Further considerations on the distribution of multiple sclerosis in Sweden

Abstract

Though the epidemiologic sources are quite different, they are internally consistent and thus provide three consecutive cross-sectional views of the distribution over time. When considered together the data may be compatible with a thesis of the origin and spread of MS within Sweden from the south-central inland lake regions of the country. Such spread within a half century is too rapid for a genetic cause, including HLA patterns.

Regional, socioeconomic and occupational groups and risk of hospital admission for multiple sclerosis: a cohort study in Sweden

“…The peak in the age-specific incidence rate was found around the ages 45-49 years and the peak in the mortality rate (not shown) was found in the age range 70-74 years. The interval between these two peaks was 25 years, which is in accord with earlier studies in Sweden [19]. In the present study, a higher incidence rate was observed among women aged 45-49, with a sex ratio (female/male) of 2.3, which is in agreement with previous studies [20].…”

“…The county of Värmland had the highest disability and mortality rates from MS [22]. The highest hospitalization rates were found in the county of Uppsala [19]. The present results are partly consistent with those of earlier studies, where the rates of MS followed a latitude gradient that increased from southern to northern Sweden [22].…”

“…In addition, early onset may influence one's choice of education and profession, which may in turn influence the results. The incidence rate of MS in our study confirms earlier findings [19], in which the crude disability incidence rate was 5.6 per 100,000 and the crude death rate was 1.7 per 100,000 inhabitants per year. The peak in the age-specific incidence rate was found around the ages 45-49 years and the peak in the mortality rate (not shown) was found in the age range 70-74 years.…”

An ecological study of industry in a high-risk region of multiple sclerosis

“…This finding, i.e. the great variation of MS rates within the county, was detected by us before and was interpreted as an indication of diffusion [20,31].…”

Vitamin D: A Candidate for the Environmental Effect in Multiple Sclerosis – Observations from Norway

“…In Norway, the first diagnoses of MS in Sami people were made in the early 1990s, and the lowest incidence of MS was found in the most northerly county, Finnmark, where the Sami population is highest [59] . Genetic admixture may confer protection also in non-Sami in the northern parts of Norway and Sweden, where the MS prevalence is lower than expected by latitude, given the decreasing north-to-south gradient that is observed across Europe [10,12,60] . Still, we find a protective association with UVR exposure and possibly also cod liver oil intake in this population [12] .…”