Micronutrients deficiency and associated sociodemographic factors in Chinese children

Estimation of calories intake, iron, zinc, and selenium among children of the underprivileged area in Sindh, Pakistan

INTRODUCTION

Malnutrition is one of the most serious community health issues in developing countries. This study estimated total energy intake, Iron (Fe), Zinc (Zn), Selenium (Se), Calcium (Ca), and Phosphate (PO4) levels among school-going children (aged 13-17 years) of the underprivileged area in Sindh, Pakistan.

METHODS

Children from Mithi City, District Tharparkar, were selected for this cross-sectional investigation. Students from various schools from both genders who fulfilled the selection criteria were selected. A questionnaire was filled, and five ml blood samples were taken to analyze blood parameters. Each participant's estimated nutrient intake (ENI) per day was assessed and matched to the recommended daily allowance (RDA) to determine their micro and macronutrient intake.

RESULTS

A total of 300 school-going children [150(50%) boys (mean age 15± 0.8 years) and 150(50%) girls (mean age 14±1.3years)] were included in this study. Total calories (1449±949 Kcal vs. 1245±215 Kcal; p < .001), carbohydrates (138±27 gm vs. 126 ±25 gm; p < .001) protein (47±9.1 gm vs. 44±6 gm; p < .001) was significantly higher among boys compared to girls. In contrast, calcium (1094±105 mg vs. 1144±100; 0.004), phosphate 1050±125 vs. 1148±147; p<0.001), iron (9.2±1.7 mg vs. 10±1.3 mg; p<0.001), and Zinc (7.4±1.8 mg vs. 9.9±1.7 mg; p<0.001) intake was significantly higher among girls than boys. Gender-wise comparison of serum metals in school-going children showed that serum iron was significantly lower among girls than boys (100.86±25.65 μg/dl vs. 78.48±28.66 μg/dl; p<0.001), and no difference was found in serum Zn, Se, and Ca levels. Total proteins were also significantly lower among girls than boys (6.48±1.01g/dl vs. 4.87±1.4301g/dl; p<0.001). Serum iron, Ca, and total proteins were significantly lower among girls with normal ranges compared to boys with normal ranges. Total protein was significantly lower among girls below normal ranges than boys with normal ranges (p < .001). The correlation of carbohydrates, protein, and fat with some serum biochemical parameters in school-going children showed that serum Fe was significantly linked with proteins (r = 0.255; p < .0.05).

CONCLUSION

Our findings showed a concurrent shortage of macro and micronutrients. The current study also revealed that total energy intake was lower than the RDA and significant Fe, Zn, and Se deficiencies. The findings highlight the importance of measures aimed at improving children's nutritional status.

Intestinal Barrier Impairment Induced by Gut Microbiome and Its Metabolites in School-Age Children with Zinc Deficiency

Zinc deficiency affects the physical and intellectual development of school-age children, while studies on the effects on intestinal microbes and metabolites in school-age children have not been reported. School-age children were enrolled to conduct anthropometric measurements and serum zinc and serum inflammatory factors detection, and children were divided into a zinc deficiency group (ZD) and control group (CK) based on the results of serum zinc. Stool samples were collected to conduct metagenome, metabolome, and diversity analysis, and species composition analysis, functional annotation, and correlation analysis were conducted to further explore the function and composition of the gut flora and metabolites of children with zinc deficiency. Beta-diversity analysis revealed a significantly different gut microbial community composition between ZD and CK groups. For instance, the relative abundances of Phocaeicola vulgatus, Alistipes putredinis, Bacteroides uniformis, Phocaeicola sp000434735, and Coprococcus eutactus were more enriched in the ZD group, while probiotic bacteria Bifidobacterium kashiwanohense showed the reverse trend. The functional profile of intestinal flora was also under the influence of zinc deficiency, as reflected by higher levels of various glycoside hydrolases in the ZD group. In addition, saccharin, the pro-inflammatory metabolites, and taurocholic acid, the potential factor inducing intestinal leakage, were higher in the ZD group. In conclusion, zinc deficiency may disturb the gut microbiome community and metabolic function profile of school-age children, potentially affecting human health.

Alteration in Gut Microbiota Associated with Zinc Deficiency in School-Age Children

Zinc deficiency could lead to a dynamic variation in gut microbial composition and function in animals. However, how zinc deficiency affects the gut microbiome in school-age children remains unclear. The purpose of this study was to profile the dynamic shifts in the gut microbiome of school-age children with zinc deficiency, and to determine whether such shifts are associated with dietary intake. A dietary survey, anthropometric measurements, and serum tests were performed on 177 school-age children, and 67 children were selected to explore the gut microbial community using amplicon sequencing. School-age children suffered from poor dietary diversity and insufficient food and nutrient intake, and 32% of them were zinc deficient. The inflammatory cytokines significantly increased in the zinc deficiency (ZD) group compared to that in the control (CK) group (p < 0.05). There was no difference in beta diversity, while the Shannon index was much higher in the ZD group (p < 0.05). At the genus level, Coprobacter, Acetivibrio, Paraprevotella, and Clostridium_XI were more abundant in the ZD group (p < 0.05). A functional predictive analysis showed that the metabolism of xenobiotics by cytochrome P450 was significantly depleted in the ZD group (p < 0.05). In conclusion, gut microbial diversity was affected by zinc deficiency with some specific bacteria highlighted in the ZD group, which may be used as biomarkers for further clinical diagnosis of zinc deficiency.

Immunity-enhancing Micronutrients and Community Pharmacists: An Opportunity to Expand Self-Care Practices among the Public

Background: The urban lifestyle and environment pose a constant immune challenge to city dwellers. A major such challenge is influenza, which creates substantial public health and socio-economic burdens. The global healthcare paradigm has begun emphasizing the importance and cost-effectiveness of self-care in partnership with healthcare professionals such as community pharmacists for the management of mild ailments. For the general public, micronutrient supplementation is an affordable and potentially feasible self-care strategy for immunity enhancement and disease management. At the same time, micronutrient deficiencies are a serious public health concern in both developing and developed areas. Objective: This review focuses on the clinical evidence for the efficacy and safety of three key micronutrients — vitamins C, D and zinc — on respiratory infections. Key findings: These micronutrients are important for optimal immune function through their complementary roles in supporting both innate and adaptive immunity, as well as epithelial barriers. The need to improve public awareness of self-care in prevention and health management is highlighted by recent public health issues and the global fight against antimicrobial resistance. Community pharmacists could play a crucial role in empowering patient autonomy. Conclusion: With this review we aim to offer insights into the supplementation of these micronutrients as a self-care approach to the management of immune health.

Longitudinal association of early childhood lead exposure and adolescent heart rate variability: influence of parental education

Lead exposure has been shown to dysregulate physiological stress responses. However, few studies have investigated the effect of lead exposure on later heart rate variability (HRV), an indicator of a stress response, in large samples of children. Furthermore, the interaction between social environmental factors and lead exposure in childhood, which commonly co-occur, remains understudied. This study examined relationships between childhood lead exposure and early adolescent physiological stress responses at different levels of parental education. Participants were 406 children from Jintan, China. Blood lead levels (BLLs) and parental education data were collected at 3-5 years of age, and HRV outcomes assessed at 12 years via frequency domain measures (LF/HF ratio) collected during an induced stress test. Results show a significant interaction between parental education and BLLs at 3-5 years. This relationship was found to be most consistent for the interaction between BLLs and mother's years of education for both the planning (β = 0.12, p = 0.046) and speaking (β = 0.11, p = 0.043) phase of the stress task, suggesting that increasing years of mother's education may enhance the deleterious influence of lead exposure on the HRV frequency measure, LF/HF ratio. This research highlights the complexity in lead exposure induced outcomes.

Lower serum selenium concentration associated with anxiety in children

PURPOSE

Few studies have examined the role of selenium in anxiety. This study aimed to evaluate the association between serum selenium concentrations and anxiety disorders and symptoms in children.

DESIGN AND METHODS

This study utilized data from 831 children participating in the China Jintan Child Cohort Study (mean age = 12.67 years; 46.1% female). Serum selenium samples were collected and anxiety was assessed using the Chinese version of the Screen for Child Anxiety Related Disorders. Six types of anxiety scores were calculated, including total anxiety, panic/somatic, generalized anxiety, separation anxiety, social anxiety, and school phobia.

RESULTS

Controlling for covariates, children with lower serum selenium concentrations were more likely to meet clinical cutoffs for total anxiety (OR = 0.992, p < 0.01), panic/somatic disorder (OR = 0.993, p < 0.05), generalized anxiety disorder (OR = 0.990, p < 0.05), social anxiety disorder (OR = 0.991, p < 0.01), and school phobia (OR = 0.989, p < 0.01), but not separation anxiety (OR = 1.000, p > 0.05). Controlling for covariates, lower serum selenium concentrations were also associated with higher continuous total anxiety, generalized anxiety, and school phobia scores (p < 0.05).

CONCLUSIONS

Lower serum selenium concentrations were associated with higher anxiety. To our knowledge, this was the first study to examine the relationship between serum selenium and anxiety disorders in a sample of children. Results indicate an association between children's micronutrient levels and anxiety disorders.

PRACTICE IMPLICATIONS

Improving child nutrition may be a promising strategy to help reduce childhood anxiety.

Serum micronutrient status, sleep quality and neurobehavioural function among early adolescents

OBJECTIVE

To examine associations between serum micronutrients and neurobehavioural function and the mediating role of sleep quality in early adolescents.

DESIGN

In this cross-sectional study, peripheral blood samples were analysed for Fe and Zn levels. The Pittsburgh Sleep Quality Index and Penn Computerized Neurocognitive Battery were used to assess sleep quality and neurobehavioural function, respectively. The logistic/linear regressions and generalised structural equation modelling were performed to estimate the associations.

SETTING

Jintan, China.

PARTICIPANTS

In total, 226 adolescents (106 females) from the Jintan Child Cohort study.

RESULTS

Adolescents with low Fe (<75 μg/dl) (OR = 1·29, P = 0·04) and low Zn (<70 μg/dl) (OR = 1·58, P < 0·001) were associated with increased odds for poor sleep quality. Adolescents with low Fe and Zn were associated with fast (Fe: β = -1353·71, P = 0·002, Zn: β = -2262·01, P = 0·02) but less-accurate (Fe: β = -0·97, P = 0·04; Zn: β = -1·76, P = 0·04) performance on non-verbal reasoning task and poor sleep quality partially mediated the associations between low Fe/Zn and non-verbal reasoning (P < 0·05). Additionally, low Fe was associated with a slower reaction on spatial processing task (β = 276·94, P = 0·04), and low Zn was associated with fast (β = -1781·83, P = 0·03), but error-prone performance (β = -1·79, P = 0·04) on spatial processing ability and slower reaction speed (β = 12·82, P = 0·03) on the attention task. We observed similar trends using a cut-off point of 75 μg/dl for low serum Zn, except for the association with attention task speed (P > 0·05).

CONCLUSION

Fe and Zn deficiencies may possibly be associated with poor sleep and neurobehavioural function among early adolescents. Poor sleep may partially mediate the relationship between micronutrients and neurobehavioural function.

Prevalence and risk factor analysis of iron deficiency and iron-deficiency anaemia among female adolescents in the Gaza Strip, Palestine

Objective

The present study aimed to determine the prevalence of anaemia, iron deficiency (ID) and iron-deficiency anaemia (IDA) among female adolescents in the Gaza Strip, Palestine, as well as the risk factors involved in these conditions.

Design

The study was conducted using the quantitative descriptive method with a cross-sectional design. Data were collected using an FFQ and sociodemographic, sedentary behaviour and physical activity questionnaires. Anthropometric measurements and blood analyses were also conducted.

Setting

The study population included all Palestinian female adolescents enrolled in secondary schools in the academic years 2015–2016. Five female secondary schools were selected randomly from five governorates of the Gaza Strip.

Subjects

Female adolescents (n330) aged 15–19 years in the selected secondary schools were enrolled randomly.

Results

Prevalence of anaemia, ID and IDA among female adolescents in the Gaza Strip, Palestine, was 35·8, 40·3 and 26·0 %, respectively. A significant association (P<0·05) existed between ID, anaemia and IDA and dietary habits, including skipping breakfast and amount of junk food intake. Also, low consumption of fruits and vegetables was associated with IDA in the female adolescents. A statistically significant association was found between mother’s education and ID but not with the other sociodemographic factors.

Conclusions

The study shows that there is an alarming problem of anaemia and IDA in the Gaza Strip, Palestine. This may indicate that there are insufficient nutrition education programmes, particularly inside schools or by the mass media.

High Prevalence of Zinc Deficiency in Rural Nigerian Preschool Children: A Community-Based Cross-Sectional Study

Background and Aims: In Nigeria, community-based epidemiological data related to the prevalence of zinc deficiency in preschool children are scarce. We assessed the prevalence of zinc deficiency and the associated socio-demographic variables in children aged between 6 and 60 months, living in a Nigerian rural community.

Materials and Methods: In this cross-sectional study, the serum zinc concentrations of 252 children aged between 6 and 60 months in a rural community in Nigeria were assessed, using atomic absorption spectrophotometry. The study population was selected by multistage random sampling and at least two children were selected from every household which had children in the study age group. The socio-demographic characteristics of the subjects were obtained, using an interviewer-administered questionnaire.

Results: A total of 252 children were studied, 134 (53.2%) males and 118 (46.8%) females. The mean age was 32.7±17.0 months, similar for both sexes. Overall, 220 (87.3%) had low serum zinc concentrations (less than 7.65µmol/L). According to age, the highest mean serum zinc concentration was 5.43±3.52µmol/L in children aged between 6 and 12 months. Correlation between serum zinc concentration and family size or socio-economic status (SES) showed that the smaller the family size and the higher the SES, the higher the serum zinc concentration.

Conclusions: The high prevalence of low serum zinc concentration indicates that zinc deficiency is a public health problem in our rural communities, requiring public health intervention.

The relationship between micronutrient status and sleep patterns: a systematic review

OBJECTIVE

To review articles on the relationship of dietary and circulating micronutrients with sleep patterns, and to identify issues surrounding implications for future research and public health practice.

DESIGN

A systematic review was conducted. PubMed, Embase and Scopus were searched through January 2016.

SETTING

Both experimental and observational studies were included. However, studies that focused on secondary sleep impairment due to comorbidities were excluded.

SUBJECTS

Individuals in different age groups, from infants to older adults.

RESULTS

A total of twenty-six articles were selected. In the articles reviewed, researchers generally supported a potential role of micronutrients, particularly Fe and Mg, in the development of sleep stages among infants and in reversing age-related alterations in sleep architecture in older adults. Micronutrient status has also been linked to sleep duration, with sleep duration positively associated with Fe, Zn and Mg levels, and negatively associated with Cu, K and vitamin B12 levels. The mechanisms underlying these relationships include the impact of micronutrients on excitatory/inhibitory neurotransmitters and the expression of circadian genes.

CONCLUSIONS

Although the number of studies on the relationship between micronutrient status and sleep remains low, evidence has emerged that suggests a link between dietary/circulating micronutrients and sleep. Future research is needed to investigate the dose-dependent as well as the longitudinal relationships between micronutrient levels and human sleep across populations, test the interactions among micronutrients on sleep outcomes, and ultimately examine the clinical relevance of micronutrients on sleep health.

Does the gender of parent or child matter in child maltreatment in China?

Child maltreatment is a public health problem worldwide, and China is no exception. However, the pattern of child maltreatment remains unknown, including whether the gender of children and their parents has an impact on the occurrence of maltreatment. This study aims at examining the rates and frequency of child maltreatment, including physical abuse, psychological abuse and neglect perpetrated by mothers and fathers. We also test whether the interaction between parents' gender and their child's gender affects the occurrence of child maltreatment in China. 997 children from the China Jintan Child Cohort Study participated in the present study and reported their maltreatment experience perpetrated by their mothers and fathers using the questionnaire, Parent-Child Conflict Tactics Scale (CTSPC_CA). Generalized linear model analyses show that boys were more likely than girls to report physical abuse, and, in particular, boys were more likely than girls to be physically abused by their fathers. On the other hand, mothers were more likely than fathers to exhibit psychological aggression and use corporal punishment for both boys and girls. There was no difference based on the child's or parent's gender in the occurrence of neglect. The findings present empirical evidence that enhances the understanding of the pattern of child maltreatment in China, provide implications for social workers and health professionals to identify children at risk of child maltreatment, and shed light on future research studies.

Cohort Profile Update: The China Jintan Child Cohort Study

The China Jintan Child Cohort study began in 2004 with 1656 pre-school participants and a research focus on studying the impact of environmental exposures, such as lead, on children's neurobehavioural outcomes. This population cohort now includes around 1000 of the original participants, who have been assessed three times over a period of 10 years. Since the original IJE cohort profile publication in 2010, participants have experienced a critical developmental transition from pre-school to school age and then adolescence. The study has also witnessed an increase in breadth and depth of data collection from the original aim of risk assessment. This cohort has added new directions to investigate the mechanisms and protective factors for the relationship between early health factors and child physical and mental health outcomes, with an emphasis on neurobehavioural consequences. The study now encompasses 11 domains, composed of repeated measures of the original variables and new domains of biomarkers, sleep, psychophysiology, neurocognition, personality, peer relationship, mindfulness and family dynamics. Depth of evaluation has increased from parent/teacher report to self/peer report and intergenerational family report. Consequently, the cohort has additional directions to include: (i) classmates of the original cohort participants for peer relationship assessment; and (ii) parental and grandparental measures to assess personality and dynamics within families. We welcome interest in our study and ask investigators to contact the corresponding author for additional information on data acquisition.

Association between Serum Copper Status and Working Memory in Schoolchildren

Trace elements such as copper are essential micronutrients. Traditionally, copper has been studied in the context of micronutrient deficiencies. Recent studies in both animals and humans, however, have revealed that elevated blood copper can also have adverse effects on cognitive function since free copper can cross the blood-brain barrier and subsequently impose oxidative stress to neuronal cells. However, most of these human studies were conducted in adult populations with and without cognitive decline, and there are few studies on the effect of excess copper on cognitive function in children. This project seeks to look at the effects of elevated copper levels on cognitive development in a population of school age children (ages 10–14 years with mean age of 12.03 years and standard deviation (SD) of 0.44) from Jintan, China. Briefly, serum copper levels and working memory test scores were collected from a sample of 826 children with a mean serum copper level of 98.10 (SD 0.75). Copper level was considered as a categorical variable (taking the first group as those with as ≤84.3 μg/dL, the second group as >84.3 and ≤110.4 μg/dL, and the third group as >110.4 μg/dL with the cut-off values defined by the first and third quartiles of the sample). Results showed a significant association between high copper levels (>110.4 μg/dL) and poorer working memory in boys but this association was not seen in lower copper levels in either sex. These results suggests that in school age children, like in adults, elevated copper levels have the potential to adversely affect cognition.

Associations between Blood Zinc Concentrations and Sleep Quality in Childhood: A Cohort Study

Little evidence is available regarding the relationship between zinc and sleep in school children. The present study aimed to examine the cross-sectional and longitudinal associations between blood zinc concentrations and sleep quality throughout childhood. A total of 1295 children from the Jintan Child Cohort in China were included in this study. Venous blood sample of zinc and subjective sleep data were collected when the children were at preschool age (3-5 years old) and early adolescence (11-15 years old). Odds ratios (ORs) reflect the odds of the sleep quality/subdomain being at a greater impairment level associated with 1 unit increase in log zinc concentration. Cross-sectional analyses showed negative correlation of blood zinc concentrations with insufficient sleep duration (OR = 0.432, p = 0.002), sleep disturbances (OR = 0.454, p = 0.009) and poor sleep quality (OR = 0.559, p = 0.049) in adolescence, but no association at preschool age (p > 0.05). Longitudinal analyses indicated that blood zinc concentrations at preschool age predict poor sleep efficiency (OR = 0.186, p = 0.000) and poor sleep quality (OR = 0.358, p = 0.020) in adolescence. Our findings suggest that sufficient zinc concentration is associated with good sleep quality, dependent on the developmental stage in childhood. Future interventional research is warranted to examine the short and long-term effect of zinc status on sleep heath.

The prevalence of wheezing and its association with serum zinc concentration in children and adolescents in Brazil

OBJECTIVE

To assess the influence of zinc serum status on the prevalence of wheezing in a sample of children and adolescents in Northeastern Brazil.

RESEARCH METHODS AND PROCEDURES

This is a cross-sectional study which included 592 students of 6-12 years old, from the public elementary schools of São Francisco do Conde, Bahia, Northeastern Brazil. Report of wheezing in the past 12 months was collected using a questionnaire of the International Study of Asthma and Allergies in Childhood Program (ISAAC) phase III, adapted to Portuguese. The determination of serum Zn levels was performed using a flame atomic absorption spectrometer. Data on anthropometric status, level of physical activity, pubertal development and socioeconomic information, for each participant were obtained. Multivariate logistic regression analyses were used to assess the associations of interest.

RESULTS

Of the students, 8.6% (95% CI 6.30-10.9) reported having wheezing. The mean (SD) serum zinc level was 114 (22.9 μg/dL). The results of the multiple logistic regression analysis showed, after adjustments, positive and significant association between low serum zinc levels and wheezing. Students categorized as being below the median for serum Zn concentration presented an almost 1.9-fold increase in the wheezing prevalence ratio (OR=1.9; 95% CI 1.03-3.53).

CONCLUSION

The main findings of this study suggest that the level of zinc may influence the risk of wheezing in late childhood on the study population.

Effect of simultaneous supplementation of vitamin A and iron on diarrheal and respiratory tract infection in preschool children in Chengdu City, China

OBJECTIVE

The goal of this study was to investigate whether vitamin A combined with iron supplementation for preschool children resulted in improved changes in children's infectious morbidity.

METHOD

In this randomized placebo-controlled and blinded field intervention trial, totally 445 preschoolers, ages 3 to 6 y old, were randomly selected. All children were randomly divided into four groups: vitamin A supplement-only group (group I), iron supplement-only group (group II), vitamin A and iron supplement group (group III), and no vitamin A and ferrous sulfate as placebo-control (group IV) for 6 mo. The morbidity of diarrhea and respiratory infections, were collected during supplementation.

RESULTS

There was evidence of the lowest incidence rate of respiratory-related illnesses and fewest symptoms of runny nose, cough, and fever for children in group III compared with children in groups I, II and IV (P < 0.05). Moreover, despite the undistinguished incidence rate of vomiting, nausea, and stomach pain, the rate of diarrhea-related illness was significantly lower for children in group III than for those in the other three groups.

CONCLUSION

The beneficial affects on infectious morbidity over 6 mo, highlight the potential of vitamin A plus an iron supplement for preschool-aged children.

Low blood zinc, iron, and other sociodemographic factors associated with behavior problems in preschoolers

Previous research supports the link among malnutrition, cognitive dysfunction, and behavioral outcomes; however, less research has focused on micronutrient deficiencies. This study investigates whether micronutrient deficiencies, specifically blood zinc and iron levels, will be associated with increased behavior problem scores, including internalizing and externalizing behaviors. 1314 Children (55% boys and 45% girls) from the Jintan Preschool Cohort in China participated in this study. Venous blood samples were collected and analyzed for zinc and iron when the children were 3-5 years old. Behavior problems were measured with the Child Behavior Checklist (CBCL), which was completed by the parents when children were in their last months of preschool (mean age 5.6 years). General linear multivariate modeling was used, with adjustment for important sociodemographic variables. The results indicate that low zinc levels alone (p = 0.024) and combined low zinc and iron levels (p = 0.022) are significantly associated with increased reports of total behavior problems. We did not find an association between low iron and behavior problems. With regards to sociodemographics, living in the suburbs is associated with increased internalizing problems, while higher mother's education and being female were associated with decreased externalizing problems. This study suggests that micronutrient deficiencies and sociodemographic facts are associated with behavior problems in preschoolers.

Parent-reported mild head injury history and behavioural performance in children at 6 years

OBJECTIVE

Mild head and brain injuries have gained increasing attention from health professionals and researchers. Little is known about mild injuries, which may not always be diagnosed or brought to medical attention. This study examines the associations between parent-reported history of mild head injury and behavioural problems in a large community-based sample of Chinese children.

METHOD

Subjects included 725 children from China. Parents reported on children's head injury history and behaviour at age 6 years using the Chinese version of the Child Behavior Checklist. Mild head injury was defined as injury without loss of consciousness or hospitalization. Standardized T-scores were compared for each of the seven clinical sub-scales and three summary behavioural measures, adjusting for confounders. Logistic models were used to calculate odds ratios (ORs) between head injury and behavioural problems.

RESULTS

Parents reported that 97 children (14%) had a single injury and 70 (10%) had multiple injuries. Compared to the controls, head-injured children had worse behavioural outcomes and a higher prevalence of behavioural problems. Multiple injuries were associated with higher risk of certain internalizing and externalizing problems.

CONCLUSION

Mild head injuries, especially incurred repeatedly, may still be a significant risk for adverse behaviours in children.

Impact of low blood lead concentrations on IQ and school performance in Chinese children

Objectives

Examine the relationships between blood lead concentrations and children's intelligence quotient (IQ) and school performance.

Participants and Methods

Participants were 1341 children (738 boys and 603 girls) from Jintan, China. Blood lead concentrations were measured when children were 3–5 years old. IQ was assessed using the Chinese version and norms of the Wechsler Preschool and Primary Scale of Intelligence – Revised when children were 6 years old. School performance was assessed by standardized city tests on 3 major subjects (Chinese, Math, and English [as a foreign language]) when children were age 8–10 years.

Results

Mean blood lead concentration was 6.43 µg/dL (SD = 2.64). For blood lead concentrations, 7.8% of children (n = 105) had ≥10.0 µg/dL, 13.8% (n = 185) had 8.0 to <10.0 µg/dL, and 78.4% (n = 1051) had <8.0 µg/dL. Compared to children with blood lead concentrations <8 µg/dL, those with blood lead concentrations ≥8 µg/dL scored 2–3 points lower in IQ and 5–6 points lower in school tests. There were no significant differences in IQ or school tests between children with blood lead concentrations groups 8–10 and ≥10 µg/dL. After adjustment for child and family characteristics and IQ, blood lead concentrations ≥10 µg/dL vs <8 µg/dL at ages 3–5 years was associated with reduced scores on school tests at age 8–10 years (Chinese, β = −3.54, 95%CI = −6.46, −0.63; Math, β = −4.63, 95%CI = −7.86, −1.40; English, β = −4.66, 95%CI = −8.09, −1.23). IQ partially mediated the relationship between elevated blood lead concentrations and later school performance.

Conclusions

Findings support that blood lead concentrations in early childhood, even <10 µg/dL, have a long-term negative impact on cognitive development. The association between blood lead concentrations 8–10 µg/dL and cognitive development needs further study in Chinese children and children from other developing countries.

Hemoglobin status associated with performance IQ but not verbal IQ in Chinese preschool children

BACKGROUND

Despite the body of literature that links anemia with poorer cognition in children and the evidence that the severity of the effects of anemia on children's cognition vary in different populations, few studies have investigated the effects of anemia on the cognitive development of Chinese children.

METHODS

This longitudinal cohort included 171 children from a developing region of China. Hemoglobin (Hb) and iron levels were taken when the children were 4 years old. At age 6, the children's cognition was tested with the Chinese Wechsler Preschool and Primary Scale of Intelligence. Psychosocial information was also used in analyses.

RESULTS

Results showed that the children who had low Hb levels had significantly lower scores in performance IQ (PIQ), but not verbal IQ. Although blood Fe levels were not shown to moderate the link between Hb levels and IQ, we found children who performed the best on IQ tests exhibited low iron levels concurrent with high Hb levels, whereas the group who performed the worst exhibited high iron but low Hb levels. We also found that psychosocial adversity did not differ significantly between children who had normal or low Hb levels, although the effect of Hb on PIQ became only suggestive after controlling for psychosocial adversity, therefore the correlation is not causal but only a suggestive association.

CONCLUSION

Our findings are in agreement with literature on the negative effects of anemia on children's cognition and point to the possibility that the portions of the brain associated with PIQ components are particularly affected by low Hb during crucial periods of development.