Austin Health

Title
Association of Latitude and Exposure to Ultraviolet B Radiation With Severity of Multiple Sclerosis: An International Registry Study.
Publication Date
2022-06-14
Author(s)
Vitkova, Marianna
Diouf, Ibrahima
Malpas, Charles
Horakova, Dana
Kubala Havrdova, Eva
Patti, Francesco
Ozakbas, Serkan
Izquierdo, Guillermo
Eichau, Sara
Shaygannejad, Vahid
Onofrj, Marco
Lugaresi, Alessandra
Alroughani, Raed
Prat, Alexandre
Larochelle, Catherine
Girard, Marc
Duquette, Pierre
Terzi, Murat
Boz, Cavit
Grand'Maison, Francois
Sola, Patrizia
Ferraro, Diana
Grammond, Pierre
Butzkueven, Helmut
Buzzard, Katherine
Skibina, Olga
Yamout, Bassem I
Karabudak, Rana
Gerlach, Oliver
Lechner-Scott, Jeannette
Maimone, Davide
Bergamaschi, Roberto
Van Pesch, Vincent
Iuliano, Gerardo
Cartechini, Elisabetta
José Sà, Maria
Ampapa, Radek
Barnett, Michael
Hughes, Stella E
Ramo-Tello, Cristina M
Hodgkinson, Suzanne
Spitaleri, Daniele L A
Petersen, Thor
Butler, Ernest Gerard
Slee, Mark
McGuigan, Chris
McCombe, Pamela Ann
Granella, Franco
Cristiano, Edgardo
Prevost, Julie
Taylor, Bruce V
Sãnchez-Menoyo, Josã Luis
Laureys, Guy
Van Hijfte, Liesbeth
Vucic, Steve
Macdonell, Richard A L
Gray, Orla
Olascoaga, Javier
Deri, Norma
Fragoso, Yara Dadalti
Shaw, Cameron
Kalincik, Tomas
Type of document
Journal Article
DOI
10.1212/WNL.0000000000200545
Abstract
The severity of multiple sclerosis (MS) varies widely among individuals. Understanding the determinants of this heterogeneity will help clinicians optimize the management of MS. The aim of this study was to investigate the association between latitude of residence, UV B radiation (UVB) exposure, and the severity of MS. This observational study used the MSBase registry data. The included patients met the 2005 or 2010 McDonald diagnostic criteria for MS and had a minimum dataset recorded in the registry (date of birth, sex, clinic location, date of MS symptom onset, disease phenotype at baseline and censoring, and ≥1 Expanded Disability Status Scale score recorded). The latitude of each study center and cumulative annualized UVB dose at study center (calculated from National Aeronautics and Space Administration's Total Ozone Mapping Spectrometer) at ages 6 and 18 years and the year of disability assessment were calculated. Disease severity was quantified with Multiple Sclerosis Severity Score (MSSS). Quadratic regression was used to model the associations between latitude, UVB, and MSSS. The 46,128 patients who contributed 453,208 visits and a cumulative follow-up of 351,196 patient-years (70% women, mean age 39.2 ± 12 years, resident between latitudes 19°35' and 56°16') were included in this study. Latitude showed a nonlinear association with MS severity. In latitudes <40°, more severe disease was associated with higher latitudes (β = 0.08, 95% CI 0.04-0.12). For example, this translates into a mean difference of 1.3 points of MSSS between patients living in Madrid and Copenhagen. No such association was observed in latitudes <40° (β = -0.02, 95% CI -0.06 to 0.03). The overall disability accrual was faster in those with a lower level of estimated UVB exposure before the age of 6 years (β = - 0.5, 95% CI -0.6 to 0.4) and 18 years (β = - 0.6, 95% CI -0.7 to 0.4), as well as with lower lifetime UVB exposure at the time of disability assessment (β = -1.0, 95% CI -1.1 to 0.9). In temperate zones, MS severity is associated with latitude. This association is mainly, but not exclusively, driven by UVB exposure contributing to both MS susceptibility and severity.
Link
Citation
Neurology 2022; 98(24): e2401-e2412
Jornal Title
Neurology

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