Elevated Plasma Melatonin Levels Are Correlated With the Non-motor Symptoms in Parkinson’s Disease: A Cross-Sectional Study

Long

et al. 2021

WJD

BACKGROUND Melatonin is reported to be related to diabetes mellitus (DM) risk; however, the effect of melatonin on diabetic retinopathy (DR) risk remains unclear. AIM The aim of this study was to determine the effect of melatonin on DR risk. METHODS A hospital-based case-control study was conducted from January 2020 to June 2020. DR was assessed using the Diabetic Retinopathy preferred practice pattern (PPP)-updated 2019 criteria. The participants were divided into the DM cases without DR (NDR) group, non-proliferative DR (NPDR) group and proliferative DR (PDR) group. Plasma melatonin concentration was detected with the enzyme-linked immunosorbent assay kit. The relationship between plasma melatonin concentration and DR risk as well as severity was assessed. RESULTS It was found that plasma melatonin was 72.83 ± 16.25, 60.38 ± 13.43, 44.48 ± 10.30 and 44.69 ± 8.95 pg/mL in healthy controls, NDR group, NPDR and PDR group, respectively. In addition, it was found that plasma melatonin could be used as a potential diagnostic biomarker for DR (AUC = 0.893, P < 0.001). There was a significant positive relationship between total bilirubin and melatonin content ( P < 0.001) based on the correlation assay. Significant associations between total bilirubin and melatonin content were also detected in the NPDR ( R 2 = 0.360, P < 0.001) and PDR ( R 2 = 0.183, P < 0.001) groups. CONCLUSION The data obtained in this study demonstrated that plasma melatonin concen-tration was decreased in DR cases and could be used as a sensitive and specific marker for the diagnosis of DR. A significant positive relationship between total bilirubin and melatonin was detected. More related studies are required to understand the role of melatonin in DR.

Section: Introductionmentioning

confidence: 99%

Plasma melatonin levels in patients with diabetic retinopathy secondary to type 2 diabetes

Long

et al. 2021

WJD

“…Indeed, studies with doses of 100 mg/day or higher are needed. Melatonin may also be involved in the pathophysiology of other non-motor symptoms in PD, but the current evidence is not convincing enough (Li et al, 2020;Batla et al, 2021) Therefore, more research is needed.…”

Section: Resultsmentioning

confidence: 99%

Melatonin as a Chronobiotic and Cytoprotective Agent in Parkinson’s Disease

Pérez-Lloret

Cardinali

2021

Front. Pharmacol.

This article discusses the role that melatonin may have in the prevention and treatment of Parkinson’s disease (PD). In parkinsonian patients circulating melatonin levels are consistently disrupted and the potential therapeutic value of melatonin on sleep disorders in PD was examined in a limited number of clinical studies using 2–5 mg/day melatonin at bedtime. The low levels of melatonin MT1 and MT2 receptor density in substantia nigra and amygdala found in PD patients supported the hypothesis that the altered sleep/wake cycle seen in PD could be due to a disrupted melatonergic system. Motor symptomatology is seen in PD patients when about 75% of the dopaminergic cells in the substantia nigra pars compacta region degenerate. Nevertheless, symptoms like rapid eye movement (REM) sleep behavior disorder (RBD), hyposmia or depression may precede the onset of motor symptoms in PD for years and are index of worse prognosis. Indeed, RBD patients may evolve to an α-synucleinopathy within 10 years of RBD onset. Daily bedtime administration of 3–12 mg of melatonin has been demonstrated effective in RDB treatment and may halt neurodegeneration to PD. In studies on animal models of PD melatonin was effective to curtail symptomatology in doses that allometrically projected to humans were in the 40–100 mg/day range, rarely employed clinically. Therefore, double-blind, placebo-controlled clinical studies are urgently needed in this respect.

“…Besides, they demonstrated that melatonin serum levels are positively correlated with the severity of the PD according to measure by the Hoehn and Yahr scale. Later on in 2020, Li et al (2020) 13 reported that the plasma melatonin levels in PD patients were significantly higher than those in healthy controls, besides they reported that both sleep dysfunctions and disorders had a significant negative correlation with plasma melatonin levels.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, regulation of circadian rhythm dysfunction may become a new target for therapeutic intervention. In the clinic, melatonin can be used as a potential biomarker reflecting the dysfunction of PD, providing new ideas for the early diagnosis and treatment of PD 13 .…”

Section: Introductionmentioning

confidence: 99%

Melatonin serum level, sleep functions, and depression level after bilateral anodal transcranial direct current stimulation in patients with Parkinson’s disease: a feasibility study

Hadoush¹,

Alqudah²,

Banihani³

et al. 2021

Sleep Sci

Objective: Parkinson's disease (PD) is associated with non-motor complications such as sleep disturbance and depression. Transcranial direct current stimulation (tDCS) showed therapeutic effects on the motor dysfunctions. However, the potential effects of tDCS therapy on melatonin hormone, sleep dysfunctions, and depression in patients with PD still unclear. This feasibility study aimed to identify any potential changes in melatonin serum level, sleep functions and depression after the bilateral anodal tDCS in patients with PD. Material and Methods: Tensessions of bilateral anodal tDCS stimulation applied over left and right prefrontal and motor areas were given to twenty-five patients with PD. Melatonin serum level, Pittsburgh sleep quality index, and geriatric depression scale examined before and after tDCS stimulation. Results: After bilateral anodal tDCS, there was a significant reduction in melatonin serum level, improvement in depression, improvements in overall sleep quality, and sleep latency. Correlations test showed significant associations between melatonin serum level reduction and changes in subjective sleep quality, and sleep duration, as well as between improvements in depression and overall sleep quality, sleep latency, and sleep disturbance. Conclusion: Bilateral anodal tDCS therapy was a feasible and safe tool that showed potential therapeutic effects on melatonin serum level, sleep quality, and depression level in patients with PD. Although the further large scale and randomized-control trial studies are crucially needed, there is still a need for such a feasibility study to be established before such trials can be implemented as is recommended in the new medical research council guidelines.