The impact of Apolipoprotein E alleles on cognitive performance in patients with Parkinson's disease

Apolipoprotein E (ApoE) is a vital component of several lipoproteins and plays a major role in lipid metabolism. APOE gene comprises of three alleles determined by two single nucleotide polymorphisms (rs429358 and rs7412) resulting in the protein isoforms, among which ApoE4 is a confirmed risk factor for Alzheimer's Disease. However, the impact of APOE genotypes on Parkinson's Disease Dementia (PDD) is still inconclusive. The PDD diagnostic criteria are very inconsistent, and could be complemented with genetic factors. Our study covers a total of 237 patients diagnosed with Parkinson's Disease (PD) according to UK PD Brain Bank criteria, who were classified as subjects with (PDD, n equals 73) and without (nPDD, n equals 164) dementia, using neuropsychological assessment tests. TaqMan real-time PCR assays were used to determine APOE allele. No statistically significant differences in APOE alleles frequencies between nPDD and PDD patients have been observed. The study results revealed that the APOE polymorphism is not associated with cognitive status in PD patients

Effects of common functional MMP12 gene polymorphisms on PD in a Polish population

The present study investigated associations of two functional MMP12 polymorphisms with PD risk and cognitive impairment in PD. A total of 478 study subjects (241 PD and 237 age and sex matched controls) were included in the study. UPDRS score, Hoehn–Yahr staging and Schwab–England scale were used to assess motor abilities and activity during daily life. All patients were classified into groups with dementia (PDD, n=72) and without dementia (nPDD, n=159) based on the neuropsychological assessment. The two most common functional single nucleotide polymorphisms (SNPs) in MMP12 gene were determined using TaqMan real-time PCR assays. Frequencies of evaluated MMP12 rs2276109 alleles and genotypes were similar in PD and the controls, whereas rs652438G allele genotypes were significantly more frequent among healthy individuals (p=0.013, OR 0.47 (0.26–0.85). The rs2276109 and rs652438 allele and genotype frequencies were not associated with dementia in PD patients. The current results suggest that MMP12 rs652438 but not MMP12 rs2276109 may affect the risk for PD, as the minor G allele genotypes might be a protective factor

Cardiovascular dysautonomia and cognition in Parkinson’s Disease — a possible relationship

Dementia in advanced Parkinson’s Disease (PD) is a fatal milestone resulting in reduced life expectancy and nursing home placement. Cognitive impairment and cardiovascular dysautonomia are common and debilitating non-motor symptoms that frequently coexist in PD since the early stages and progress in subsequent years.In particular, blood pressure (BP) abnormalities, including orthostatic hypotension (OH), supine hypertension (SH) and the loss of nocturnal BP fall (non-dipping) in PD have been associated with cognitive deterioration. They usually have multifactorial aetiology, including neuronal (central and peripheral) mechanisms and concomitant intake of medications. BP abnormalities can influence cognition in many ways, including repeated cerebral hypoperfusion leading to cerebral ischaemic lesions, higher burden of white matter hyperintensities, and possible impact on neurodegenerative process in PD. They are often asymptomatic and remain unrecognised, hence 24-hour ambulatory BP monitoring is recommended in patients with clinical symptoms of dysautonomia. Management is challenging and should address the multifactorial nature of BP disturbances. The aim of this review was to present the state of current knowledge regarding the possible relationship between cardiovascular dysautonomiaand cognition in PD, its diagnosis and treatment

Arterial Blood Pressure Variability and Other Vascular Factors Contribution to the Cognitive Decline in Parkinson’s Disease

Dementia is one of the most disabling non-motor symptoms in Parkinson’s disease (PD). Unlike in Alzheimer’s disease, the vascular pathology in PD is less documented. Due to the uncertain role of commonly investigated metabolic or vascular factors, e.g., hypertension or diabetes, other factors corresponding to PD dementia have been proposed. Associated dysautonomia and dopaminergic treatment seem to have an impact on diurnal blood pressure (BP) variability, which may presumably contribute to white matter hyperintensities (WMH) development and cognitive decline. We aim to review possible vascular and metabolic factors: Renin-angiotensin-aldosterone system, vascular endothelial growth factor (VEGF), hyperhomocysteinemia (HHcy), as well as the dopaminergic treatment, in the etiopathogenesis of PD dementia. Additionally, we focus on the role of polymorphisms within the genes for catechol-O-methyltransferase (COMT), apolipoprotein E (APOE), vascular endothelial growth factor (VEGF), and for renin-angiotensin-aldosterone system components, and their contribution to cognitive decline in PD. Determining vascular risk factors and their contribution to the cognitive impairment in PD may result in screening, as well as preventive measures

Pharmacokinetics of levodopa and 3-O-methyldopa in parkinsonian patients treated with levodopa and ropinirole and in patients with motor complications

Parkinson’s disease (PD) is a progressive, neurodegenerative disorder primarily affecting dopaminergic neuronal systems, with impaired motor function as a consequence. The most effective treatment for PD remains the administration of oral levodopa (LD). Long-term LD treatment is frequently associated with motor fluctuations and dyskinesias, which exert a serious impact on a patient’s quality of life. The aim of our study was to determine the pharmacokinetics of LD: used as monotherapy or in combination with ropinirole, in patients with advanced PD. Furthermore, an effect of ropinirole on the pharmacokinetics of 3-OMD (a major LD metabolite) was assessed. We also investigated the correlation between the pharmacokinetic parameters of LD and 3-OMD and the occurrence of motor complications. Twenty-seven patients with idiopathic PD participated in the study. Thirteen patients received both LD and ropinirole, and fourteen administered LD monotherapy. Among 27 patients, twelve experienced fluctuations and/or dyskinesias, whereas fifteen were free of motor complications. Inter- and intra-individual variation in the LD and 3-OMD concentrations were observed. There were no significant differences in the LD and 3-OMD concentrations between the patients treated with a combined therapy of LD and ropinirole, and LD monotherapy. There were no significant differences in the LD concentrations in patients with and without motor complications; however, plasma 3-OMD levels were significantly higher in patients with motor complications. A linear one-compartment pharmacokinetic model with the first-order absorption was adopted for LD and 3-OMD. Only mean exit (residence) time for 3-OMD was significantly shorter in patients treated with ropinirole. Lag time, V/F, CL/F and t(max) of LD had significantly lower values in patients with motor complications. On the other hand, AUC were significantly higher in these patients, both for LD and 3-OMD. 3-OMD C(max) was significantly higher in patients with motor complications as well. Our results showed that ropinirole does not influence LD or 3-OMD concentrations. Higher 3-OMD levels play a role in inducing motor complications during long-term levodopa therapy