Exposure to exogenous estrogens and progestogens from oral contraceptives (OCPs) is associated with a reduced risk for developing amyotrophic lateral sclerosis (ALS) in women, according to results from a case-control study published in Neurology.
Researchers evaluated patient data from the Euro-MOTOR study to determine the influence of exogenous hormone exposure on the odds of developing ALS. Patients from The Netherlands, Ireland, and 3 different regions of Italy were recruited over a span of 4 years.
Cases of ALS (n=653) were matched with healthy controls (n=1217) for age (±5 years), and a validated questionnaire recorded each patient’s reproductive history, contraceptive use, gynecologic surgical history, and use of hormone replacement therapy (HRT).
According to the findings, controls used OCPs more often than patients with ALS (odds ratio [OR] 0.65; 95% CI, 0.51-0.84). In addition, patients who reported a history of OCP use had significantly lower odds of developing ALS compared with patients reporting no OCP use (OR 0.65; 95% CI, 0.51-0.84).
There were also reduced odds for ALS incidence in patients who began taking OCPs at a younger age (OR 0.56; 95% CI, 0.41-0.77) and older age (OR 0.74; 95% CI, 0.55-0.99) compared with subjects who had never taken OCPs. In addition, the investigators found that patients from The Netherlands who used HRT had a reduced risk for developing ALS (OR 0.57; 95% CI, 0.37-0.85) compared with patients from the other 2 countries.
The investigators of this study noted that OCP use rates were noticeably different across study sites, and OCP and HRT formulations may differ between countries.
Despite the potential limitations of this case-control study, the researchers suggest that their findings “indicate that sex hormones may play an important role in modulating ALS risk.”
Rooney JPK, Visser AE, D’Ovidio F, et al. A case-control study of hormonal exposures as etiologic factors for ALS in women: Euro-MOTOR. Neurology. 2017;89(12):1283-1290.