Reproductive factors and Parkinson's disease risk in Danish women
Article first published online: 22 APR 2014
© 2014 The Author(s) European Journal of Neurology © 2014 EAN
European Journal of Neurology
Volume 21, Issue 9, pages 1168–e68, September 2014
How to Cite
Greene, N., Lassen, C. F., Rugbjerg, K. and Ritz, B. (2014), Reproductive factors and Parkinson's disease risk in Danish women. European Journal of Neurology, 21: 1168–e68. doi: 10.1111/ene.12450
- Issue published online: 25 JUL 2014
- Article first published online: 22 APR 2014
- Manuscript Accepted: 17 MAR 2014
- Manuscript Received: 26 NOV 2013
- National Institutes of Environmental Health Sciences. Grant Number: R01 ES013717
- Danish Cancer Society
- case−control studies;
- Parkinson's disease;
- reproductive factors
Background and purpose
Parkinson's disease is more common in men than women by a ratio of about 1.5:1 and yet there is no consensus to date as to whether female reproductive factors including hormone use affect Parkinson's disease risk. Our objective was to examine the relationship between Parkinson's disease and female reproductive factors in the largest population-based Parkinson's disease case−control study to date.
Seven hundred and forty-three female Parkinson's disease cases diagnosed between 1996 and 2009 were selected from the Danish National Hospital Register, diagnoses confirmed by medical record review, and the cases were matched by birth year to 765 female controls randomly selected from the Danish Civil Registration System. Covariate information was collected in computer-assisted telephone interviews covering an extensive array of topics including reproductive and lifestyle factors.
After adjusting for smoking, caffeine and alcohol use, education, age, and family Parkinson's disease history, inverse associations between Parkinson's disease and early menarche (first period at ≤11 years), oral contraceptives, high parity (≥4 children) and bilateral oophorectomy were found; adjusted odds ratios and 95% confidence limits were respectively 0.68 (0.45–1.03) for early menarche, 0.87 (0.69–1.10) for oral contraceptives, 0.79 (0.59–1.06) for high parity and 0.65 (0.45–0.94) for bilateral oophorectomy. Little support for associations between Parkinson's disease and fertile life length, age at menopause or post-menopausal hormone treatment was found.
Reproductive factors related to women's early- to mid-reproductive lives appear to be predictive of subsequent Parkinson's disease risk whereas factors occurring later in life seem less important.