Body size and the risk of multiple sclerosis in Norway and Italy: the EnvIMS study

Kristin Wesnes; Trond Riise; Ilaria Casetta; Jelena Drulovic; Enrico Granieri; Trygve Holmøy; Margitta T Kampman; Anne-Marie Landtblom; Klaus Lauer; Andreas Lossius; Sandra Magalhaes; Tatjana Pekmezovic; Kjetil Bjørnevik; Christina Wolfson; Maura Pugliatti; Kjell-Morten Myhr

doi:10.1177/1352458514546785

Body size and the risk of multiple sclerosis in Norway and Italy: the EnvIMS study

Mult Scler. 2015 Apr;21(4):388-95. doi: 10.1177/1352458514546785. Epub 2014 Sep 2.

Authors

Kristin Wesnes¹, Trond Riise², Ilaria Casetta³, Jelena Drulovic⁴, Enrico Granieri³, Trygve Holmøy⁵, Margitta T Kampman⁶, Anne-Marie Landtblom⁷, Klaus Lauer⁸, Andreas Lossius⁹, Sandra Magalhaes¹⁰, Tatjana Pekmezovic¹¹, Kjetil Bjørnevik², Christina Wolfson¹², Maura Pugliatti¹³, Kjell-Morten Myhr¹⁴

Affiliations

¹ University of Bergen/The Norwegian MS Competence Centre, Haukeland University Hospital, Norway kristin.wesnes@gmail.com.
² University of Bergen/The Norwegian MS Competence Centre, Haukeland University Hospital, Norway.
³ Section of Clinical Neurology, University of Ferrara, Italy.
⁴ Clinic of Neurology, Faculty of Medicine, University of Belgrade, Serbia.
⁵ Institute of Clinical Medicine, Faculty of Medicine, University of Oslo/Akershus University Hospital, Norway.
⁶ University of Tromsø/University Hospital of North Norway, Norway.
⁷ Division of Neurology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
⁸ Darmstadt, Germany.
⁹ Institute of Clinical Medicine, Faculty of Medicine, University of Oslo/Institute of Immunology, Oslo University Hospital Rikshospitalet, Norway.
¹⁰ Department of Epidemiology and Biostatistics and occupational health, McGill University, Montreal, Canada.
¹¹ Institute of Epidemiology, Faculty of Medicine, University of Belgrade, Serbia.
¹² Research institute of the McGill University Health Centre, Montreal, Canada.
¹³ University of Bergen, Norway/ Department of Clinical and Experimental Medicine, University of Sassari, Italy.
¹⁴ The Norwegian MS Competence Centre, Haukeland University Hospital/The KG Jebsen Centre for MS-Research, University of Bergen, Norway.

PMID: 25182290
DOI: 10.1177/1352458514546785

Abstract

Background: Obesity may be a risk factor for developing multiple sclerosis (MS).

Objective: We examined if body size influences the risk of MS in a population-based, case control study.

Methods: A total of 953 cases and 1717 controls from Norway and 707 cases and 1333 controls from Italy reported their body size by choosing a silhouette 1 to 9 (largest) every fifth year from age 5 to 30 and at time of study. The body size-related MS risk was defined by odds ratios (ORs) in logistic regression analyses adjusting for age, smoking and outdoor activity.

Results: In Norway a large body size (silhouettes 6-9) compared to silhouette 3 increased the risk of MS, especially at age 25 (OR 2.21; 95% CI 1.09-4.46 for men and OR 1.43; 95% CI 0.90-2.27 for women). When comparing silhouette 9 to 1, we found a significant dose-response from age 10 until age 30 peaking at age 25 (sex-adjusted OR 2.83; 95% CI 1.68-4.78). The association was present for at least 15 years prior to disease onset. No significant associations were found in Italy.

Conclusions: Obesity from childhood until young adulthood is a likely risk factor for MS with a seemingly stronger effect in Norway than in Italy.

Keywords: Multiple sclerosis; body mass index; body size; case control studies; epidemiology; obesity; vitamin D.

Publication types

Multicenter Study
Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Body Mass Index
Body Size*
Case-Control Studies
Child
Female
Humans
Italy / epidemiology
Male
Multiple Sclerosis / epidemiology*
Norway / epidemiology
Obesity / epidemiology*
Odds Ratio
Risk Factors
Young Adult