Diabetes-Parkinson's Link Grows Stronger

Mar. 23 -- WEDNESDAY, March 28 (HealthDay News) -- As people with obesity-linked type 2 diabetes age, their risk of getting Parkinson's disease also climbs, a new study warns.

In fact, excess weight may explain why diabetics are at increased risk of getting the neurological disorder, a Finnish study suggests.

"These findings are important from a clinical and public health point of view," said study author Dr. Gang Hu, senior researcher at the National Public Health Institute in Helsinki. "Type 2 diabetes is increasing rapidly in all populations, and its impact on various health outcomes are not fully known or even explored."

His team's study -- the first large effort to follow people over time and evaluate the diabetes-Parkinson's link -- is published in the April issue of Diabetes Care.

Parkinson's disease affects about 1.5 million Americans, according to the National Parkinson Foundation. It occurs when certain brain cells or neurons die or become impaired. These cells normally produce a substance called dopamine, which helps regulate coordinated movement. Symptoms of Parkinson's include tremor, slow movement and difficulties keeping one's balance.

In type 2 diabetes, the body doesn't properly use insulin or doesn't make enough insulin, which is crucial for the body's uptake of glucose for energy. Excess weight is the major risk factor for type 2 diabetes.

A few other studies have looked at how prevalent type 2 diabetes is among patients with Parkinson's, but, according to Hu, "the results are inconsistent."

His team's study included more than 51,000 Finnish men and women with no prior history of Parkinson's, between the ages of 25 and 74, at the beginning of the trial.

During the 18 years of follow-up, 324 men and 309 women developed Parkinson's disease.

When Hu and his team evaluated the subjects' medical histories, they found that people with type 2 diabetes were 83 percent more likely to get Parkinson's.

The increased risk was still present even after the researchers took into account body mass index (BMI), alcohol intake, coffee/tea intake, smoking and physical activity.