Associations between diet and disease progression and symptomatology in multiple sclerosis: A systematic review of observational studies.

BACKGROUND: Although many people with MS (pwMS) modify their diet after diagnosis, there is still no consensus on dietary recommendations for pwMS. A number of observational studies have explored associations of diet and MS progression, but no studies have systematically reviewed the evidence. This systematic review aimed to provide an objective synthesis of the evidence for associations between diet and MS progression, including symptoms and clinical outcomes from observational studies. METHODS: We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic database searches were performed for studies completed up to 26 July 2023 using PubMed (Medline), Web of Science, CINAHL, Embase (Ovid), and Scopus, followed by citation and reference list checking. We included studies using diet quality scores or dietary indices. Studies assessing individual foods, nutrients, or dietary supplements were excluded. We used the Newcastle-Ottawa Scale to assess the risk of bias of included studies. RESULTS: Thirty-two studies met the inclusion criteria. Of these, 20 were cross-sectional and 12 prospective. The most frequent outcomes assessed were disability (n = 19), quality of life (n = 12), fatigue (n = 12), depression (n = 9), relapse (n = 8), anxiety (n = 3), and magnetic resonance imaging (MRI) outcomes (n = 4). Based on prospective studies, this review suggests that diet might be associated with quality of life and disability. There were also potential effects of higher diet quality scores on improved fatigue, disability, depression, anxiety, and MRI outcomes but more evidence is needed from prospective studies. CONCLUSIONS: Observational studies show some evidence for an association between diet and MS symptoms, particularly quality of life and disability. However, the impact of diet on other MS outcomes remains inconclusive. Ultimately, our findings suggest more evidence is needed from prospective studies and well-designed tailored intervention studies to confirm associations.

Diet and omega-3 and vitamin D supplement use predict five-year fatigue and disability trajectories in people with multiple sclerosis.

BACKGROUND: Fatigue and disability are indicators of disease progression experienced by many people with multiple sclerosis (pwMS). Understanding trajectories of these outcomes, and their predictors, may provide insight to potential interventions for MS management. METHODS: Survey data from 839 pwMS from the Health Outcomes and Lifestyle in pwMS study were analysed. Fatigue was defined as mean Fatigue Severity Scale >5, and severe disability as Patient Determined Disease Steps >5. Group-based trajectory modelling was used to identify fatigue and disability trajectories over five-years. Dietary predictors associated with outcome trajectory group membership were assessed using log-binomial regression. Demographic and clinical characteristics were considered in multivariable models. RESULTS: Distinct trajectories for fatigue and disability were identified. For fatigue, 58 % of pwMS were assigned to low-, and 42 % to high-, fatigue trajectory groups. For disability, 85 % of pwMS were assigned to low-, and 15 % to high-, disability groups. Baseline high-quality diet, and omega-3 and vitamin D supplement use, were associated with reduced risk of being in high-fatigue and high-disability trajectories, while meat and dairy consumption were associated with increased risk. CONCLUSIONS: A high-quality diet, avoiding meat and dairy, and omega-3 and vitamin D supplement use, individually predict better fatigue and disability trajectories. Dietary modifications should be considered in MS management.

Plasma neurofilament light in behavioural variant frontotemporal dementia compared to mood and psychotic disorders.

OBJECTIVE: Blood biomarkers of neuronal injury such as neurofilament light (NfL) show promise to improve diagnosis of neurodegenerative disorders and distinguish neurodegenerative from primary psychiatric disorders (PPD). This study investigated the diagnostic utility of plasma NfL to differentiate behavioural variant frontotemporal dementia (bvFTD, a neurodegenerative disorder commonly misdiagnosed initially as PPD), from PPD, and performance of large normative/reference data sets and models. METHODS: Plasma NfL was analysed in major depressive disorder (MDD, n = 42), bipolar affective disorder (BPAD, n = 121), treatment-resistant schizophrenia (TRS, n = 82), bvFTD (n = 22), and compared to the reference cohort (Control Group 2, n = 1926, using GAMLSS modelling), and age-matched controls (Control Group 1, n = 96, using general linear models). RESULTS: Large differences were seen between bvFTD (mean NfL 34.9 pg/mL) and all PPDs and controls (all < 11 pg/mL). NfL distinguished bvFTD from PPD with high accuracy, sensitivity (86%), and specificity (88%). GAMLSS models using reference Control Group 2 facilitated precision interpretation of individual levels, while performing equally to or outperforming models using local controls. Slightly higher NfL levels were found in BPAD, compared to controls and TRS. CONCLUSIONS: This study adds further evidence on the diagnostic utility of NfL to distinguish bvFTD from PPD of high clinical relevance to a bvFTD differential diagnosis, and includes the largest cohort of BPAD to date. Using large reference cohorts, GAMLSS modelling and the interactive Internet-based application we developed, may have important implications for future research and clinical translation. Studies are underway investigating utility of plasma NfL in diverse neurodegenerative and primary psychiatric conditions in real-world clinical settings.

Stressful life events and depression and fatigue in people with multiple sclerosis: a cross-sectional analysis of an international cohort.

BACKGROUND: Relationships between stressful life events (SLEs) and health outcomes in people living with multiple sclerosis (plwMS), beyond relapse, are not well-established. We examined associations between SLEs and fatigue and symptoms of depression in plwMS. METHODS: 948 participants were queried whether they had experienced any of the 16 SLEs (Holmes-Rahe Social Readjustment Rating Scale) in the preceding 12 months. SLEs were summated to estimate SLE number and SLE load (weighted for the degree of associated stress). Cross-sectional associations between SLE (number, load and individual) and fatigue, and depressive symptoms were examined using log-binomial or log-multinomial regression adjusted for age, sex, relapse symptoms, education, MS type at baseline, disability, fatigue, comorbidity, depression, and antidepressant/antifatigue medications, as appropriate. Sub-analyses restricted to SLEs with a negative emotional impact were performed. RESULTS: Median SLE number and load were 2 (IQR 1-2) and 57 (IQR 28-97), respectively. SLE number and load were not associated with a higher prevalence of fatigue, or depressive symptoms, even when restricting analyses to SLEs with a perceived negative emotional impact. A new relationship or family member with a negative impact was associated with a threefold and 2.5-fold higher prevalence of depressive symptoms, respectively. Serious illness was associated with a 28% higher prevalence of depressive symptoms. CONCLUSION: Psychological support for SLEs, and/or intervention targeted to SLE appraisal, may be beneficial in mitigating the adverse effects of SLEs with a perceived negative emotional impact on depressive symptoms in plwMS. Potential associations between serious illness and increased prevalence of depressive symptoms may warrant further investigation.

Examining the environmental risk factors of progressive-onset and relapsing-onset multiple sclerosis: recruitment challenges, potential bias, and statistical strategies.

It is unknown whether the currently known risk factors of multiple sclerosis reflect the etiology of progressive-onset multiple sclerosis (POMS) as observational studies rarely included analysis by type of onset. We designed a case-control study to examine associations between environmental factors and POMS and compared effect sizes to relapse-onset MS (ROMS), which will offer insights into the etiology of POMS and potentially contribute to prevention and intervention practice. This study utilizes data from the Primary Progressive Multiple Sclerosis (PPMS) Study and the Australian Multi-center Study of Environment and Immune Function (the AusImmune Study). This report outlines the conduct of the PPMS Study, whether the POMS sample is representative, and the planned analysis methods. The study includes 155 POMS, 204 ROMS, and 558 controls. The distributions of the POMS were largely similar to Australian POMS patients in the MSBase Study, with 54.8% female, 85.8% POMS born before 1970, mean age of onset of 41.44 ± 8.38 years old, and 67.1% living between 28.9 and 39.4° S. The POMS were representative of the Australian POMS population. There are some differences between POMS and ROMS/controls (mean age at interview: POMS 55 years vs. controls 40 years; sex: POMS 53% female vs. controls 78% female; location of residence: 14.3% of POMS at a latitude ≤ 28.9°S vs. 32.8% in controls), which will be taken into account in the analysis. We discuss the methodological issues considered in the study design, including prevalence-incidence bias, cohort effects, interview bias and recall bias, and present strategies to account for it. Associations between exposures of interest and POMS/ROMS will be presented in subsequent publications.

Changes in employment status over time in multiple sclerosis following a first episode of central nervous system demyelination, a Markov multistate model study.

BACKGROUND AND PURPOSE: Understanding predictors of changes in employment status among people living with multiple sclerosis (MS) can assist health care providers to develop appropriate work retention/rehabilitation programs. We aimed to model longitudinal transitions of employment status in MS and estimate the probabilities of retaining employment status or losing or gaining employment over time in individuals with a first clinical diagnosis of central nervous system demyelination (FCD). METHODS: This prospective cohort study comprised adults (aged 18-59 years) diagnosed with FCD (n = 237) who were followed for more than 11 years. At each review, participants were assigned to one of three states: unemployed, part-time, or full-time employed. A Markov multistate model was used to examine the rate of state-to-state transitions. RESULTS: At the time of FCD, participants with full-time employment had an 89% chance of being in the same state over a 1-year period, but this decreased to 42% over the 10-year follow-up period. For unemployed participants, there was a 92% likelihood of remaining unemployed after 1 year, but this probability decreased to 53% over 10 years. Females, those who progressed to clinically definite MS, those with a higher relapse count, and those with a greater level of disability were at increased risk of transitioning to a deteriorated employment state. In addition, those who experienced clinically significant fatigue over the follow-up period were less likely to gain employment after being unemployed. CONCLUSIONS: In our FCD cohort, we found a considerable rate of employment transition during the early years post-diagnosis. Over more than a decade of follow-up post-FCD, we found that females and individuals with a greater disability and a higher relapse count are at higher risk of losing employment.

Using qualitative free-text data to investigate the lived experience of the COVID-19 pandemic for a large cohort of Australians with different multiple sclerosis related disability levels.

BACKGROUND: No large-scale qualitative studies have investigated the lived experience of people living with multiple sclerosis (PwMS) during the pandemic according to their disability level. We used qualitative research methods to investigate the lived experience of a large cohort of Australians living with differing multiple sclerosis (MS)-related disability levels during the COVID-19 pandemic. We also provided useful contextualisation to existing quantitative work. METHODS: This was a retrospective survey-based mixed-methods cohort study. A quality-of-life study was conducted within the Australian MS Longitudinal Study during the pandemic. Disability severity was calculated using the Patient Determined Disease Steps. Qualitative free-text data regarding COVID-19 impacts was collected/analysed for word frequency and also thematically (inductively/deductively using sophisticated grounded theory) using NVivo software. We also triangulated word frequency with emerging themes. RESULTS: N=509 PwMS participated providing n=22 530 words of COVID-19-specific data. Disability severity could be calculated for n=501 PwMS. The word 'working' was important for PwMS with no disability, and 'support' and 'isolation' for higher disability levels. For PwMS with milder disability, thematic analysis established that multitasking increased stress levels, particularly if working from home (WFH) and home-schooling children. If not multitasking, WFH was beneficial for managing fatigue. PwMS with severe disability raised increased social isolation as a concern including prepandemic isolation. CONCLUSIONS: We found negative impacts of multitasking and social isolation for PwMS during the pandemic. WFH was identified as beneficial for some. We recommend targeted resourcing decisions for PwMS in future pandemics including child-care relief and interventions to reduce social isolation and suggest that these could be incorporated into some form of advanced care planning. As the nature of work changes postpandemic, we also recommend a detailed investigation of WFH for PwMS including providing tailored employment assistance.

Impact of multiple sclerosis on male sexual and reproductive health.

Multiple sclerosis (MS) is a chronic inflammatory and autoimmune neurodegenerative disease characterized by the destruction of myelin in the central nervous system, leading to significant health and quality of life burdens for patients. MS is most prevalent in younger individuals aged 20-40, a critical period when many patients hope to establish relationships and start families. While neurological disability, such as fatigue, sensory dysfunction, spasticity, and cognitive dysfunction, have been greatly improved with the advances in managing MS, physicians are frequently confronted with sexual and reproductive problems among younger male people with MS (PwMS). These issues mainly include erectile dysfunction, ejaculatory disorders, reduced libido, decreased sperm quality, and impaired male fertility. Despite recent studies indicating that MS negatively impacts the sexuality and fertility of male PwMS, these issues have not received sufficient attention. Genetic factors, autoimmunity, chronic inflammation, psychological factors, and the use of drugs may contribute to sexual/reproductive dysfunction in PwMS. However, like the overall understanding of MS pathophysiology, the complete mechanisms of its development remain unclear. In this study, we review the existing literature to summarize the range of sexual and reproductive issues unique to males with MS, explore potential underlying mechanisms, and aim to improve these issues in male PwMS. By shedding light on this overlooked aspect of MS, we hope to enhance the care and well-being of male PwMS facing these challenges.

Longitudinal associations between quality of diet and disability over 7.5 years in an international sample of people with multiple sclerosis.

BACKGROUND AND PURPOSE: Modifiable lifestyle factors, including diet, have been implicated in multiple sclerosis (MS) progression, but prospective evidence is limited. The aim of this study was to examine prospective relationships between quality of diet and subsequent disability over 7.5 years in an international cohort of people living with MS (pwMS). METHODS: Data from 602 participants in the HOLISM (Health Outcomes and Lifestyle In a Sample of people with Multiple sclerosis) study were analysed. Quality of diet was assessed using the modified Diet Habits Questionnaire (DHQ). Disability was assessed using the Patient-determined MS Severity Score (P-MSSS). Characteristics of disability were assessed by log-binomial, log-multinomial and linear regression, adjusted for demographic and clinical covariates, as appropriate. RESULTS: Higher baseline total DHQ scores (>80-89, >89%) were associated with lower risks of increased P-MSSS at 7.5 years (adjusted risk ratio [aRR] 0.46, 95% confidence interval [CI] 0.23, 0.91 and aRR 0.48, 95% CI 0.26, 0.89, respectively), and with less P-MSSS accrual (aß = -0.38, 95% CI -0.78, 0.01 and aß = -0.44, 95% CI -0.81, -0.06). Of the DHQ domains, fat subscore was most strongly associated with subsequent disability. Participants with reducing baseline-to-2.5- years total DHQ scores had greater risk of increased P-MSSS at 7.5 years (aRR 2.77, 95% CI 1.18, 6.53) and higher P-MSSS accrual (aß = 0.30, 95% CI 0.01, 0.60). Participants reporting baseline meat and dairy consumption had greater risk of increased P-MSSS at 7.5 years (aRR 2.06, 95% CI 1.23, 3.45 and aRR 2.02, 95% CI 1.25, 3.25) and higher P-MSSS accrual (aß = 0.28, 95% CI 0.02, 0.54 and aß = 0.43, 95% CI 0.16, 0.69, respectively). However, reported meat consumption was confounded by quality of diet. Changes in meat or dairy consumption from baseline were inconsistently associated with subsequent disability. CONCLUSIONS: We show for the first time robust long-term associations between quality of diet and subsequent disability progression in pwMS. Subject to replication, dietary modification may represent a point of intervention for reducing disability in pwMS.

Longitudinal epidemiology of multiple sclerosis in Townsville, Queensland, Australia, 2012-2022.

BACKGROUND: Townsville (population=195,564, latitude=19.3°S) is the largest city in the Northern Queensland region of Australia, an area previously defined as a low/medium-prevalence zone for multiple sclerosis (MS). However, the epidemiology of MS in this region since 1981 is unknown. AIMS: To assess the 2012 to 2022 epidemiology of MS in Townsville. METHODS: Demographic/clinical data extracted from medical records of MS cases identified by public and private clinicians. Prevalence, and incidence and mortality rates estimated for 2012 and 2022 and age-standardised to the 2022 Australian population. Differences in estimates assessed by Poisson regression. RESULTS: Females and relapsing-remitting MS comprised most cases. The 2012 prevalence was 45.0/100,000 (50.4/100,000 age-standardised, F/M sex ratio=2.0). Prevalence increased by 188% in 2022, with a crude prevalence of 86.9/100,000 (91.7/100,000 age-standardised, F/M sex ratio=2.7). 2012-22 MS onset incidence rate was 3.8/100,000 person-years (age-standardised 3.5/100,000, F/M sex ratio=2.7). Mean age increased from 49.4 to 57.3 years. Age-standardised mortality rate was 0.9/100,000 person-years, with standardised mortality ratio=1.0. DISCUSSION: These results show that Townsville is a high-frequency region for MS, with prevalence and incidence on par with that seen at higher latitudes in Australia. These results have implications for clinical practice in the region and for organisational resource allocation.

The association between disability progression, relapses, and treatment in early relapse onset MS: an observational, multi-centre, longitudinal cohort study.

The indirect contribution of multiple sclerosis (MS) relapses to disability worsening outcomes, and vice-versa, remains unclear. Disease modifying therapies (DMTs) are potential modulators of this association. Understanding how these endo-phenotypes interact may provide insights into disease pathogenesis and treatment practice in relapse-onset MS (ROMS). Utilising a unique, prospectively collected clinical data from a longitudinal cohort of 279 first demyelinating event cases followed for up to 15 years post-onset, we examined indirect associations between relapses and treatment and the risk of disability worsening, and vice-versa. Indirect association parameters were estimated using joint models for longitudinal and survival data. Early relapses within 2.5 years of MS onset predicted early disability worsening outcomes (HR = 3.45, C.I 2.29-3.61) per relapse, but did not contribute to long-term disability worsening thereinafter (HR = 0.21, C.I 0.15-0.28). Conversely, disability worsening outcomes significantly contributed to relapse risk each year (HR = 2.96, C.I 2.91-3.02), and persisted over time (HR = 3.34, C.I 2.90-3.86), regardless of DMT treatments. The duration of DMTs significantly reduced the hazards of relapses (1st-line DMTs: HR = 0.68, C.I 0.58-0.79; 3rd-line DMTs: HR = 0.37, C.I 0.32-0.44) and disability worsening events (1st-line DMTs: HR = 0.74, C.I 0.69-0.79; 3rd-line DMTs: HR = 0.90, C.I 0.85-0.95), respectively. Results from time-dynamic survival probabilities further revealed individuals having higher risk of future relapses and disability worsening outcomes, respectively. The study provided evidence that in ROMS, relapses accrued within 2.5 years of MS onset are strong indicators of disability worsening outcomes, but late relapses accrued 2.5 years post onset are not overt risk factors for further disability worsening. In contrast, disability worsening outcomes are strong positive predictors of current and subsequent relapse risk. Long-term DMT use and older age strongly influence the individual outcomes and their associations.

Study protocol for an online lifestyle modification education course for people living with multiple sclerosis: the multiple sclerosis online course (MSOC).

BACKGROUND: People living with multiple sclerosis (plwMS) seek access to information on evidence-based lifestyle-related risk factors associated with multiple sclerosis (MS). As the internet has made delivery of lifestyle information increasingly accessible and cost-effective, we designed the Multiple Sclerosis Online Course (MSOC) to deliver a multimodal lifestyle modification program for plwMS. Two MS online courses were developed: the intervention course based on lifestyle recommendations of the Overcoming Multiple Sclerosis (OMS) program and the standard-care course representing standard lifestyle recommendations from other MS websites. We examined for feasibility in a pilot randomised controlled trial (RCT), where satisfactory completion and accessibility were achieved across both study arms. From this success, a protocol for a larger RCT was developed to examine the effectiveness of MSOC in improving health-related quality of life (HRQoL) and other health outcomes in plwMS. METHODS/DESIGN: This single-blinded RCT will recruit n = 1,054 plwMS. Participants in the intervention arm will receive access to a MSOC with seven modules providing evidence-based information on the OMS program. Participants in the control group will receive access to a MSOC of identical format, with seven modules providing general MS-related information and lifestyle recommendations sourced from popular MS websites, e.g. MS societies. Participants will complete questionnaires at baseline and at 6, 12, and 30 months after course completion. The primary endpoint is HRQoL, as measured by MSQOL-54 (both physical and mental health domains) at 12 months following course completion. Secondary outcomes are changes to depression, anxiety, fatigue, disability, and self-efficacy as measured by Hospital Anxiety and Depression Scale, Patient-Determined Disease Steps and University of Washington Self-Efficacy Scale, respectively, assessed at each timepoint. Further assessments will include quantitative post-course evaluation, adoption and maintenance of behaviour change from follow-up survey data, and qualitative analysis of participants' outcomes and reasons for course completion or non-completion. DISCUSSION: This RCT aims to determine whether an online intervention course delivering evidence-based lifestyle modification recommendations based on the Overcoming Multiple Sclerosis program to plwMS is more effective at improving HRQoL, and other health outcomes post-intervention, compared with an online standard-care course. TRIAL REGISTRATION: This trial was registered prospectively with the Australian New Zealand Clinical Trials Registry, www.anzctr.org.au , identifier ACTRN12621001605886. DATE OF REGISTRATION: 25 November 2021.

Engagement with three or more healthy lifestyle behaviours is associated with improved quality of life over 7.5 years in people with multiple sclerosis.

BACKGROUND AND PURPOSE: People with multiple sclerosis (pwMS) report reduced quality of life (QoL). Engagement with healthy lifestyle behaviours, including consuming a healthy diet, regular physical activity, and adequate vitamin D exposure, is associated with higher QoL. We aim to assess whether individual lifestyle behaviours are more beneficial to QoL than others, and whether there are additive benefits to QoL by engaging in multiple healthy behaviours concurrently. METHODS: Data from pwMS who completed an online survey at baseline, and at 2.5-, 5- and 7.5-year follow-up, were analysed. Behaviours assessed were consumption of a no-meat/dairy-plus-omega-3 supplementation diet, meditation practice, physical activity, non-smoking, and vitamin D exposure. Mental QoL (mQoL) and physical QoL (pQoL) were assessed by the Multiple Sclerosis Quality of Life (MSQOL-54) questionaire. Linear regression analyses were performed to assess associations of individual behaviours at baseline and follow-up time points with QoL, as well as between number of behaviours and QoL. RESULTS: At baseline, healthy diet and regular physical activity were associated with higher mQoL (5.3/100 and 4.0/100) and higher pQoL (7.8/100 and 6.7/100). Prospectively, diet was positively associated with mQoL, and physical activity with both mQoL and pQoL. At baseline, engagement with ≥3 behaviours was positively associated with mQoL and pQoL, with additive positive associations for each additional behaviour. Prospectively, engagement with ≥3 behaviours was positively associated with mQoL and pQoL, with strongest associations observed with engagement with five behaviours. CONCLUSION: Consumption of a healthy diet, and regular physical activity, are both potential interventions to improve QoL. Engagement with multiple lifestyle behaviours may provide additional benefits and should be encouraged and supported for multiple sclerosis management.

The risk of secondary progressive multiple sclerosis is geographically determined but modifiable.

Geographical variations in the incidence and prevalence of multiple sclerosis have been reported globally. Latitude as a surrogate for exposure to ultraviolet radiation but also other lifestyle and environmental factors are regarded as drivers of this variation. No previous studies evaluated geographical variation in the risk of secondary progressive multiple sclerosis, an advanced form of multiple sclerosis that is characterized by steady accrual of irreversible disability. We evaluated differences in the risk of secondary progressive multiple sclerosis in relation to latitude and country of residence, modified by high-to-moderate efficacy immunotherapy in a geographically diverse cohort of patients with relapsing-remitting multiple sclerosis. The study included relapsing-remitting multiple sclerosis patients from the global MSBase registry with at least one recorded assessment of disability. Secondary progressive multiple sclerosis was identified as per clinician diagnosis. Sensitivity analyses used the operationalized definition of secondary progressive multiple sclerosis and the Swedish decision tree algorithm. A proportional hazards model was used to estimate the cumulative risk of secondary progressive multiple sclerosis by country of residence (latitude), adjusted for sex, age at disease onset, time from onset to relapsing-remitting phase, disability (Multiple Sclerosis Severity Score) and relapse activity at study inclusion, national multiple sclerosis prevalence, government health expenditure, and proportion of time treated with high-to-moderate efficacy disease-modifying therapy. Geographical variation in time from relapsing-remitting phase to secondary progressive phase of multiple sclerosis was modelled through a proportional hazards model with spatially correlated frailties. We included 51 126 patients (72% female) from 27 countries. The median survival time from relapsing-remitting phase to secondary progressive multiple sclerosis among all patients was 39 (95% confidence interval: 37 to 43) years. Higher latitude [median hazard ratio = 1.21, 95% credible interval (1.16, 1.26)], higher national multiple sclerosis prevalence [1.07 (1.03, 1.11)], male sex [1.30 (1.22, 1.39)], older age at onset [1.35 (1.30, 1.39)], higher disability [2.40 (2.34, 2.47)] and frequent relapses [1.18 (1.15, 1.21)] at inclusion were associated with increased hazard of secondary progressive multiple sclerosis. Higher proportion of time on high-to-moderate efficacy therapy substantially reduced the hazard of secondary progressive multiple sclerosis [0.76 (0.73, 0.79)] and reduced the effect of latitude [interaction: 0.95 (0.92, 0.99)]. At the country-level, patients in Oman, Tunisia, Iran and Canada had higher risks of secondary progressive multiple sclerosis relative to the other studied regions. Higher latitude of residence is associated with a higher probability of developing secondary progressive multiple sclerosis. High-to-moderate efficacy immunotherapy can mitigate some of this geographically co-determined risk.

A pro-inflammatory diet in people with multiple sclerosis is associated with an increased rate of relapse and increased FLAIR lesion volume on MRI in early multiple sclerosis: A prospective cohort study.

BACKGROUND: A pro-inflammatory diet has been posited to induce chronic inflammation within the central nervous system (CNS), and multiple sclerosis (MS) is an inflammatory disease of the CNS. OBJECTIVE: We examined whether Dietary Inflammatory Index (DII®)) scores are associated with measures of MS progression and inflammatory activity. METHODS: A cohort with a first clinical diagnosis of CNS demyelination was followed annually (10 years, n = 223). At baseline, 5- and 10-year reviews, DII and energy-adjusted DII (E-DIITM) scores were calculated (food frequency questionnaire) and assessed as predictors of relapses, annualised change in disability (Expanded Disability Status Scale) and two magnetic resonance imaging measures; fluid-attenuated inversion recovery (FLAIR) lesion volume and black hole lesion volume. RESULTS: A more pro-inflammatory diet was associated with a higher relapse risk (highest vs. lowest E-DII quartile: hazard ratio = 2.24, 95% confidence interval (CI) = -1.16, 4.33, p = 0.02). When we limited analyses to those assessed on the same manufacturer of scanner and those with a first demyelinating event at study entry (to reduce error and disease heterogeneity), an association between E-DII score and FLAIR lesion volume was evident (ß = 0.38, 95% CI = 0.04, 0.72, p = 0.03). CONCLUSION: There is a longitudinal association between a higher DII and a worsening in relapse rate and periventricular FLAIR lesion volume in people with MS.

Modelling accessibility of adult neurology care in Australia, 2020-2034.

Introduction: In 2015/2016, annual national expenditure on neurological conditions exceeded $A3 billion. However, a comprehensive study of the Australian neurological workforce and supply/demand dynamics has not previously been undertaken. Methods: Current neurological workforce was defined using neurologist survey and other sources. Workforce supply modelling used ordinary differential equations to simulate neurologist influx and attrition. Demand for neurology care was estimated by reference to literature regarding incidence and prevalence of selected conditions. Differences in supply versus demand for neurological workforce were calculated. Potential interventions to increase workforce were simulated and effects on supply versus demand estimated. Results: Modelling of the workforce from 2020 to 2034 predicted an increase in neurologist number from 620 to 89. We estimated a 2034 capacity of 638 024 Initial and 1 269 112 Review encounters annually, and deficits against demand estimated as 197 137 and 881 755, respectively. These deficits were proportionately greater in regional Australia, which has 31% of Australia's population (Australian Bureau of Statistics) but is served by only 4.1% of its neurologists as determined by our 2020 survey of Australia and New Zealand Association of Neurologists members. Nationally, simulated additions to the neurology workforce had some effect on the review encounter supply deficit (37.4%), but in Regional Australia, this impact was only 17.2%. Interpretation: Modelling of the neurologist workforce in Australia for 2020-2034 demonstrates a significant shortfall of supply relative to current and projected demand. Interventions to increase neurologist workforce may attenuate this shortfall but will not eliminate it. Thus, additional interventions are needed, including improved efficiency and additional use of support staff.

Self-reported ongoing adherence to diet is associated with lower depression, fatigue, and disability, in people with multiple sclerosis.

Introduction: Increasingly, dietary improvements have been shown to have positive associations with health outcomes in people with multiple sclerosis (pwMS). However, adhering to a MS-specific or high-quality diet may be a challenge. We therefore assessed the level of diet-adherence necessary to improve health outcomes of depression, fatigue, and disability. Methods: Data from an international population of pwMS followed over 7.5 years (n = 671) were analyzed. Self-reported diet quality via diet habits questionnaire (DHQ), and adherence to six MS-diets [Ashton Embry Best Bet, McDougall, Overcoming MS (OMS), Paleolithic (Paleo), Swank, and Wahls] were queried at two timepoints. Four levels of diet adherence were assessed: non-adherence at either timepoint; ceased at second timepoint; commenced at second timepoint; and ongoing at both timepoints. Associations between adherence to OMS and high-quality diet (DHQ score > median) with depression, fatigue, and disability, were assessed by log-binomial regression models adjusted for confounders. Results: Forty-two percent of pwMS reported ongoing-adherence to a MS-diet at both timepoints, OMS (33%), Swank (4%), Wahls (1.5%), other (<1%). Of these, only OMS-diet adherence was analyzed for associations due to data availability. Ongoing-adherence to the OMS-diet or a high-quality diet, was associated with lower depression compared to non-adherence [OMS: Risk ratios (RR) = 0.80, p = 0.021; DHQ: RR = 0.78, p = 0.009] and ceased-adherence (OMS: RR = 0.70, p = 0.008; DHQ: RR = 0.70, p = 0.010), respectively. Ongoing-adherence to OMS-diet was associated with lower fatigue (RR = 0.71, p = 0.031) and lower severe disability (RR = 0.43, p = 0.033) compared to ceased-adherence. Conclusion: Results suggest potential benefits of adherence to the OMS- or a high-quality diet on MS health outcomes, with ongoing-adherence likely best. Diet modification and maintenance may serve as a point of intervention to manage MS symptoms, especially depression, in pwMS.

Higher diet quality is associated with short and long-term benefits on SF-6D health state utilities: a 5-year cohort study in an international sample of people with multiple sclerosis.

BACKGROUND/PURPOSE: Health state utilities (HSU) are a subjective measure of an individual's health-related quality of life (HRQoL), adjusted by societal or patient relative preference weights for living in different states of health-related quality of life (HRQoL), derived from patient-reported responses to multi-attribute utility instrument (MAUI), and can be used as inputs for cost-utility analyses and in clinical assessment. This research assessed associations of diet with subsequent HSU in a large international cohort of people living with multiple sclerosis (MS), a progressive autoimmune condition of the central nervous system. METHODS: HSUs were generated from responses to Short-Form Six-Dimension (SF-6D) MAUI, and quality-of-the-diet by Diet Habits Questionnaire (DHQ). Cross-sectional, and short- and long-term prospective associations of DHQ with HSU evaluated by linear regression at 2.5- and 5-years. Pooled prospective associations between DHQ and HSU evaluated using linear and quantile regression. Analyses adjusted for relevant demographic and clinical covariates. RESULTS: Among 839 participants, baseline DHQ scores showed short- and long-term associations with subsequent HSU, each 10-unit increase in total DHQ score associated with 0.008-0.012 higher HSU (out of 1.00). These associations were dose-dependent, those in the top two quartiles of baseline DHQ scores having 0.01-0.03 higher HSU at follow-up, 0.03 being the threshold for a minimally clinically important difference. Fat, fiber, and fruit/vegetable DHQ subscores were most strongly and consistently associated with better HSU outcomes. However, baseline meat and dairy consumption were associated with 0.01-0.02 lower HSU at subsequent follow-up. CONCLUSIONS: A higher quality-of-the-diet showed robust prospective relationships with higher HSUs 2.5- and 5-years later, substantiating previous cross-sectional relationships in this cohort. Subject to replication, these results suggest interventions to improve the quality-of-the-diet may be effective to improve HRQoL in people living with MS.

Gene-environment interactions increase the risk of paediatric-onset multiple sclerosis associated with household chemical exposures.

BACKGROUND: We previously reported an association between household chemical exposures and an increased risk of paediatric-onset multiple sclerosis. METHODS: Using a case-control paediatric multiple sclerosis study, gene-environment interaction between exposure to household chemicals and genotypes for risk of paediatric-onset multiple sclerosis was estimated.Genetic risk factors of interest included the two major HLA multiple sclerosis risk factors, the presence of DRB1*15 and the absence of A*02, and multiple sclerosis risk variants within the metabolic pathways of common household toxic chemicals, including IL-6 (rs2069852), BCL-2 (rs2187163) and NFKB1 (rs7665090). RESULTS: 490 paediatric-onset multiple sclerosis cases and 716 controls were included in the analyses. Exposures to insect repellent for ticks or mosquitos (OR 1.47, 95% CI 1.06 to 2.04, p=0.019), weed control products (OR 2.15, 95% CI 1.51 to 3.07, p<0.001) and plant/tree insect or disease control products (OR 3.25, 95% CI 1.92 to 5.49, p<0.001) were associated with increased odds of paediatric-onset multiple sclerosis. There was significant additive interaction between exposure to weed control products and NFKB1 SNP GG (attributable proportions (AP) 0.48, 95% CI 0.10 to 0.87), and exposure to plant or disease control products and absence of HLA-A*02 (AP 0.56; 95% CI 0.03 to 1.08). There was a multiplicative interaction between exposure to weed control products and NFKB1 SNP GG genotype (OR 2.30, 95% CI 1.00 to 5.30) but not for other exposures and risk variants. No interactions were found with IL-6 and BCL-2 SNP GG genotypes. CONCLUSIONS: The presence of gene-environment interactions with household toxins supports their possible causal role in paediatric-onset multiple sclerosis.

Genetically determined serum serine level has a novel causal effect on multiple sclerosis risk and predicts disability progression.

BACKGROUND: There are currently no specific biomarkers for multiple sclerosis (MS). Identifying robust biomarkers for MS is crucial to improve disease diagnosis and management. METHODS: This study first used six Mendelian randomisation methods to assess causal relationship of 174 metabolites with MS, incorporating data from European-ancestry metabolomics (n=8569-86 507) and MS (n=14 802 MS cases, 26 703 controls) genomewide association studies. Genetic scores for identified causal metabolite(s) were then computed to predict MS disability progression in an independent longitudinal cohort (AusLong study) of 203 MS cases with up to 15-year follow-up. RESULTS: We found a novel genetic causal effect of serine on MS onset (OR=1.67, 95% CI 1.51 to 1.84, p=1.73×10-20), such that individuals whose serine level is 1 SD above the population mean will have 1.67 times the risk of developing MS. This is robust across all sensitivity methods (OR ranges from 1.49 to 1.67). In an independent longitudinal MS cohort, we then constructed time-dynamic and time-fixed genetic scores based on serine genetic instrument single-nucleotide polymorphisms, where higher scores for raised serum serine level were associated with increased risk of disability worsening, especially in the time-dynamic model (RR=1.25, 95% CI 1.10 to 1.42, p=7.52×10-4). CONCLUSIONS: These findings support investigating serine as an important candidate biomarker for MS onset and disability progression.