Fernando Botello-Villagrana

Parkinson’s disease (PD) is the second most common neurodegenerative disorder worldwide and is characterized by progressive motor and non-motor manifestations. Its rising prevalence poses significant challenges for clinical management and public health. Type 2 diabetes mellitus (T2DM), the most frequent metabolic disorder, shares several pathogenic mechanisms with PD, including mitochondrial dysfunction, insulin resistance, and oxidative stress. Epidemiological studies suggest a higher incidence of PD among individuals with T2DM, with growing evidence that diabetes may accelerate the onset and progression of motor and cognitive symptoms. This narrative review summarizes current knowledge on the relationship between T2DM and PD, with emphasis on epidemiological associations, shared biological pathways, and the therapeutic implications of antidiabetic agents. Available data indicate that patients with both PD and T2DM tend to experience a faster progression of motor and cognitive decline. Clinical trials assessing hypoglycemic agents have reported heterogeneous findings: pioglitazone failed to demonstrate neuroprotective effects, while exenatide showed temporary improvements in motor function that were not sustained after treatment discontinuation. Experimental studies also suggest possible neuroprotective actions of metformin and dipeptidyl peptidase 4 inhibitors, although well-designed clinical trials are still lacking. The interaction between T2DM and PD highlights the importance of metabolic factors in neurodegeneration. Further studies are required to determine the impact of diabetes and its treatments on the PD course and to explore antidiabetic drugs as potential disease-modifying therapies.

Introduction: While there is a growing body of evidence indicating a potential connection between Parkinson’s disease and diabetes mellitus, there is a lack of focus on investigating how diabetes correlates with the severity of both motor and non-motor symptoms in Parkinson’s disease. Objective: This study examined and contrasted both motor and non-motor symptoms in patients diagnosed with Parkinson’s disease, stratified by the presence or absence of diabetes. Methods: A total of 40 Parkinson’s disease patients, divided into two groups (with and without diabetes), were assessed using various scales, including the Movement Disorders Society – Unified Parkinson’s Disease Rating Scale, Scales for Outcomes in Parkinson’s Disease - Autonomic Dysfunction and Non-Motor Symptoms, Beck Depression Inventory, Montreal Cognitive Assessment, and Parkinson’s Disease Questionnaire-39. Demographic and clinical characteristics were also recorded. Statistical analyses included t-tests, Mann-Whitney U tests, and Fisher’s exact test. Results: Significant differences were observed in the motor sub-score of postural instability and gait disturbance symptoms, autonomic total scores, urinary function domain, depression scores, and quality of life in the mobility and emotional domains between the Parkinson’s disease non-diabetes, and Parkinson’s disease - diabetes groups. Conclusions: Our study unveiled differences in motor and Non-Motor Symptoms among patients with Parkinson’s disease and diabetes, underscoring the influence of diabetes on manifestations of the disease.