Sun exposure and multiple sclerosis risk in Norway and Italy: The EnvIMS study

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

doi:10.1177/1352458513513968

Sun exposure and multiple sclerosis risk in Norway and Italy: The EnvIMS study

Mult Scler. 2014 Jul;20(8):1042-9. doi: 10.1177/1352458513513968. Epub 2014 Jan 10.

Authors

Kjetil Bjørnevik¹, Trond Riise², Ilaria Casetta³, Jelena Drulovic⁴, Enrico Granieri³, Trygve Holmøy⁵, Margitta T Kampman⁶, Anne-Marie Landtblom⁷, Klaus Lauer⁸, Andreas Lossius⁹, Sandra Magalhaes¹⁰, Kjell-Morten Myhr¹¹, Tatjana Pekmezovic¹², Kristin Wesnes², Christina Wolfson¹³, Maura Pugliatti¹⁴

Affiliations

¹ Department of Global Public Health and Primary Care, University of Bergen, Norway Department of Neurology, The Norwegian Multiple Sclerosis Competence Centre, Haukeland University Hospital, Norway kjetil.bjornevik@igs.uib.no.
² Department of Global Public Health and Primary Care, University of Bergen, Norway Department of Neurology, The Norwegian Multiple Sclerosis Competence Centre, Haukeland University Hospital, Norway.
³ Department of Biomedical and Surgical Sciences, 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, Norway Department of Neurology, Akershus University Hospital, Norway.
⁶ Department of Clinical Neurology, University of Tromsø, Norway Department of Neurology, University Hospital of North Norway, Norway.
⁷ Division of Neurology, Department of Clinical and Experimental Medicine, UHL, County Council, Linköping University, Sweden.
⁸ Griesheim, Darmstadt, Germany.
⁹ Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway Institute of Immunology, Oslo University Hospital Rikshospitalet, Norway.
¹⁰ Department of Epidemiology and Biostatistics and Occupational Health, McGill University, Canada.
¹¹ Department of Neurology, The Norwegian Multiple Sclerosis Competence Centre, Haukeland University Hospital, Norway The KG Jebsen Centre for MS-Research, Department of Clinical Medicine, University of Bergen, Bergen, Norway.
¹² Institute of Epidemiology, Faculty of Medicine, University of Belgrade, Serbia.
¹³ Research Institute of the McGill University Health Centre, Canada.
¹⁴ Department of Global Public Health and Primary Care, University of Bergen, Norway Department of Clinical and Experimental Medicine, University of Sassari, Italy.

PMID: 24414538
DOI: 10.1177/1352458513513968

Abstract

Objectives: The objective of this paper is to estimate the association between multiple sclerosis (MS) and measures of sun exposure in specific age periods in Norway and Italy.

Methods: A total of 1660 MS patients and 3050 controls from Italy and Norway who participated in a multinational case-control study (EnvIMS) reported sun habits during childhood and adolescence.

Results: A significant association between infrequent summer outdoor activity and increased MS risk was found in Norway and in Italy. The association was strongest between the ages of 16 and 18 years in Norway (odds ratio (OR) 1.83, 95% confidence interval (CI) 1.30-2.59), and between birth and age 5 years in Italy (OR 1.56, 95% CI 1.16-2.10). In Italy a significant association was also found during winter (OR 1.42, 95% CI 1.03-1.97). Frequent sunscreen use between birth and the age of 6 years was associated with MS in Norway (OR 1.44, 95% CI 1.08-1.93) after adjusting for outdoor activity during the same period. Red hair (OR 1.67, 95% CI 1.06-2.63) and blonde hair (OR 1.36, 95% CI 1.09-1.70) were associated with MS after adjusting for outdoor activity and sunscreen use.

Conclusion: Converging evidence from different measures underlines the beneficial effect of sun exposure on MS risk.

Keywords: Multiple sclerosis; epidemiology; sun exposure; sunscreen; vitamin D.

Publication types

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

MeSH terms

Adolescent
Adult
Age of Onset
Case-Control Studies
Child
Child, Preschool
Female
Hair Color
Humans
Infant
Infant, Newborn
Italy / epidemiology
Logistic Models
Male
Middle Aged
Multiple Sclerosis / diagnosis
Multiple Sclerosis / epidemiology*
Multiple Sclerosis / prevention & control
Norway / epidemiology
Odds Ratio
Protective Factors
Risk Assessment
Risk Factors
Seasons
Sunlight*
Sunscreening Agents / administration & dosage
Time Factors
Young Adult

Substances

Sunscreening Agents