the day of maximum improvement and the EDSS before the onset of the relapse).

RESULTS

Severe attacks were most likely to occur in patients who are males, single, presenting with poly-symptomatic presentation, slower tempo of evolution of attack symptoms, longer duration of the attack, absence of DMTs at the time of the attack. The risk of having a severe relapse is more than 3 times when the patient is single. Regarding attack outcome, poorly recovered attacks were more common in patients with older age at disease onset and at attack onset, male sex, higher number of relapses, longer duration of illness prior to the attack, severe relapses, polysymptomatic presentation, associated cognitive symptoms, slower tempo of symptom evolution, longer duration of the attack, patients on OCPs, smoking, and presence of black holes in brain MRI. The risk of having relapses with partial or no recovery is more than five times when the patient has black holes in brain MRI and more than 4 times when the patient is a smoker.

CONCLUSION

Bearing in mind the demographic characteristics as well as the clinical and paraclinical characteristics of each attack and their relation to attack severity and outcome are a key to understanding the individual disease course of every patient and hence tailoring the best therapeutic plan suitable for his individual needs. In other words, prompt, rapid intervention in male patients, polysymptomatic attacks, slower tempo of evolution of attack symptoms and longer duration of the attack should be adopted since these factors are predictive of severe relapses as well as poor relapse outcome.

Sex and age as determinants of the seroprevalence of anti-measles IgG among European healthcare workers: A systematic review and meta-analysis

INTRODUCTION

The international literature shows good evidence of a significant rate of measles susceptibility among healthcare workers (HCWs). As such, they are an important public health issue.

METHODS

We conducted a systematic review and meta-analysis to estimate the prevalence of susceptible HCWs in EU/EEA countries and in the UK and to explore the characteristics (sex and age differences) and management of those found to be susceptible.

RESULTS

Nineteen studies were included in the meta-analysis. The prevalence of measles-susceptible HCWs was 13.3% (95 %CI: 10.0-17.0%). In a comparison of serosusceptible female vs. male HCWs, the RR was 0.92 (95 %CI = 0.83-1.03), and in a comparison of age classes (born after vs. before 1980) the RR was 2.78 (95 %CI = 2.20-3.50). The most recent studies proposed the mandatory vaccination of HCWs.

DISCUSSION

According to our meta-analysis, the prevalence of serosusceptible European HCWs is 13%; HCWs born in the post-vaccination era seem to be at higher risk. Healthcare professionals susceptible to measles are a serious epidemiological concern. Greater efforts should therefore be made to identify those who have yet to be vaccinated and actively encourage their vaccination.

Total Dairy Consumption Is Not Associated With Likelihood of a First Clinical Diagnosis of Central Nervous System Demyelination

Background

The evidence associating consumption of dairy products and risk of MS is contradictory and inconclusive.

Objective

To test associations between dairy consumption and the likelihood of a first clinical diagnosis of central nervous system demyelination (FCD), a common precursor to MS.

Methods

We used data from the 2003–2006 Ausimmune Study, a population-based Australian, multicentre, matched case-control study (272 cases, 519 controls). Total dairy consumption (servings/day) was calculated by summing consumption of milk, cheese and yogurt. Covariate-adjusted treatment effects using augmented inverse probability weighting was used to test for associations with FCD. We conducted sensitivity analyses in the subset of participants who had had a classic first demyelinating event (FDE), defined as a single, first episode of symptoms suggestive of CNS demyelination.

Results

There were no statistically significant associations between total dairy consumption (per one serving/day) and FCD (adjusted OR 1.00; 95% CI 0.93, 1.07; p = 0.979). However, yogurt consumption (vs. no yogurt consumption) was associated with an 11% decreased likelihood of FDE (adjusted OR 0.89; 95% CI 0.89, 0.79; p = 0.046).

Conclusion

While total dairy consumption was not associated with FCD in this Australian case-control study, yogurt consumption was associated with reduced likelihood of FDE.

Multiple sclerosis and inflammatory bowel disease: A systematic review and meta‐analysis

Background

Multiple sclerosis (MS) and inflammatory bowel disease (IBD) are two autoimmune diseases that seriously affect patients' quality of life. Previous studies have established an association between MS and IBD, including Crohn's disease (CD) and ulcerative colitis (UC), but the results were inconsistent. The aim of this study was to quantify the prevalences of and the association between MS and IBD.

Methods

The PubMed, Web of Science, and Embase databases were searched through November 2020 for studies reporting data on MS among patients with IBD and vice versa. The main outcomes were the proportion of MS in patients with IBD and vice versa, as well as the association (risk ratio [RR]) of IBD in MS and that of MS in IBD.

Results

Based on the analysis of 17 studies, the prevalence of MS in patients with IBD was 0.2% (95% CI 0.1–0.4%), while the prevalence of IBD in patients with MS was 0.6% (95% CI 0.4–0.9%). Patients with MS had a higher prevalence of IBD than controls (RR = 1.53, 95% CI 1.38–1.70, p < 0.00001). There was a similarly high risk of developing CD (RR 1.41, 95% CI 1.14–1.74, p = 0.001) or UC (RR 1.42, 95% CI 1.17–1.71, p = 0.0003) in patients with MS (p for subgroup differences: 0.97). Patients with IBD had a higher prevalence of MS than controls (RR = 1.91, 95% CI 1.06–3.45, p = 0.03).

Conclusions

Clinicians should be aware of the increased risk of IBD or MS comorbidity during the diagnostic process. Systematic diagnosis and management at an earlier stage are suggested.

Utilization of Multiple Sclerosis Therapies in the Middle East Over a Decade: 2009-2018

BACKGROUND

The multiple sclerosis (MS) landscape has changed over the past two decades across the world and in the Middle East. The Middle East is an ethnically diverse region located between 12° and 42° of latitude and 35° and 54° of longitude and varying altitudes. The magnitude of the shifts observed in the epidemiology and management of MS differ in each region and from country to country.

OBJECTIVES

The aim of this study was to provide a clinicodemographic overview of the cohorts of patients contributed to MSBase, a large international MS registry, in the Middle East and describe disease-modifying treatment (DMT) utilization in the different countries within the region. Understanding the differences between these cohorts is integral to interpretation of the studies conducted using registry data and provides insight into clinical practice in these cohorts.

METHODS

The MSBase registry was searched for patients with MS or clinically isolated syndrome from the Middle Eastern countries with data captured between 2009 and 2018. In 2-year epochs, and with special focus on the most recent epoch (2017-2018), we explored the demographic, clinical characteristics and treatment exposures of the studied cohorts and reported the results using standard descriptive statistics.

RESULTS

Over the 10-year study period, 13,356 patients from 17 centers in 8 Middle Eastern countries fulfilled the inclusion criteria. The represented countries were Egypt, Iran, Kuwait, Lebanon, Oman, Saudi Arabia, Turkey and the United Arab Emirates. Overall, the represented cohort was young (median 36 years, quartiles 29-45) and captured relatively early after the onset of MS (median disease duration < 10 years, quartiles 3-12). The relapsing-remitting phenotype was the most prevalent phenotype in all countries (73-97%) and the highest proportion of progressive MS was reported in Saudi Arabia (12%). Median Expanded Disability Status Scale (EDSS) ranged from 0 to 3, depicting a mildly disabled cohort, with the exception of Saudi Arabia where the median EDSS was 4 (quartiles 1.5-6.5). The median relapse frequency was highest in Lebanon (median 1.03, 95% CI 0.94-1.16) followed by Egypt (median 1.02, 95% CI 0.89-1.24) and lowest in Saudi Arabia (median 0.70, 95% CI 0.58-0.95) and Kuwait (median 0.75, 95% CI 0.71-0.80). The treatment landscape greatly varied between different countries. Platform injectable therapies were mostly utilized in Egypt, Iran and Turkey (86%, 79% and 53%, respectively), while oral therapies and monoclonal antibodies were more commonly used in Kuwait, Lebanon and the United Arab Emirates (87.2%, 67.3% and 58.7%, respectively).

CONCLUSION

Patients in the Middle East enrolled in a large multinational registry are representative of the general MS population. The spectrum of therapies used in the individual countries, however, is highly variable. Further studies that include rural and non-academic practices are needed to enhance our understanding of the MS cohorts in the Middle East.

Role of environmental factors in multiple sclerosis

INTRODUCTION

Environmental factors play a significant role in the pathogenesis and progression of multiple sclerosis (MS), either acting alone or by interacting with other environmental or genetic factors. This cumulative exposure to external risk factors is highly complex and highly variable between individuals.

AREAS COVERED

We narratively review the current evidence on the role of environment-specific risk factors in MS onset and progression, as well as the effect of gene-environment interactions and the timing of exposure We have reviewed the latest literature, by Ovid Medline, retrieving the most recently published systematic reviews and/or meta-analyses and more recent studies not previously included in meta-analyses or systematic reviews.

EXPERT OPINION

There is some good evidence supporting the impact of some environmental risk factors in increasing the risk of developing MS. Tobacco smoking, low vitamin D levels and/or low sun exposure, Epstein Barr Virus (EBV) seropositivity and a history of infectious mononucleosis may increase the risk of developing MS. Additionally, there is some evidence that gene-smoking, gene-EBV, and smoking-EBV interactions additively affect the risk of MS onset. However, the evidence for a role of other environmental factors in MS progression is limited. Finally, there is some evidence that tobacco smoking, insufficient vitamin D levels and/or sun exposure have impacts on MS phenotypes and various markers of disease activity including relapse, disability progression and MRI findings. Clearly the effect of environmental factors on MS disease course is an area that requires significantly more research.

Genetically Predicted Milk Intake and Risk of Neurodegenerative Diseases

Milk intake has been associated with risk of neurodegenerative diseases in observational studies. Nevertheless, whether the association is causal remains unknown. We adopted Mendelian randomization design to evaluate the potential causal association between milk intake and common neurodegenerative diseases, including multiple sclerosis (MS), Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), and Parkinson’s disease (PD). Genetic associations for neurodegenerative diseases were obtained from the International Multiple Sclerosis Genetics Consortium (n = 80,094), FinnGen consortium (n = 176,899), AD GWAS (n = 63,926), Web-Based Study of Parkinson’s Disease (n = 308,518), PDGene (n = 108,990), and ALS GWAS (n = 80,610). Lactase persistence variant rs4988235 (LCT-13910 C > T) was used as the instrumental variable for milk intake. Genetically predicted higher milk intake was associated with a decreased risk of MS and AD and with an increased risk of PD. For each additional milk intake increasing allele, the odds ratios were 0.94 (95% confidence intervals [CI]: 0.91–0.97; p = 1.51 × 10⁻⁴) for MS, 0.97 (0.94–0.99; p = 0.019) for AD and 1.09 (95%CI: 1.06–1.12, p = 9.30 × 10⁻⁹) for PD. Genetically predicted milk intake was not associated with ALS (odds ratio: 0.97, 95%CI: 0.94–1.01, p = 0.135). Our results suggest that genetically predicted milk intake is associated with a decreased risk of MS and AD but with an increased risk of PD. Further investigations are needed to clarify the underlying mechanisms.

Matching participant address with public records database in a US national longitudinal cohort study

Background

Epidemiological studies utilize residential histories to assess environmental exposure risk. The validity from using commercially-sourced residential histories within national longitudinal studies remains unclear. Our study assessed predictors of non-agreement between baseline addresses from the commercially-sourced LexisNexis database and participants in the national longitudinal study, REasons for Geographic and Racial Differences in Stroke (REGARDS). Additionally, we assessed differences in stroke risk by neighborhood socioeconomic score (nSES) based on participant reported address compared to nSES from LexisNexis/REGARDS matched baseline address.

Methods

From January 2003–October 2007, REGARDS enrolled 30,239 black and white adults aged 45 and older within the continental United States and collected their baseline address. ArcGIS Desktop 10.5.1 with ESRI 2016 Business Analyst Data was used to geocode baseline addresses from LexisNexis and REGARDS. Logistic regression was used to estimate the likelihood that LexisNexis address matched REGARDS baseline address for each participant. Survival analysis was used to estimate association between nSES and incident stroke.

Results

Approximately 91% of REGARDS participants had a LexisNexis address. Of these geocoded addresses, 93% of REGARDS baseline addresses matched LexisNexis addresses. Odds of agreement between LexisNexis and REGARDS was higher for older-aged participants (OR = 1.02 per year, 95% CI: 1.01, 1.02), blacks compared to whites (OR = 1.16, 95% CI: 1.05, 1.29), females compared to males (OR = 1.15, 95% CI: 1.04, 1.26), participants with an income of $34k-74k compared to an income less than $20k (OR = 1.62, 95% CI: 1.39, 1.89). Odds of agreement were lower for residents in Midwest compared to residents in the south (OR = 0.82, 95% CI: 0.73, 0.94). No significant differences in nSES-stroke associations were observed between REGARDS only and LexisNexis/REGARDS matched addresses; however, differences in interactions were observed.

Conclusion

Agreement between LexisNexis and REGARDS addresses varied by sociodemographic groups, potentially introducing bias in studies reliant on LexisNexis alone for residential address data.

•

Approximately 9% of REGARDS participants did not have a LexisNexis address history available.

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Of participants with both REGARDS and LexisNexis addresses available, 93% of these addresses matched.

•

Agreement between REGARDS and LexisNexis address varied by socio-demographics—potentially biasing environmental exposures.

•

Compared to LexisNexis, REGARDS addresses may be valuable in detecting interactions contributing to stroke disparities.

Risk Factors Associated with Multiple Sclerosis: A Case-Control Study in Damascus, Syria

Objectives

To assess the probable risk factors associated with Multiple sclerosis among Syrian patients in the city of Damascus.

Method

In a case-control study conducted from May to September 2020, 140 MS patients and 140 healthy controls were selected from two main hospitals in Damascus. Data regarding risk factors associated with MS was collected via a structured questionnaire and complementary laboratory tests. The statistical analysis was carried out by the SPSS Statistical Software Version 26.

Results

Factors such as smoking, family history of MS, migraine, and vitamin D deficiency were associated with a higher risk of developing MS: Smoking (OR = 2.275 95% CI (1.348-3.841) P = 0.002). Family history of MS (OR = 3.970 95% CI (1.807-8.719) P ≤ 0.001). Migraine (OR = 3.011 95% CI (1.345-6.741) P = 0.005). Vitamin D deficiency (OR = 4.778 95% CI (2.863-7.972) P ≤ 0.001). However, factors such as diabetes, hypertension, a surgical history of appendectomy, tonsillectomy, and being the first-born in a family were statistically irrelevant: Diabetes (OR = 0.652 95% CI (0.226-1.882) P = 0.426). Hypertension (OR = 1.445 95% CI (0.724-2.885) P = 0.295) Appendectomy (OR = 1.269 95% CI (0.486-3.317) P = 0.626) Tonsillectomy (OR = 1.280 95% CI (0.576-2.843) P = 0.544). First-born Child (OR = 0.933 95% CI (0.558-1.562) P = 0.793).

Conclusion

Our study suggests that smoking, vitamin D deficiency, family history of MS, and migraine are probable risk factors for multiple sclerosis. Therefore, engaging in outdoor activities and maintaining a healthy diet-for females in particular-is highly recommended.

Current review and next steps for artificial intelligence in multiple sclerosis risk research

In the last few decades, the prevalence of multiple sclerosis (MS), a chronic inflammatory disease of the nervous system, has increased, particularly in Northern European countries, the United States, and United Kingdom. The promise of artificial intelligence (AI) and machine learning (ML) as tools to address problems in MS research has attracted increasing interest in these methods. Bayesian networks offer a clear advantage since they can integrate data and causal knowledge allowing for visualizing interactions between dependent variables and potential confounding factors. A review of AI/ML research methods applied to MS found 216 papers using terms "Multiple Sclerosis", "machine learning", "artificial intelligence", "Bayes", and "Bayesian", of which 90 were relevant and recently published. More than half of these involve the detection and segmentation of MS lesions for quantitative analysis; however clinical and lifestyle risk factor assessment and prediction have largely been ignored. Of those that address risk factors, most provide only association studies for some factors and often fail to include the potential impact of confounding factors and bias (especially where these have causal explanations) that could affect data interpretation, such as reporting quality and medical care access in various countries. To address these gaps in the literature, we propose a causal Bayesian network approach to assessing risk factors for MS, which can address deficiencies in current epidemiological methods of producing risk measurements and makes better use of observational data.

Shared breastfeeding & other early multiple sclerosis risk factors: A case-control study

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease. Etiology is thought to be multifactorial with genetic and environmental factors interplay. Our objective in this study is to evaluate culture specific and other early life risk factors for MS. We examined the association between MS and breastfeeding including shared breastfeeding, parental consanguinity, being born abroad or living abroad during childhood, prematurity, vaccination, tonsillectomy, rank among siblings, number of siblings, number of household members (HHM) at birth, and age first time joining school.

METHODS

This is an age and sex matched case-control study that was conducted in Riyadh, Kingdom of Saudi Arabia (KSA). We enrolled 300 cases and 601 controls. A structured questionnaire about demographics, consanguinity and potential environmental factors was answered by participants. Data was analyzed using logistic regression adjusting for covariates occurring later in life such as waterpipe smoking and performing Hajj.

RESULTS

About two thirds of the cases and the controls were females. Mean age was 34.8 (9.2) for the cases and 33.6 (10.6) for the controls. We found that shared breastfeeding (OR=0.58; 95% CI, 0.35-0.96, p = 0.033), and older age first joining school (OR=0.83; 95% CI, 0.73-0.94, p = 0.005) were associated with decrease risk of MS. While longer duration of breastfeeding by biological mother (OR=1.03; 95% CI, 1.01-1.04, p = 0.001), rank among siblings of ≥6 (OR=1.69; 95% CI, 1.11-2.56, p = 0.014), and larger number of HHM at birth (OR=2.32; 95% CI, 1.64-3.28, p = 0.001) were associated with increased risk. Patients with MS were less likely to receive formula with breastfeeding than controls (OR=0.72; 95% CI, 0.51-0.99, p = 0.046). No association was found with breastfeeding by biological mother, number of siblings, prematurity, being born abroad or living abroad during childhood, vaccination, consanguinity, or tonsillectomy.

CONCLUSION

The findings of this case-control study add to the accumulating evidence that early life factors could modify the risk of developing MS. Among these, novel associations with shared breastfeeding and number of HHM at birth are suggested. Future studies are needed to verify the observed results.

COVID-19 and Multiple Sclerosis: Predisposition and Precautions in Treatment

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), leading to Coronavirus disease 2019 (COVID-19), is not always confined to the respiratory tract, while patients with can develop neurological manifestations. The patients with multiple sclerosis (MS) pose challenges in this pandemic situation, because of the immunosuppressive medications they get and the fact that viral infections may contribute to MS exacerbation and relapses as an environmental factor in genetically predisposed individuals. Herein, possible consequences of COVID-19 which may carry for the MS patients and the underlying mechanisms of its impact are discussed.

Effects of Exercise on Memory Interference in Neuropsychiatric Disorders

There are several mechanisms that cause memory impairment, including motivated forgetting, active forgetting, natural decay, and memory interference. Interference occurs when one is attempting to recall something specific, but there is conflicting information making it more difficult to recall the target stimuli. In laboratory settings, it is common to measure memory interference with paired associate tasks-usually utilizing the AB-CD, AB-AC, AB-ABr, or AB-DE AC-FG method. Memory impairments are frequent among those with neuropsychiatric disorders such as depression, schizophrenia, and multiple sclerosis. The memory effects of each condition differ, but are all related to alterations in brain physiology and general memory deterioration. Exercise, or physical activity, has been demonstrated to attenuate memory interference in some cases, but the mechanisms are still being determined. Further research is needed on memory interference, in regard to exercise and neuropsychiatric disorders.

Childhood infections, vaccinations, and tonsillectomy and risk of first clinical diagnosis of CNS demyelination in the Ausimmune Study

BACKGROUND

The association between childhood vaccinations and infections and risk of multiple sclerosis is unclear; few studies have considered age at vaccination/infection.

OBJECTIVE

To explore age-related associations between childhood vaccinations, infection and tonsillectomy and risk of a first clinical diagnosis of CNS demyelination.

METHODS

Data on case (n = 275, 76.6% female; mean age 38.6 years) and age- and sex-matched control (n = 529) participants in an incident population-based case-control study included self-reported age at time of childhood vaccinations, infections, and tonsillectomy. Conditional logistic regression models were used to calculate adjusted odds ratios (AOR) and 95% confidence intervals (CI).

RESULTS

Poliomyelitis vaccination prior to school-age was associated with increased risk of a first clinical diagnosis of CNS demyelination (AOR = 2.60, 95%CI 1.02-6.68), based on a very small unvaccinated reference group. Late (11-15 years) rubella vaccination (compared to none) was associated with lower odds of being a case (AOR = 0.47, 95%CI 0.27-0.83). Past infectious mononucleosis at 11-15 years (AOR = 2.84, 95%CI 1.0-7.57) and 16-20 years (AOR = 1.92, 95%CI 1.12-3.27) or tonsillectomy in adolescence (11-15 years: AOR = 2.45, 95%CI 1.12-5.35), including after adjustment for IM, were associated with increased risk of a first clinical diagnosis of CNS demyelination.

CONCLUSIONS

Age at vaccination, infection or tonsillectomy may alter the risk of subsequent CNS demyelination. Failing to account for age effects may explain inconsistencies in past findings.

Incidence and prevalence of multiple sclerosis in persian gulf area: A systematic review and meta-analysis

BACKGROUND

There is an unapprehended diversity in the epidemiology of multiple sclerosis (MS) in different geographical regions. In this study, for the first time, we systematically review the studies estimating the incidence and/or prevalence of MS in the Persian Gulf area. The goal is to obtain the overall incidence and prevalence of MS and elucidate the reasons for the geographical variation.

METHODS

A comprehensive literature search was carried out using MEDLINE and EMBASE through articles published between January 1985 and December 2018 on MS epidemiology in Persian Gulf countries including Bahrain, Iran, Iraq, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates. Search terms included 'Multiple sclerosis', 'Incidence', 'Prevalence', 'Epidemiology', 'Persian Gulf', 'Arabian Gulf' and name of each country. Only full-text articles published in English were included. All abstracts were considered and two trained reviewers evaluated the study quality using an assessment tool specifically designed for this study.

RESULTS

39 studies met the inclusion criteria. The mean age at disease onset varied in each country and the pooled mean age of onset was 23.11. The overall pooled MS incidence was 5.03/100,000 person-years (95% CI: 0.04 - 10.02). Prevalence was 39.31/100,000 (95% CI: 29.12 - 49.50) and the result of the meta-regression method showed that prevalence increased by 2.3% per year between 1985-2018 (p = 0.04). Quality scores ranged from 4/7 to 8/8.

CONCLUSION

The prevalence and incidence of MS in the Persian Gulf region has gone through significant changes during the past decades. This study highlights the need for future studies of MS prevalence and incidence, which will further elucidate the possible etiologies leading to periodical and geographical variations in MS incidence.

Association of infections with multiple sclerosis in Gulf Cooperation Council countries: a review

Multiple sclerosis (MS) is an autoimmune disease that affects the central nervous system, causing inflammation, demyelination, and neurodegeneration. Infection can play a role in its etiology. Herein, a review is presented of studies that have reported an association between infection and MS risk in countries of the Arabian Gulf region. Searches of the PubMed, Google Scholar, and Science Direct databases were carried out using various search terms, and relevant studies published through January 2019 on the epidemiology of MS in Gulf Cooperation Council countries identified. MS has been found to be associated with measles in Saudi Arabia and Epstein–Barr virus in Kuwait whereas no association has been identified between risk of MS and varicella-zoster virus, mumps, or human herpesvirus-6. However, few epidemiological studies on this topic have been conducted in countries of the Gulf region. Longitudinal and serological studies to establish robust evidence between infection and risk of MS are highly recommended, and a regional MS registry is needed.

Environmental and genetic risk factors for MS: an integrated review

Recent findings have provided a molecular basis for the combined contributions of multifaceted risk factors for the onset of multiple sclerosis (MS). MS appears to start as a chronic dysregulation of immune homeostasis resulting from complex interactions between genetic predispositions, infectious exposures, and factors that lead to pro-inflammatory states, including smoking, obesity, and low sun exposure. This is supported by the discovery of gene-environment (GxE) interactions and epigenetic alterations triggered by environmental exposures in individuals with particular genetic make-ups. It is notable that several of these pro-inflammatory factors have not emerged as strong prognostic indicators. Biological processes at play during the relapsing phase of the disease may result from initial inflammatory-mediated injury, while risk factors for the later phase of MS, which is weighted toward neurodegeneration, are not yet well defined. This integrated review of current evidence guides recommendations for clinical practice and highlights research gaps.

Sociodemographic, environmental and lifestyle risk factors for multiple sclerosis development in the Western region of Saudi Arabia. A matched case control study

Objectives:

To examine the association of exposure to sociodemographic, environmental, and lifestyle risk factors during adolescence with the development of multiple sclerosis (MS).

Methods:

We conducted a case-control study between October 2017 and January 2018 at King Fahd General Hospital (KFH) in Madinah, Saudi Arabia. Data were collected by direct physician-subject interviews. We utilized a questionnaire modified from the environmental risk factors in multiple sclerosis questionnaire (EnvIMS-Q). Chi-square tests were used to examine associations of selected risk factors with the development of MS, a p-value of <0.05 was considered significant.

Results:

A total of 80 cases and 160 controls were enrolled into the study. Smoking during adolescence significantly increased the risk of MS, with an adjusted odds ratio (AOR) of 4.165, and a 95% confidence interval (CI) of 1.449-11.974. Large body size, assessed using a figure rating scale, also increased the risk of MS (AOR=8.970, 95% CI=1.032-77.983), as well as a history of measles infection (AOR=3.758, 95% CI=1.455-9.706). Furthermore, exposure to sunlight during the weekend for more than 4 hours/day decreased the risk of MS (AOR=0.063, 95% CI=0.006-0.654), so did the consumption of fish for more than once per week (AOR=0.206, 95% CI=0.055-0.773).

Conclusion:

The risk of developing MS is significantly increased by exposure during adolescence to smoking, a history of measles infection, and large body size (obesity).

Infectious exposure, antibiotic use, and multiple sclerosis: A population-based incident case-control study

BACKGROUND

The existing reports regarding the potential role of infections as well as antibiotic use in multiple sclerosis (MS) etiology are inconclusive.

OBJECTIVES

We aimed to investigate the association of viral infections as well as antibiotic use and the risk of developing MS.

MATERIALS & METHODS

This was a population-based incident case-control study of 547 incident cases and 1057 general population controls obtained from 22 municipality areas of Tehran (7/8/2013-17/2/2015). Multiple logistic regression models were used to determine the adjusted associations.

RESULTS

Overall antibiotic use for ≥14 days during 3 years before the index date, significantly decreased the odds of MS OR 0.69 (95%CI: 0.53-0.91, P = .008). The results were consistent for different types of antibiotics, including penicillin OR 0.50 (95%CI: 0.34-0.75, P = .001) and cephalosporins OR 0.25 (95%CI: 0.12-0.50, P < .001). History of IM was associated with a more than 5fold increased risk of MS OR = 5.7 (95%CI, 1.28-25.37). There was no statistically significant association between any other single or cumulative number of viral infections with subsequent risk of MS (P > .05).

CONCLUSIONS

Considering the possibility of reverse causation, the results of this large case-control study suggest that use of antibiotics may be associated with a decreased risk of MS. However, viral disease other than infectious mononucleosis was not associated with MS risk.

Environmental risk factors in neuromyelitis optica spectrum disorder: a case-control study

Neuromyelitis optica spectrum disorder (NMOSD) has unknown risk factors. The aim of this study was to identify the environmental risk factors for NMOSD. A case-control study was conducted in Tehran from 2015 to 2016 among 100 patients with NMOSD. Sex-matched healthy controls (n = 400) were selected through random digit dialing (RDD). Logistic regression was used to estimate unadjusted and adjusted ORs (odds ratio) at 95% confidence intervals (CI) via SPSS. Compared with the control population, in NMOSD patients, the adjusted OR for low dairy consumption per week was (OR = 18.09; 95% CI 6.91, 47.37), following low sea food intake (OR = 13.91; 95% CI 6.13, 31.57) and low fruit and vegetable consumption (OR = 6.23; 95% CI 3.07, 12.62). The lower heavy physical activity (OR: 16.11, 95% CI 7.03, 36.91) among patients had risen the risk of NMOSD. A past history of head trauma was considered a risk for NMOSD (OR: 8.39, 95% CI 4.97, 14.16). The association between NMOSD and intentional abortion only among females (OR: 7.42, 95% CI 2.81, 19.55) was detected. This study indicates significant associations between dietary habits, life style, history of head trauma and intentional abortion in female and the later diagnosis of NMOSD.

Age-Period-Cohort Modeling of Multiple Sclerosis Incidence Rates in Kuwait: 1980-2014

BACKGROUND

Multiple sclerosis (MS) is a complex immune-mediated disorder of the central nervous system with undefined etiology. Genetic predisposition and environmental factors play an imperative role in MS causation and its sustained increasing burden worldwide. This study examined the age, period, and cohort effects on MS incidence rates in Kuwait.

METHODS

In this retrospective cohort study, data on MS cases diagnosed between January 1, 1980 and December 31, 2014 and registered in National MS Registry and reference population were obtained. Age-period-cohort (APC) analysis was conducted using a loglinear Poisson regression model to supplement the descriptive and graphical presentation. Descriptive statistics were complemented with APC parameters' estimates including net drift, local drift, age at onset curve, and longitudinal age trend. Age effect was presented as incidence rates (per 105 person-years), whereas period and cohort effects were presented as adjusted relative rates.

RESULTS

A total of 1,131 cases were diagnosed in 1,385,923 person-years. Overall age-standardized MS incidence rate was 64.5 (95% CI 52.4-79.8). An estimated annual percentage change revealed 7.4% annual increase in MS incidence rate during the study period (Net drift = 7.4%; 95% CI 4.1-10.8%). APC "fitted" age-at-onset curve showed a bimodal pattern with peaked incidence rates at 20-24 years and 45-49 years of age. Compared with the referent period (1980-1984) and cohort (1970-1974), MS incidence rates progressively and significantly (p < 0.001) increased during subsequent time periods and in successive cohorts. Results of APC analysis are descriptive in nature and specific etiological hypotheses were not evaluated. However, the findings of this study substantiated the notion of multiplicity of genetic and/or environmental risk factors' contributions.

CONCLUSION

A substantial increase in MS incidence rates was recorded, which significantly varied in all 3 temporal dimensions during the study period. Future studies may contemplate biological basis for recorded temporal increase in MS risk.