Smoking and age-at-onset of both motor and non-motor symptoms in Parkinson's disease

This is an interesting study that sets out to look at whether smoking history is associated with the age of onset of motor and non-motor symptoms in patients with PD.... lots of observational study data links smoking to a protective effect on PD.... it follows that in those that do get PD, smoking may delay the manifestation of certain signs. It is interesting that perhaps the features most indicative of synucleinopathies (motor signs and RBD) show the strongest associations with smoking status. Depression and constipation (although common in PD) are not PD specific and for constipation the prevalence appears low overall in this group. Ansomia here was ascertained using a questionnaire, which is in adequate because the correlation between objective and subjective anosmia is poor.

Parkinsonism Relat Disord. 2017 Sep 29. pii: S1353-8020(17)30354-1. doi: 10.1016/j.parkreldis.2017.09.022. [Epub ahead of print]
Gigante AF, Martino T, Iliceto G, Defazio G.

http://www.prd-journal.com/article/S1353-8020(17)30354-1/fulltext

INTRODUCTION: Several evidence suggest that smoking may decrease the risk of Parkinson's disease and is associated with an older age-at-onset of motor signs. The relation between smoking and age-at-onset of non-motor symptoms has never been analyzed. Objective of the study is to evaluate whether smoking habit and pack-years of smoking are associated with a delay of age-at-onset of motor signs, and of some non-motor symptoms.

METHODS: The study population consisted of 262 consecutive parkinsonian patients. Information on relevant demographic/clinical data focused on motor signs, REM sleep behavior disorder, constipation, depression, and hyposmia. Patients were stratified according to smoking habit (ever-versus never-smoker) and number of pack-years of smoking was computed. Repeatability of data on age-at-onset was checked 6 months after the initial interview in a randomly recruited subsample.

RESULTS: Smoking habit and number of pack-years smoked were associated with an older in age-at-onset of motor signs, REM sleep behavior disorder and depression. By contrast, smoking did not affect age-at-onset of hyposmia and constipation.

CONCLUSION: information from this study confirms that smoking may be associated with an older age-at-onset of motor signs, and that a similar effect can be observed on some non-motor symptoms like REM sleep behavior and depression.