Constipation is frequent in Parkinson's disease (PD), although its onset in relation to clinical PD has not been well characterized.
However, a new study has now examined the association between the frequency of bowel movements and the future risk of PD, in the hope that this could provide a greater understanding of the progression and etiology of this disease.
The study used data on the frequency of bowel movements in 6790 men, aged from 51 to 75 years and without PD. The information was collected between 1971 and 1974 in the Honolulu Heart Program.
The incidence of PD in the study population was then monitored over a follow-up period of 24 years.
|Constipation can increase future risk of Parkinson's 2.7-fold.|
During this time, 96 of the men in the study went on to develop PD, at an average of 12 years into follow-up.
The age-adjusted incidence of PD was found to decline significantly and consistently from 19 cases per 10,000 person-years in men with less than one bowel movement per day, to just under 4 cases per 10,000 person years in those with an average of more than two bowel movements each day.
These results were then further adjusted to additionally take into account other possible causative variables. Factors included pack-years of cigarette smoking, coffee consumption, laxative use, jogging, and the intake of fruit, vegetables, and grains.
Following this, the incidence of PD in men with less than one bowel movement a day was found to be 2.7-fold higher than in men with one movement each day.
Additionally, the risk of PD in men having less than one bowel movement per day increased to a 4.1-fold excess, when compared with men had bowel movements twice a day.
This risk rose still further to a 4.5-fold excess when compared to men with more than two bowel movements per day.
The research indicates that infrequent bowel movements are associated with an elevated risk of future PD.
However, Dr R. Abbott, a member of the research group that carried out the work, concludes, "Further study is needed to determine whether constipation is part of early PD processes or is a marker of susceptibility or environmental factors that may cause PD."