Association Between Body Mass Index and Response to Disease-Modifying Therapies in Patients With Relapsing-Remitting Multiple Sclerosis at King Abdulaziz University Hospital: A Retrospective Study.

Background Multiple sclerosis (MS) is an immune-mediated inflammatory disease that attacks myelinated axons in the central nervous system, destroying the myelin and axon to varying degrees and producing significant physical disability. So far, many studies have found that having a high body mass index (BMI) is associated with severe autoimmune and neurodegenerative disease course. However, the impact of BMI on disease-modifying therapy (DMT) response in terms of decreasing relapses and improving overall health remains unknown. Aims and objectives The study aimed to demonstrate the effect of BMI on DMT responsiveness in patients with relapse-remitting MS at a tertiary hospital. Methods and material A single-center retrospective study was conducted at a tertiary care center in Jeddah, Saudi Arabia. The study included 89 individuals with relapsing-remitting MS who had their BMI measured within six months of their first clinical relapse, as well as their clinical response to the DMT (number of relapses on a single DMT after six months of initiation) and MRI changes (development of new T2 lesions or gadolinium-enhancing lesions on single DMT six months after DMT initiation). Results Demographic data revealed a female predominance of 71.9%, and 51.7% of the patients had a normal weight. The most commonly prescribed DMT was Gilenya at 47.2%. A significant relationship was found between BMI and the total number of clinical relapses (p=0.038), with the co-existence of a positive correlation between BMI and the number of relapses after at least six months of initiation of DMT. Additionally, MS patients who had both positive MRI changes and obesity had a significantly higher BMI mean than non-obese. Conclusion Increased BMI appeared to be associated with a lower response to DMT, as overweight patients had a worse course than normal and underweight patients. Pharmacokinetic differences are the most likely factors implicated in medication responsiveness.