In Weinstock and Walters of RLS

In Weinstock and Walters [8], 43% of RLS-associated conditions have also been associated with systemic iron deficiency. Iron is distributed heterogeneously in different regions and WST Cell Proliferation Colorimetric Assay Kit plus cells; brain iron homeostasis is required for its normal function [9]. Iron deficiency is undoubtedly the most common nutritional disorder worldwide, affecting more than 2 billion people ([10] apud [11]). Iron has a fundamental function on the correct dopaminergic system operation, particularly being a coenzyme of Tyrosine Hydroxylase; the evidences that show us a possible dopaminergic dysfunction are several; most of the genes involved have a relationship with dopamine metabolism (gene of receptor D2, gene of receptor D4 DRD4, gene of dopamine transporter DAT 1), and the recent articles of functional neuroimaging bring a dopaminergic dysfunction at the level of frontoestriatal circuit [12].
Methods A search on PubMed was established and the keywords used in this search were ‘Iron Metabolism,’ ‘Iron Deficiency’ and ‘Restless Legs Syndrome’; 145 articles were screened and we divided them into different topics (Table 1). Discussions occurred to select the articles within the stipulated period 2001 and 05/08/2014 and the chosen keywords, and, 20 articles of the 145 found were selected. The following data were extracted: (1) study design, (2) patients characteristics, such as number of volunteers, age and gender and (3) consequences of iron deficiency in RLS. Articles between 2001 and 05/08/2014 were used in the study. As inclusion criteria, we used references that reflect our personal selection of articles as being the most informative, using only English articles.
Results
Conclusion The pathophysiology of RLS remains unclear, although roles for dopamine dysfunction and brain iron deficiency have been proposed [28]. A low ferritin level (< 50ng/ml) is documented in the literature to be related to RLS in the general population [29]. Dysregulation of iron metabolic pathways has been demonstrated in a large number of neurodegenerative movement disorders [30]. Serum iron levels have relationships with sleep quality, daytime sleepiness, depression, fatigue, and quality of life [31]. Literature suggests future studies relating to levels of iron and pregnancy, ADHD and RLS. Measurement of hepcidin or pro-hepcidin in all RLS-associated disorders and determination of whether reduction of inflammation by treating the underlying systemic disorder could improve RLS symptoms and alter CNS and/or peripheral hepcidin and iron level also are important. And another point is exploring immunological and inflammatory properties of NOS, nitric oxide and the hypoxia inducible in the pathway of RLS [5].
Acknowledgments This research was supported by fellowships from Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP #2011/21729-3).