Prevalence of neuromyelitis optica spectrum disorder in the United States.

BACKGROUND: Neuromyelitis optic spectrum disorder (NMOSD) is a rare demyelinating, autoimmune disease and the burden in United States is not well characterized. OBJECTIVE: The objective of this study was to determine the 2022 US prevalence of NMOSD. METHODS: We constructed a cross-sectional study using aggregated electronic health record data for 25.7 million patients who had a 2022 clinical encounter. The data originated from the TriNetX US Collaborative Network of 55 healthcare organizations that span all 50 states. NMOSD prevalence was determined by querying for age-interval, sex, and race combinations, with direct standardization to the 2022 US Census data. RESULTS: There were 1772 NMOSD patients among 25,743,039 patients for a prevalence of 6.88/100,000. Prevalence was the highest in Blacks (12.99/100,000) who represented 27.7% of NMOSD patients, then Asians (9.41/100,000and Whites (5.58/100,000). Among females, the prevalence of NMOSD was 9.48/100,000, and Black and Asian females had a 2.65- and 1.94-times higher prevalence than White females. In males, the prevalence of NMOSD was 3.52/100,000 and it did not differ by race. We observed a 3/5:1 female-to-male ratio in NMOSD. The age- and sex-adjusted 2022 estimate of persons with NMOSD in the United States was 15,413 females and 6233 males. CONCLUSION: We estimate that there were near 22,000 Americans living with NMOSD in 2022.

Long-term trajectories of ambulatory impairment in multiple sclerosis.

BACKGROUND: Ambulatory impairment is a common and complex manifestation of multiple sclerosis (MS), and longitudinal patterns are not well understood. OBJECTIVE: To characterize longitudinal walking speed trajectories in a general MS patient population and in those with early disease (⩽ 5 years from onset), identify subgroups with similar patterns, and examine associations with individual attributes. METHODS: Using a retrospective cohort study design, latent class growth analysis was applied to longitudinal timed 25-foot walk (T25-FW) data from 7683 MS patients, to determine T25-FW trajectories. Associations were evaluated between trajectory assignment and individual attributes. Analyses were repeated for 2591 patients with early disease. RESULTS: In the general patient population, six trajectories were discerned, ranging from very minimal to very high impairment at baseline, with variability in impairment accrual. The clusters with moderate to very high walking impairment were associated with being female, older and Black American, longer symptom duration, progressive course, and depressive symptoms. In the early disease subset, eight trajectories were discerned that included two subgroups that rapidly accrued impairment. CONCLUSION: We identified novel subgroups of MS patients will distinct long-term T25-FW trajectories. These results underscore that socially disadvantaged and economically marginalized MS patients are the most vulnerable for severe ambulatory impairment.

The impact of cigarette smoking on cognitive processing speed and brain atrophy in multiple sclerosis.

BACKGROUND: Smoking is associated with an increased risk of multiple sclerosis (MS) and disability worsening. The relationship between smoking, cognitive processing speed, and brain atrophy remains uncertain. OBJECTIVE: To quantify the impact of smoking on processing speed and brain volume in MS and to explore the longitudinal relationship between smoking and changes in processing speed. METHODS: A retrospective study of MS patients who completed the processing speed test (PST) between September 2015 and March 2020. Demographics, disease characteristics, smoking history, and quantitative magnetic resonance imaging (MRI) were collected. Cross-sectional associations between smoking, PST performance, whole-brain fraction (WBF), gray matter fraction (GMF), and thalamic fraction (TF) were assessed using multivariable linear regression. The longitudinal relationship between smoking and PST performance was assessed by linear mixed modeling. RESULTS: The analysis included 5536 subjects of whom 1314 had quantitative MRI within 90 days of PST assessment. Current smokers had lower PST scores than never smokers at baseline, and this difference persisted over time. Smoking was associated with reduced GMF but not with WBF or TF. CONCLUSION: Smoking has an adverse relationship with cognition and GMF. Although causality is not demonstrated, these observations support the importance of smoking cessation counseling in MS management.

A higher burden of multiple sclerosis genetic risk confers an earlier onset.

BACKGROUND: Age at onset of multiple sclerosis (MS) is an objective, influential predictor of the evolution of MS independent of disease duration. OBJECTIVES: Determine the influence of MS genetic predisposition on age of onset. METHODS: We conducted a comprehensive investigation of MS risk variants and age at onset in 3495 non-Latinx white individuals, including for combinations of HLA-DRB1*15:01 alleles and quintiles of an unweighted genetic risk score (GRS) for 198 of 200 autosomal MS risk variants that reside outside the major histocompatibility complex. RESULTS: The mean age at onset was 32 years, 29% were male, and 46% were HLA-DRB1*15:01 carriers. For those with the greatest genetic risk burden (the highest GRS quintile with two HLA-DRB1*15:01 alleles) were on average 5 years younger at onset (p = 0.002) than those with the lowest genetic risk burden (the lowest GRS quintile with no HLA-DRB1*15:01 alleles). There was a strong inverse relationship between the MS genetic risk burden and age at onset of MS (p < 5 × 10-8). CONCLUSION: We demonstrate a significant gradient between elevated MS genetic risk burden and an earlier onset of MS, suggesting that a higher MS genetic risk burden accelerates onset of the disease.

Nicotinic acetylcholine receptors α7 and α9 modifies tobacco smoke risk for multiple sclerosis.

INTRODUCTION: Tobacco smoke exposure is an established risk factor for multiple sclerosis (MS), yet how it confers risk is not known. Evidence from observational studies suggests nicotine may be a protective component. Animal studies further support this hypothesis, demonstrating nicotine's protective effect in MS is mediated by the presence and absence of α7 and α9 nicotinic acetylcholine receptors (nAChRs), respectively. OBJECTIVE: To determine if variation in the genes encoding α7 and α9 nAChRs (cholinergic receptor nicotinic alpha 7 (CHRNA7) and alpha 9 (CHRNA9)) will modify MS risk conferred by tobacco smoking. METHODS: A multi-stage gene-environment (G×E) framework was utilized, including a case-control analysis (286 cases, 176 controls) with haplotype- and gene-based analyses, followed by an extension case-only (1053 cases) analysis for overlapping variants. RESULTS: The results suggest that CHRNA7 and CHRNA9 modifies MS risk conferred by tobacco smoke, where risk among smokers was increased in carriers of the minor CHRNA9 haplotype and in non-carriers the minor CHRNA7 haplotype. The findings are consistent with the pharmacology of these receptors and animal studies of MS. CONCLUSION: This study implicates novel processes in MS initiation and demonstrate the need for further G×E studies to advancing our understanding of the missing heritability of MS.

Predicting self-reported depression after the onset of multiple sclerosis using genetic and non-genetic factors.

BACKGROUND: Persons with multiple sclerosis (PwMS) are disproportionately burdened by depression compared to the general population. While several factors associated with depression and depression severity in PwMS have been identified, a prediction model for depression risk has not been developed. In addition, it is unknown if depression-related genetic variants, including Apolipoprotein E (APOE), would be informative for predicting depression in PwMS. OBJECTIVE: To develop a depression prediction model for PwMS who did not have a history of depression prior MS onset. METHODS: The study population included 917 non-Hispanic white PwMS. An optimized multivariable Cox proportional hazards model for time to depression was generated using non-genetic variables, to which APOE and a depression-related genetic risk score were included. RESULTS: Having a mother who had a history of depression, having obstructive pulmonary disease, obesity and other physical disorders at MS onset, and affect-related symptoms at MS onset predicted depression risk (hazards ratios (HRs): 1.6-2.3). Genetic variables improved the prediction model's performance. APOE ε4/ε4 and ε2/x conferred increased (HR = 2.5, p = 0.026) and decreased (HR = 0.65, p = 0.046) depression risk, respectively. CONCLUSION: We present a prediction model aligned with The Precision Medicine Initiative, which integrates genetic and non-genetic predictors to inform depression risk stratification after MS onset.

Age of hypertension onset in multiple sclerosis patients.

BACKGROUND/OBJECTIVE: Hypertension (HTN) is common in multiple sclerosis (MS), and it is associated with poorer outcomes. We sought to characterize HTN age at onset (AAO) by MS status. METHODS/RESULTS: There were 130,050 incident HTN patients, among whom there were 892 MS patients. We conducted multivariable linear regression adjusting for patient attributes. Sex- and race-stratified models were conducted. HTN AAO did not differ in patients with and without MS (p = 0.17). Similar null associations were observed in the sex- and race-specific analyses. CONCLUSION: While there are complex relationships between HTN and MS, there are no differences in HTN AAO by MS status.

Estimating the prevalence of multiple sclerosis using 56.6 million electronic health records from the United States.

BACKGROUND/OBJECTIVE: In 2019, the 2010 U.S. multiple sclerosis (MS) prevalence was robustly estimated (265.1-309.2/100,000) based on large administrative health-claims datasets. Using 56.6 million electronic health records (EHRs), we sought to generate complementary age, sex, and race standardized estimates. METHODS/RESULTS: Using de-identified EHRs and 2018 U.S. Census data, we estimated an age- and sex-standardized MS prevalence of 219.5/100,000 which increased to 274.5/100,000 when accounting for White and Black race alone. Women aged 50 to 69 years had the highest prevalence (>600/100,000). Among White and Black Americans, the age- and sex-standardized prevalence was 283.7 and 226.1 per 100,000, respectively. CONCLUSION: Using 56.6 million EHRs and standardizing for age, sex, and race (White and Black Americans only), we estimated at least 810,504 Americans were living with MS in 2018.

Smokers with MS have greater decrements in quality of life and disability than non-smokers.

BACKGROUND: Tobacco smoke plays a pathogenic role in multiple sclerosis (MS) and may accelerate disease progression, yet, some people with MS continue to smoke after disease onset. The average smoker reports diminished health-related quality of life (HRQOL) across many populations. OBJECTIVES: To describe the relationships between smoking status and HRQOL, disease activity, and global disability in a US population with MS. METHODS: We compared smokers to non-smokers in 950 responders to the Spring 2014 update survey completed by North American Research Committee on Multiple Sclerosis (NARCOMS) registry participants. HRQOL was assessed using Short Form-12 version 2 (SF-12v2), disease activity was investigated using eight Performance Scales (PS) and three Functionality Scales (FS). Global disability was evaluated using Patient Determined Disease Steps (PDDS) and an item response theory (IRT) summed score based on the PS and FS. RESULTS: Smokers had lower HRQOL ( p < 0.0001), reported more disease activity ( p < 0.05) and greater deficits in all PS and FS ( p = 6 × 10-7 to 0.05), except mobility. Smokers and non-smokers did not differ by PDDS but had substantially greater IRT global disability ( p = 2 × 10-7). CONCLUSION: Active smoking is meaningfully associated with deficits across multiple domains in people with MS and adds to the growing literature of the need for MS-tailored smoking cessation programs.

Racial disparities in hypertension management among multiple sclerosis patients.

BACKGROUND: Hypertension adversely impacts the multiple sclerosis (MS) disease course and is more common among Black Americans. Disparities in care due to structural racism may lead to suboptimal hypertension detection and control in Black American MS patients. OBJECTIVES: To determine if uncontrolled hypertension is more common in Black or White Americans with MS and whether race impacts the likelihood of receiving anti-hypertensive treatment. METHODS: A retrospective cohort study was conducted using longitudinal data from American participants in the Multiple Sclerosis Partners Advancing Technology and Health Solutions (MS PATHS) multi-institutional registry. Data was collected from 7 sites in the United States between May 2015 and November 2020. Patients with uncontrolled hypertension, defined as ≥2 blood pressure measurements ≥140/90 mmHg, were identified in the dataset. Racial differences in uncontrolled hypertension and odds of anti-hypertensive treatment were evaluated using logistic regression. Predictors of anti-hypertensive treatment in those with uncontrolled hypertension were determined by race. RESULTS: The analysis included 10,673 MS patients, of whom 1,442 (13.5%) were Black Americans. Despite a lower mean age (45.7 vs. 49.2 years), Black Americans had a 31% increased odds of uncontrolled hypertension compared to White Americans. After adjustment for relevant covariates, mean systolic blood pressure was 1.84 mmHg (95% confidence interval=1.07-2.61) higher in Black Americans than White Americans, and mean diastolic blood pressure was 1.28 mmHg (95% confidence interval=0.74-1.82) higher. Black Americans were also more likely to be on anti-hypertensive therapy (OR=1.68, 95% confidence interval=1.30-2.18) and were exposed to an adjusted average of 0.61 (95% confidence interval=0.45-0.78) more anti-hypertensive treatments than White Americans (p<0.001). Age, comorbid diabetes mellitus, and comorbid hyperlipidemia were positively associated with use of anti-hypertensive treatments in all patients with uncontrolled hypertension. CONCLUSION: Black American MS patients have significantly increased odds of uncontrolled hypertension, but also higher odds of receiving anti-hypertensive treatment.

Demographic and Clinical Characteristics of Antipsychotic Drug-Treated Older Adults with Bipolar Disorder from the Global Aging & Geriatric Experiments in Bipolar Disorder Database (GAGE-BD).

Objectives: Antipsychotic drugs (APS) are widely used to treat patients with bipolar disorder (BD), but there is limited information in older-age bipolar disorder (OABD). This analysis of the Global Aging & Geriatric Experiments in Bipolar Disorder Database (GAGE-BD) investigated characteristics of OABD patients prescribed APS vs. those not prescribed APS. Experimental Design: The observational analysis used baseline, cross-sectional data from 16 international studies for adults aged ≥ 50 years with BD comprising 1,007 individuals with mean age 63.2 years (SD = 9.0), 57.4% women, and mean age of onset 31.6 years (SD = 15.0). The dependent variable was current APS treatment status. The independent variables included demographic and clinical variables, and a random effect for study, that were included in generalized mixed models. Principal Observations: 46.6% of individuals (n = 469) were using APS. The multivariate model results suggest that those treated with APS were younger (p = 0.01), less likely to be employed (p < 0.001), had more psychiatric hospitalizations (p = 0.009) and were less likely to be on lithium (p < 0.001). Of individuals on APS, only 6.6% of those (n = 27) were on first-generation antipsychotics (FGAs) and experienced a greater burden of psychiatric hospitalizations (p = 0.012). Conclusions: APS are widely prescribed in OABD, observed in nearly half of this sample with great variation across sites. Individuals with OABD on APS have more severe illness, more frequent hospitalizations and are more often unemployed vs. those not on APS. Future studies need to examine longitudinal outcomes in OABD prescribed APS to characterize underlying causal relationships.