St. Paul, Minn. – Men with constipation are more likely to later develop Parkinson’s disease, according to a study published in the August 14 issue of Neurology, the scientific journal of the American Academy of Neurology. Men with constipation problems were nearly three times as likely to develop Parkinson’s disease over the next 24 years as men who were not constipated.
While constipation is a major gastrointestinal disorder among people already diagnosed with Parkinson''''s disease, this is the first prospective study to show that constipation can predate symptoms of Parkinson’s by many years.
“This is an important finding because it could help us understand how the disease progresses,” said study author Robert D. Abbott, PhD, of the University of Virginia School of Medicine in Charlottesville and the Pacific Health Research Institute in Honolulu, Hawaii. “It could also help us more effectively identify people with early or suspected disease or people at high risk for developing the disease in the future.”
Abbott said more research is needed to determine whether constipation is one of the first signs of Parkinson’s disease or whether it is a marker in people who have a greater susceptibility to developing the disease due to genetic or environmental factors.
The study is part of a large study called the Honolulu Heart Program, which started following men living on the island of Oahu, Hawaii, in the 1960s. This study involved 6,790 men age 51 to 75 who were followed for 24 years. Of those, 96 men developed Parkinson’s disease.
Constipation is defined as less than one bowel movement per day and is thought to afflict about 5 percent of the general population. In this study, men who were constipated were 2.7 times more likely to develop Parkinson’s as men who had an average of one bowel movement per day. As bowel movement frequency increased, the risk of Parkinson’s decreased.
Constipated men were 4.1 times more likely to develop Parkinson’s as men with an average of two bowel movements per day and 4.5 times more likely to develop the disease as men with more than two bowel movements per day.
The researchers took into account the differences that age, smoking, coffee consumption, laxative use, jogging, and intake of fruits, vegetables and grains could have on gastrointestinal functioning and Parkinson''''s disease.
“Adjustments for those factors made no change in the results – the strong tie between bowel movement frequency and the risk of Parkinson’s disease remained,” Abbott said.
Researchers don''''t fully understand the relationship between constipation and already-diagnosed Parkinson''''s.
"The same processes that cause the motor symptoms of Parkinson’s may also affect the colon''''s functioning," Abbott said. "There may also be some abnormalities in the muscles involved in bowel movements."
Abbott noted that constipation alone does not put a person at high risk for developing Parkinson’s disease. "Obviously most people with constipation never develop Parkinson''''s," he said. "But if people have constipation that does not respond to use of laxatives along with other factors, such as a family history of the disease or other motor problems, then they may be at higher risk of developing the disease."
The Honolulu Heart Program is supported by grants from the United States Department of the Army and the National Institutes of Health and by Department of Veterans Affairs Medical Research funds.
The American Academy of Neurology, an association of more than 19,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as stroke, Alzheimer's disease, epilepsy, Parkinson's disease, autism and multiple sclerosis.
For more information about the American Academy of Neurology, visit www.aan.com.
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