Multiple sclerosis is rare in tropical areas, but quite common in
developed countries. Hence, latitude has been accepted as a causal
factor for prevalence of multiple sclerosis. However, developed
countries have also strong economic power, which may be measured by real
gross domestic product per capita.
Bivariate and multivariate regression models were used to assess the
association of the prevalence of multiple sclerosis of 62 countries with
real gross domestic product per capita and latitude.
gross domestic product per capita and latitude are positively
associated with the prevalence of multiple sclerosis. Real gross
domestic product per capita is a much stronger predictor of prevalence
ofmultiple sclerosis than latitude.
The strong correlation between the real gross domestic product per
capita and the prevalence rates of multiple sclerosis is pointing to a
new direction in research on the causes of multiple sclerosis. It is
plausible that certain lifestyles and consumption behaviors that require
high purchasing power might be associated with an increased risk of
It easy to try and link MS susceptibility to something when you
know of the geographical distribution. We could also say that the
distribution of MS is associated with having a certain type of car,
because we know there are more of them in certain countries. Just
check-out the car passing you in the fast-lane. But then you need to
see if all MS or disproportionately more people with MS have a flash car and do this
affluence and MS analysis within the country.