Insulin Resistance May Be Largely Undetected In Non-Diabetics With Parkinson’s Disease

A recent study suggests nearly two-thirds of non-diabetic patients with Parkinson’s disease (PD) and normal blood sugar levels may be insulin resistant, Science Daily reports.

Research findings suggest that insulin resistance is much more common in PD patients than previously understood, and goes largely undetected, perhaps even more so in overweight PD patients. The exact prevalence of insulin resistance, however, is unknown.

The study was published in the Journal of Parkinson’s Disease.

According to the article, insulin resistance is being scrutinized as a “potential driver of neurodegeneration” and a reduced glucose tolerance has been a recognized risk factor for PD for quite some time. The link, the evidence suggests, may be insulin resistance.

Insulin resistance, a condition which can be reversed, puts the patient at higher risk for developing type 2 diabetes.

Michelle Tagliati, MD from the Department of Neurology at Cedar-Sinai Medical Center in Los Angeles, California, was the lead investigator on the study. Tagliati said that this study is the first of its kind to address the issue of insulin resistance in non-diabetic patients with PD.

“There is growing interest in the study of this relationship and the use of diabetes medications in the treatment of PD. However, there is little information regarding the prevalence of insulin resistance in PD.”

Tagliati and team tested 154-diabetics with PD for fasting blood sugar and insulin levels in order to determine the prevalence of insulin resistance, while also investigating the correlation between insulin resistance and, among other things, motor and non-motor symptoms of PD. Researchers also recorded height and weight of each study participant, also using a widely-used formula to find out if each patient had a reduced insulin response. Study participants also had movement and cognitive performance recorded.

According to results, just over 58 percent of the study participants had undiagnosed insulin resistance, even after normal results were found through multiple tests used in diagnosing and treating both type 1 and type 2 diabetes, including a normal fasting glucose. However, researchers did not find a link between cognitive decline and insulin resistance, and a substantial percentage (41 percent) of lean PD patients with insulin resistance.

Lead researcher investigator Tagliati said the results are important in understanding how common insulin resistance is.

“This increases the importance of finding new treatments and lifestyle interventions that can address this metabolic dysfunction with multiple implications, from diabetes to neurodegenerative disorders like PD and Alzheimer’s disease.”