Table of contents
- Initially came across this report which mentioned changing MS sex ratio
- Temporal trends in the incidence of multiple sclerosis - A systematic review
- Argentina multiple sclerosis sex ratio 1.8 X in 1940 ==> 2.7 X in 1990
- 100 years ago men got MS more often than women
- Sex ratio of multiple sclerosis and clinical phenotype - April 2010
- Multiple Sclerosis sex ratio increasing - especially if more Northern or RR
- Sex Ratio of Multiple Sclerosis - 2013
- Questions by the founder of VitaminDWiki
- Hypothesis: Placentas cause more autoimmune diseases in females
Environmental factors and multiple sclerosis - 2008
" In native-born Canadians, estimated female-to-male ratios changed from 1 in the early 1900s to 3·5;  a similar increase is seen in European migrants to Canada (Ebers, Orton, and Sadovnick, unpublished data). Notably, this increase began long before the introduction of oral contraceptives, refrigeration, or perhaps the increase in popularity of smoking in women. In Scotland, a similar change is more recent, the ratio being at unity in the 1950s  but now exceeding 3. These findings further indicate that individuals who have the same genetic background change their risk of MS through environmental differences."
- 31) Orton, SM, Herrera BM, Yee IM, Sadovnick AD, Ebers GC. Increasing sex ratio of multiple sclerosis in Canada. Lancet Neurol 2006; 5: 932–36
- 53) Sutherland JM. Observations on the prevalence of multiple sclerosis in Northern Scotland. Brain 1956; 79: 635–34.
Gender ratio trends over time in multiple sclerosis patients from Argentina - April 2017
The change in the sex ratio in multiple sclerosis is driven by birth cohort effects - 2016
- "An increase in the number of female RR MS patients over time accounts for the increasing sex ratio of MS"
Geographical Variations in Sex Ratio Trends over Time in Multiple Sclerosis - Oct 2012
Download the PDF from VitaminDWiki
"Results: 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 83u N and 45u N (from 1.93 to 4.55; p,0.0001) and between 45u N to 35u N (from 1.46 to 2.30; p,0.05) latitude, while a sex ratio stability over time was found in the subgroup from areas between 12u S and 55u S latitude. The sex ratio increase mainly affected relapsing-remitting (RR) MS."
- "This intriguing epidemiological phenomenon warrants particular attention because the sex ratio of MS parallels MS incidence, and the increasing frequency of MS among females is a key driver of the increasing prevalence of this devastating disorder worldwide. A change that occurs within a century is too short a time for a genetic cause. This suggests that environmental factor/s are at work in a sex-specific manner."
- Speculates on various reasons, discounts each reason, has no data
- How had I not been aware of the changes in MS sex ratio before Aug 2018?
- Women appear to be at increased risk of getting RR MS - Is it a different form?
- Women appear to be at increased risk of other autoimmune diseases - has Autoimmune ratio also changed?
- Are women wanting lighter color of skin and staying out of the sun more?
- Might it be associated with the widespread use of birth control pills?
- Might it be associated with fewer births? (see following item)