Ofer Amram1, Nadine Schuurman2, Ellen Randall3, Feng Zhu4, Jameelah Saeedi5, Peter Rieckmann6, Irene Yee7, Helen Tremlett8. 1. Department of Nutrition and Exercise Physiology, Elson S. Floyd College of Medicine, Washington State University, P O Box 1495, Spokane, WA 99210-1495, USA. 2. Department of Geography, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6. 3. School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, Canada V6T 1Z9. 4. Division of Neurology, Faculty of Medicine and the Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2221 Wesbrook Mall, Vancouver, Canada V6T 2B5. 5. Neurology Department, National Neuroscience Institute, King Fahad Medical City, P.O. Box 59046, M.B.N.020007, Riyadh 11525, Saudi Arabia. 6. Department of Neurology, Sozialstiftung Bamberg, Teaching Hospital of the Friedrich-Alexander Universität Erlangen, Buger Str. 80, D-96049 Bamberg, Germany. 7. Division of Neurology, Faculty of Medicine and the Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2221 Wesbrook Mall, Vancouver, Canada V6T 2B5; Department of Medical Genetics, Faculty of Medicine, University of British Columbia, C201 - 4500 Oak Street, Vancouver, Canada V6H 3N1. 8. Division of Neurology, Faculty of Medicine and the Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2221 Wesbrook Mall, Vancouver, Canada V6T 2B5. Electronic address: helen.tremlett@ubc.ca.
Abstract
BACKGROUND: Studies have indicated an association between low Ultraviolet B (UVB) exposure and an increased risk of developing multiple sclerosis (MS). Few studies, however, have explored whether UVB exposure is associated with the age at MS symptom onset. OBJECTIVE: We investigated the potential association between cumulative early life ambient UVB exposure and age at MS onset, using satellite data to measure ambient UVB exposure. METHODS: Adult onset MS patients were selected from the University of British Columbia's MS genetic database (1980-2005). Patients' places of residence from birth to age 18 years were geocoded (latitude and longitude) and assigned UVB values using NASA's Total Ozone Mapping Spectrometer (TOMS) dataset. Linear regression was used to explore the relationship between cumulative UVB exposure (measured for age periods 0-6, 7-12, 13-18, 0-12, and 0-18) and age at MS onset. RESULTS: 3226 patients were included in the analysis. Of these, 74% were female, with an overall mean symptom onset age of 33.3 years. At onset, a total of 2944 (91%) had a relapsing-remitting disease course, 254 (8%) had primary progressive and the disease course for 28 (1%) was unknown. No significant associations between cumulative early life ambient UVB exposure and age at MS onset were observed. Patient sex, MS phenotype, and immigration to Canada after age 18 were significantly associated with age of onset (p < 0.01). CONCLUSIONS: Early life ambient UVB, as measured by satellite imagery, was not significantly associated with the age at MS onset.
BACKGROUND: Studies have indicated an association between low Ultraviolet B (UVB) exposure and an increased risk of developing multiple sclerosis (MS). Few studies, however, have explored whether UVB exposure is associated with the age at MS symptom onset. OBJECTIVE: We investigated the potential association between cumulative early life ambient UVB exposure and age at MS onset, using satellite data to measure ambient UVB exposure. METHODS: Adult onset MS patients were selected from the University of British Columbia's MS genetic database (1980-2005). Patients' places of residence from birth to age 18 years were geocoded (latitude and longitude) and assigned UVB values using NASA's Total Ozone Mapping Spectrometer (TOMS) dataset. Linear regression was used to explore the relationship between cumulative UVB exposure (measured for age periods 0-6, 7-12, 13-18, 0-12, and 0-18) and age at MS onset. RESULTS: 3226 patients were included in the analysis. Of these, 74% were female, with an overall mean symptom onset age of 33.3 years. At onset, a total of 2944 (91%) had a relapsing-remitting disease course, 254 (8%) had primary progressive and the disease course for 28 (1%) was unknown. No significant associations between cumulative early life ambient UVB exposure and age at MS onset were observed. Patient sex, MS phenotype, and immigration to Canada after age 18 were significantly associated with age of onset (p < 0.01). CONCLUSIONS: Early life ambient UVB, as measured by satellite imagery, was not significantly associated with the age at MS onset.
Authors: Mariana Oliveira; André Padrão; André Ramalho; Mariana Lobo; Ana Cláudia Teodoro; Hernâni Gonçalves; Alberto Freitas Journal: Int J Environ Res Public Health Date: 2020-11-13 Impact factor: 3.390