Geographical Variations in Sex Ratio Trends over Time in Multiple Sclerosis

Maria Trojano*, Guglielmo Lucchese, Giusi Graziano, Bruce V. Taylor, Steve, Jr. Simpson, Vito Lepore, Francois Grand'Maison, Pierre Duquette, Guillermo Izquierdo, Pierre Grammond, Maria Pia Amato, Roberto Bergamaschi, Giorgio Giuliani, Cavit Boz, Raymond Hupperts, Vincent Van Pesch, Jeannette Lechner-Scott, Edgardo Cristiano, Marcela Fiol, Celia Oreja-GuevaraMaria Laura Saladino, Freek Verheul, Mark Slee, Damiano Paolicelli, Carla Tortorella, Mariangela D'Onghia, Pietro Iaffaldano, Vita Direnzo, Helmut Butzkueven

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

A female/male (F/M) ratio increase over time in multiple sclerosis (MS) patients was demonstrated in many countries around the world. So far, a direct comparison of sex ratio time-trends among MS populations from different geographical areas was not carried out.In this paper we assessed and compared sex ratio trends, over a 60-year span, in MS populations belonging to different latitudinal areas.Data of a cohort of 15,996 (F = 11,290; M = 4,706) definite MS with birth years ranging from 1930 to 1989 were extracted from the international MSBase registry and the New Zealand MS database. Gender ratios were calculated by six decades based on year of birth and were adjusted for the F/M born-alive ratio derived from the respective national registries of births.Adjusted sex ratios showed a significant increase from the first to the last decade in the whole MS sample (from 2.35 to 2.73; p = 0.03) and in the subgroups belonging to the areas between 83? N and 45? N (from 1.93 to 4.55; p
Original languageEnglish
Article numbere48078
JournalPLOS ONE
Volume7
Issue number10
DOIs
Publication statusPublished - 25 Oct 2012

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