Is there an association between multiple sclerosis and osteoarthritis in Germany? A retrospective cohort study of 8,600 patients from Germany

Osteoarthritis and Neurological Disorder Diagnoses in Adults: A Meta-Analysis Examining Associations With Parkinson's Disease, Multiple Sclerosis, and Alzheimer's Disease

Osteoarthritis (OA) is a highly prevalent joint disorder that is emerging as a global threat to health. OA is associated with low-grade chronic systemic inflammation that can affect overall health, leading to a sedentary lifestyle and potentially increased risk of neurological disorders (ND) such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). A meta-analysis was conducted following the Preferred Reporting Items for 2020 Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE, Web of Science, and Embase databases were searched to identify records. The inclusion criteria for this analysis were original research articles reporting on OA and neurological disorder diagnoses (AD, PD, or MS) with non-OA comparator groups. Logarithmic odds ratios (LORs) were calculated and input into a random-effects meta-analysis using the restricted maximum-likelihood estimator. Subgroup analyses examined the associations between OA, AD, PD, and MS. A subsequent meta-regression analysis was performed to explore potential sources of heterogeneity, focusing on comorbidities and demographic factors. Publication bias was evaluated using funnel plots, Egger's test, and trim-and-fill analysis. Nine studies were included in this meta-analysis (six case-control designs, two cross-sectional designs, and one population-based cohort design) of 1,837,716 cases. The pooled odds ratio (OR) indicated a significant association between OA and ND diagnosis (OR = 1.246; confidence interval (CI): 1.01-1.53). Subsequent subgroup analyses were not statistically significant but indicated an association with PD (OR = 1.31, CI: 0.80-2.12), MS (OR = 1.12, CI: 0.80-2.81), and AD (OR = 1.50, CI: 0.80-2.81). This meta-analysis revealed that individuals with OA have approximately 25% higher odds of an accompanying ND diagnosis compared to those without OA. Importantly, these findings represent statistical associations only and do not imply causation or directionality but provide insight into factors, including shared risk factors, overlapping symptoms, or other underlying mechanisms that may influence the observed relationships.

Infectious mononucleosis is associated with an increased incidence of multiple sclerosis: Results from a cohort study of 32,116 outpatients in Germany

Background

The pathogenesis of multiple sclerosis (MS) has not yet been fully uncovered. There is increasing evidence that Epstein-Barr-Virus (EBV) infection, which affects over 90% of people during life and causes infectious mononucleosis, leads to an increased incidence of MS, and thus may play a crucial role in the pathophysiology of the disease.

Methods

Using the Disease Analyzer database (IQVIA) featuring diagnoses as well as basic medical and demographic data of outpatients from general practices in Germany, we identified a total of 16,058 patients with infectious mononucleosis that were matched to a cohort of equal size without infectious mononucleosis based on patients’ age, sex, index year and yearly consultation frequency. Incidence of MS was compared within a 10-year follow-up period.

Results

Within 10 years from the index date, the incidence of MS was 22.6 cases per 100,000 person-years among patient with infectious mononucleosis but only 11.9 cases per 100,000 person-years among individuals without infectious mononucleosis. In regression analysis, infectious mononucleosis was significantly associated with the incidence of MS (HR: 1.86, 95% CI: 1.09-3.16). Subgroup analysis revealed the strongest association between infectious mononucleosis and MS in the age group between 14 and 20 years (HR: 3.52, 95% CI: 1.00-12.37) as well as a stronger association in men compared to women.

Conclusion

Infectious mononucleosis is associated with an increased incidence of MS especially in younger individuals. Our data support the growing evidence of a decisive involvement of EBV in the currently unknown pathophysiology of MS and should trigger further research efforts to better understand and potentially prevent cases of this disabling disease in future.