To estimate the prevalence of constipation, hyposmia, and REM sleep behavior disorder (RBD), and their association with Parkinson’s disease (PD) in a cohort of US Black women.

The BWHS is a prospective cohort of 59,000 US Black women aged 21-69 at enrollment in 1995.  Participants are followed biennially through postal and online questionnaires. Self-reported health conditions, including PD, are validated using physician records and supplemental questionnaires. The 2024 cohort questionnaire contained questions on constipation (bowel movement ≤ every other day, and/or laxative use ≥ weekly), hyposmia (perceived smell problems), and probable RBD (acting out of dreams).  We estimated age-adjusted odds ratios and 95% confidence intervals (CI) to examine the cross-sectional association of these features with PD.

To date, 14,272 women have completed the online questionnaire, including 24 with a previous diagnosis of PD.  Among them 32% reported constipation, 6% reported hyposmia, and 8% reported probable RBD; approximately 5% reported two or more features. All features examined were significantly associated with PD, with the strongest association observed for hyposmia (OR=13.55; 95% CI 6.04-30.38), followed by probable RBD (OR=8.39; 95% CI 3.76-18.75). Having all three features versus none was associated with OR of 179.43 (95% CI 46.67, 689.80).