Risk of Parkinson disease in women: effect of reproductive characteristics

OBJECTIVE: To investigate the association between some fertile life characteristics and Parkinson disease (PD) in women. METHODS: Women affected by PD and control subjects were matched one to one by age (+/-2 years). One hundred thirty-one women with idiopathic PD and 131 matched control subjects were interviewed. Controls were randomly selected from the resident list of the same municipality of residence of cases. All subjects had a Mini-Mental State Examination score of > or =24. Cumulative length of pregnancies, age at menarche, age and type of menopause, and estrogen use before and after menopause were investigated in cases and controls through a structured questionnaire. Models of matched pair univariate analysis and conditional logistic regression analyses were used to calculate adjusted odds ratio (OR), 95% CI, and two-tailed p values for the investigated variables. RESULTS: PD was significantly associated with a fertile life length shorter than 36 years (OR 2.07; 95% CI 1.00 to 4.30) and a cumulative length of pregnancies longer than 30 months (OR 2.19; 95% CI 1.22 to 3.91). An inverse association between PD and surgical menopause (adjusted OR 0.30; 95% CI 0.13 to 0.77) was also found. CONCLUSIONS: An association between factors reducing estrogen stimulation during life and PD was found. These results support the hypothesis that endogenous estrogens play a role in the development of PD.