Individual and Joint Action of Environmental Factors and Risk of MS

Dietary Patterns and Their Associations with Symptom Levels Among People with Multiple Sclerosis: A Real-World Digital Study

INTRODUCTION

The objective of the study was to investigate long-term food intake patterns and establish possible associations between the inferred dietary habits and levels of reported symptoms among people with multiple sclerosis (MS) in Denmark.

METHODS

The present study was designed as a prospective cohort study. Participants were invited to register daily food intake and MS symptoms and were observed during a period of 100 days. Dropout and inclusion probabilities were addressed using generalized linear models. Dietary clusters were identified among 163 participants using hierarchical clustering on principal component scores. Associations between the dietary clusters and the levels of self-assessed MS symptoms were estimated using inverse probability weighting. Furthermore, the effect of a person's position on the first and second principal dietary component axis on symptom burden was investigated.

RESULTS

Three dietary clusters were identified: a Western dietary cluster, a plant-rich dietary cluster and a varied dietary cluster. Analyses further indicated a vegetables-fish-fruit-whole grain axis and a red-meat-processed-meat axis. The plant-rich dietary cluster showed reduction in symptom burden in nine pre-defined MS symptoms compared to the Western dietary cluster (between 19 and 90% reduction). This reduction was significant for pain and bladder dysfunction as well as across all nine symptoms (pooled p value = 0.012). Related to the two dietary axes, high intake of vegetables resulted in 32-74% reduction in symptom burden compared to low levels of vegetable intake. Across symptoms, this was significant (pooled p value = 0.015), also regarding walking difficulty and fatigue.

CONCLUSIONS

Three dietary clusters were identified. Compared to levels of self-assessed MS-related symptoms, and adjusted for potential confounders, the results suggested less symptom burden with increased intake of vegetables. Although the research design limits the possibilities of establishing causal inference, the results indicate that general guidelines for healthy diet may be relevant as a tool in coping with MS symptoms.

Geochemistry of multiple sclerosis in Finland

Multiple sclerosis (MS) affects some 3 million people around the world and the prevalence is increasing. The MS incidence increases with distance from the equator forming a north-to-south gradient. The cause of this gradient and the cause of MS in general are largely unknown. Sulphide-bearing marine and lake sediments, when exposed to oxygen after drainage, form sulphuric acid resulting in the development of acid sulphate soils. From these soils major neurotoxic metals such as iron, aluminum and manganese and trace metals such as nickel, copper and cadmium are released into the surrounding environment. As these soils are largely used for farming, obvious routes to human metal exposure exist. Here we compare the distribution of acid sulphate soils in Finland to the geographic localisation of MS cases using data from a national acid sulphate soil mapping project and historical MS distribution data. Finland has among the highest MS prevalences in the world and several independent nationwide surveys have shown the highest prevalence in western Finland, stable over time. Acid sulphate soil distribution colocalizes with MS, both on a regional (nationwide) scale and local (proximity to rivers) scale. A toxicokinetic LADME model for MS pathogenesis is presented. We propose that neurotoxic metals leaching from acid sulphate soils contribute to the clustering of MS in Finland.

Effect of Seasonal Variation on Relapse Rate in Patients With Relapsing-Remitting Multiple Sclerosis in Saudi Arabia

Multiple sclerosis (MS) is becoming a global subject of study in which some demographic variations are thought to be correlated with its activity. Relapsing-remitting multiple sclerosis (RRMS) is the most common demyelinating disorder, characterized by periods of exacerbating attacks, followed by partial or complete remission. Several factors might play a role in disease progression and relapse frequency, such as vitamin D, ultraviolet B radiation, estrogen levels, smoking, obesity, and unhealthy lifestyles. In this study, we identified the relationship between seasonal variation and relapse rate and correlated the latter with sex, age, and vitamin D levels in patients with RRMS in Jeddah, Saudi Arabia. We retrospectively collected data from 182 RRMS patients between 2016 and 2021. A total of 219 relapses were documented in 106 patients (58.2 %). The relapse per patient ratio showed a sinusoidal pattern, peaking in January at a rate of 0.49 and troughed in June at a rate of 0.18. There was no difference in relapse rates between men and women (p =0.280). There was a significant negative correlation between vitamin D levels and relapse rate (r = −0.312, p =0.024). Therefore, the relapse rate was higher during the winter and was correlated with low vitamin D levels. However, relapses are likely multifactorial, and more population-based studies are needed to understand the role of environmental variables in MS exacerbation. A better understanding of this relationship will allow for improved treatment and possibly better prevention of relapse.

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.

Two healthy lifestyle scores are associated with lower subsequent fatigue risk using inverse probability weighting in an international longitudinal cohort of people with multiple sclerosis

BACKGROUND AND PURPOSE

Several modifiable lifestyle factors have been associated with the onset and health outcomes of multiple sclerosis (MS), including clinically significant fatigue. A combined lifestyle score approach represents one method of assessing their relationship with clinical outcomes. The aim was to examine the association of two lifestyle scores with clinically significant fatigue and change thereof over 2.5 years' follow-up using inverse probability treatment weighting (IPTW).

METHODS

Data on sociodemographic, lifestyle, and clinical characteristics surveyed from an international cohort of people with MS at baseline and at 2.5-year follow-up were used. Fatigue was defined by the Fatigue Severity Scale (FSS >5) and healthy lifestyle by the Healthy Lifestyle Index Score (HLIS) and the Smoking, Nutrition, Alcohol Consumption and Physical Activity (SNAP) score. Analyses were by IPTW accounting for age, sex, MS type, disability, treated comorbidity number, immunomodulatory medication use, prescription antifatigue medication use, and ongoing relapse symptoms.

RESULTS

In total, 1268 participants completed the FSS at both time points; approximately 62% had fatigue. Using doubly robust IPTW, high (>11/20) HLIS (odds ratio [OR] 0.90, 95% confidence interval [CI] 0.81-0.98) and high (>3/5) SNAP (OR 0.82, 95% CI 0.73-0.90) were each associated with lower risk of fatigue at follow-up. Evaluating change in fatigue, a higher SNAP score was associated with a lower risk of fatigue (OR 0.89, 95% CI 0.80-0.97) but the score for HLIS did not reach statistical significance (OR 0.93, 95% CI 0.85-1.01).

CONCLUSION

These results suggest a robust role for key lifestyle factors in preventing clinically significant fatigue and may represent a place for lifestyle modification in improving clinical outcomes in MS.

Nutritional status of multiple sclerosis (MS) patients attending Kasr Alainy MS unit: an exploratory cross-sectional study

BACKGROUND

Nutrition was claimed to be a factor in MS causation, course, complications, and management. Several studies were conducted to assess the nutritional status of MS patients; however, few studies were conducted to assess this problem in Egypt. Therefore, the purpose of the current study was to assess the nutritional status of a sample of MS patients.

METHODS

The researchers conducted an exploratory cross-sectional study among 76 relapsing-remitting MS (RRMS) patients attending Kasr Alainy Multiple Sclerosis Unit (KAMSU) from October 2018 to January 2019 to assess the nutritional status of a sample of MS patients. Data were collected using a structured interview questionnaire including an inquiry about the socioeconomic status, and nutritional status using anthropometric measurements, patient-generated subjective global assessment (PG-SGA), semi-quantitative food frequency questionnaires (SQFFQ), and hemoglobin level measurement. Assessment of fatigue was done using the Modified Fatigue Impact Scale 5-items version.

RESULTS

The mean age of the study participants was 30 ± 6 years. The disease duration ranged from 2 to 264 months. Malnutrition was prevalent among 67.1% (27.6 % overweight, 36.8% obese, and 2.6% underweight). Half of the investigated patients were anemic. According to the PG-SGA, more than half of the studied patients (53.9%) were classified as moderately or suspected malnourished. The unhealthy dietary habits such as taking only a few meals, junk food intake and skipping breakfast were observed in considerable proportions of the group. The SQFFQ revealed overconsumption of energy and fat, and less than acceptable consumption of dietary fibers by most of the studied patients.

CONCLUSIONS

Overweight, obesity, anemia, and unhealthy dietary habits were prevalent among the RRMS patients attending the KAMSU. Nutrition care service is extremely needed for this group of patients.

On the Relationship Between Sun Exposure and All-Cause Mortality

Increasing sun exposure is related to lower prevalence of death in cardiovascular disease (CVD), type 2 diabetes, and other noncancer non-CVD. In this chapter we aim to make a short update on the knowledge regarding sun exposure and all-cause mortality. Data support the hypothesis that low sun exposure habits are a major risk factor for all-cause mortality. Low sun exposure is related to an increased risk of death due to CVD and noncancer/non-CVD, and a minor reduction in risk of cancer. Active sun exposure habits have a dual effect; it increases the incidence of skin cancer, but also improves the prognosis in terms of all-cause mortality. In a low solar intensity region, we should carefully assess both risk and benefits of sun exposure in order to obtain balanced recommendations.

Multiple Sclerosis and Smoking

Multiple sclerosis (MS) is a common, severe neurological disease that affects millions of people worldwide. Nevertheless, the actual cause of MS remains unknown. Smoking has been studied with respect to MS development and progression. The objectives of this review were to examine the relationship between smoking and MS and to understand the possible molecular mechanisms underlying the association. PubMed was searched for articles related to the study topic published between 2012 and 2020 using the search terms "multiple sclerosis," "smoking," "risk factors," "cigarettes," and "molecular mechanisms." Studies show a significant relationship between smoking and the risk of MS. Furthermore, smoking has been linked to the progression of MS at the patient and population levels. However, the underlying mechanism remains to be explored in further studies; researchers still disagree on how the relationship between smoking and MS arises in different populations. Evidence from randomized controlled trials, systematic reviews, and epidemiological studies shows that smokers have a higher risk of developing MS and experiencing related adverse symptoms and complications.

Mechanisms of pathophysiology of blood vessels in patients with multiple sclerosis treated with ozone therapy: a systematic review

Multiple sclerosis (MS) defines as an intricate disease with numerous pathophysiological processes, including: inflammation, demyelination, oxidative stress, axonal damage, and repair mechanisms that interfere in this disease and highly related to the pathogenesis of MS. In parallel, recent studies have shown that the ozone administration could be very useful in treating neurological disorders and inflammatory and degenerative neurological diseases. In this review, we examine the recent literature on the pathophysiology of blood vessels in patients with multiple sclerosis treated with ozone therapy. (www.actabiomedica.it)

How people with multiple sclerosis experience the influence of nutrition and lifestyle factors on the disease

Purpose: Increasing knowledge suggests that nutrition and lifestyle factors affect multiple sclerosis. This study explores how people with multiple sclerosis experience daily multiple sclerosis disease activity and the influence of nutrition and lifestyle factors (e.g., stress, sleep, and environmental temperature).Methods: Four phases mix qualitative and quantitative elements in an exploratory study. The initial two phases consisted of an exploratory study with 14 participants followed by 15 semi-structured interviews. Results from the two first phases were substantiated in a survey completed by 425 respondents (response rate: 42.5%). Finally, findings and inconsistencies were elaborated in three focus group interviews.Results: In the initial exploratory study, several of the participants linked nutrition and lifestyle factors to disease activity. Results from the semi-structured interviews showed that particularly stress, meat, fatty foods, and processed sugar were perceived to have a negative impact on disease activity, and some participants had experienced immediate effects of these factors on their disease activity. The survey supported these findings that were further elaborated in focus groups.Conclusion: People with multiple sclerosis perceive nutrition and lifestyle to affect daily disease activity. Individuals who have experienced links between their multiple sclerosis, and nutrition and lifestyle attribute some of these changes to e.g., stress, and the consumption of sugar, meat, and fatty food.Implications for rehabilitationA majority of the participants in this study perceived nutrition and lifestyle factors to have an effect on their multiple sclerosis, particularly stress, meat, fatty foods, and processed sugar.Some participants with multiple sclerosis experienced that nutrition, stress, environmental temperature, and physical activity had a direct effect on the severity of daily symptom manifestations.Nutrition and lifestyle factors that potentially influence multiple sclerosis disease activity should be considered when organizing rehabilitation and care to better meet the needs of the individual with multiple sclerosis.

The Genetic Background of Mice Influences the Effects of Cigarette Smoke on Onset and Severity of Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is the most common inflammatory disorder of the central nervous system (CNS) in young adults leading to severe disability. Besides genetic traits, environmental factors contribute to MS pathogenesis. Cigarette smoking increases the risk of MS in an HLA-dependent fashion, but the underlying mechanisms remain unknown. Here, we explored the effect of cigarette smoke exposure on spontaneous and induced models of experimental autoimmune encephalomyelitis (EAE) by evaluating clinical disease and, when relevant, blood leukocytes and histopathology. In the relapsing-remitting (RR) transgenic model in SJL/J mice, we observed very low incidence in both smoke-exposed and control groups. In the optico-spinal encephalomyelitis (OSE) double transgenic model in C57BL/6 mice, the early onset of EAE prevented a meaningful evaluation of the effects of cigarette smoke. In EAE models induced by immunization, daily exposure to cigarette smoke caused a delayed onset of EAE followed by a protracted disease course in SJL/J mice. In contrast, cigarette smoke exposure ameliorated the EAE clinical score in C57BL/6J mice. Our exploratory studies therefore show that genetic background influences the effects of cigarette smoke on autoimmune neuroinflammation. Importantly, our findings expose the challenge of identifying an animal model for studying the influence of cigarette smoke in MS.

Dietary Interventions and Multiple Sclerosis

Multiple Sclerosis (MS) is a chronic, disabling neurologic disease that has its onset in young adulthood. While the knowledge about underlying pathogenesis of MS has improved significantly over the last few decades, the exact cause still eludes us. Despite the availability of several United States Food and Drug Administration-approved disease-modifying therapies (DMT) for MS in the last two decades, the disease remains disabling for many. DMT use is limited by its partial effectiveness, significant side effects in many cases, and high cost that leads people with MS (PwMS) to look for alternative management options. Dietary intervention as a possible mode to help MS seems very appealing to PwMS; however, scientific data supporting this notion remains sparse. New information on the role of various non-MS health factors, especially vascular disease risk factors such as hypertension, hyperlipidemia, salt intake, and obesity, that may play a role in MS pathogenesis appears very intriguing as it may partly explain the heterogeneity seen in MS activity and disability. This review will highlight the emerging information on various dietary approaches that may affect MS and their possible underlying mechanism.

Obesity and multiple sclerosis: prevalence, susceptibility and progression in disability

Recent emerging data indicate that obesity is an important risk factor for multiple sclerosis (MS) susceptibility and may be associated with MS disability progression. Marked interactions between obesity and human leukocyte antigen (HLA) genotype with regard to the risk of MS have been reported. Evidence from Mendelian randomization studies also point to a causal relationship between obesity and MS risk. In this report, we aimed to analyze the current evidence of the relationship between obesity and risk of MS and disability progression, examine data on the interaction between obesity and HLA risk genes of MS and Mendelian randomization studies and to explore the plausible biological mechanisms that may underlie this relationship.

The relationship between sun exposure and all-cause mortality

Women with low sun exposure are at a dose-dependently increased risk of all-cause mortality, mainly due to an increased risk of death from cardiovascular or noncancer/noncardiovascular disease compared higher exposure.

Environmental control of autoimmune inflammation in the central nervous system

Multiple sclerosis (MS) is a chronic autoimmune inflammatory demyelinating disorder of the central nervous system (CNS), which causes severe disability and requires extensive medical attention and treatment. While the infiltration of pathogenic immune cells into the CNS leads to the formation of inflammatory lesions in its initial relapsing-remitting stage, late stages of MS are characterized by progressive neuronal loss and demyelination even without continued interaction with the peripheral immune compartment. Several genetic and environmental factors modulate and influence these processes on multiple levels. Genetic variants confer a predisposition for the development of MS, but are not accessible to therapeutic intervention as of today. However, migration studies suggest that environmental factors influence disease development, activity and progression. This article reviews mechanisms of disease pathogenesis in MS and their modulation by environmental factors such as geographical localization, the gut microbiome and the diet.

Avoidance of sun exposure as a risk factor for major causes of death: a competing risk analysis of the Melanoma in Southern Sweden cohort

OBJECTIVE

Women with active sunlight exposure habits experience a lower mortality rate than women who avoid sun exposure; however, they are at an increased risk of skin cancer. We aimed to explore the differences in main causes of death according to sun exposure.

METHODS

We assessed the differences in sun exposure as a risk factor for all-cause mortality in a competing risk scenario for 29 518 Swedish women in a prospective 20-year follow-up of the Melanoma in Southern Sweden (MISS) cohort. Women were recruited from 1990 to 1992 (aged 25-64 years at the start of the study). We obtained detailed information at baseline on sun exposure habits and potential confounders. The data were analysed using modern survival statistics.

RESULTS

Women with active sun exposure habits were mainly at a lower risk of cardiovascular disease (CVD) and noncancer/non-CVD death as compared to those who avoided sun exposure. As a result of their increased survival, the relative contribution of cancer death increased in these women. Nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking. Compared to the highest sun exposure group, life expectancy of avoiders of sun exposure was reduced by 0.6-2.1 years.

CONCLUSION

The longer life expectancy amongst women with active sun exposure habits was related to a decrease in CVD and noncancer/non-CVD mortality, causing the relative contribution of death due to cancer to increase.

Is Geo-Environmental Exposure a Risk Factor for Multiple Sclerosis? A Population-Based Cross-Sectional Study in South-Western Sardinia

Background

South-Western Sardinia (SWS) is a high risk area for Multiple Sclerosis (MS) with high prevalence and spatial clustering; its population is genetically representative of Sardinians and presents a peculiar environment. We evaluated the MS environmental risk of specific heavy metals (HM) and geographical factors such as solar UV exposure and urbanization by undertaking a population-based cross-sectional study in SWS.

Methods

Geochemical data on HM, UV exposure, urbanization and epidemiological MS data were available for all SWS municipalities. Principal Component Analysis (PCA) was applied to the geochemical data to reduce multicollinearity and confounding criticalities. Generalized Linear Mixed Models (GLMM) were applied to evaluate the causal effects of the potential risk factors, and a model selection was performed using Akaike Information Criterion.

Results

The PCA revealed that copper (Cu) does not cluster, while two component scores were extracted: 'basic rocks', including cobalt, chromium and nickel, and 'ore deposits', including lead and zinc. The selected multivariable GLMM highlighted Cu and sex as MS risk factors, adjusting for age and 'ore deposits'. When the Cu concentration increases by 50 ppm, the MS odds are 2.827 (95% CI: 1.645; 5.07) times higher; females have a MS odds 2.04 times (95% CI: 1.59; 2.60) higher than males.

Conclusions

The high frequency of MS in industrialized countries, where pollution by HM and CO poisoning is widespread, suggests a relationship between environmental exposure to metals and MS. Hence, we suggested a role of Cu homeostasis in MS. This is a preliminary study aimed at generating hypotheses that will need to be confirmed further.

Population attributable fractions and joint effects of key risk factors for multiple sclerosis

AIM

We examined the combined effect of having multiple key risk factors and the interactions between the key risk factors of multiple sclerosis (MS).

METHODS

We performed an incident case-control study including cases with a first clinical diagnosis of central nervous system demyelination (FCD) and population-based controls.

RESULTS

Compared to those without any risk factors, those with one, two, three, and four or five risk factors had increased odds of being an FCD case of 2.12 (95% confidence interval (CI), 1.11-4.03), 4.31 (95% CI, 2.24-8.31), 7.96 (95% CI, 3.84-16.49), and 21.24 (95% CI, 5.48-82.40), respectively. Only HLA-DR15 and history of infectious mononucleosis interacted significantly on the additive scale (Synergy index, 3.78; p = 0.03). The five key risk factors jointly accounted for 63.8% (95% CI, 43.9-91.4) of FCD onset. High anti-EBNA IgG was another important contributor.

CONCLUSIONS

A high proportion of FCD onset can be explained by the currently known risk factors, with HLA-DR15, ever smoking and low cumulative sun exposure explaining most. We identified a significant interaction between HLA-DR15 and history of IM in predicting an FCD of CNS demyelination, which together with previous observations suggests that this is a true interaction.

Factors associated with onset, relapses or progression in multiple sclerosis: A systematic review

Multiple sclerosis (MS) is a chronic disease of the central nervous system with an unidentified etiology. We systematically reviewed the literature on the possible risk factors associated with MS disease onset, relapses and progression from 1960 to 2012 by accessing six databases and including relevant systematic reviews, meta-analyses, case-control or cohort studies. The focus was on identifying modifiable risk factors. Fifteen systematic reviews and 169 original articles were quality assessed and integrated into a descriptive review. Best evidence, which included one or more prospective studies, suggested that lower exposure to sunlight and/or lower serum vitamin D levels were associated with an increased risk of developing MS onset and subsequent relapses, but a similar quality of evidence was lacking for disease progression. Prospective studies indicated that cigarette smoking may increase the risk of MS as well as accelerate disease progression, but whether smoking altered the risk of a relapse was largely unknown. Infections were implicated in both risk of developing MS and relapses, but data for progression were lacking. Specifically, exposure to the Epstein-Barr virus, particularly if this manifested as infectious mononucleosis during adolescence, was associated with increased MS risk. Upper respiratory tract infections were most commonly associated with an increase in relapses. Relapse rates typically dropped during pregnancy, but there was no strong evidence to suggest that pregnancy itself altered the risk of MS or affected long-term progression. Emerging research with the greatest potential to impact public health was the suggestion that obesity during adolescence may increase the risk of MS; if confirmed, this would be of major significance.

Obesity and brain inflammation: a focus on multiple sclerosis

The increase in prevalence of obesity in industrialized societies is an indisputable fact. However, the apparent passive role played by adipocytes, in pathophysiological terms, has been gradually substituted by a metabolically active performance, relevant to many biochemical mechanisms that may contribute to a chronic low-grade inflammatory status, which increasingly imposes itself as a key feature of obesity. This chronic inflammatory status will have to be integrated into the complex equation of many diseases in which inflammation plays a crucial role. Multiple sclerosis (MS) is a chronic inflammatory condition typically confined to the central nervous system, and many work has been produced to find possible points of contact between the biology of this immune-mediated disease and obesity. So far, clinical data are not conclusive, but many biochemical features have been recently disclosed. Brain inflammation has been implicated in some of the mechanisms that lead to obesity, which has also been recognized as an important player in inducing some degree of immune dysfunction. In this review, we collected evidence that allows establishing bridges between obesity and MS. After considering epidemiological controversies, we will focus on possible shared mechanisms, as well as on the potential contributions that disease-modifying drugs may have on this apparent relationship of mutual interference.

Calcium-phosphate metabolism in patients with multiple sclerosis

INTRODUCTION AND OBJECTIVES

The purpose of this study was to evaluate the concentration of 25-hydroxycholecalciferol and parameters of calcium-phosphate metabolism at different periods of relapsing-remitting multiple sclerosis (RRMS).

MATERIALS AND METHODS

Forty-five patients, residents of Poland (49°-50°, N), were enrolled in the study, i.e. 15 immediately after the diagnosis of RRMS, 15 at the early stage and 15 at the advanced stage of RRMS. The results were compared to values obtained in 20 age- and sex-matched controls.

RESULTS

Lower serum concentrations of 25-hydroxycholecalciferol and ionised calcium were found in patients compared to the control group. In patients with the disease duration of 5-6 years, concentrations of 25-hydroxycholecalciferol and ionised calcium were lower than in patients in the earlier period of RRMS. The inverse and clearer direction of changes was found in parathormone serum concentration in patients compared to the controls. In patients with a longer disease duration, a significantly lower 25-hydroxycholecalciferol concentration was found in female patients compared to male patients. In patients, more frequent 25-hydroxycholecalciferol and unsaturated fatty acids' supplementation was observed compared to the controls.

CONCLUSIONS

In RRMS patients, calcium-phosphate metabolism is disturbed which increases during disease progression.

Environmental risk factors and multiple sclerosis: an umbrella review of systematic reviews and meta-analyses

BACKGROUND

The cause of multiple sclerosis is believed to involve environmental exposure and genetic susceptibility. We aimed to summarise the environmental risk factors that have been studied in relation to onset of multiple sclerosis, assess whether there is evidence for diverse biases in this literature, and identify risk factors without evidence of biases.

METHODS

We searched PubMed from inception to Nov 22, 2014, to identify systematic reviews and meta-analyses of observational studies that examined associations between environmental factors and multiple sclerosis. For each meta-analysis we estimated the summary effect size by use of random-effects and fixed-effects models, the 95% CI, and the 95% prediction interval. We estimated the between-study heterogeneity expressed by I(2) (defined as large for I(2)≥50%), evidence of small-study effects (ie, large studies had significantly more conservative results than smaller studies), and evidence of excess significance bias (ie, more studies than expected with significant results).

FINDINGS

Overall, 44 unique meta-analyses including 416 primary studies of different risk factors and multiple sclerosis were examined, covering a wide range of risk factors: vaccinations, comorbid diseases, surgeries, traumatic events and accidents, exposure to environmental agents, and biochemical, infectious, and musculoskeletal biomarkers. 23 of 44 meta-analyses had results that were significant at p values less than 0·05 and 11 at p values less than 0·001 under the random-effects model. Only three of the 11 significant meta-analyses (p<0·001) included more than 1000 cases, had 95% prediction intervals excluding the null value, and were not suggestive of large heterogeneity (I(2)<50%), small-study effects (p for Egger's test >0·10), or excess significance (p>0·05). These were IgG seropositivity to Epstein-Barr virus nuclear antigen (EBNA) (random effects odds ratio [OR] 4·46, 95% CI 3·26-6·09; p for effect size=1·5 × 10(-19); I(2)=43%), infectious mononucleosis (2·17, 1·97-2·39; p=3·1 × 10(-50); I(2)=0%), and smoking (1·52, 1·39-1·66; p=1·7 × 10(-18;)I(2)=0%).

INTERPRETATION

Many studies on environmental factors associated with multiple sclerosis have caveats casting doubts on their validity. Data from more and better-designed studies are needed to establish robust evidence. A biomarker of Epstein-Barr virus (anti-EBNA IgG seropositivity), infectious mononucleosis, and smoking showed the strongest consistent evidence of an association.

FUNDING

None.

Clinically significant fatigue: prevalence and associated factors in an international sample of adults with multiple sclerosis recruited via the internet

Background

Fatigue contributes a significant burden of disease for people with multiple sclerosis (PwMS). Modifiable lifestyle factors have been recognized as having a role in a range of morbidity outcomes in PwMS. There is significant potential to prevent and treat fatigue in PwMS by addressing modifiable risk factors.

Objectives

To explore the associations between clinically significant fatigue and demographic factors, clinical factors (health-related quality of life, disability and relapse rate) and modifiable lifestyle, disease-modifying drugs (DMD) and supplement use in a large international sample of PwMS.

Methods

PwMS were recruited to the study via Web 2.0 platforms and completed a comprehensive survey measuring demographic, lifestyle and clinical characteristics, including health-related quality of life, disability, and relapse rate.

Results

Of 2469 participants with confirmed MS, 2138 (86.6%) completed a validated measure of clinically significant fatigue, the Fatigue Severity Scale. Participants were predominantly female from English speaking countries, with relatively high levels of education, and due to recruitment methods may have been highly pro-active about engaging in lifestyle management and self-help. Approximately two thirds of our sample (1402/2138; 65.6% (95% CI 63.7–67.7)) screened positive for clinically significant fatigue. Bivariate associations were present between clinically significant fatigue and several demographic, clinical, lifestyle, and medication variables. After controlling for level of disability and a range of stable socio-demographic variables, we found increased odds of fatigue associated with obesity, DMD use, poor diet, and reduced odds of fatigue with exercise, fish consumption, moderate alcohol use, and supplementation with vitamin D and flaxseed oil.

Conclusion

This study supports strong and significant associations between clinically significant fatigue and modifiable lifestyle factors. Longitudinal follow-up of this sample may help clarify the contribution of reverse causation to our findings. Further research is required to explore these associations including randomized controlled trials of lifestyle interventions that may alleviate fatigue.

Vascular comorbidities in the onset and progression of multiple sclerosis

Vascular comorbidities are common in the general population and are associated with adverse health outcomes. In people with multiple sclerosis (MS), an increasing amount of evidence suggests that vascular comorbidities are also common, but an association with MS risk and disability has not been conclusively established. This review aims to critically examine published data on the relationship between vascular comorbidities (including vascular risk factors) and MS. The evidence suggests an increased risk of MS in people with a high BMI during childhood or adolescence but not adulthood. People with established MS appear to have a slightly increased risk of cardiovascular disease and a greater proportion of people with MS die from cardiovascular disease, which has important implications for clinicians trying to identify risk factors for cardiovascular disease and reviewing treatment options. In relation to whether vascular comorbidities influence MS clinical disability or other aspects of the disease course, the key finding was that having type-2-diabetes, hypertension, dyslipidaemia or peripheral vascular disease at any point in the disease course may be associated with a greater progression in disability. Additionally, a negative effect of high cholesterol and triglycerides and a positive effect of higher HDL (high density lipoprotein) levels on acute inflammatory activity were observed on magnetic resonance imaging. The results of the published clinical trials of statins as an intervention in MS were however conflicting and care needs to be taken when treating people with MS with statins. Taken together, the literature seems to indicate a potential association of vascular comorbidities with MS risk and disability, but the number of prospective studies was sparse, thus precluding ascription of causality. We therefore recommend that future studies of the frequency and effects of vascular comorbidities on MS risk and disability should be prospective and objective where relevant.

Non-parametric analysis of seasonality in birth and multiple sclerosis risk in second generation of migrants in Kuwait

Background

There are inconsistent reports about multiple sclerosis (MS) risk among migrants from low to high MS risk geographical regions. This study assessed the overall MS incidence and evaluated seasonality in birth and subsequent MS risk later in the life in second generation of migrants born and lived in Kuwait.

Methods

We assessed the overall and gender-specific MS risk in second generation of migrants born and lived in Kuwait between January 1, 1950 and April 30, 2013. Data on migrants’ MS patients diagnosed and registered in Kuwait National MS Registry were used. Hewitt’s non-parametric test was carried out to evaluate the seasonality in migrants’ MS births in comparison with the second generation migrants’ births in general population.

Results

During the study period, an overall risk of migrants’ MS births (per 100,000 non-Kuwaiti births in general population) was 23.8 (95% CI: 20.8 – 27.0). Gender-specific MS risk showed that non-Kuwaiti female had statistically significant (p = 0.003) higher risk (28.6; 95% CI: 24.2 – 33.7) than non-Kuwaiti males (18.7; 95% CI: 15.1–23.0). The month-specific distribution of migrants’ MS births compared with migrants’ births in general population did not differ significantly (χ² goodness-of-fit test statistic = 9.51, p = 0.575). Hewitt’s non-parametric test revealed an evidence of slight but statistically non-significant (p = 0.090) increased tendency of migrants’ MS births during September through February.

Conclusions

The proportion of migrants’ MS births (per 100,000 migrants’ births in general population) over the study period was 23.8 (95% CI: 20.8 – 27.0), which was statistically significantly higher than the previously reported Kuwaiti national MS births (16.2; 95% CI: 15.1–17.4) in Kuwait. Non-parametric analysis showed slight but statistically non-significant increased tendency of migrants’ MS births from September through February. Knowledge of MS risk factors and how and when they act among genetically vulnerable individuals from gestation to early adulthood will help design prevention strategies.

Month of birth and risk of multiple sclerosis in Kuwait: a population-based registry study

BACKGROUND

Multiple sclerosis (MS) is a complex immune-mediated disorder of central nervous system with undefined etiology. This study examined the month of birth effect on subsequent MS risk later in the life in Kuwait.

METHODS

The month of birth of MS patients enrolled in Kuwait MS Registry between 1 January 1950-30 April 2013 was compared with the month of births in the general population during the comparable period. Multivariable log-linear Poisson regression model was used to analyze the data.

RESULTS

Data on 1035 confirmed MS patients were collected, of which 65.2% were female and 77.1% were Kuwaiti. The overall risk of MS births (per 10(5) births in general population) was 28.5 (95% confidence interval (CI): 26.8-30.3). Multivariable log-linear Poisson regression model showed a significant (p=0.004) peak in the number of MS births during December (θo=340(o)). During this month, the risk of MS birth was 1.3 times the risk of MS birth in the trough month after adjusting for the effects of gender and nationality (adjusted relative risk=1.3; 95% CI: 1.1-1.6). The amplitude (α±standard deviation: 0.13±0.014) of sinusoidal curve showed a significant (p=0.004) difference of 13% from the mean to maximum MS births during peak month.

CONCLUSIONS

This study showed a statistically significant month of birth effect on MS risk with 13% excess MS births during December in Kuwait. Future studies may contemplate ascertaining the seasonal factors eliciting the observed association. The insight gained by unraveling such factors may help curtail MS risk in this and other similar settings in the region.

The association of diet with quality of life, disability, and relapse rate in an international sample of people with multiple sclerosis

Objectives

To explore the association between dietary factors including fat, fruit and vegetable intake, dairy and meat consumption, and health-related quality of life (HRQOL), disability and relapse rate in a large international sample of people with multiple sclerosis (MS).

Methods

Participants with MS were recruited to the study via Web 2.0 platforms and completed a comprehensive survey measuring demographic and clinical characteristics, HRQOL, disability, relapse rate, and the Diet Habits Questionnaire (DHQ).

Results

Of 2469 participants with confirmed MS, 2087 (84.5%) provided complete data on their dietary habits (DHQ total score). Multivariate regression models demonstrated that every 10-point increase on the DHQ total score was associated with nearly a six-point and five-point increase in physical and mental HRQOL, respectively, and 30.0% reduced likelihood of a higher level of disability. After controlling for age and gender, and the other dietary covariates, ‘healthy’ consumption of fruit and vegetables and dietary fat predicted better quality of life and less likelihood of higher disability when compared to respondents with a ‘poor’ diet. For those with relapsing–remitting MS, the DHQ total significantly predicted a lower relapse rate and reduced odds of increasing disease activity, but the model fit was poor and the predicted change only marginal.

Discussion

This study supports significant associations of healthy dietary habits with better physical and mental HRQOL and a lower level of disability. Further research is urgently required to explore these associations including randomized controlled trials of dietary modification for people with MS.

Transcriptomic profile reveals gender-specific molecular mechanisms driving multiple sclerosis progression

Background

Although the most common clinical presentation of multiple sclerosis (MS) is the so called Relapsing-Remitting MS (RRMS), the molecular mechanisms responsible for its progression are currently unknown. To tackle this problem, a whole-genome gene expression analysis has been performed on RRMS patients.

Results

The comparative analysis of the Affymetrix Human Gene 1.0 ST microarray data from peripheral blood leucocytes obtained from 25 patients in remission and relapse and 25 healthy subjects has revealed 174 genes altered in both remission and relapse, a high proportion of them showing what we have called “mirror pattern”: they are upregulated in remission and downregulated in relapse or vice versa. The coexpression analysis of these genes has shown that they are organized in three female-specific and one male-specific modules.

Conclusions

The interpretation of the modules of the coexpression network suggests that Epstein-Barr virus (EBV) reactivation of B cells happens in MS relapses; however, qPCR expression data of the viral genes supports that hypothesis only in female patients, reinforcing the notion that different molecular processes drive disease progression in females and males. Besides, we propose that the “primed” state showed by neutrophils in women is an endogenous control mechanism triggered to keep EBV reactivation under control through vitamin B12 physiology. Finally, our results also point towards an important sex-specific role of non-coding RNA in MS.

IL7Rα expression and upregulation by IFNβ in dendritic cell subsets is haplotype-dependent

The IL7Rα gene is unequivocally associated with susceptibility to multiple sclerosis (MS). Haplotype 2 (Hap 2) confers protection from MS, and T cells and dendritic cells (DCs) of Hap 2 exhibit reduced splicing of exon 6, resulting in production of relatively less soluble receptor, and potentially more response to ligand. We have previously shown in CD4 T cells that IL7Rα haplotypes 1 and 2, but not 4, respond to interferon beta (IFNβ), the most commonly used immunomodulatory drug in MS, and that haplotype 4 (Hap 4) homozygotes have the highest risk of developing MS. We now show that IL7R expression increases in myeloid cells in response to IFNβ, but that the response is haplotype-dependent, with cells from homozygotes for Hap 4 again showing no response. This was shown using freshly derived monocytes, in vitro cultured immature and mature monocyte-derived dendritic cells, and by comparing homozygotes for the common haplotypes, and relative expression of alleles in heterozygotes (Hap 4 vs not Hap 4). As for T cells, in all myeloid cell subsets examined, Hap 2 homozygotes showed a trend for reduced splicing of exon 6 compared to the other haplotypes, significantly so in most conditions. These data are consistent with increased signaling being protective from MS, constitutively and in response to IFNβ. We also demonstrate significant regulation of immune response, chemokine activity and cytokine biosynthesis pathways by IL7Rα signaling in IFNβ -treated myeloid subsets. IFNβ-responsive genes are over-represented amongst genes associated with MS susceptibility. IL7Rα haplotype may contribute to MS susceptibility through reduced capacity for IL7Rα signalling in myeloid cells, especially in the presence of IFNβ, and is currently under investigation as a predictor of therapeutic response.

Association of fish consumption and Ω 3 supplementation with quality of life, disability and disease activity in an international cohort of people with multiple sclerosis

The role of fish consumption and omega 3 supplementation in multiple sclerosis (MS) is controversial, although there is some evidence to support a beneficial effect. We surveyed a large cohort of people with MS recruited via Web 2.0 platforms, requesting information on type of MS, relapse rates, disability, health-related quality of life, frequency of fish consumption and omega 3 supplementation, including type and dose, using validated tools where possible. We aimed to determine whether there was an association between fish consumption and omega 3 supplementation and quality of life, disability and disease activity for people with MS. Univariate and multivariate analyses were undertaken. Of 2469 respondents, 1493 (60.5%) had relapsing-remitting MS. Those consuming fish more frequently and those taking omega 3 supplements had significantly better quality of life, in all domains, and less disability. For fish consumption, there was a clear dose-response relationship for these associations. There were also trends towards lower relapse rates and reduced disease activity; flaxseed oil supplementation was associated with over 60% lower relapse rate over the previous 12 months. Further dietary studies and randomised controlled trials of omega 3 supplementation for people with MS are required, preferably using flaxseed oil.

Fungal infection in cerebrospinal fluid from some patients with multiple sclerosis

Multiple sclerosis (MS) is the prototypical inflammatory disease of the central nervous system and spinal cord, leading to axonal demyelination of neurons. Recently, we have found a correlation between fungal infection and MS in peripheral blood of patients. The present work provides evidence of fungal infection in the cerebrospinal fluid (CSF) of some MS patients. Thus, fungal antigens can be demonstrated in CSF, as well as antibodies reacting against several Candida species. Comparison was made between CSF and blood serum for the presence of fungal antigens (proteins) and antibodies against different Candida spp. Analyses of both CSF and serum are complementary and serve to better evaluate for the presence of disseminated fungal infection. In addition, PCR analyses indicate the presence of DNA from different fungal species in CSF, depending on the patient analyzed. Overall, these findings support the notion that fungal infection can be demonstrated in CSF from some MS patients. This may constitute a risk factor in this disease and could also help in understanding the pathogenesis of MS.

Smoking: effects on multiple sclerosis susceptibility and disease progression

Multiple sclerosis (MS) is associated with both genetic and environmental factors that influence disease susceptibility. Exposure to cigarette smoke is emerging as a viable environmental risk factor for MS that contributes to both increased disease susceptibility and more rapid disease advancement. The relative risk for MS development is approximately 1.5 for smokers compared with nonsmokers. Furthermore, there may be important interactions between smoking, an individual's genetic background, and other environmental risk exposures. This review summarizes the current evidence supporting the association of smoking with MS risk and disease course, with additional comments on causation.

Multiple sclerosis is not a disease of the immune system

Multiple sclerosis is a complex neurodegenerative disease, thought to arise through autoimmunity against antigens of the central nervous system. The autoimmunity hypothesis fails to explain why genetic and environmental risk factors linked to the disease in one population tend to be unimportant in other populations. Despite great advances in documenting the cell and molecular mechanisms underlying MS pathophysiology, the autoimmunity framework has also been unable to develop a comprehensive explanation of the etiology of the disease. I propose a new framework for understanding MS as a dysfunction of the metabolism of lipids. Specifically, the homeostasis of lipid metabolism collapses during acute-phase inflammatory response triggered by a pathogen, trauma, or stress, starting a feedback loop of increased oxidative stress, inflammatory response, and proliferation of cytoxic foam cells that cross the blood brain barrier and both catabolize myelin and prevent remyelination. Understanding MS as a chronic metabolic disorder illuminates four aspects of disease onset and progression: 1) its pathophysiology; 2) genetic susceptibility; 3) environmental and pathogen triggers; and 4) the skewed sex ratio of patients. It also suggests new avenues for treatment.

Which clinical risk factors determine a pathological urodynamic evaluation in patients with multiple sclerosis? an analysis of 100 prospective cases

BACKGROUND

Urinary tract symptoms are an underestimated problem in multiple sclerosis (MS).

OBJECTIVE

Hundred urodynamics of MS patients have been evaluated prospectively.

DESIGN, SETTING AND PARTICIPANTS

In an inpatient rehabilitation, all persons with MS who also suffered from urinary tract symptoms received a voiding diary, post-void sonography and an urodynamic examination according to International Continence-Society-Standard.

RESULTS AND LIMITATIONS

Between 10/2009 and 3/2011, 100 patients (79 women; 21 men; mean EDSS, 4.52 ± 2.26) were examined who had primary progressive MS (9×), relapsing-remitting MS (41×), secondary progressive MS (43×) and CIS (1×). The mean duration of MS was 10.26 ± 10.09 years and mean duration of LUTS, 6.9 ± 7.75 years. Urodynamic testing showed normal findings in 22 patients, detrusor overactivity in 7, increased bladder sensation without detrusor overactivity in 21, detrusor-sphincter dyssynergia in 26, detrusor hypocontractility in 12, detrusor acontractility in 4 and unclear diagnosis in 8 patients. Statistically significant risk factors for pathological urodynamic findings were as follows: wheelchair dependency, use of more than one incontinence pad per day and a MS type other than relapsing-remitting.

CONCLUSIONS

The urodynamic investigation at hand showed urinary tract dysfunction in 78 of 100 MS patients with lower urinary tract symptoms (LUTS). The long latency between the occurrence of MS and/or the beginning of LUTS and the first neuro-urological evaluation indicates a deficit in treatment. Beyond national guidelines, all MS patients should at regular intervals be questioned about LUTS and receive urodynamic assessment especially according to the presented risk profile.

Role of vitamin D in multiple sclerosis: implications for disease management

SUMMARY This review discusses the evidence on the role of vitamin D in multiple sclerosis (MS) and whether vitamin D supplementation is effective for the management of MS. People with MS are at high risk of vitamin D deficiency, osteoporosis and fractures. Observational data suggest that higher vitamin D levels are associated with lower relapse risk and there is promising evidence on its effect on MRI measures, disability progression, mental health and fatigue. However, there is currently insufficient randomized controlled trial evidence to recommend vitamin D supplementation with the aim to improve those outcomes. There is sufficient evidence to justify assessing and correcting vitamin D and calcium levels to optimize bone health in people with MS at high absolute risk of fracture.

Modulation of the immune system by UV radiation: more than just the effects of vitamin D?

Humans obtain most of their vitamin D through the exposure of skin to sunlight. The immunoregulatory properties of vitamin D have been demonstrated in studies showing that vitamin D deficiency is associated with poor immune function and increased disease susceptibility. The benefits of moderate ultraviolet (UV) radiation exposure and the positive latitude gradients observed for some immune-mediated diseases may therefore reflect the activities of UV-induced vitamin D. Alternatively, other mediators that are induced by UV radiation may be more important for UV-mediated immunomodulation. Here, we compare and contrast the effects of UV radiation and vitamin D on immune function in immunopathological diseases, such as psoriasis, multiple sclerosis and asthma, and during infection.