Dementia is associated with insulin resistance in patients with Parkinson's disease

J Neurol Sci. 2012 Apr 15;315(1-2):39-43. doi: 10.1016/j.jns.2011.12.008. Epub 2012 Jan 21.


Background: Parkinson's disease is a neurodegenerative disorder involving the basal ganglia. Type-2 Diabetes Mellitus is an important risk factor for Alzheimer disease and vascular dementia. However, the association between Parkinson's disease and Diabetes Mellitus is controversial.

Objective: To investigate glucose metabolism abnormalities in 110 Parkinson's disease patients with and without dementia.

Subjects and methods: We evaluated Insulin Resistance, glucose and insulin levels after a 2-h-oral-glucose-tolerance-test in 53 Parkinson's disease with dementia and 57 with Parkinson's disease without dementia, with normal fasting glucose.

Results: BMI, waist circumference, fasting glucose and insulin values, HbA1c, triglycerides, blood lipid profile, depression rating, educational levels, levodopa-dosage and antipsychotic use were similar in both groups. Disease duration and motor impairment were higher in patients with Parkinson's disease and dementia group. After 2-h-oral-glucose-tolerance-test, the prevalence of glucose metabolism abnormalities was significantly higher in group with Parkinson's disease and dementia group (p=0.03). The insulin resistance was present in 62% patients with Parkinson's disease with dementia, of whom 30% had also impaired glucose tolerance, 5,6% newly diagnosed Diabetes Mellitus and 26% only Insulin Resistance. These percentages were significantly higher in group with Parkinson's disease and dementia, also after adjustment for disease duration and motor disability.

Conclusions: Our study suggests that PD patients with dementia are two times more likely to have insulin resistance than patients with PD.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Blood Glucose / metabolism
  • Case-Control Studies
  • Dementia / blood*
  • Dementia / epidemiology*
  • Dementia / physiopathology
  • Female
  • Humans
  • Insulin Resistance / physiology*
  • Male
  • Middle Aged
  • Parkinson Disease / blood*
  • Parkinson Disease / epidemiology*
  • Parkinson Disease / physiopathology
  • Population Surveillance
  • Prospective Studies
  • Risk Factors


  • Blood Glucose