Exploring the role of Orexin-A neuropeptide in Parkinson's disease: A systematic review and meta-analysis.

BACKGROUND: Parkinson's disease (PD) is a progressive neurological condition that affects movement and coordination. Orexin-A (OXA) is an excitatory neuropeptide that is found throughout the central nervous system. There is growing interest in investigating the potential diagnostic and therapeutic utility of OXA in PD. To date, studies have reported a wide range of OXA concentrations in patients with PD. In this review, we discuss the current understanding of the dysregulation of OXA in PD and analyze its levels in the CSF. METHODS: We searched six databases (PubMed, Scopus, Web of Science, EMBASE, ProQuest, and EBSCOHost) and preprint servers using a predetermined search strategy through 4th March 4, 2023. The search keywords included "Parkinson's disease", "Orexin-A", "Hypocretin-1", "cerebrospinal fluid", and "CSF". Studies that reported OXA/Hypocretin-1 levels in the CSF of patients with PD were included. Two researchers independently reviewed the records and extracted data. FINDINGS: Eighteen studies involving 244 patients were analyzed. CSF Orexin-A concentrations were lower in patients with Parkinson's disease than in controls, with a mean difference of -59.21 (95 % CI: -89.10 to -29.32). The mean OXA levels were 281.52 (95 % CI: 226.65-336.40). CONCLUSION: Our analysis reveals lower concentrations of orexin-A in the cerebrospinal fluid of Parkinson's disease patients compared to controls, but within the normal range. These findings suggest a potential, but not significant, disruption in the orexinergic system associated with the disease.

Under-representation of low-income countries in the literature - targeting the bummock of neglected tropical diseases.

More than 50% of the world's youth and many economies with the greatest growth rates are in tropical and subtropical regions of Africa, Asia, and Latin America. Many prevailing diseases in these areas comprise neglected tropical diseases (NTDs) - the 13 bacterial and parasitic infections that predominantly affect the poorest one-sixth of the world's population. The lack of published data, heightened by the disregard of researchers of developed countries, amounts to the 'missing piece' when attempting to draw a global picture of such diseases using systematic reviews or meta-analyses because of the imbalance in distribution. Defining and measuring the problem, evaluating the effectiveness and cost of interventions, and assessing cost-effectiveness are all necessary steps in determining health priorities for eradicating these NTDs.