AUTHOR=Manouchehrinia Ali , Hedström Anna Karin , Alfredsson Lars , Olsson Tomas , Hillert Jan , Ramanujam Ryan 

TITLE=Association of Pre-Disease Body Mass Index With Multiple Sclerosis Prognosis

JOURNAL=Frontiers in Neurology

VOLUME=Volume 9 - 2018

YEAR=2018

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2018.00232

DOI=10.3389/fneur.2018.00232

ISSN=1664-2295

ABSTRACT=Both high body mass index (BMI) and smoking tobacco are known risk factors for developing multiple sclerosis (MS). However, it is unclear whether BMI, like smoking, is a risk factor for the secondary progressive (SP) course. We therefore sought to determine if high/low BMI at age 20 is associated to risk of SP development, in the context of smoking status.

Using data from MS patients with BMI and smoking information available, we examined relapsing onset patients with MS onset after 20 years of age. Cox regressions were conducted on smokers and non-smokers, with BMI as the main exposure. In total, 5598 relapsing onset MS patients were included. 

The models demonstrated that BMI>30 was associated to increased risk of SPMS in smokers (hazard ratio 1.50, p=0.036). Obesity at age 20 in MS patients who smoked is associated with increased risk of SP course. Since this risk is confined to smokers, the interaction observation may give insight to disease driving mechanisms.