Untreated Parkinson’s patients who also have type 2 diabetes mellitus may be at a higher risk of developing impulse control disorders, severe depression, apathy, and sleep problems, research suggests.
The study, “Preexisting Diabetes Mellitus is Associated with More Frequent Depression and Impulse Control Disorders in Drug Naïve Parkinson’s Disease” will be presented during the 14th International Conference on Alzheimer’s and Parkinson’s Diseases and related neurological disorders March 26-31 in Lisbon, Portugal.
Higher doses of dopamine agonists — which act as a substitute for (or mimic) dopamine in the brain — and longer treatment periods have been seen to make Parkinson’s patients more prone to developing impulse control disorders, including gambling, compulsive shopping, over-eating, and compulsive sexual behaviors.
Evidence indicates that type 2 diabetes increases the risk of developing Parkinson’s disease. Interestingly, an association among type 2 diabetes, depression, and impulse control behaviors has also been suggested.
Researchers from the University of Pécs in Hungary sought to study the impact of pre-existing type 2 diabetes mellitus on Parkinson’s-related non-motor symptoms and on impulse control behaviors in people with Parkinson’s not yet taking prescribed antiparkinsonian medications.
The team performed detailed neurological and neuropsychological examinations on 299 newly diagnosed Parkinson’s patients who were not on any medication.
Of these Parkinson’s patients, 77 (25.8%) had pre-existing type 2 diabetes. Diabetic Parkinson’s patients were older, heavier (with a higher body mass index) and included more men. Importantly, and in comparison to non-diabetic Parkinson’s patients, diabetic patients had more severe depression, apathy, sleep problems and more severe non-motor symptoms, measured by the Non-Motor-Experiences of Daily Living part of the Movement Disorders Society-sponsored Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) and the Non-motor Symptoms Scale.
Scientists also reported that 40.3% of Parkinson’s patients with diabetes had impulse control behaviors, which was significantly different from the 22.3% observed in the non-diabetic sample.
Untreated Parkinson’s patients with diabetes were 3.58 times more likely to have impulse control disorders. Due to this, type 2 diabetes mellitus was considered to be an independent predicting factor for the development of these behavior disorders.
“Preexisting diabetes may be a risk factor for more frequent impulse control disorders and more frequent and more severe depression, apathy and sleep problems in drug naïve PD patients. However, further prospective longitudinal studies are warranted to study its effects on the disease course,” the researchers concluded.