HealthDay News — Poor olfaction is associated with increased risk of incident Parkinson’s disease (PD), according to a study published in Neurology.
Honglei Chen, MD, PhD, from the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina, and colleagues examined olfaction in relation to incident PD among 1510 white and 952 black participants of the Health, Aging, and Body Composition study. Olfaction of study participants was assessed with the Brief Smell Identification Test (BSIT) in 1999-2000.
The researchers identified a total of 42 incident PD cases, including 30 white and 12 black participants, during an average of 9.8 years of follow-up. Poor sense of smell (indicated by lower BSIT score) correlated with increased risk of PD. The hazard ratio [HR] was 1.3 (95% CI, 0.5-3.6) and 4.8 (95% CI, 2-11.2) for the second (t2) and lowest (t1) compared with the highest tertile (t3) of BSIT (P <.00001).
In the first 5 years of follow-up and thereafter, there were significant associations for incident PD (HR t1/[t2+t3]), 4.2 [95% CI, 1.7-10.8] and 4.1 [95% CI, 1.7-9.8]). The association was stronger in white than black participants and for men vs women.
“Poor olfaction predicts PD in short and intermediate terms; the possibility of stronger associations among men and white participants warrants further investigation,” the authors write.
Chen H, Shrestha S, Huang X, et al. Olfaction and incident Parkinson disease in US white and black older adults [published online September 6, 2017]. Neurology. doi:10.1212/WNL.0000000000004382