Gender difference in the effect of uric acid on striatal dopamine in early Parkinson's disease

Abstract

Background and purposeHigh uric acid (UA) levels have been shown to exert a neuroprotective effect in Parkinson's disease (PD) by inhibiting oxidative stress in the nigrostriatal pathway. However, the association between striatal dopamine activity and UA level has not been clarified.MethodsA total of 213 patients with early PD were enrolled. All patients underwent positron emission tomography using 18F‐N‐(3‐fluoropropyl)‐2beta‐carbon ethoxy‐3beta‐(4‐iodophenyl) nortropane and a venous blood test for quantification of serum UA. All patients were stratified into either the lower UA group or the higher UA group using the median UA level. After normalizing the positron emission tomography images, differences in the regional standardized uptake value ratios (SUVRs) were analyzed with a volume‐of‐interest template. All tested SUVRs were also compared after categorizing patients by gender.ResultsThe UA affected dopamine transporter SUVRs in different ways by gender. In female patients, the higher UA level group showed a smaller reduction in dopamine transporter uptake in the posterior putamen, whereas there was no such association observed in male patients.ConclusionsHigher UA levels were correlated with higher dopamine transporter uptake in the putamen in female patients with early PD. This finding suggests that UA has a neuroprotective effect, as demonstrated by the relatively preserved striatal dopamine activity in women.

Agricultural work and reduced circulating uric acid are both associated with initial hospital admission for Parkinson’s disease

“…That UA has a protective effect is further indicated by the positive correlation with age of onset, supporting recent findings (Oh et al 2019) that higher concentrations may delay the degenerative process and hence the emergence of symptoms. That this was only identified in the subjects who were not agricultural workers is notable; it may reflect the effect of a UA threshold which is not reached in most agricultural workers with further reduced UA concentrations, or it may indicate that other factors, such as pesticide exposure, are more important in determining risk of PD in this group.…”

Prevalence and Risk Factors for Malnutrition in Patients With Parkinson's Disease

“…Our results show that hyperuricemia is a sign of good nutrition, and the reasons may be as follows. Research shows that oxidative stress is a leading factor in the pathogenesis of idiopathic PD, and two intrinsic antioxidative molecules, i.e., bilirubin and UA, are known to protect dopaminergic neurons from oxidative stress in PD (22). Another study showed that the higher UA level group in female PD patients showed a smaller reduction in dopamine transporter uptake in the posterior putamen (23).…”

The Novel Coronavirus 2019-nCoV: Epidemiological Situation and Measures Undertaken in Morocco

“…These measures are necessary because limiting social contact of affected people was crucial for the control of COVID-19, as asymptomatic or mildly symptomatic patients can spread the virus [16]. Subsequently, the decision to update the case definition of infection has shown an increase in new positive cases after the onset of the disease in people with no notion of travel (Figure 1) [17,18] and (Figure 2) [17]. This update has taken into consideration the evolution of the national epidemiological situation of COVID-19, marked by the emergence of the disease in some people with no notion of travel.…”

“…In addition, as of 9 April, the percentage of cases not yet recovered is estimated at 85%. (Figure 4) [17,18] and (Figure 5) [17].…”

“…Indeed, as of 9 April, more than 75% of the cases presented to the health services in a critical situation [14]. Moreover, older people and people with comorbidities (such as asthma, diabetes, heart disease) appear to be more vulnerable to becoming severely ill with the virus [21] (Figure 6) [17,18] and (Figure 7) [17,18].…”