THE RISK OF MULTIPLE-SCLEROSIS IN THE USA IN RELATION TO SOCIOGEOGRAPHIC FEATURES - A FACTOR-ANALYTIC STUDY

The multiple sclerosis (MS) case-control ratio by state originating fr om the U.S. veteran series from World War II (Kurtzke Neurology 1979; 29: 1228-1235) was geographically compared with 46 sociogeographic var iables from the period 1935-1958. Latitude was, by far, the variable m ost closely associated with MS in univariate testing. Multivariate ana lysis by factor analysis revealed that the MS rate was associated with 2 independent settings (''factors''). The first one was defined mainl y socioeconomically and was characterized by indicators of higher affl uence; better nutrition with a higher meat consumption in particular, and a higher sanitary level were the prominent features. The second MS -related bundle comprised characteristics of a colder climate along wi th further dietary variables (i.e. a diet low in fish and high in dair y products). The findings suggest a possible interaction of both socio economic and geoclimate features in the etiology of MS; sanitation, di et and climate being of particular interest.