Association of leptin with orthostatic blood pressure changes in Parkinson's disease

Orthostatic hypotension is involved in cognitive impairment in patients with multiple system atrophy: a multi-center cohort study in China

BACKGROUND

Orthostatic hypotension (OH) is a common symptom of multiple system atrophy (MSA), however, its role in cognitive impairment and the mechanism in these patients remains unclear. This study aims to assess the role of OH on cognitive impairment in MSA patients, as well as to explore the potential association of cerebral autoregulation (CA) and white matter hyperintensities (WMHs) on cognitive impairment.

METHODS

This observational study was conducted in three general hospitals in China from January 2018 to October 2023, with patients at one center followed up for 6 months after enrollment. The primary outcomes included cognitive function assessed using the Mini-Mental State Examination (MMSE) and Montreal cognitive assessment (MoCA). Secondary outcomes included the results of the Head-up tilt test, scores for CA and the extent of WMHs.

RESULTS

The 132 MSA patients included 72 men (54.54%) with a mean age of 61.16 (7.80) years. Among them, 80 patients (60.61%) had orthostatic hypotension, and 48 patients (36.36%) had cognitive impairment. OH plays an important role in cognitive impairment in MSA patients (OR = 0.328,95% CI 0.135-0.797, P = 0.014). Cognitive impairment was associated with impaired CA (OR = 0.088,95% CI 0.012-0.657, P = 0.018) and severe WMHs (OR = 0.030,95% CI 0.002-0.423, P = 0.009), particularly in the presence of OH.

CONCLUSION

OH is associated with cognitive impairment in MSA patients, and cognitive decline is linked to impaired CA and increased WMHs. Future studies are needed to explore the mechanisms underlying cognitive impairment in MSA patients.

Identification of Potential miRNA-mRNA Regulatory Network Contributing to Parkinson's Disease

Parkinson's disease (PD) is a common neurodegenerative disease, and the mechanism underlying PD pathogenesis is not completely understood. Increasing evidence indicates that microRNAs (miRNAs) play a critical regulatory role in the pathogenesis of PD. This study aimed to explore the miRNA-mRNA regulatory network for PD. The differentially expressed miRNAs (DEmis) and genes (DEGs) between PD patients and healthy donors were screened from the miRNA dataset GSE16658 and mRNA dataset GSE100054 downloaded from the Gene Expression Omnibus (GEO) database. Target genes of the DEmis were selected when they were predicted by three or four online databases and overlapped with DEGs from GSE100054. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were then conducted by Database for Annotation, Visualization and Integrated Discovery (DAVID) and Metascape analytic tools. The correlation between the screened genes and PD was evaluated with the online tool Comparative Toxicogenomics Database (CTD), and protein-protein interaction (PPI) networks were built by the STRING platform. We further investigated the expression of genes in the miRNA-mRNA regulatory network in blood samples collected from PD patients and healthy donors via qRT-PCR. We identified 1505 upregulated and 1302 downregulated DEGs, and 77 upregulated and 112 downregulated DEmis were preliminarily screened from the GEO database. Further functional enrichment analysis identified 10 PD-related hub genes, including RAC1, IRS2, LEPR, PPARGC1A, CAMKK2, RAB10, RAB13, RAB27B, RAB11A, and JAK2, which were mainly involved in Rab protein signaling transduction, AMPK signaling pathway, and signaling by Leptin. A miRNA-mRNA regulatory network was then constructed with 10 hub genes, and their interacting miRNAs overlapped with DEmis, including miR-30e-5p, miR-142-3p, miR-101-3p, miR-32-3p, miR-508-5p, miR-642a-5p, miR-19a-3p, and miR-21-5p. Analysis of clinical samples verified significant upregulation of LEPR and downregulation of miR-101-3p and miR-30e-5p in PD patients as compared with healthy donors. Thus, the miRNA-mRNA regulatory network was initially constructed and has the potential to provide novel insights into the pathogenesis and treatment of PD.

Leptin: an entry point for the treatment of peripheral tissue fibrosis and related diseases

Leptin is a small peptide mainly secreted by adipocyte, which acts on the central nervous system of the hypothalamus to regulate the body's energy balance by inhibiting food intake, it also can directly act on specific cells through leptin receptors (for example, ObRa, which exists in the blood-brain barrier or kidneys), thereby affect cell metabolism. Excessive deposition of extracellular matrix (ECM) causes damage to normal tissues or destruction of organ structure, which will eventually lead to tissue or organ fibrosis. The sustainable development of fibrosis can lead to structural damage and functional decline of organs, and even exhaustion, which seriously threatens human health and life. In recent years, studies have found that leptin directly alleviates the fibrosis process of various tissues and organs in mammals. Therefore, we speculate that leptin may become a significant treatment for fibrosis of various tissues and organs in the future. So, the main purpose of this review is to explore the specific mechanism of leptin in the process of fibrosis in multiple tissues and organs, and to provide a theoretical basis for the treatment of various tissues and organs fibrosis and related diseases caused by it, which is of great significance in the future.

The Interactions between Adipose Tissue Secretions and Parkinson's disease; The Role of Leptin

Leptin is a hormone that regulates appetite by acting on receptors in the hypothalamus, where it modifies food intake to maintain equilibrium with the body energy resources. Leptin and its receptors are widely distributed in the central nervous system, suggesting that they may give neuronal survival signals. The potential of leptin to decrease/increase neuronal damage and neuronal plasticity in Parkinson's diseases (PD) is the subject of this review, which outlines our current knowledge of how leptin acts in the brain. Although leptin-mediated neuroprotective signaling results in neuronal death prevention, it can affect neuroinflammatory cascades and also neuronal plasticity which contribute to PD pathology. Other neuroprotective molecules, such as insulin and erythropoietin, share leptin-related signaling cascades, and therefore constitute a component of the neurotrophic effects mediated by endogenous hormones. With the evidence that leptin dysregulation causes increased neuronal vulnerability to damage in PD, using leptin as a target for therapeutic modification is an appealing and realistic option.

The Role of Gut Microbiota in the Progression of Parkinson's Disease and the Mechanism of Intervention by Traditional Chinese Medicine

Parkinson's disease (PD) is a common degenerative disease of the nervous system that seriously affects the quality of life of the patients. The pathogenesis of PD is not yet fully clear. Previous studies have confirmed that patients with PD exhibit obvious gut microbiota imbalance, while intervention of PD by regulating the gut microbiota has become an important approach to the prevention and treatment of this disease. Traditional Chinese medicine (TCM) has been shown to be safe and effective in treating PD. It has the advantages of affecting multiple targets. Studies have shown TCM can regulate gut microbiota. However, the specific mechanism of action is still unclear. Therefore, this article will mainly discuss the association of the alteration of the gut microbiota and the incidence of PD, the advantages of TCM in treating PD, and the mechanism of regulating gut microbiota by TCM to treat PD. It will clarify the target and mechanism of TCM treating PD by acting gut microbiota and provided a novel methodology for the prevention and treatment of PD.

Potential Crosstalk Between Parkinson's Disease and Energy Metabolism

Parkinson's disease (PD) is characterized by the accumulation of alpha-synuclein (α-Syn) in the substantia nigra (SN) and the degeneration of nigrostriatal dopaminergic (DAergic) neurons. Some studies have reported that the pathology of PD originates from the gastrointestinal (GI) tract, which also serves as an energy portal, and develops upward along the neural pathway to the central nervous system (CNS), including the dorsal motor nucleus of vagus (DMV), SN, and hypothalamus, which are also involved in energy metabolism control. Therefore, we discuss the alterations of nuclei that regulate energy metabolism in the development of PD. In addition, due to their anti-inflammatory, antiapoptotic and antioxidative roles, metabolism-related peptides are involved in the progression of PD. Furthermore, abnormal glucose and lipid metabolism are common in PD patients and exacerbate the pathological changes in PD. Therefore, in this review, we attempt to explain the correlation between PD and energy metabolism, which may provide possible strategies for PD treatment.

Sex differences in underweight and body mass index in Chinese early de novo patients with Parkinson's disease

OBJECTIVE

There have been studies investigating sex differences in clinical manifestation of Parkinson's disease (PD). However, sex differences in underweight and body mass index (BMI) in de novo PD patients lacked systematic study. We aimed to compare sex differences in clinical features and related factors of underweight and BMI in Chinese de novo PD patients.

MATERIALS AND METHODS

A total of 253 untreated PD inpatients and 218 controls were recruited from Ningbo. BMI, demographics, Montreal Cognitive Assessment (MoCA), supine and upright blood pressure, Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), homocysteine (HCY), uric acid, glycated hemoglobin, and lipid parameters were examined. Patients were assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) motor scores and Hoehn and Yahr (HY) Rating Scale.

RESULTS

Female patients had a significantly lower incidence of underweight and higher BMI than male patients, and there were sex differences in serum lipids, HCY levels, and depression severity. Binary regression analysis showed that only in male patients was underweight associated with the UPDRS motor score and lower ΔSBP and ΔDBP values (all p < .05). Further multiple regression analysis indicated, in addition to the correlations between BMI and ΔSBP and ΔDBP values in both sexes (all p < .001), BMI was also associated with MoCA and lower UPDRS motor scores in male patients and lower HAMD scores in female patients.

CONCLUSION

Our study suggests that there are significant sex differences in the prevalence of underweight, BMI, and factors associated with underweight and BMI among de novo PD patients.

Prevalence, risk factors, and clinical correlations of underweight in Chinese newly diagnosed and drug-naïve patients with Parkinson's disease

OBJECTIVE

Studies have shown that patients with Parkinson's disease (PD) will experience weight loss during the progression of the illness, which suggests an increased rate of underweight. However, few studies have addressed underweight in early de novo population. This study aimed to examine the prevalence, risk factors, and clinical correlations of underweight in Chinese newly diagnosed and drug-naïve patients with PD.

METHODS

A total of 245 inpatients with newly diagnosed PD and 213 age-, sex-, and education-matched healthy controls were enrolled in Ningbo. BMI, demographics, supine and upright blood pressure, Montreal Cognitive Assessment (MoCA), Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD) together with fasting blood glucose, low-density lipoprotein, total cholesterol, uric acid (UA), and homocysteine were collected in all subjects. Hoehn and Yahr (HY) rating and Unified Parkinson's Disease Rating Scale (UPDRS) motor scores were also measured in patients.

RESULTS

Overall, 35 (14.3%) patients were underweight and 14 (6.6%) controls were underweight. Binary regression analyses showed that low MoCA (p = 0.035), ΔSBP and ΔDBP values (both p < 0.001) were risk factors for underweight. Furthermore, correlation analysis indicated that BMI was associated with HY grade, UPDRS motor, HAMA, HAMD, MoCA, ΔSBP, ΔDBP, and UA values, stepwise multiple regression revealed significant correlations between BMI and ΔSBP (p < 0.001), ΔDBP (p = 0.001), MoCA (p = 0.002), UPDRS motor (p = 0.005), and HAMD scores (p = 0.014).

CONCLUSIONS

Our study showed that the prevalence of underweight was significantly higher in Chinese newly diagnosed and drug-naïve patients with PD than in the healthy population, and several clinical variables were risk factors for underweight.

Difference in cardiovascular response during orthostatic stress in Parkinson's disease and multiple system atrophy

Although orthostatic hypotension is more prominent in multiple system atrophy (MSA) than in Parkinson's disease (PD), there is no study comparing the degree of decrease in total peripheral resistance and cardiac response during orthostatic stress between both diseases. In this study, we examined whether there is a difference in cardiovascular response between MSA and PD. We examined the results of the head-up tilt test in 68 patients with MSA, 28 patients with cardiac non-denervated PD, and 70 patients with cardiac denervated PD whose total peripheral resistance after 60° tilting was lower than the value at 0°. Differences in cardiac output and blood pressure changes were compared against the decrease in total peripheral resistance. There was no difference in the degree of decrease in total peripheral resistance among the three groups. However, the slope of the regression line revealed that the increase in cardiac output against the change in total peripheral resistance was significantly lower in the MSA group than in the cardiac non-denervated and denervated PD groups, and that the decrease in systolic blood pressure against the change in total peripheral resistance was significantly greater in the MSA group than in the cardiac non-denervated and denervated PD groups. In MSA, the cardiac response during orthostatic stress is lower than that in PD, possibly underlying the fact that orthostatic hypotension is more prominent in MSA than in PD.

Association of orthostatic blood pressure with the symptoms of orthostatic hypotension and cognitive impairment in patients with multiple system atrophy

The degree and frequency of orthostatic hypotension (OH) are high in patients with multiple system atrophy (MSA); however, the association of orthostatic blood pressure (BP) with the symptoms of OH and cognitive impairment in these patients remains unclear. The aim of this study was to clarify whether absolute BP and/or changes in BP during standing are related to OH symptoms and cognitive impairment in patients with MSA. Thirty-two patients with MSA were examined using the head-up tilt and cognitive function tests. OH symptoms were evaluated using a patient-reported scale. The results were compared with those for 15 age- and sex-matched healthy controls. Seventeen of the 32 (53.1%) patients had OH, with eight of them exhibiting OH symptoms, which were related to the absolute BP value at 60° tilt. However, OH symptoms were not related to the degree of decrease in BP during the tilt test, and they were frequently observed in patients with a mean BP of <80 mmHg at 60° tilt (sensitivity, 67%; specificity, 91%). Cognitive dysfunction assessed by the Mini-Mental State Examination (MMSE; ≤ 26) was also associated with a low mean BP at 60° tilt (odds ratio, 1.32; 95% confidence interval, 1.04-1.67; p = 0.02). The upright BP value is associated with OH symptoms and the MMSE score in patients with MSA. Thus, careful observation of OH symptoms can enable early management of BP and the detection of cognitive impairment in these patients.

Relationship between cardiac parasympathetic dysfunction and the anteroposterior diameter of the medulla oblongata in multiple system atrophy

PURPOSE

Neurodegeneration of the nucleus ambiguus and the dorsal vagal motor nucleus has been implicated in cardiac parasympathetic dysfunction in multiple system atrophy (MSA). The nucleus ambiguus and the dorsal vagal motor nucleus, which are located in the medulla oblongata (MO), control the autonomic-specifically, the parasympathetic-functions of the body. The aim of our study was to investigate the relationship between cardiac parasympathetic dysfunction and the anteroposterior diameter of the MO in MSA by quantitatively analyzing magnetic resonance imaging (MRI) outcome measures.

METHODS

We retrospectively assessed 40 consecutive patients with probable MSA and 25 age- and sex-matched controls. The anteroposterior diameter of the MO at two locations (MO diameter-A and -B) and the diameters of the midbrain and pons were measured by conventional MRI. A cardiac parasympathetic function score (CP-score) and cardiac sympathetic function score (CS-score) were generated by calculating the z-scores of multiple autonomic function tests. The relationship between the scores and the measured diameters of the brainstem was also investigated.

RESULTS

The CP-score and CS-score were significantly lower in the patients with MSA than in the controls (CP-score: 0.61 ± 0.75 vs. - 0.38 ± 0.52, p < 0.001; CS-score: 0.91 ± 1.06 vs. - 0.57 ± 1.07, p < 0.001). Also, in the patients with MSA, the CP-score was significantly correlated with MO diameter-A (r = 0.40, p = 0.010), and the CS-score was significantly correlated with the diameter of the midbrain (r = 0.33, p = 0.038).

CONCLUSION

The anteroposterior diameter of the MO is a potential imaging marker of parasympathetic dysfunction in MSA.

Impact of orthostatic hypotension on wheelchair use in patients with Parkinson's disease

Wheelchair use is an important indicator of disease progression in Parkinson's disease (PD). Here, we investigated whether orthostatic hypotension (OH) affects the time to wheelchair use. We examined 33 PD patients with OH and 95 without OH. Median time to start using a wheelchair calculated from the time of disease onset was significantly shorter in patients with OH than in those without OH (12.0 vs 19.0 years; p < 0.001). Thus, appropriate management of OH and motor function is necessary.

Widespread Cardiac and Vasomotor Autonomic Dysfunction in Non-Val30Met Hereditary Transthyretin Amyloidosis

Objective The autonomic functions of hereditary transthyretin (ATTRm) amyloidosis, traditionally referred to as familial amyloid polyneuropathy, have primarily been investigated in patients with Val30Met mutations, and information regarding non-Val30Met patients is scarce. The aim of this study was to systematically investigate the cardiac and peripheral vasomotor autonomic functions in non-Val30Met patients. Methods The coefficient of variation of R-R intervals (CVR-R), responses to the Valsalva manoeuvre, head-up tilt test results, noradrenaline infusion test results, and the (123) I-metaiodobenzylguanidine (MIBG) uptake on myocardial scintigraphy were assessed in five patients. The predominant manifestations were neuropathy in three patients (Val94Gly, Val71Ala, and Pro24Ser), cardiomyopathy in one (Thr60Ala), and oculoleptomeningeal involvement in one (Tyr114Cys). Results Although one patient with predominant cardiomyopathy did not manifest orthostatic hypotension during the head-up tilt test, the CVR-R, responses to the Valsalva manoeuvre, and myocardial MIBG uptake indicated the presence of cardiac sympathetic and parasympathetic dysfunction in all patients. The total peripheral resistance at 60° tilt did not increase from the baseline values in any of the examined patients. An infusion of low-dose noradrenaline induced an increase in the systolic blood pressure, except in one patient with mild neuropathy. Conclusion Cardiac and peripheral vasomotor autonomic dysfunctions were prevalent in non-Val30Met patients, irrespective of their phenotype, suggesting a common pathology of autonomic involvement. However, the vasoconstrictor function was preserved, even in a patient with advanced neuropathy.

Cardiac and peripheral vasomotor autonomic functions in late-onset transthyretin Val30Met familial amyloid polyneuropathy

The objective of this study was to systematically investigate cardiac and peripheral vasomotor autonomic functions in late-onset transthyretin Val30Met familial amyloid polyneuropathy (FAP ATTR Val30Met) patients from non-endemic areas. The coefficient of variation of R-R intervals (CVR-R), responses to the Valsalva manoeuvre, head-up tilt test with impedance cardiography, noradrenaline infusion test, and (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy were assessed in eight patients. Although only four patients manifested orthostatic hypotension during the head-up tilt test, CVR-R, responses to the Valsalva manoeuvre, and myocardial MIBG uptake indicated a higher prevalence of cardiac sympathetic and parasympathetic dysfunction. Total peripheral resistance at 60° tilt did not increase from baseline values in five of six examined patients. An infusion of low-dose noradrenaline induced an increase in systolic blood pressure in all patients. The extent of the change in systolic blood pressure negatively correlated to that in total peripheral resistance (p < 0.05). Patients with poor vasoconstrictor responses to orthostatic stress tended to exhibit severe reduction of unmyelinated fibres in sural nerve biopsy specimens. In conclusion, both cardiac and peripheral vasomotor autonomic dysfunctions were prevalent in late-onset FAP ATTR Val30Met patients from non-endemic areas, even in those without orthostatic intolerance. However, vasoconstriction by alpha-adrenoceptor agonists was preserved even after denervation, carrying important implications for the management of orthostatic hypotension in FAP.

Lower body mass index is associated with orthostatic hypotension in Parkinson's disease

INTRODUCTION

Lower body mass index (BMI) is associated with orthostatic hypotension (OH) in the general population, especially in the elderly; however, no studies have addressed this issue in Parkinson's disease (PD).

METHODS

We investigated the results of the head-up tilt test and BMI of patients with PD, and evaluated whether BMI is related to orthostatic systolic blood pressure (SBP) change during the head-up tilt test. PD patients were divided into male and female groups, and further divided into middle-aged (age<65years) and elderly (age≥65years) subgroups in each sex.

RESULTS

OH was observed in 13 of 64 male and 12 of 75 female patients with PD. BMI was lower in patients with OH than in those without, in both men and women. In the elderly group, a significant correlation between BMI and orthostatic SBP change was found (men, r=0.47, p=0.006; women, r=0.43, p=0.005), and a BMI below mean-0.5 standard deviation increased OH odds (men: BMI<20.5; odds ratio, 6.79; 95% CI, 1.06-43.36; women: BMI<18.5; odds ratio, 5.11; 95% CI, 1.05-24.96).

CONCLUSION

Lower BMI is a predisposing factor of OH in elderly patients with PD.