According to a recent study published in JAMA Neurology, people with multiple sclerosis (MS) are far more likely to experience disease activity when they have comorbidities. Researchers led by Dr Amber Salter of UT Southwestern Medical Center's Department of Neurology, have shown that patients with multiple sclerosis (MS) who also suffer from other health issues have less success with disease-modifying therapies (DMTs), which has important consequences for future treatment plans.

The study used a two-stage meta-analysis approach, analysing individual participant data from 17 phase 3 clinical trials of MS DMTs conducted between November 2001 and March 2018. Over the course of two years, 16,794 individuals were monitored, with 67.2% of them being female. The main result was evidence of disease activity (EDA), which included confirmed relapses, worsening of disability, or the discovery of new lesions on magnetic resonance imaging (MRI).

The findings were remarkable. Over the two-year follow-up period, 61% of people demonstrated EDA, indicating a significant incidence of disease progression in MS patients, even when receiving DMT treatment. Importantly, the study discovered that comorbidities had a significant impact on poor outcomes. Those with three or more comorbid diseases had a 14% greater risk of EDA than those without any comorbidities (adjusted hazard ratio [AHR], 1.14; 95% CI, 1.02-1.28). 

Dr. Salter emphasised the importance of these findings, saying, "Our research reveals that comorbidities are more than merely side effects in MS; they actively contribute to disease development. Addressing these issues should be a top goal in both clinical practice and continuing studies." 

The study also highlighted the particular effects of cardiometabolic and mental disorders on MS disease activity. Patients with two or more cardiometabolic illnesses, such as hypertension, hyperlipidaemia, or ischaemic heart disease, had a 21% greater risk of disease activity than those without these conditions (AHR, 1.21; 95% confidence interval, 1.08-1.37). These findings highlight the critical role cardiovascular health plays in MS outcomes. 

In addition to cardiometabolic concerns, psychological disorders posed a significant danger. Researchers linked a single psychiatric condition, such as depression or anxiety, to a 7% higher risk of EDA (AHR, 1.07; 95% CI, 1.02-1.14). This finding implies that mental health issues can worsen disease progression in MS patients, affecting treatment outcomes. 

The study's findings highlight the vital relevance of managing comorbidities in MS patients, not just as secondary concerns but also as primary factors impacting disease progression. The doctor stated, "Comorbidities can act as mediators for other negative prognostic factors in MS, which means that controlling these conditions may improve overall outcomes for patients." 

Given that approximately two-thirds of trial participants showed symptoms of disease activity over the research period while receiving DMTs, the findings suggest that existing treatment techniques may not adequately satisfy MS patients' complex health needs. Comorbidities, particularly those related to cardiometabolic and mental health, may pose a significant barrier to the efficacy of these treatments. 

Furthermore, the authors of the study recommend that future clinical trials for MS medicines take comorbidities into account during the design phase. This allowed researchers to better understand how these factors interact with MS progression and change treatment methods accordingly. 

The findings present a compelling justification for a more comprehensive approach to MS care. Preventing and controlling comorbidities, particularly cardiovascular and psychiatric diseases, should be top priorities in both clinical practice and clinical trials. Effective treatment of these comorbidities may delay the onset of disease activity, thereby improving MS patients' quality of life.

The findings also raise concerns regarding the long-term viability of DMTs in the face of uncontrolled comorbidities. MS is a lifelong condition, and the prevalence of comorbidities grows with age; therefore, personalised treatment approaches that address the entire spectrum of a patient's health are likely to produce better results. 

This study serves as a crucial reminder that the treatment for MS cannot solely focus on the disease itself. Dr. Salter concluded: "Effective management of MS must include the treatment of comorbidities to mitigate their adverse effects on disease progression."