Plasma Selenium is Positively Related to Performance in Neurological Tasks Assessing Coordination and Motor Speed

Laboratory of Epidemiology, Demography and Biometry, National Institue on Aging, Bethesda, Maryland, USA.
Movement Disorders (Impact Factor: 5.68). 09/2010; 25(12):1909-15. DOI: 10.1002/mds.23218
Source: PubMed


Parkinson's disease (PD) is a degenerative process affecting the striato nigral system (SN). Its etiology, although obscure, may involve oxidative damage. Selenium, an antioxidant, was shown to protect the SN in animal models. In the current study, we investigate the association between plasma selenium concentrations and the presence of "soft" neurological signs related to the SN. Plasma selenium concentration was assessed in participants of age ≥65 years in the InCHIANTI study, a population-based cohort study in Tuscany, Italy. PD was defined based on standard criteria. "Soft" neurological signs were ascertained by physical examination. A total of 1,012 participants were included. No association was found between the presence of PD and plasma selenium. There was, however, a strong association between plasma selenium and timed performance-based assessments. Lower levels of selenium were significantly associated withdecreased performance in neurological tests of coordination among older adults. Prospective studies are needed to further investigate the effects of selenium on SN dysfunction.

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Available from: Kushang V. Patel, Mar 11, 2014
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    • "A few studies have reported the adverse effects of long-term Se deficiency on neurobehavioral development in mice (Watanabe and Satoh, 1995; Hong et al., 2006). In human, low Se level in the elderly was associated with cognitive decline, reduced coordination, motor speed and muscle strength (Lauretani et al., 2007; Shahar et al., 2010). But a typical feature of Se is the relatively narrow range between deficiency, essentiality, and toxicity doses (Nogueira and Rocha, 2011). "
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    ABSTRACT: Either deficient or excessive of essential nutrients had adverse effects. Effects of different levels of prenatal zinc (Zn) and selenium (Se) on fetal neurobehavioral development remain unclear. To determine the effects of different cord serum levels of Zn and Se on neurobehavioral development in neonates and to explore possible threshold level of Zn and Se based on fetal neurodevelopment, we conducted this epidemiological research. In the multi-center study, we investigated these questions in 927 mother-newborn pairs in Shanghai, China, from 2008 through 2009. Umbilical cord serum concentrations of Zn and Se were measured and Neonatal Behavioral Neurological Assessments (NBNA) tests were conducted. The median cord serum Zn and Se concentrations were 794.3μg/L and 63.1μg/L, respectively. A nonlinear relationship was observed between cord serum Zn and NBNA after adjusting for potential confounders. NBNA score decreased with increasing Zn levels after 794.3μg/L (adjusted ß=-3.0, 95% CI: -3.6 to -2.4, p<0.001). Additionally, an invert U-shape with a threshold Se of 100μg/L was observed between cord serum Se and NBNA. The adjusted regression coefficient was 4.4 (95% CI: 3.6 to 5.2, p<0.001) for Se<100μg/L while -3.6 (95% CI:-6.1 to -1.1, p<0.01) for Se≥100μg/L. Of the 927 infants, 50% had a high level Zn (≥794.3μg/L) and 8.6% had a high level Se (≥100μg/L). High levels of both Zn and Se mainly had adverse effects on behavior and passive tone (p<0.001). Taken together, our study suggested that a threshold of cord blood Zn and Se was existed for fetal neurodevelopment and the prevalence of excessive Zn was high. Thus, the supplementation of Zn during pregnancy should be considered with caution in Shanghai, China.
    Full-text · Article · Apr 2013 · NeuroToxicology
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    • "SeM incorporates non-specifically into proteins in competition with Met [12]. As an organic part of the Se pool, the reduction of its levels has been correlated with an enhanced risk of aging disorders [13]–[15]. In principle, Met substitution by SeM is regarded as a structurally inert change that is exploited for the phasing of macromolecular structures in X-ray crystallography [10]. "
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    ABSTRACT: The capacity of a polypeptide chain to engage in an amyloid formation process and cause a conformational disease is contained in its sequence. Some of the sequences undergoing fibrillation contain critical methionine (Met) residues which in vivo can be synthetically substituted by selenomethionine (SeM) and alter their properties. Using peptide synthesis, biophysical techniques and cell viability determinations we have studied the effect of the substitution of methionine (Met) by selenomethionine (SeM) on the fibrillogenesis and toxic properties of Aβ40 and HuPrP(106-140). We have found that the effects display site-specificity and vary from inhibition of fibrillation and decreased toxicity ([SeM(35)]Aβ40, [SeM(129)]HuPrP(106-140) and [SeM(134)]HuPrP(106-140)), retarded assembly, modulation of polymer shape and retention of toxicity ([SeM(112)]HuPrP(106-140) to absence of effects ([SeM(109)]HuPrP(106-140)). This work provides direct evidence that the substitution of Met by SeM in proamyloid sequences has a major impact on their self-assembly and toxic properties, suggesting that the SeM pool can play a major role in dictating the allowance and efficiency of a polypeptide chain to undergo toxic polymerization.
    Full-text · Article · Nov 2011 · PLoS ONE
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    • ") . Increasing levels of BSe were associated with better motor function . Lower plasma Se levels have been associated with decreased motor coordination among patients with Parkinson ' s disease ( Richwine et al . 2005 ; Shahar et al . 2010"
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    ABSTRACT: Several reports indicate that drinking water arsenic (WAs) and manganese (WMn) are associated with children's intellectual function. Very little is known, however, about possible associations with other neurologic outcomes such as motor function. We investigated the associations of WAs and WMn with motor function in 304 children in Bangladesh, 8-11 years of age. We measured As and Mn concentrations in drinking water, blood, urine, and toenails. We assessed motor function with the Bruininks-Oseretsky test, version 2, in four subscales-fine manual control (FMC), manual coordination (MC), body coordination (BC), and strength and agility-which can be summarized with a total motor composite score (TMC). REsults: Log-transformed blood As was associated with decreases in TMC [β = -3.63; 95% confidence interval (CI): -6.72, -0.54; p < 0.01], FMC (β = -1.68; 95% CI: -3.19, -0.18; p < 0.05), and BC (β = -1.61; 95% CI: -2.72, -0.51; p < 0.01), with adjustment for sex, school attendance, head circumference, mother's intelligence, plasma ferritin, and blood Mn, lead, and selenium. Other measures of As exposure (WAs, urinary As, and toenail As) also were inversely associated with motor function scores, particularly TMC and BC. Square-transformed blood selenium was positively associated with TMC (β = 3.54; 95% CI: 1.10, 6.0; p < 0.01), FMC (β = 1.55; 95% CI: 0.40, 2.70; p < 0.005), and MC (β = 1.57; 95% CI: 0.60, 2.75; p < 0.005) in the unadjusted models. Mn exposure was not significantly associated with motor function. Our research demonstrates an adverse association of As exposure and a protective association of Se on motor function in children.
    Full-text · Article · Jul 2011 · Environmental Health Perspectives
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