Season of birth as a risk factor for multiple sclerosis in Brazil

Made available in DSpace on 2019-09-12T16:53:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2013 Risk factors for development of multiple sclerosis (MS) are still a matter of debate. Latitude gradient, vitamin D deficiency and season of birth are among the most investigated environmental factors associated with the disease. Several international studies suggest that birth in spring is a substantial risk factor for MS. We investigated the season of birth as a potential risk for MS in different geographical regions of Brazil. We conducted a cross-sectional retrospective study with 2257 clinically definite MS patients enrolled in 13 Brazilian MS clinics in the south, southeast, and northeast regions of Brazil. Demographic and clinical data relating to date of birth and clinical features of the disease were collected and analysed, and subsequently compared with birth date among the general Brazilian population. The distribution of date of birth of MS patients showed an increase in spring and a decrease in autumn, with no difference being observed in the other seasons. In conclusion, season of birth is a probable risk factor for MS in most parts of Brazil. These findings may be related to the role that vitamin D plays in MS pathogenesis. (C) 2013 Elsevier B.V. All rights reserved. [Becker, Jefferson; Hauck, Laura; Gomes, Irenio] Hosp Sao Lucas PUCRS, BR-90610000 Porto Alegre, RS, Brazil [Callegaro, Dagoberto; Lino, Angelina] Hosp Clin USP, Sao Paulo, Brazil [Lana-Peixoto, Marco Aurelio] CIEM Univ Fed Minas Gerais, Belo Horizonte, MG, Brazil [Ferreira, Maria Lucia B.] Hosp Restauracao, Recife, PE, Brazil [Melo, Ailton] Hosp Univ Prof Edgard Santos UFBA, Salvador, BA, Brazil [da Gama, Paulo Diniz] Conjunto Hosp Sorocaba PUCSP, Sorocaba, SP, Brazil [Souza, Doralina G. B.; Barreira, Amilton Antunes] Hosp Clin FMRP USP, Ribeirao Preto, SP, Brazil [Souza, Doralina G. B.] Univ Estadual Paulista, UNESP, Botucatu, SP, Brazil [Teixeira, Carlos A. C.] Univ Fed Ceara, Fortaleza, CE, Brazil [Kaimen-Maciel, Damacio Ramon] Univ Estadual Londrina, Londrina, PR, Brazil [Goncalves, Marcus Vinicius] Clin Neurol Joinville, Joinville, SC, Brazil [Matta, Andre P. C.] Univ Fed Fluminense, Niteroi, RJ, Brazil [Abraham, Ronaldo] Universidade de Taubaté (Unitau), Dept Med [Furtado, Luis Edmundo T. A.] Univ Fed Ceara, Sobral, CE, Brazil