Increased Female MS Incidence and Differences in Gender-Specific Risk in Medium- and High-Risk Regions in Finland from 1981–2010. (10th November 2013)

• Record Type: Journal Article
• Authors: Holmberg, Markus; Murtonen, Annukka; Elovaara, Irina; Sumelahti, Marja-Liisa
• Other Names: Patti Francesco Academic Editor.
• Is Part Of: Multiple sclerosis international. Volume 2013(2013)
• Publication Date: 2013-11-10
• Subjects: Multiple sclerosis -- Periodicals; 616.834005
• DOI: 10.1155/2013/182516
• Languages: English
• ISSNs: 2090-2654

Abstract

Abstract : Background . MS incidence has increased among females, suggesting the presence of environmental effect. Object . Regional differences and temporal changes in gender-specific MS incidence were studied in Finland. Methods . Cases from Jan 1, 1981 to Dec 31, 2010 in Pirkanmaa, Seinäjoki and Vaasa districts were included. The standardized incidence rates (SIR), incidences per 10 5 person years with 95% confidence intervals (CI), and female-to-male ratios (F/M) were determined by district. Results . 1617 cases were included. Compared to Pirkanmaa, the MS risk was 1.9-fold (95% CI: 1.7–2.0) greater in Seinäjoki and 1.2-fold (95% CI: 1.1–1.4) in Vaasa, and the risk was high for both genders. The incidence trend stabilized in Seinäjoki and Vaasa, accompanied by an increase in the F/M ratio. A steady increase in Pirkanmaa was accompanied by a high F/M ratio. Conclusion . A high female preponderance accompanied a general increase in incidence since the 1990s, suggesting the influence of environmental factors. In high-risk districts, increased MS risk prevailed in both genders. High risk reflects both genetic and environmental effects. These effects may be shared with autoimmune diseases such as type 1 diabetes mellitus; the incidence of which follows MS in Finland. Population-based case-control studies are needed to identify these factor effects.