People with diabetes may have a heightened risk of developing Parkinson's disease, especially at a relatively young age, a new study finds. Published in the journal Diabetes Care, the study adds to recent research linking diabetes to Parkinson's disease.
But neither this report nor the earlier ones prove that diabetes, itself, raises a person's risk of Parkinson's - a disorder in which movement-regulating brain cells gradually become disabled or die. Instead, researchers suspect that it's more likely diabetes and Parkinson's share some common underlying causes.
The new study looked at health insurance claims from more than one million Taiwanese adults - including a little over 600,000 with diabetes. Researchers found that over nine years, people with diabetes were more likely to be diagnosed with Parkinson's disease. They were diagnosed at a rate of 3.6 cases per 10,000 people each year, versus 2.1 per 10,000 among people without diabetes.
When the researchers factored in age, sex and certain other health conditions, they found that diabetes was still linked to an increased risk of Parkinson's - especially at a relatively young age. Among women in their 40s and 50s, those with diabetes had twice the risk of Parkinson's that diabetes-free women did.
The same was true among men in their 20s and 30s, though that was based on only a handful of Parkinson's cases: there were four cases among young men with diabetes, and two among those without diabetes. Exactly what it all means is unclear, according to Drs. Yu Sun and Chung-Yi Li, who led the study.
But on average, people develop Parkinson's diagnosis around age 60, the researchers noted in an email to Reuters Health. "Our findings tend to suggest a relationship between diabetes and early-onset Parkinson's disease," said Sun and Li, who are based at En Chu Kong Hospital and National Cheng Kung University in Taiwan.
That's in line with a study of Danish adults published last year, the researchers noted. (See Reuters Health story of April 15, 2011). Still, it's impossible to say for sure that diabetes, itself, is to blame. One reason is that the current study had limited information, according to Sun and Li.