Background and aim: Parkinson's disease (PD) is a common neurodegenerative movement disorder. Treatment aims at symptoms control and prevention of complications. Although type 2 diabetes (T2D) is a well-established risk factor for cerebrovascular diseases, evidence is lacking with regards to the possible association between T2D and PD. With the present study we aimed at investigating the prevalence and relative time of occurrence of T2D in a cohort of PD patients from an Italian tertiary level center and compare it with the Italian general population.

Methods: For this retrospective observational study, the database of the Parkinson Institute ASST Pini-CTO in Milan was queried. We have selected from the database to include and analyze in the study the records of consecutive patients with an established diagnosis of PD based on the UK Parkinson disease Brain Bank criteria followed at our Institute over a 10-year period, from January 2010 to December 2019.

Results: A total of 8380 patients were included in the study. At the last follow-up visit, 673 (8.4%) PD patients had T2D. Standardized prevalence of T2D was lower among PD patients compared to the Italian general population (3.8 % vs. 5.3%, p<.05) . Age at PD onset was approximately 67 years in those who had already diagnosed with T2D, a higher mean onset age of 7 years compared with both PD patients with later occurrence of T2D and PD patients without T2D (p<.001) . A multivariate regression analysis showed that PD onset in patients who had T2D for seven years or less was delayed by an average of 2.7 years, while patients with a T2D duration for over seven years displayed a mean delay of 5.7 years compared with patients without T2D before PD onset (p<.001) .

Discussion: As per our knowledge so far no other conditions or agents are associated with a delay in the onset of PD. Data from this study show that patients with T2D have a significant delay in PD onset. Causes may be further investigated looking at treatments, hormones, metabolic changes and dietary regimen of T2D. Whether this delay has an impact on the prevalence of PD in the T2D population, remains unclear and need to be studied.


S. Colosimo: None. E. Cereda: None. F. Del Sorbo: None. D. Calandrella: None. M. Barichella: None. G. Pezzoli: None.


Fondazione Grigioni per il Parkinson, Brain and Malnutrition in Chronic Diseases Association

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