Association between different diabetes medication classes and risk of Parkinson's disease in people with diabetes

Glucagon-like peptide-1 receptor agonists for major neurocognitive disorders

Disease-modifying treatments for major neurocognitive disorders, including Alzheimer's disease, Parkinson's disease and other cognitive deficits, are among the main unmet needs in modern medicine. Glucagon-like peptide-1 receptor agonists (GLP-1RAs), currently licensed for the treatment of type 2 diabetes mellitus and obesity, offer a novel, multilayered mechanism for intervention in neurodegeneration through intermediate, aetiology-agnostic pathways, likely involving metabolic, inflammatory and several other relevant neurobiological processes. In vitro and animal studies have revealed promising signals of neuroprotection, with preliminary supportive evidence emerging from recent pharmacoepidemiological investigations and clinical trials. In this article, we comprehensively review studies that investigate the impact of GLP-1RAs on the various aetiologies of cognitive impairment and dementia syndromes. Focusing on evidence from human studies, we highlight how brain energy homeostasis, neurogenesis, synaptic functioning, neuroinflammation and other cellular stress responses, pathological protein aggregates, proteostasis, cerebrovascular system and blood-brain barrier dynamics may underlie GLP-1RA putative neuroprotective effects. We then report and appraise evidence from clinical studies, including observational investigations, clinical trials and pooled analyses. Finally, we discuss current challenges and perspectives ahead for research and clinical implementation of GLP-1RAs for the care of people with major neurocognitive disorders, including their individual brain penetrance potential, the need for response biomarkers and disease stage-based indications, their possible non-specific effects on brain health, their profile in terms of adverse events and other unwanted effects, the lack of long-term data for efficacy and safety, and issues surrounding cost and availability of treatment.

Anti-diabetic drug use and reduced risk of Parkinson's disease: A community-based cohort study

BACKGROUND

Emerging evidence suggests a potential association between certain anti-diabetic drugs and a reduced risk of Parkinson's disease (PD). Limited population-based studies have investigated users of newer anti-diabetic drugs such as GLP-1 agonists or SGLT2 inhibitors.

OBJECTIVE

The aim of this study was to assess the risk of PD among individuals with type 2 diabetes mellitus (T2DM) who were treated with various types of anti-diabetic drugs over time.

METHODS

A population-based cohort comprising T2DM patients aged over 30 who used metformin, GLP-1 agonists, thiazolidinediones, sulfonylureas, DPP4 inhibitors, SGLT2 inhibitors, or meglitinides between January 1, 1999 and December 31, 2018. Data were obtained between the diabetes registration and drug purchase databases of Maccabi Healthcare Services. Time-dependent Cox regression models, adjusted for sex, age, and comorbidities were employed to calculate the adjusted hazard ratios (HRs) for the PD risk associated with different anti-diabetic drugs over time.

RESULTS

The study population comprised 86,229 T2DM patients, with 53.9 % males. The mean age at the first anti-diabetic drug purchase was 59.0 ± 11.0 and 62.0 ± 11.0 years for men and women respectively. Compared to metformin, several drug types were associated with a significantly lower PD risk: thiazolidinediones (HR = 0.91, 95 % CI:0.074-1.14); DPP4 inhibitors (HR = 0.60, 95 % CI:0.53-0.67); meglitinides (HR = 0.63, 95 % CI:0.53-0.74); GLP-1 agonists (HR = 0.54, 95 % CI:0.39-0.73); and SGLT2 inhibitors (HR = 0.15, 95 % CI:0.10-0.21).

CONCLUSIONS

Our results suggest a reduced risk of PD with certain anti-diabetic drugs, particularly SGLT2 inhibitors and GLP-1 agonists. Validation through extensive big-data studies is essential to confirm these results and to optimize PD prevention and management.

Glucagon-Like Peptide-1 Receptor Agonists and Risk of Parkinson's Disease in Patients with Type 2 Diabetes: A Population-Based Cohort Study

BACKGROUND

Previous studies have suggested that glucagon-like peptide-1 receptor agonists (GLP-1RAs) may have a disease-modifying effect in the development of Parkinson's disease (PD), but population studies yielded inconsistent results.

OBJECTIVE

The aim was to compare the risk of PD associated with GLP-1RAs compared to dipeptidyl peptidase 4 inhibitors (DPP4i) among older adults with type 2 diabetes (T2D).

METHODS

Using U.S. Medicare administrative data from 2016 to 2020, we conducted a population-based cohort study comparing the new use of GLP-1RA with the new use of DPP4i among adults aged ≥66 years with T2D. The primary endpoint was a new diagnosis of PD. A stabilized inverse probability of treatment weighting (sIPTW)-adjusted Cox proportional hazards regression model was employed to estimate the hazard ratio (HR) and 95% confidence intervals (CI) for PD between GLP-1RA and DPP4i users.

RESULTS

This study included 89,074 Medicare beneficiaries who initiated either GLP-1RA (n = 30,091) or DPP4i (n = 58,983). The crude incidence rate of PD was lower among GLP-1RA users than DPP4i users (2.85 vs. 3.92 patients per 1000 person-years). An sIPTW-adjusted Cox model showed that GLP-1RA users were associated with a 23% lower risk of PD than DPP4i users (HR, 0.77; 95% CI, 0.63-0.95). Our findings were largely consistent across different subgroup analyses such as sex, race, and molecular structure of GLP-1RA.

CONCLUSION

Among Medicare beneficiaries with T2D, the new use of GLP-1RAs was significantly associated with a decreased risk of PD compared to the new use of DPP4i. © 2024 International Parkinson and Movement Disorder Society.

Statin use and the risk of Parkinson's disease in persons with diabetes: A nested case-control study

AIMS

Persons with diabetes may have an elevated risk of Parkinson's disease (PD). Statin use could also modify the progression of PD. The aim was to study whether there is an association between statin exposure and risk of PD in persons with diabetes.

METHODS

A nationwide, nested case-control study restricted to people with diabetes was performed as part of nationwide register-based Finnish study on PD (FINPARK). Study included 2017 PD cases and their 7934 matched controls without PD. Persons with PD were diagnosed between 1999 and 2015, and statin use (1995-2015) was determined from Prescription Register. In the main analysis, exposure at least 3 years before outcome was considered. Cumulative exposure was categorized into tertiles, and associations were analysed with conditional logistic regression (adjusted with comorbidities and number of antidiabetic drugs).

RESULTS

Prevalence of statin use was similar in PD cases and controls, with 54.2% of cases and 54.4% controls exposed before the lag time (adjusted odds ratio [aOR] = 1.03; 95% confidence interval [CI]: 0.92-1.15). Those in the highest cumulative statin exposure tertile had higher risk of PD than statin nonusers (aOR = 1.22; 95% CI: 1.04-1.43), or those in the lowest cumulative statin exposure tertile (aOR = 1.29; 95% CI: 1.07-1.57).

CONCLUSION

Our nationwide study that controlled for diabetes duration and used 3-year lag between exposure and outcome to account for reverse causality does not provide support for the hypothesis that statin use decreases the risk of PD.

Frailty and Parkinson's disease: the role of diabetes mellitus

Parkinson's disease (PD) is a chronic neurodegenerative disease associated with a progressive loss of dopaminergic neurons, clinically characterized by motor and non-motor signs. Frailty is a clinical condition of increased vulnerability and negative health outcomes due to the loss of multiple physiological reserves. Chronic hyperglycemia and insulin resistance, which characterize diabetes mellitus (DM), have been reported to alter dopaminergic activity, increase the risk of PD, and influence the development of frailty. Even though diabetes may facilitate the development of frailty in patients with PD, this relationship is not established and a revision of the current knowledge is necessary. Furthermore, the synergy between DM, PD, and frailty may drive clinical complexity, worse outcomes, and under-representation of these populations in the research. In this review, we aimed to discuss the role of diabetes in the development of frailty among patients with PD. We summarized the clinical characteristics and outcomes of patients with concomitant DM, PD, and frailty. Finally, interventions to prevent frailty in this population are discussed.

Cross-Regional Data Initiative for the Assessment and Development of Treatment for Neurological and Mental Disorders

Purpose

To describe and categorize detailed components of databases in the Neurological and Mental Health Global Epidemiology Network (NeuroGEN).

Methods

An online 132-item questionnaire was sent to key researchers and data custodians of NeuroGEN in North America, Europe, Asia and Oceania. From the responses, we assessed data characteristics including population coverage, data follow-up, clinical information, validity of diagnoses, medication use and data latency. We also evaluated the possibility of conversion into a common data model (CDM) to implement a federated network approach. Moreover, we used radar charts to visualize the data capacity assessments, based on different perspectives.

Results

The results indicated that the 15 databases covered approximately 320 million individuals, included in 7 nationwide claims databases from Australia, Finland, South Korea, Taiwan and the US, 6 population-based electronic health record databases from Hong Kong, Scotland, Taiwan, the Netherlands and the UK, and 2 biomedical databases from Taiwan and the UK.

Conclusion

The 15 databases showed good potential for a federated network approach using a common data model. Our study provided publicly accessible information on these databases for those seeking to employ real-world data to facilitate current assessment and future development of treatments for neurological and mental disorders.

Use of dipeptidyl peptidase-4 inhibitors was associated with a lower risk of Parkinson's disease in diabetic patients

Diabetes mellitus is a risk factor for Parkinson's disease (PD). While animal studies have supported the benefits of incretin-based therapies, including dipeptidyl peptidase-4 (DPP4) inhibitors, in PD, clinical research has yielded controversial results. This cohort study aimed to assess the relationship between PD incidence and the utilization of DPP4 inhibitor in diabetic patients. Using Taiwan's National Health Insurance Research Database from 2009 to 2018, diabetic patients receiving metformin plus at least one second-line oral antidiabetic (OAD) were enrolled. The patients were categorized as DPP4 inhibitor users and non-users. Propensity score matching was employed to establish a 1:1 ratio between DPP4 inhibitor users and non-users. Among the 205,910 patients enrolled, 149 were diagnosed with PD during follow-up. The incidence rate was 0.29 per 1000 person-years for DPP4 inhibitor users and 0.55 per 1000 person-years for the non-users. DPP4 inhibitor users exhibited a significantly lower risk of PD (adjusted hazard ratio, 0.51; 95% CI 0.39-0.68). Among DPP4 inhibitor users, vildagliptin showed the strongest correlation with a reduction in the risk of PD. This study demonstrates that the use of DPP4 inhibitors along with metformin in diabetic patients is associated with a lower risk of PD compared to those using other OADs.

Do oral antidiabetic medications alter the risk of Parkinson's disease? An updated systematic review and meta-analysis

BACKGROUND

Diabetes mellitus is a known risk factor for Parkinson's disease (PD), but does this risk vary with antidiabetic medications is still unclear. This meta-analysis aims to compile evidence from the literature to assess the risk of idiopathic PD with various oral antidiabetic medications.

METHODS

Databases PubMed, CENTRAL, Scopus, Web of Science, and Embase were searched till 5th April 2023. Adjusted outcomes were pooled to generate a hazard ratio (HR) on the risk of PD with different antidiabetic medications.

RESULTS

Fifteen studies with 2,910,405 diabetic patients were eligible. Pooled analysis failed to show any significant difference in the risk of PD among users of metformin (HR: 1.05 95% CI: 0.91, 1.22 I2 = 81%), glitazones (HR: 0.84 95% CI: 0.68, 1.05 I2 = 91%), glucagon-like peptide-1 agonists (HR: 0.63 95% CI: 0.26, 1.55 I2 = 33%), and sulfonylureas (HR: 1.13 95% CI: 0.96, 1.32 I2 = 76%). However, a meta-analysis of four studies showed that dipeptidyl peptidase-4 inhibitor use was associated with reduced risk of PD in diabetics (HR: 0.69 95% CI: 0.56, 0.86 I2 = 46%). Insufficient data was available on sodium-glucose cotransporter-2 inhibitors, α-glucosidase inhibitors, and glinides.

CONCLUSIONS

Limited retrospective evidence indicates that DPP4i may reduce the risk of idiopathic PD in diabetics. Metformin, sulfonylureas, glucagon-like peptide-1 agonists, and glitazones were not associated with any change in the risk of PD. Further studies taking into confounding factors and using a common comparator group are needed to strengthen present evidence.

Dopamine in the Regulation of Glucose Homeostasis, Pathogenesis of Type 2 Diabetes, and Chronic Conditions of Impaired Dopamine Activity/Metabolism: Implication for Pathophysiological and Therapeutic Purposes

Dopamine regulates several functions, such as voluntary movements, spatial memory, motivation, sleep, arousal, feeding, immune function, maternal behaviors, and lactation. Less clear is the role of dopamine in the pathophysiology of type 2 diabetes mellitus (T2D) and chronic complications and conditions frequently associated with it. This review summarizes recent evidence on the role of dopamine in regulating insular metabolism and activity, the pathophysiology of traditional chronic complications associated with T2D, the pathophysiological interconnection between T2D and chronic neurological and psychiatric disorders characterized by impaired dopamine activity/metabolism, and therapeutic implications. Reinforcing dopamine signaling is therapeutic in T2D, especially in patients with dopamine-related disorders, such as Parkinson's and Huntington's diseases, addictions, and attention-deficit/hyperactivity disorder. On the other hand, although specific trials are probably needed, certain medications approved for T2D (e.g., metformin, pioglitazone, incretin-based therapy, and gliflozins) may have a therapeutic role in such dopamine-related disorders due to anti-inflammatory and anti-oxidative effects, improvement in insulin signaling, neuroinflammation, mitochondrial dysfunction, autophagy, and apoptosis, restoration of striatal dopamine synthesis, and modulation of dopamine signaling associated with reward and hedonic eating. Last, targeting dopamine metabolism could have the potential for diagnostic and therapeutic purposes in chronic diabetes-related complications, such as diabetic retinopathy.

Identification of Drugs Associated with Lower Risk of Parkinson's Disease Using a Systematic Screening Approach in a Nationwide Nested Case-Control Study

Introduction

Drugs for other indications may be repurposable as disease-modifying drugs for Parkinson's disease (PD). A systematic hypothesis-free approach can enable identification of candidates for repurposing. We applied a hypothesis-free systematic approach to identify drugs associated with lower risk of PD to discover candidates with potential for repurposing as disease-modifying drugs for PD and to illustrate challenges in observational studies that simultaneously investigate multiple repurposing candidates.

Methods

The Finnish Parkinson's disease study (FINPARK), a nationwide nested case-control study, was randomized to screening (10,183 cases, 67,849 controls) and replication (10,184 cases, 67,754 controls) samples, including cases diagnosed in 1998-2015. After screening all univariable associations of register-derived exposure to individual-drug, group- and subgroup level since 1995 (exposure ≥3 years before outcome, threshold P = 0.1), different exposure periods were used in confounder-adjusted replication analyses.

Results

In screening stage, the group-level (antipsoriatics and antigout preparations) and subgroup-level (cicatrizants, topical antipsoriatics, antigout preparations and mydriatics and cycloplegics) associations were mainly due to individual drugs. Seven other drugs (eg methotrexate, drugs for chronic obstructive pulmonary disease, COPD and/or asthma) were associated with lower risk. Associations of antigout preparations and antipsoriatics were replicated. COPD/asthma drugs, methotrexate and diabetes drugs were studied in separate, indication-restricted designs.

Discussion

The results reflect the known risk factors and the implied role of the immune system in PD pathogenesis and spurious associations. They underline the importance of controlling for confounding by indication, which is challenging to apply to systematic screening.

Thiazolidinedione use and risk of Parkinson's disease in patients with type 2 diabetes mellitus

The health burden of Parkinson's disease (PD) and diabetes increases rapidly in China. However, no population-based study of the association between glucose lowering agents and PD incidence has been conducted in mainland Chinese population. Preclinical studies indicate that thiazolidinediones (TZDs) have neuroprotective effects against PD through stimulating peroxisome proliferator-activated receptor gamma. Nevertheless, debate remains in human studies. We assembled a retrospective cohort of type 2 diabetes mellitus (T2DM) patients who were new users of TZDs or alpha glucosidase inhibitors (AGIs) using the Yinzhou Regional Health Care Database. A Cox model with inverse probability of treatment weighting (IPTW) was applied to estimate the hazard ratio (HR) of PD incidence associated with the use of TZDs compared with AGIs. The final cohort included 12,704 new users of TZDs and 49,696 new users of AGIs. The incidence of PD was 135 per 100,000 person-years in TZD users and 203 per 100,000 person-years in the AGI group. An inverse association between use of TZDs and incidence of PD, with a HR of 0.74 (95% confidence interval, 0.59-0.92), was observed after adjusting for potential confounding using IPTW. The results of various subgroup analyses and sensitivity analyses were consistent with the findings of the primary analysis. Our results indicated that the use of TZD is associated with a decreased risk of PD incidence in a mainland Chinese population with T2DM. Given the heavy disease burden of PD and diabetes in China, these findings could provide some evidence for developing effective prevention and control measures to reduce the future incidence of PD in China.