Inverse association between smoking and idiopathic Parkinson's disease

Abstract

An evaluation is made of the effect of smoking during the period of life between 20 and 50 years of age and idiopathic Parkinson's disease in a case-control study carried out in Navarra. An inverse association is observed: for the number of smokers (OR = 0.66, CI 90% 0.41-1.05); for the number of years smoking (OR =0.22, CI 90% 0.05-0.97); and for the quantity of cigarettes smoked (z = 2.2298, p = 0.02). Likewise, a dose-response relationship exists between the number of cigarettes consumed and the risk of Parkinson's disease (p = 0.01). The same effect is maintained on analysing the data by matching 1:1 (OR = 0.59, CI 90% 0.31-1.10). All of this contributes to giving consistency to the protective effect of smoking against idiopathic Parkinson's disease. The anti-oxidant status, measured by means of different parameters in peripheral blood, is lower in the cases than in the tests for reduced glutathione (GSH) (p = 0.001) and is an independent variable with respect to smoking.