Waist circumference and risk of Parkinson’s disease

The obesity pandemic and its impact on non-communicable disease burden

The rising prevalence of overweight and obesity across the globe is a major threat both to public health and economic development. This is mainly due to the link of obesity with the development and outcomes of non-communicable diseases (NCDs). NCDs are a leading cause of global death and disability, and reducing the burden of NCDs on patients and healthcare systems is of critical importance to improve public health. Obesity is projected to be the number one preventable risk factor for NCDs by 2035, and there is an urgent need to tackle the growing obesity rates in order to reduce NCD incidence and severity. Here, we review the current understanding of the impact of obesity on NCD burden in general, as well as the epidemiological and mechanistic relationship between obesity and some of the most common classes of NCDs. By literature review, we found that over 70% of NCDs have a documented association with obesity, highlighting the importance of a better understanding of the pathophysiologies underlying obesity/overweight as well as the interaction between obesity and NCDs in order to reduce global disease burden.

Exploring the link between estimated glucose disposal rate and Parkinson's disease: cross-sectional and mortality analysis of NHANES 2003-2016

Objectives

To investigate the association between estimated glucose disposal rate (eGDR), a surrogate marker of insulin resistance, and Parkinson's disease (PD) risk, and to examine the relationship between eGDR and all-cause mortality among PD patients.

Methods

Using data from the National Health and Nutrition Examination Survey (NHANES) 2003-2016, we conducted a cross-sectional study of 20,767 participants aged ≥40 years. eGDR was calculated using waist circumference, hypertension status, and HbA1c levels. PD cases were identified through anti-parkinsonian medication use. The association between eGDR and PD was examined using weighted logistic regression models with progressive adjustment for potential confounders. Survival analysis was performed in 255 PD patients to assess the relationship between eGDR and all-cause mortality.

Results

Among participants, 256 had PD (weighted prevalence: 1.23%). Higher eGDR was associated with lower odds of PD in crude analysis (OR: 0.906, 95% CI: 0.856-0.960, P < 0.001). After full adjustment, the highest eGDR tertile showed significantly lower odds of PD compared to the lowest tertile (OR: 0.574, 95% CI: 0.337-0.976, P = 0.040). Restricted cubic spline analysis revealed a significant M-shaped non-linear relationship between eGDR and PD risk (P for non-linearity < 0.001). In survival analysis, higher eGDR was associated with lower mortality risk (adjusted HR: 0.875, 95% CI: 0.775-0.987, P = 0.030), with an inverted U-shaped relationship observed (P for non-linearity = 0.0352).

Conclusion

Higher eGDR levels are associated with lower PD risk and better survival in PD patients, suggesting that insulin sensitivity might play a role in PD pathogenesis and progression. These findings highlight the potential importance of metabolic health in PD.

Epidemiologic Risk and Prevention and Interventions in Parkinson Disease: From a Nutrition-Based Perspective

Parkinson disease (PD) is a prevalent neurodegenerative disorder associated with aging. Current treatments for PD primarily focus on alleviating symptoms rather than altering the progression of the disease. The sporadic form of PD, which accounts for most cases, is thought to arise from a complex interaction between genetic predispositions and environmental factors. This review aimed to examine epidemiologic evidence regarding nutrition-related exposure factors and their associations with risk of developing PD. We proposed a tentative conclusion for each factor based on the available evidence. These associations may vary by gender and depend on dietary intake patterns and adherence. We also reviewed clinical trials on nutrition-related interventions for PD symptoms and progression. Future clinical trials may benefit from combining nutrition factors in intervention and testing within single-gender cohorts or subgroups defined by epidemiologic outcomes.

Value of blood biomarkers in the diagnosis of Parkinson's disease: a case-control study from Xinjiang

OBJECTIVE

Based on the data of Parkinson's disease patients in Xinjiang, China, to explore the clinical application value of blood biomarkers in diagnosing Parkinson's disease patients.

METHODS

The research subjects were patients with Parkinson's disease who were diagnosed and hospitalized at the Second Affiliated Hospital of Xinjiang Medical University between January 2021 and January 2023 and those who underwent health check-ups at the hospital, 243 and 249 cases were included, respectively, and those who underwent health check-ups were used as a healthy control group of the Parkinson's disease patient group.

RESULTS

Significant differences in age, systolic blood pressure, cystatin C, and uric acid distributions were found between healthy controls and Parkinson's patients (P < 0.05), and multivariate analysis showed that there was a correlation between body mass index, uric acid, and Parkinson's disease (P < 0.05), and that those who were overweight or obese, and those who had a low level of uric acid, had a greater probability of suffering from Parkinson's disease (B > 0). There were significant differences in gender, cystatin C, and urea between Parkinson's patients with a disease duration of < 5 years and those with a disease duration of ≥ 5 years (P < 0.05). In multivariate analysis, there was a correlation between gender and duration of Parkinson's disease (P < 0.05), and the duration of the disease was greater in male patients than in females.

CONCLUSION

Uric acid combined with body mass index is informative for early screening of Parkinson's disease.

Association of waist circumference with all cause mortality in Parkinson's disease

Despite many previous studies on the association between metabolic syndrome and Parkinson disease (PD), only few studies have investigated the association between waist circumference (WC) and PD. The aim of this study is to investigate the association between WC and all-cause mortality in patients with PD. Among the whole nationwide population data from Korea National Health Insurance Service, newly diagnosed PD (ICD-10 code G20 and rare intractable disease registration code V124), between 2008 and 2017, were selected. All-cause mortality was the primary outcome. Anthropometric data, including WC and body mass index (BMI) were obtained from health screening data. The Cox proportional hazards model was used to assess mortality risk according to WC. Among the 22,118 patients with PD, 9,179 (41.50%) died during the 10-year follow-up period. WCs < 70 cm among males and < 65 cm among females were significantly associated with increased mortality in patients with PD (HR = 1.19, 95% CI, 1.05-1.34). After adjusting for BMI, WC of ≥ 90 cm in males or ≥ 85 cm in females, which are the criteria for central obesity, increased mortality risk significantly (M 90-100, F 85-95: HR = 1.13, 95% CI, 1.05-1.22; M ≥ 100, F ≥ 95: HR = 1.50, 95% CI, 1.33-1.68). The association between WC and PD mortality revealed a J-shaped pattern among males and a U-shaped pattern among females. Central obesity is a significant risk factor for mortality in patients with PD after adjusting for BMI. Our results suggest that management of WC is crucial for PD patients and that BMI should be considered in the WC management plan for mortality in PD.

Novel Insights Into the Causal Effects and Shared Genetics Between Body Fat and Parkinson Disease

AIMS

Existing observational studies examining the effect of body fat on the risk of Parkinson disease (PD) have yielded inconsistent results. We aimed to investigate this causal relationship at the genetic level.

METHODS

We employed two-sample Mendelian randomization (TSMR) to investigate the causal effects of body fat on PD, with multiple sex-specific body fat measures being involved. We performed Bayesian colocalization analysis and cross-trait meta-analysis to reveal pleiotropic genomic loci shared between body mass index (BMI) and PD. Finally, we used the MAGMA tool to perform tissue enrichment analysis of the genome-wide association study hits of BMI.

RESULTS

TSMR analysis suggests that except waist circumference, higher measures of body fatness are associated with a decreased risk of PD, including BMI (OR: 0.83), body fat percentage (OR: 0.69), body fat mass (OR: 0.77), and hip circumference (OR: 0.83). The observed effects were slightly more pronounced in females than males. Colocalization analysis highlighted two colocalized regions (chromosome 3p25.3 and chromosome 17p12) shared by BMI and PD and pointed to some genes as possible players, including SRGAP3, MTMR14, and ADORA2B. Cross-trait meta-analysis successfully identified 10 novel genomic loci, involving genes of TOX3 and MAP4K4. Tissue enrichment analysis showed that BMI-associated genetic variants were enriched in multiple brain tissues.

CONCLUSIONS

We found that nonabdominal body fatness exerts a robust protective effect against PD. Our colocalization analysis and cross-trait meta-analysis identified pleiotropic genetic variation shared between BMI and PD, providing new clues for understanding the association between body fat and PD.

Association Between Body Composition Patterns, Cardiovascular Disease, and Risk of Neurodegenerative Disease in the UK Biobank

BACKGROUND AND OBJECTIVES

Accumulating evidence connects diverse components of body composition (e.g., fat, muscle, and bone) to neurodegenerative disease risk, yet their interplay remains underexplored. This study examines the associations between patterns of body composition and the risk of neurodegenerative diseases, exploring the mediating role of cardiovascular diseases (CVDs).

METHODS

This retrospective analysis used data from the UK Biobank, a prospective community-based cohort study. We included participants free of neurodegenerative diseases and with requisite body composition measurements at recruitment, who were followed from 5 years after recruitment until April 1, 2023, to identify incident neurodegenerative diseases. We assessed the associations between different components and major patterns of body composition (identified by principal component analysis) with the risk of neurodegenerative diseases, using multivariable Cox models. Analyses were stratified by disease susceptibility, indexed by polygenetic risk scores for Alzheimer and Parkinson diseases, APOE genotype, and family history of neurodegenerative diseases. Furthermore, we performed mediation analysis to estimate the contribution of CVDs to these associations. In addition, in a subcohort of 40,790 participants, we examined the relationship between body composition patterns and brain aging biomarkers (i.e., brain atrophy and cerebral small vessel disease).

RESULTS

Among 412,691 participants (mean age 56.0 years, 55.1% female), 8,224 new cases of neurodegenerative diseases were identified over an average follow-up of 9.1 years. Patterns identified as "fat-to-lean mass," "muscle strength," "bone density," and "leg-dominant fat distribution" were associated with a lower rate of neurodegenerative diseases (hazard ratio [HR] = 0.74-0.94) while "central obesity" and "arm-dominant fat distribution" patterns were associated with a higher rate (HR = 1.13-1.18). Stratification analysis yielded comparable risk estimates across different susceptibility groups. Notably, 10.7%-35.3% of the observed associations were mediated by CVDs, particularly cerebrovascular diseases. The subcohort analysis of brain aging biomarkers corroborated the findings for "central obesity," "muscle strength," and "arm-dominant fat distribution" patterns.

DISCUSSION

Our analyses demonstrated robust associations of body composition patterns featured by "central obesity," "muscle strength," and "arm-dominant fat distribution" with both neurodegenerative diseases and brain aging, which were partially mediated by CVDs. These findings underscore the potential of improving body composition and early CVD management in mitigating risk of neurodegenerative diseases.

Cholecystokinin (CCK): a neuromodulator with therapeutic potential in Alzheimer's and Parkinson's disease

Cholecystokinin (CCK) is a neuropeptide modulating digestion, glucose levels, neurotransmitters and memory. Recent studies suggest that CCK exhibits neuroprotective effects in Alzheimer's disease (AD) and Parkinson's disease (PD). Thus, we review the physiological function and therapeutic potential of CCK. The neuropeptide facilitates hippocampal glutamate release and gates GABAergic basket cell activity, which improves declarative memory acquisition, but inhibits consolidation. Cortical CCK alters recognition memory and enhances audio-visual processing. By stimulating CCK-1 receptors (CCK-1Rs), sulphated CCK-8 elicits dopamine release in the substantia nigra and striatum. In the mesolimbic pathway, CCK release is triggered by dopamine and terminates reward responses via CCK-2Rs. Importantly, activation of hippocampal and nigral CCK-2Rs is neuroprotective by evoking AMPK activation, expression of mitochondrial fusion modulators and autophagy. Other benefits include vagus nerve/CCK-1R-mediated expression of brain-derived neurotrophic factor, intestinal protection and suppression of inflammation. We also discuss caveats and the therapeutic combination of CCK with other peptide hormones.

Lifestyle Modulators of Neuroplasticity in Parkinson's Disease: Evidence in Human Neuroimaging Studies

Parkinson's disease (PD) is a neurodegenerative disease characterized by both motor and non-motor symptoms. A progressive neuronal loss and the consequent clinical impairment lead to deleterious effects on daily living and quality of life. Despite effective symptomatic therapeutic approaches, no disease-modifying therapies are currently available. Emerging evidence suggests that adopting a healthy lifestyle can improve the quality of life of PD patients. In addition, modulating lifestyle factors can positively affect the microstructural and macrostructural brain levels, corresponding to clinical improvement. Neuroimaging studies may help to identify the mechanisms through which physical exercise, dietary changes, cognitive enrichment, and exposure to substances modulate neuroprotection. All these factors have been associated with a modified risk of developing PD, with attenuation or exacerbation of motor and non-motor symptomatology, and possibly with structural and molecular changes. In the present work, we review the current knowledge on how lifestyle factors influence PD development and progression and the neuroimaging evidence for the brain structural, functional, and molecular changes induced by the adoption of positive or negative lifestyle behaviours.

Western diet-induced obesity results in brain mitochondrial dysfunction in female Ossabaw swine

Diet-induced obesity is implicated in the development of a variety of neurodegenerative disorders. Concurrently, the loss of mitochondrial Complex I protein or function is emerging as a key phenotype across an array of neurodegenerative disorders. Therefore, the objective of this study was to determine if Western diet (WD) feeding in swine [carbohydrate = 40.8% kCal (17.8% of total calories from high fructose corn syrup), protein = 16.2% kcal, fat = 42.9% kCal, and 2% cholesterol] would result in Complex I syndrome pathology. To characterize the effects of WD-induced obesity on brain mitochondria in swine, high resolution respirometry measurements from isolated brain mitochondria, oxidative phosphorylation Complex expression, and indices of oxidative stress and mitochondrial biogenesis were assessed in female Ossabaw swine fed a WD for 6-months. In line with Complex I syndrome, WD feeding severely reduced State 3 Complex I, State 3 Complex I and II, and uncoupled mitochondrial respiration in the hippocampus and prefrontal cortex (PFC). State 3 Complex I mitochondrial respiration in the PFC inversely correlated with serum total cholesterol. WD feeding also significantly reduced protein expression of oxidative phosphorylation Complexes I-V in the PFC. WD feeding significantly increased markers of antioxidant defense and mitochondrial biogenesis in the hippocampi and PFC. These data suggest WD-induced obesity may contribute to Complex I syndrome pathology by increasing oxidative stress, decreasing oxidative phosphorylation Complex protein expression, and reducing brain mitochondrial respiration. Furthermore, these findings provide mechanistic insight into the clinical link between obesity and mitochondrial Complex I related neurodegenerative disorders.

Butyrate Improves Neuroinflammation and Mitochondrial Impairment in Cerebral Cortex and Synaptic Fraction in an Animal Model of Diet-Induced Obesity

Neurodegenerative diseases (NDDs) are characterized by cognitive impairment and behavioural abnormalities. The incidence of NDDs in recent years has increased globally and the pathological mechanism is not fully understood. To date, plentiful evidence has showed that metabolic alterations associated with obesity and related issues such as neuroinflammation, oxidative stress and mitochondrial dysfunction may represent an important risk factor, linking obesity and NDDs. Numerous studies have indicated a correlation between diet and brain activities. In this context, a key role is played by mitochondria located in the synaptic fraction; indeed, it has been shown that high-fat diets cause their dysfunction, affecting synaptic plasticity. In this scenario, the use of natural molecules that improve brain mitochondrial function represents an important therapeutic approach to treat NDDs. Recently, it was demonstrated that butyrate, a short-chain fatty acid is capable of counteracting obesity in an animal model, modulating mitochondrial function. The aim of this study has been to evaluate the effects of butyrate on neuroinflammatory state, oxidative stress and mitochondrial dysfunction in the brain cortex and in the synaptic fraction of a mouse model of diet-induced obesity. Our data have shown that butyrate partially reverts neuroinflammation and oxidative stress in the brain cortex and synaptic area, improving mitochondrial function and efficiency.

Glucagon-like peptide-1 (GLP-1) receptor agonists and neuroinflammation: Implications for neurodegenerative disease treatment

Chronic, excessive neuroinflammation is a key feature of neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). However, neuroinflammatory pathways have yet to be effectively targeted in clinical treatments for such diseases. Interestingly, increased inflammation and neurodegenerative disease risk have been associated with type 2 diabetes mellitus (T2DM) and insulin resistance (IR), suggesting that treatments that mitigate T2DM pathology may be successful in treating neuroinflammatory and neurodegenerative pathology as well. Glucagon-like peptide-1 (GLP-1) is an incretin hormone that promotes healthy insulin signaling, regulates blood sugar levels, and suppresses appetite. Consequently, numerous GLP-1 receptor (GLP-1R) stimulating drugs have been developed and approved by the US Food and Drug Administration (FDA) and related global regulatory authorities for the treatment of T2DM. Furthermore, GLP-1R stimulating drugs have been associated with anti-inflammatory, neurotrophic, and neuroprotective properties in neurodegenerative disorder preclinical models, and hence hold promise for repurposing as a treatment for neurodegenerative diseases. In this review, we discuss incretin signaling, neuroinflammatory pathways, and the intersections between neuroinflammation, brain IR, and neurodegenerative diseases, with a focus on AD and PD. We additionally overview current FDA-approved incretin receptor stimulating drugs and agents in development, including unimolecular single, dual, and triple receptor agonists, and highlight those in clinical trials for neurodegenerative disease treatment. We propose that repurposing already-approved GLP-1R agonists for the treatment of neurodegenerative diseases may be a safe, efficacious, and cost-effective strategy for ameliorating AD and PD pathology by quelling neuroinflammation.