The impact of modifiable risk factors on lesion burden in patients with early multiple sclerosis

Some studies have indicated the importance of considering smoking, vitamin D deficiency and obesity as negative prognostic factors for clinical and MRI outcomes in multiple sclerosis (MS). This study aimed to evaluate the possible effects of these modifiable risk factors on brain MRI lesion burden of patients with early MS, also exploring the influence on initial clinical features.

MS patients were enrolled at diagnosis time and examined for smoking, body mass index (BMI), serum level of lipids and 25(OH) vitamin D. Brain MRIs' were acquired and lesion volume assessed by Jim software. Clinical data (disease course, disease duration, and EDSS score) were also collected.

64 patients were enrolled, of these 4 (6.2%) had a primary progressive course. Mean age was 39.8 ± 11.1 years and mean EDSS 1.5 ± 1.1. Forty (62.5%) patients were smokers and 40 (62.5%) were overweight (BMI>25). Insufficient levels of vitamin D (<20 ng/mL) were reported in 36 (56.2%) patients, while 24 (37.5%) patients had an altered lipid profile with total cholesterol >200 mg/dl and LDL >100 mg/dl. No association between early clinical features and modifiable risk factors were reported. Multiple regression analysis showed an association between lesion burden and smoking status (p 0.003), while no association was reported with BMI, altered lipid profile and vitamin D insufficiency.

Several risk factors may play a role in evolution of MS. Our results show that smoking status, probably due to chronic vascular and neurotoxic effects of the cigarette components, can affect the brain damage from the early stages of MS. No association was observed with the other explored modifiable risk factors, although an effect due to the small sample size cannot be excluded.