Antioxidant status in blood of obese children: the relation between trace elements, paraoxonase, and arylesterase values

Association Between the Serum Copper Levels and Environmental Tobacco Exposure on the Risk of Overweight and Obesity in Children: a Study Based on the National Health and Nutrition Examination Survey

This study was to assess the individual effects of serum copper levels and environmental tobacco exposure and their joint effects on the risk of overweight and obesity among children and adolescents of 6 to 19 year olds. We analyzed cross-sectional data from 1849 children and adolescents participating in the National Health and Nutrition Examination Survey (NHANES) collected between 2011 and 2016. Environmental tobacco exposure was determined by cotinine levels. The serum copper level was divided into < median group and ≥ median groups according to the median of 109.81 µg/dL. The outcome was overweight/obese in children and adolescents. Weighted multinomial multivariate logistic regression models were used to assess the association of serum copper and cotinine levels, with the risk of overweight/obesity, and the joint effects on the risk of overweight and obesity among children and adolescents. The subgroup analyses based on age, gender, and household smoking status were conducted. Among 1849 children and adolescents, 332 children and adolescents had overweight BMI, and 450 children and adolescents had obese BMI. Higher serum copper levels were associated with the risk of obesity in children and adolescents (odds ratio (OR) 2.96, 95% confidence interval (CI) 1.39-6.31, P = 0.006). A positive association between increasing levels of cotinine levels and the risk of overweight (OR 1.83, 95% CI 1.16-2.87, P = 0.010) and obesity (OR 2.56, 95% CI 1.03-6.40, P = 0.044) in children and adolescents was observed. A remarkable association was found between higher serum copper in combination with higher cotinine levels and the risk of overweight (OR 3.23, 95% CI 1.19-8.83, P = 0.023) and obesity (OR 8.76, 95% CI 2.14-35.87, P = 0.003) in children and adolescents. The subgroup analyses revealed positive associations between high serum copper levels in combination with high cotinine levels and overweight and obesity in children and adolescents aged ≥ 12 years, of female sex, and without smoking family members. There may exist a joint effect of serum copper levels and environmental tobacco exposure on overweight/obesity among children and adolescents. These findings offer an insight that early weight control and reduction of tobacco exposure and the detection of serum copper levels may be important in reducing the risk of obesity in children.

Overweight, Obesity, Hypertriglyceridemia, and Insulin Resistance Are Positively Associated with High Serum Copper Levels in Mexican Adults

Recently, the role of trace elements in the pathophysiology of obesity, insulin resistance (IR), and metabolic diseases has been explored. In this cross-sectional study, we aimed to assess the association of overweight, obesity, and cardiometabolic traits with serum copper (Cu) levels in 346 Mexican adults. Serum Cu level was measured by inductively coupled plasma mass spectrometry (ICP-MS). Anthropometrical data were collected, and biochemical parameters were measured. The triglyceride-glucose (TyG) index was used as a surrogate marker to evaluate IR. Overweight and obesity status was positively associated with the serum Cu level (β = 19.434 ± 7.309, p = 0.008). Serum Cu level was observed to have a positive association with serum triglycerides level (β = 0.160 ± 0.045, p < 0.001) and TyG (β = 0.001 ± 0.001, p < 0.001). Additionally, high serum Cu level was positively associated with overweight and obesity status (odds ratio [OR] = 1.9, 95% confidence interval [95% CI] 1.1-3.4, p = 0.014), hypertriglyceridemia (OR = 3.0, 95% CI 1.7-5.3, p < 0.001), and IR (OR = 2.6, 95% CI 1.4-4.6, p = 0.001). In conclusion, our results suggest that overweight, obesity, hypertriglyceridemia, and IR are positively associated with serum Cu levels in Mexican adults.

Association between plasma and dietary trace elements and obesity in a rural Chinese population

Trace elements may play an important role in obesity. This study aimed to assess the plasma and dietary intake levels of four trace elements, Mn, Cu, Zn and Se in a rural Chinese population, and analyse the relationship between trace elements and obesity. A cross-sectional study involving 2587 participants was conducted. Logistic regression models were used to analyse the association between trace elements and obesity; restricted cubic spline (RCS) models were used to assess the dose-response relationship between trace elements and obesity; the weighted quantile sum (WQS) model was used to examine the potential interaction of four plasma trace elements on obesity. Logistic regression analysis showed that plasma Se concentrations in the fourth quartile (Q4) exhibited a lower risk of developing obesity than the first quartile (Q1) (central obesity: OR = 0·634, P = 0·002; general obesity: OR = 0·525, P = 0·005). Plasma Zn concentration in the third quartile (Q3) showed a lower risk of developing obesity in general obesity compared with the first quartile (Q1) (OR = 0·625, P = 0·036). In general obesity, the risk of morbidity was 1·727 and 1·923 times higher for the second and third (Q2, Q3) quartiles of dietary Mn intake than for Q1, respectively. RCS indicated an inverse U-shaped correlation between plasma Se and obesity. WQS revealed the combined effects of four trace elements were negatively associated with central obesity. Plasma Zn and Se were negatively associated with obesity, and dietary Mn was positively associated with obesity. The combined action of the four plasma trace elements had a negative effect on obesity.

Single and Combined Associations of Plasma and Urine Essential Trace Elements (Zn, Cu, Se, and Mn) with Cardiovascular Risk Factors in a Mediterranean Population

Trace elements are micronutrients that are required in very small quantities through diet but are crucial for the prevention of acute and chronic diseases. Despite the fact that initial studies demonstrated inverse associations between some of the most important essential trace elements (Zn, Cu, Se, and Mn) and cardiovascular disease, several recent studies have reported a direct association with cardiovascular risk factors due to the fact that these elements can act as both antioxidants and pro-oxidants, depending on several factors. This study aims to investigate the association between plasma and urine concentrations of trace elements and cardiovascular risk factors in a general population from the Mediterranean region, including 484 men and women aged 18−80 years and considering trace elements individually and as joint exposure. Zn, Cu, Se, and Mn were determined in plasma and urine using an inductively coupled plasma mass spectrometer (ICP-MS). Single and combined analysis of trace elements with plasma lipid, blood pressure, diabetes, and anthropometric variables was undertaken. Principal component analysis, quantile-based g-computation, and calculation of trace element risk scores (TERS) were used for the combined analyses. Models were adjusted for covariates. In single trace element models, we found statistically significant associations between plasma Se and increased total cholesterol and systolic blood pressure; plasma Cu and increased triglycerides and body mass index; and urine Zn and increased glucose. Moreover, in the joint exposure analysis using quantile g-computation and TERS, the combined plasma levels of Zn, Cu, Se (directly), and Mn (inversely) were strongly associated with hypercholesterolemia (OR: 2.03; 95%CI: 1.37−2.99; p < 0.001 per quartile increase in the g-computation approach). The analysis of urine mixtures revealed a significant relationship with both fasting glucose and diabetes (OR: 1.91; 95%CI: 1.01−3.04; p = 0.046). In conclusion, in this Mediterranean population, the combined effect of higher plasma trace element levels (primarily Se, Cu, and Zn) was directly associated with elevated plasma lipids, whereas the mixture effect in urine was primarily associated with plasma glucose. Both parameters are relevant cardiovascular risk factors, and increased trace element exposures should be considered with caution.

Serum zinc levels are associated with obesity and low-density lipoprotein cholesterol in Mexican adults

PURPOSE

Little is known about the association between serum zinc (Zn) levels and obesity in the Mexican population. Therefore, we tested the association between serum Zn levels, obesity status, and serum lipid levels in a sample of Mexican adults.

METHODS

Anthropometric data and serum levels of total cholesterol, high- and low-density lipoprotein cholesterol (HDL-C and LDL-C, respectively), and triglycerides were analyzed in 96 Mexican adults. Serum Zn was measured with inductively coupled plasma mass spectrometry. An individual data meta-analysis of the association between serum Zn, overweight, and obesity status was performed in 172 adults from two different provinces in Mexico.

RESULTS

Serum Zn was negatively associated with body mass index (BMI, β = -0.034 ± 0.013, p = 2.0 ×10^-6) and obesity (odds ratio [OR]= 0.990, 95% confidence interval [CI]= 0.980-0.999, p = 3.4 ×10^-5). The association between Zn level and obesity in Mexican adults was confirmed with an individual data meta-analysis (OR= 0.977, 95% CI= 0.966-0.988, p = 3.4 ×10^-5). In addition, a significant interaction effect between serum Zn level and sex was observed on LDL-C level (β = 7.010 ± 3.295, p = 0.037). Serum Zn was negatively associated with LDL-C levels in women (β = -0.188 ± 0.074, p = 0.016).

CONCLUSION

Our results confirm the negative association of serum Zn level with obesity. For the first time, we show a sex-specific association between serum Zn and LDL-C levels in a Mexican population. However, further studies are needed in larger and more varied Mexican cohorts to replicate and confirm our findings.

Relationship Between Plasma Copper Concentration and Body Fat Distribution in Children in China: a Cross-Sectional Study

This study aimed to explore the association of the plasma copper concentration with body fat distribution and the potential mediating effect of inflammation status in children. A total of 454 children were recruited in this study. Dual-energy X-ray absorptiometry was applied to measure the fat mass (FM) and fat mass percentages (FM%) at whole body, trunk, appendicular, android, and gynoid regions. Android to gynoid fat mass ratio and fat mass to lean mass (FM/LM) ratio at whole body, trunk, and appendicular sites were calculated. Plasma copper concentration was measured via inductively coupled plasma mass spectrometry. C-reactive protein (CRP) was determined by ELISA. After adjusting for covariates, multiple linear regression analyses showed that, for every additional unit increase in the plasma copper concentration, the FM, FM%, and FM/LM at whole body and subregions increased by 0.030-0.472 kg (P < 0.001-0.019), 0.013-1.04% (P = 0.007-0.042), and 0.021-0.030 (P < 0.001), respectively. Mediating analysis suggested that CRP significantly mediated 22.0-30.6% (P < 0.001) of the estimated association of copper with FM% and FM/LM at whole body and limbs. Thus, children with higher plasma levels of copper tended to have a higher regional and overall body fat deposition, and this relationship was partly mediated by inflammatory status.

The Relationship Between Serum Copper and Overweight/Obesity: a Meta-analysis

The relationship between serum copper (Cu) level and overweight/obesity remains controversial. The purpose of this meta-analysis is to evaluate the relationship. A comprehensive literature search was performed in PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases for relevant articles until March 20, 2019. The random-effect model (REM) was adopted to compute the combined standardized mean difference (SMD) with 95% confidence interval (CI). Publication bias was estimated using the visualization of funnel plots and Egger's test. In the end, twenty-one articles were included in the meta-analysis. Compared with controls, serum Cu level was higher in obese children (SMD (95% CI) 0.74 (0.16, 1.32)) and in obese adults (SMD (95% CI) 0.39 (0.02, 0.76)). There was no significant difference in serum Cu between overweight and control groups in children (SMD (95% CI) 1.52 (- 0.07, 3.12)) and in adults (SMD (95% CI) 0.16 (- 0.06, 0.38)). Moreover, subgroup analysis revealed a higher serum Cu level in obese children (SMD (95% CI) 0.90 (0.36, 1.45)) and obese adults (SMD (95% CI) 0.47 (0.05, 0.88)) compared with healthy weight controls. The SMD differs significantly between obese children diagnosed by weight-for-height and controls (SMD (95% CI) 1.56 (0.57, 2.55)), and there was a significant difference of serum Cu level between obese adults diagnosed by BMI (WHO) and controls (SMD (95% CI) 0.54 (0.08, 1.01)). This meta-analysis indicates that a higher serum Cu level might be associated with the risk of obesity in children and adults, and these findings need to be further confirmed.

The association between serum zinc level and overweight/obesity: a meta-analysis

PURPOSE

The association between serum zinc level and overweight/obesity remains controversial. Hence, we performed a meta-analysis to summarize the relationships.

METHODS

A systematic literature search was performed in PubMed, Web of Science and Embase for relevant English articles up to April 20, 2018. The pooled standardized mean difference (SMD) with 95% confidence interval (CI) was calculated with the random-effect model.

RESULTS

For children and adults, the results showed that serum zinc level was significantly lower in the cases compared to controls ([SMD (95% CI): - 1.13 (- 2.03, - 0.23), Z = 2.45, P for Z = 0.014; I² = 97.1%, P for I² < 0.001] and [SMD (95% CI): - 0.41 (- 0.68, - 0.15), Z = 3.03, P for Z = 0.002; I² = 62.9%, P for I² = 0.009], respectively). The difference of serum zinc level between overweight adults and controls was not statistically significant [SMD (95% CI): - 0.09 (- 0.27, 0.09), Z = 0.97, P for Z = 0.334; I² = 0.0%, P for I² = 0.411]. In subgroup analyses, a lower serum zinc level in obese children compared with non-obese controls was observed [SMD (95% CI): - 2.14 (- 3.20, - 1.09)], and the SMD differ significantly between obese adults and controls in the case-control studies [SMD (95% CI): - 0.49 (- 0.90, - 0.08)].

CONCLUSION

Our meta-analysis suggested that the serum zinc level was significantly lower in obese children and adults. More large observational studies are required to confirm these results in future research.

Trace Elements and Paraoxonase-1 Activity in Lower Extremity Artery Disease

Oxidative stress and inflammation are candidate mechanisms to explain the potential role of exposure to metals and reduced activity of paraoxonase-1 (PON1) in age-related diseases. Both may be risk factors contributing to atherosclerosis. In the present study, inductively coupled mass spectrometry was used to explore multiple trace elements, while in-house methods were employed to measure PON1-related variables in patients with lower extremity artery disease (LEAD). Healthy controls were matched for sex, age, body weight, and relevant genotype variants. Serum concentrations of As, Ba, Cu, and Sr were higher in patients than those in controls, with a strong predictive ability to discriminate between groups. Differences in serum Pb, Cd, and Zn were negligible. Serum Cu increased when the disease was more severe, but a negative trend was noted for serum As, B, Ba, and Zn. The only variable associated with ankle-brachial index was serum Zn. Serum PON1 activity was significantly lower in LEAD patients. When the ability of serum trace elements to modulate PON1 activity was explored, the analysis revealed a unique association with serum Zn. The current results strongly suggest that Zn may have a protective effect in non-coronary atherosclerosis and indicate that this element may exert its anti-inflammatory and antioxidant functions through interactions with PON1 activity. These findings deserve confirmation and further research. In particular, the periodic evaluation of serum trace elements and the prescription of Zn supplements are easy measures to implement and that can improve the treatment of patients with LEAD.

Serum concentrations of trace elements and their relationships with paraoxonase-1 in morbidly obese women

The metabolic alterations associated with obesity include mineral dysregulation. Essential trace elements are nutrients with a relevant function in a large number of cellular processes and multiple roles in the correct functioning of metabolic enzymes. Paraoxonase-1 (PON1) is an antioxidant and anti-inflammatory enzyme that is compromised in obesity. In the present study, the potential alterations in trace elements in morbidly obese women were assessed in relation to serum PON1 activity and concentration, as well as to other obesity-related comorbidities such as diabetes mellitus and fatty liver. We recruited 41 morbidly obese women and 51 control individuals. The serum concentrations of 30 elements, PON1 paraoxonase and lactonase activities, and PON1 concentration were measured. We observed significant alterations in the levels of As, Ba, Cu, Ca, Fe, Mg, Na, Se, Sr, and Zn in obese women; some of them (As, Ca, Cr, Cu, Mg, and Se) being significantly correlated with serum PON1 values. The most relevant changes were observed in the concentrations of As, Sr and Mg, the last of which was also significantly associated with diabetes mellitus. The current results raise the possibility that increased ingestion and/or storage of a number of trace elements may be factors predisposing to obesity-related comorbidities and metabolic alterations.

The Essential Element Manganese, Oxidative Stress, and Metabolic Diseases: Links and Interactions

Manganese (Mn) is an essential element that is involved in the synthesis and activation of many enzymes and in the regulation of the metabolism of glucose and lipids in humans. In addition, Mn is one of the required components for Mn superoxide dismutase (MnSOD) that is mainly responsible for scavenging reactive oxygen species (ROS) in mitochondrial oxidative stress. Both Mn deficiency and intoxication are associated with adverse metabolic and neuropsychiatric effects. Over the past few decades, the prevalence of metabolic diseases, including type 2 diabetes mellitus (T2MD), obesity, insulin resistance, atherosclerosis, hyperlipidemia, nonalcoholic fatty liver disease (NAFLD), and hepatic steatosis, has increased dramatically. Previous studies have found that ROS generation, oxidative stress, and inflammation are critical for the pathogenesis of metabolic diseases. In addition, deficiency in dietary Mn as well as excessive Mn exposure could increase ROS generation and result in further oxidative stress. However, the relationship between Mn and metabolic diseases is not clear. In this review, we provide insights into the role Mn plays in the prevention and development of metabolic diseases.

Fingernail selenium levels in relation to the risk of obesity in Chinese children: A cross-sectional study

Selenium (Se) has been suggested to be beneficial to obesity development. However, limited studies have evaluated the association between Se and childhood obesity and the findings are inconsistent.The aim of this study was to examine the association of Se levels with obesity in children in a cross-sectional study.A total of 62 obese (21 girls) and 65 normal-weight children (27 girls) aged 7 to 13 years were recruited in Shanghai, China. Obesity was defined as body mass index (BMI) ≥ its 95th age- and sex-specific percentile for children. Participant demographic data and parental information were obtained through a self-administered questionnaire. Se concentration in fingernail clippings was quantified using flame atomic absorption spectrophotometry.The average age was 10.9 years (standard deviation = 1.0) and the mean BMI was 21.2 kg/m (standard deviation = 5.0). Fingernail Se levels were relatively higher among normal-weight children as compared with obese participants, though the difference was not statistically significant (P = .79). Se levels were inversely associated with the risk of childhood obesity after adjustment for potential confounders. The multivariable-adjusted odds ratio (95% confidence interval) was 0.24 (0.07-0.84) comparing participants in the highest with those who in the lowest tertile of Se levels (Plinear-trend = .03).Our study supported an inverse association between fingernail Se levels and the risk of obesity in Chinese children. Data generated from the present study are useful for designing future prospective cohort studies and/or randomized clinical trials.

Minerals in thalassaemia major patients: An overview

Thalassaemia major (TM) is a hereditary blood disease characterised by reduced or absent production of beta globin chains. Erythrocyte transfusions are given to raise the haemoglobin level in patients with thalassaemia major. However, transfusions have been related to increased risk of iron overload and tissue damage related to excess iron. Both elevated oxidative stress due to iron overload and increased hemolysis lead to over utilisation of minerals required for antioxidant enzymes activities. Iron chelators have been used to prevent iron overload in thalassaemia major patients, but these chelators have the possibility of removing minerals from the body. Thalassaemia patients are more at risk for mineral deficiency because of increased oxidative stress and iron chelation therapies. Growth and maturational delay, cardiomyopathy, endocrinopathies and osteoporosis are the complications of thalassaemia. Minerals may play a particular role to prevent these complications. In the current review, we provide an overview of minerals including zinc (Zn), copper (Cu), selenium (Se), magnesium (Mg) and calcium (Ca) in thalassaemia major patients. We, also, underline that some complications of thalassaemia can be caused by an increased need for minerals or lack of the minerals.

Metals and Paraoxonases

The paraoxonases (PONs) are a three-gene family which includes PON1, PON2, and PON3. PON1 and PON3 are synthesized primarily in the liver and a portion is secreted in the plasma, where they are associated with high-density lipoproteins (HDLs), while PON2 is an intracellular enzyme, expressed in most tissues and organs, including the brain. PON1 received its name from its ability to hydrolyze paraoxon, the active metabolite of the organophosphorus (OP) insecticide parathion, and also more efficiently hydrolyzes the active metabolites of several other OPs. PON2 and PON3 do not have OP-esterase activity, but all PONs are lactonases and are capable of hydrolyzing a variety of lactones, including certain drugs, endogenous compounds, and quorum-sensing signals of pathogenic bacteria. In addition, all PONs exert potent antioxidant effects. PONs play important roles in cardiovascular diseases and other oxidative stress-related diseases, modulate susceptibility to infection, and may provide neuroprotection (PON2). Hence, significant attention has been devoted to their modulation by a variety of dietary, pharmacological, lifestyle, or environmental factors. A number of metals have been shown in in vitro, animal, and human studies to mostly negatively modulate expression of PONs, particularly PON1, the most studied in this regard. In addition, different levels of expression of PONs may affect susceptibility to toxicity and neurotoxicity of metals due to their aforementioned antioxidant properties.

The Potential Role of Iron and Copper in Pediatric Obesity and Nonalcoholic Fatty Liver Disease

Obesity is a rapidly growing health problem and is paralleled by a multitude of comorbidities, including nonalcoholic fatty liver disease (NAFLD). NAFLD has become the most common chronic liver disease in both adults and children. The current understanding of NAFLD is still fragmentary. While simple steatosis is characterized by the interplay between excessive free fatty acid accumulation and hepatic insulin resistance, the progression to NASH has been related to oxidative stress and a proinflammatory state with dysbalanced adipokine, cytokine levels, and endotoxin-mediated immune response. In addition, oxidative stress has been suggested to play a central role for the sequelae leading to NASH. Trace elements are critical in regulatory, immunologic, and antioxidant functions resulting in protection against inflammation and peroxidation and consequently against the known comorbidities of obesity. Disruptions of the metal detoxification processes located in the liver are plausibly related to NAFLD development via oxidative stress. Perturbations of iron and copper (Cu) homeostasis have been shown to contribute to the pathogenesis of NAFLD. This review presents current data from pediatric studies. In addition, data from adult studies are summarized where clinical relevance may be extrapolated to pediatric obesity and NAFLD.

Interaction between blood selenium concentration and a levels of oxidative stress and antioxidative capacity in healthy children

The study aimed at defining the relationship between blood selenium concentration (Se-B) and levels of oxidative stress and antioxidative capacity in healthy children. The studies were conducted on 337 children (mean age: 8.53±1.92 years). The groups of individuals with Se-B <1st quartile (group I, Se-B<70μg/L), with Se-B fitting the range of 1st quartile and median (group II, Se-B: 70-76.9μg/L), with Se-B between the median and 3rd quartile (group III, Se-B: 77-83.9μg/L) and those with Se-B above the 3rd quartile (group IV, Se-B≥84μg/L) were distinguished. Level of oxidative stress was defined using determination of urine malonyldialdehyde concentration (MDA) and urine 8-hydroxy-2-deoxyguanosine concentration (8-OHdg). Urine total antioxidant status (TAS) was determined. In group IV TAS was significantly higher than in groups I-III. A positive correlation was detected between Se-B and TAS. In healthy children an appropriately high Se-B seems to ensure higher total antioxidative status.