Changed serum trace element profile in Down's syndrome

Selenium level correlates negatively with antibodies but positively with thyroid function in children with down syndrome: an Indonesian study

Background

Children with Down syndrome (DS) are prone to developing autoimmune thyroid disease (AITD). Previous studies found lower selenium (Se) levels in children with AITD. Glutathione peroxidase-3 (GPx3) and selenoprotein-P (SePP) are widely used to measure Se levels. DS children tend to have lower Se levels, the main contributor to hypothyroidism in this population. This study aimed to analyze the Se's role in AITD in Indonesian children with DS.

Methods

This cross-sectional study was conducted between February 2021-June 2022 at the Pediatric Outpatient Clinic of Dr Soetomo Hospital. DS children aged 1 month to 18 years were enrolled using consecutive sampling. Thyroid-stimulating hormone, free thyroxine, thyroid peroxidase (TPO-Ab) and thyroglobulin (Tg-Ab) autoantibody, GPx3, and SePP levels were measured in plasma samples using enzyme-linked immunosorbent assays. Statistical analyses used Chi-square, Mann-Whitney, and Spearman's rank correlation (r _s). All results with p<0.05 were considered statistically significant.

Results

Among 62 children with DS, SePP and GPx3 levels were significantly lower in those with AITD than those without AITD (p=0.013 and p=0.018, respectively). SePP and GPx3 levels correlated significantly with lower TPO-Ab (r _s=-0.439 with p=1×10^-5 and r _s=-0.396 with p=0.001, respectively) and Tg-Ab (r _s=-0.474 with p=1×10^-5 and r _s=-0.410 with p=0.001, respectively) levels. SePP levels correlated significantly with lower thyroid dysfunction incidence (r _s=-0.252, p=0.048) in the AITD group.

Conclusion

Selenium deficiency contributes to autoimmune process in the thyroid and to thyroid dysfunction in children with Down syndrome. Our findings recommend increasing Se levels through Se-containing foods to reduce the risks of AITD and thyroid dysfunction in DS children with AITD.

A Search for Similar Patterns in Hair Trace Element and Mineral Content in Children with Down's Syndrome, Obesity, and Growth Delay

The objective of the present study was to perform comparative analysis of hair trace element and mineral levels in children with Down's syndrome, growth delay, and obesity in order to reveal common and specific patterns. Hair Zn (14, 7, and 15%), Ca (38%, 24%, and 47%), and Mg (33%, 31%, and 49%) levels in children with Down's syndrome, obesity, and growth delay were lower than the respective control values. At the same time, patients with Down's syndrome and growth delay were characterized by 27% and 21%, as well as 24% and 20% lower hair Co as well as Cu content than healthy examinees. Certain alterations were found to be disease-specific. Particularly, in Down's syndrome children, hair Cr, Fe, and V levels were significantly lower, whereas hair P content exceeded the control values. Obese children were characterized by significantly increased hair Cr content. At the same time, hair Mn and Si levels in children with growth delay were lower as compared with the controls. In regression models, all three studied diseases were considered as negative predictors of hair Cu content. Down's syndrome and growth delay, but not obesity, were inversely associated with hair Co content. Both Down's syndrome and obesity were inversely associated with hair Zn content. Based on the revealed similarities in altered hair element, content it is proposed that deficiency of essential elements may predispose Down's syndrome patients to certain syndrome comorbidities including growth delay and obesity, although further detailed studies are required.

Copper accumulation in the brain causes the elevation of oxidative stress and less anxious behavior in Ts1Cje mice, a model of Down syndrome

Elevated oxidative stress (OS) is widely accepted to be involved in the pathogenesis of Down syndrome (DS). However, the mechanisms underlying the elevation of OS in DS are poorly understood. Biometals, in particular copper and iron, play roles in OS. We therefore focused on biometals in the brain with DS. In this study, we analyzed the profile of elements, including biometals, in the brain of Ts1Cje mice, a widely used genetic model of DS. An inductively coupled plasma-mass spectrometry (ICP-MS)-based comparative metallomic/elementomic analysis of Ts1Cje mouse brain revealed a higher level of copper in the hippocampus and cerebral cortex, but not in the striatum, in comparison to wild-type littermates. The expression of the copper transporter CTR1, which is involved in the transport of copper into cells, was decreased in the ependymal cells of Ts1Cje mice, suggesting a decrease in the CTR1-mediated transport of copper into the ependymal cells, which excrete copper into the cerebrospinal fluid. To evaluate the pathological significance of the accumulation of copper in the brain of Ts1Cje mice, we examined the effects of a diet with a low copper content (LoCD) on the elevated lipid peroxidation, the accumulation of hyperphosphorylated tau, and some behavioral anomalies. Reducing the copper concentration in the brain by an LoCD restored the enhanced lipid peroxidation and phosphorylation of tau in the brain and reduced anxiety-like behavior, but not hyperactivity or impaired spatial leaning, in Ts1Cje mice. The findings highlight the reduction of accumulation of copper in the brain may be a novel therapeutic strategy for DS.

Hair Mineral and Trace Element Content in Children with Down's Syndrome

The objective of the present study was to assess the level of minerals and trace elements in 40 children with Down's syndrome and 40 controls aged 1-2 years old. Hair mineral and trace element analysis was performed using inductively coupled plasma mass spectrometry. The obtained data demonstrate that hair levels of Mg, P, I, Cr, Si, Zn, and Pb in Down's syndrome patients exceeded the respective control values by 36, 36, 93, 57, 45, 28, and 54%, whereas hair mercury was more than twofold lower in children with Down's syndrome. The observed difference in the levels of trace elements was age-dependent. In particular, in 1-year-olds, major differences were observed for essential elements (Cr, Si, Zn), whereas in 2-year-olds-for toxic elements (Hg, Pb). At the same time, hair P levels in Down's syndrome patients were 14 and 35% higher at the age of 1 and 2 years in comparison to the respective controls. Multiple regression analysis demonstrated that a model incorporating all elements, being characterized by a significant group difference, accounted for 42.5% of status variability. At the same time, only hair phosphorus was significantly interrelated with Down's syndrome status (β = 0.478; p < 0.001). Principal component analysis (PCA) used As, Ca, Cr, Fe, Hg, I, Mg, P, Pb, Se, Si, Sn, and Zn as predictors, with the resulting R² = 0.559. The OPLS-DA models also separated between Down's and health control groups. Therefore, 1-2-year-old patients with Down's syndrome are characterized by significant alterations of mineral and trace element status.

Systematic review and meta-analysis shows a specific micronutrient profile in people with Down Syndrome: Lower blood calcium, selenium and zinc, higher red blood cell copper and zinc, and higher salivary calcium and sodium

Different metabolic profiles as well as comorbidities are common in people with Down Syndrome (DS). Therefore it is relevant to know whether micronutrient levels in people with DS are also different. This systematic review was designed to review the literature on micronutrient levels in people with DS compared to age and sex-matched controls without DS. We identified sixty nine studies from January 1967 to April 2016 through main electronic medical databases PubMed, Scopus, and Web of knowledge. We carried out meta-analysis of the data on four essential trace elements (Cu, Fe, Se, and Zn), six minerals (Ca, Cl, K, Mg, Na, and P), and five vitamins (vitamin A, B9, B12, D, and E). People with DS showed lower blood levels of Ca (standard mean difference (SMD) = -0.63; 95% confidence interval (CI): -1.16 to -0.09), Se (SMD = -0.99; 95% CI: -1.55 to -0.43), and Zn (SMD = -1.30; 95% CI: -1.75 to -0.84), while red cell levels of Zn (SMD = 1.88; 95% CI: 0.48 to 3.28) and Cu (SMD = 2.77; 95% CI: 1.96 to 3.57) were higher. They had also higher salivary levels of Ca (SMD = 0.85; 95% CI: 0.38 to 1.33) and Na (SMD = 1.04; 95% CI: 0.39 to 1.69). Our findings that micronutrient levels are different in people with DS raise the question whether these differences are related to the different metabolic profiles, the common comorbidities or merely reflect DS.

Plasma antioxidant enzymes and lipoperoxidation status in children with Down syndrome

OBJECTIVES

Oxidative stress (OS) may play a critical role in cell aging and neurologic disorders that are often seen in Down syndrome (DS) patients. The aim of this study was to determine the antioxidant enzyme level and lipoperoxidation status in blood from DS children.

DESIGN AND METHODS

In a cross-sectional study, we recruited a total of 36 DS children and 40 healthy controls (HCs). All subjects were free of infection according to the C reactive protein (CRP) value and routine peripheral blood profile. The activities of total superoxide dismutases (SODs), extracellular glutathione peroxidase (GPx3),malondialdehyde (MDA) and nitric oxide synthase (NOS) concentrations in peripheral blood were measured by spectrophotometric methods. The relationship of SOD and GPx3 was analyzed in the two groups.

RESULTS

The two groups were similar with respect to age, gender and peripheral blood profiles. The total SOD activity was significantly increased, while the GPx3 activity was significantly reduced in the DS group compared to the HCs (p=0.000, p=0.033 respectively). The MDA level was higher in DS children (p=0.013). There was no significant difference in NOS between DS and HCs (p=0.708). A significant negative correlation between GPx3 and SOD activity was identified in DS (r=-0.14, p=0.018) but not in the HC group.

CONCLUSIONS

Abnormal redox metabolism takes place in DS individuals. Reducing GPx3 may be a compensatory mechanism of protection against intracellular OS. Moreover, monitoring of decreases in GPx3 activity may be a useful biomarker for evaluating OS in DS patients.

Oxidative stress and Down syndrome. Do antioxidants play a role in therapy?

Oxidative stress is a phenomenon associated with imbalance between production of free radicals and reactive metabolites (e.g. superoxide and hydrogen peroxide) and the antioxidant defences. Oxidative stress in individuals with Down syndrome (DS) has been associated with trisomy of the 21st chromosome resulting in DS phenotype as well as with various morphological abnormalities, immune disorders, intellectual disability, premature aging and other biochemical abnormalities. Trisomy 21 in patients with DS results in increased activity of an important antioxidant enzyme Cu/Zn superoxide dismutase (SOD) which gene is located on the 21st chromosome along with other proteins such as transcription factor Ets-2, stress inducing factors (DSCR1) and precursor of beta-amyloid protein responsible for the formation of amyloid plaques in Alzheimer disease. Mentioned proteins are involved in the management of mitochondrial function, thereby promoting mitochondrial theory of aging also in people with DS. In defence against toxic effects of free radicals and their metabolites organism has built antioxidant defence systems. Their lack and reduced function increases oxidative stress resulting in disruption of the structure of important biomolecules, such as proteins, lipids and nucleic acids. This leads to their dysfunctions affecting pathophysiology of organs and the whole organism. This paper examines the impact of antioxidant interventions as well as positive effect of physical exercise on cognitive and learning disabilities of individuals with DS. Potential therapeutic targets on the molecular level (oxidative stress markers, gene for DYRK1A, neutrophic factor BDNF) after intervention of natural polyphenols are also discussed.

Oxidative stress and cognitive ability in adults with Down syndrome

AIMS

We aimed to study the hypothesis that high levels of superoxide dismutase (SOD1), previously reported in Down syndrome, would be associated with poorer ability on cognitive tests. Compensatory rises in the activity of glutathione peroxidase (GPx) was expected to be associated with better ability, so that a high ratio between SOD1 and GPx was hypothesised to be the best predictor of poorer cognitive performance.

METHODS

32 adults with Down syndrome between the ages of 18 and 45 years donated blood samples for SOD1 and GPx assays and urine for Isoprostane 8,12-iso-iPF(2alpha)-VI assay, a specific biomarker of lipid peroxidation in vivo. Informants rated functional ability and memory function for all participants, and those adults with DS that was able to, also completed psychometric assessments of language ability and memory.

RESULTS

Neither SOD1 nor GPx were related to the elevated markers of lipid peroxidation previously described in living adults with DS, and our hypothesis that an increased SOD1/GPx ratio would be correlated with worse performance on cognitive or functional measures was not supported. Contrary to our hypothesis, we found that low SOD1/GPx ratios were associated with worse memory ability, which remained after controlling for confounders such as sex, age or nutritional supplements.

CONCLUSIONS

The anti-oxidant system in DS is implicated in the cognitive phenotype associated with the chromosomal disorder, but the variations in the phenotype could result from several possible gene or gene product interactions. Much further research is required before it will be possible to counteract the oxidative stress associated with DS.

Selenium in global food systems

Food systems need to produce enough of the essential trace element Se to provide regular adult intakes of at least 40 μg/d to support the maximal expression of the Se enzymes, and perhaps as much as 300 μg/d to reduce risks of cancer. Deprivation of Se is associated with impairments in antioxidant protection, redox regulation and energy production as consequences of suboptimal expression of one or more of the Se-containing enzymes. These impairments may not cause deficiency signs in the classical sense, but instead contribute to health problems caused by physiological and environmental oxidative stresses and infections. At the same time, supranutritional intakes of Se, i.e. intakes greater than those required for selenocysteine enzyme expression, appear to reduce cancer risk. The lower, nutritional, level is greater than the typical intakes of many people in several parts of the world, and few populations have intakes approaching the latter, supranutritional, level. Accordingly, low Se status is likely to contribute to morbidity and mortality due to infectious as well as chronic diseases, and increasing Se intakes in all parts of the world can be expected to reduce cancer rates.

Down syndrome and thyroid dysfunction: Should nutritional support be the first-line treatment?

Individuals with Down syndrome (DS) not only have increased risk of hypothyroidism, they also tend to develop a relatively novel mild form of neonatal hypothyroidism. One problem that may predispose those with trisomy 21 to hypothyroidism is the overexpression of the gene DYRK1A, which may have an affect on the thyroid. While thyroxine supplementation (such as Synthroid) is increasingly being advised for those with DS, this treatment may have both positive and negative effects. Nutritional support for hypothyroidism offers some of the same benefits as drug therapy but without the likely negative long-term effects. Early 20th century practitioners used bovine glandulars for those with DS children, which were believed to help support thyroid function. Some doctors in more recent times have also included iodine, L-tyrosine, selenium, and zinc. As nutrition for those with DS has been safely used by some practitioners for many decades, it is suggested that nutritional thyroid support, and not necessarily thyroxine, should be considered for use as a first line treatment for those with trisomy 21. This paper also hypothesizes that nutritional interventions begun prenatally by the mother, may possibly also be of benefit.

Brain, aging and neurodegeneration: role of zinc ion availability

Actual fields of research in neurobiology are not only aimed at understanding the different aspects of brain aging but also at developing strategies useful to preserve brain compensatory capacity and to prevent the onset of neurodegenerative diseases. Consistent with this trend much attention has been addressed to zinc metabolism. In fact, zinc acts as a neuromodulator at excitatory synapses and has a considerable role in the stress response and in the functionality of zinc-dependent enzymes contributing to maintaining brain compensatory capacity. In particular, the mechanisms that modulate the free zinc pool are pivotal for safeguarding brain health and performance. Alterations in zinc homeostasis have been reported in Parkinson's and Alzheimer's disease as well as in transient forebrain ischemia, seizures and traumatic brain injury, but little is known regarding aged brain. There is much evidence that that age-related changes, frequently associated to a decline in brain functions and impaired cognitive performances, could be related to dysfunctions affecting the intracellular zinc ion availability. A general agreement emerges from studies of humans' and rodents' old brains about an increased expression of metallothionein (MT) isoforms I and II, but dyshomogenous results are reported for MT-III, and it is still uncertain whether these proteins maintain in aging the protective role, as it occurs in adult/young age. At the same time, there is considerable evidence that amyloid-beta deposition in Alzheimer's disease is induced by zinc, but the pathological significance and the causes of this phenomenon are still an open question. The scientific debate on the role of zinc and of some zinc-binding proteins in aging and neurodegenerative disorders, as well as on the beneficial effect of zinc supplementation in aged brain and neurodegeneration, is extensively discussed in this review.

Can cognitive deterioration associated with Down syndrome be reduced?

Individuals with Down syndrome have signs of possible brain damage prior to birth. In addition to slowed and reduced mental development, they are much more likely to have cognitive deterioration and develop dementia at an earlier age than individuals without Down syndrome. Some of the cognitive impairments are likely due to post-natal hydrogen peroxide-mediated oxidative stress caused by overexpression of the superoxide dismutase (SOD-1) gene, which is located on the triplicated 21st chromosome and known to be 50% overexpressed. However, some of this disability may also be due to early accumulation of advanced protein glycation end-products, which may play an adverse role in prenatal and postnatal brain development. This paper suggests that essential nutrients such as folate, vitamin B6, vitamin C, vitamin E, selenium, and zinc, as well as alpha-lipoic acid and carnosine may possibly be partially preventive. Acetyl-L-carnitine, aminoguanidine, cysteine, and N-acetylcysteine are also discussed, but have possible safety concerns for this population. This paper hypothesizes that nutritional factors begun prenatally, in early infancy, or later may prevent or delay the onset of dementia in the Down syndrome population. Further examination of these data may provide insights into nutritional, metabolic and pharmacological treatments for dementias of many kinds. As the Down syndrome population may be the largest identifiable group at increased risk for developing dementia, clinical research to verify the possible validity of the prophylactic use of anti-glycation nutrients should be performed. Such research might also help those with glycation complications associated with diabetes or Alzheimer's.

A Low-Grade Follicular Thyroid Carcinoma in a Woman with down Syndrome

Aims

Analysis of a thyroid neoplasm in a person with Down syndrome.

Method

Report of a case and review of the literature.

Results

A 34-year-old woman with Down syndrome developed a right thyroid low-grade follicular carcinoma. She is alive 20 years after the discovery of the initial tumor. A review of the literature including epidemiological studies revealed only one unspecified cancer, one papillary carcinoma and one lymphoma. Persons with Down syndrome present an excess of goiter and thyroiditis and often are overweight and have low serum selenium, all these conditions being risk factors for thyroid carcinomas.

Conclusion

Thyroid malignant neoplasms are very rare in persons with Down syndrome. We suspect that some constitutional, hormonal and genetic factors could protect these subjects against thyroid carcinoma.

Down syndrome and epilepsy: a nutritional connection?

Non-Asian individuals with Down syndrome are much more likely to develop epileptic seizure disorders than individuals without Down syndrome. Examination of nutrient and metabolite levels in patients with these two seemingly disparate disorders reveals numerous similarities. Compared to individuals without these disorders, individuals with Down syndrome and individuals with seizures may have lower levels of vitamin A, vitamin B1, folate, vitamin B12, vitamin C, magnesium, manganese, selenium, zinc, carnitine, carnosine, choline, and possibly serine. Excesses of copper, cysteine, phenylalanine, and superoxide dismutase are also sometimes encountered in both disorders. In addition to common nutritional lower levels and excesses, disorders of metabolism involving vitamin B6, vitamin D, calcium, and tryptophan may play a common role. This paper hypothesizes that nutritional factors may account for the high joint occurrence of these conditions. Further examination of these data may provide insights into nutritional, metabolic and pharmacological treatments for both conditions.

Antioxidative metabolism in Down syndrome

Down syndrome is the most common cause of mental retardation, affecting 1 in 700-800 liveborn infants. Although numerous biochemical abnormalities accompanying the syndrome have not yet been completely clarified, the antioxidant defense system enzymes have shown to be altered due to increased gene dosage on chromosome 21 and overproduction of superoxide dismutase (SOD-1 or Cu/Zn SOD). The purpose of this study was to investigate the activities of SOD-1 and glutathione peroxidase (GSH-Px) enzymes and the levels of their cofactors zinc (Zn), copper (Cu) and selenium (Se) in plasma of 20 Down syndrome patients. In comparison with age and sex-matched controls (n = 15), plasma GSH-Px, SOD, and Cu levels were significantly decreased in the patient group, but Zn and Se concentrations remained unchanged.