Serum transferrin and ferritin in pubertal boys: relations to body growth, pubertal stage, erythropoiesis, and iron deficiency

Age, sex, and cell type-resolved hypothalamic gene expression across the pubertal transition in mice

BACKGROUND

The hypothalamus plays a central role in regulating puberty. However, our knowledge of the postnatal gene regulatory networks that control the pubertal transition in males and females is incomplete. Here, we investigate the age-, sex- and cell-type-specific gene regulation in the hypothalamus across the pubertal transition.

METHODS

We used RNA-seq to profile hypothalamic gene expression in male and female mice at five time points spanning the onset of puberty (postnatal days (PD) 12, 22, 27, 32, and 37). By combining this data with hypothalamic single nuclei RNA-seq data from pre- and postpubertal mice, we assigned gene expression changes to their most likely cell types of origin. In our colony, pubertal onset occurs earlier in male mice, allowing us to focus on genes whose expression is dynamic across ages and offset between sexes, and to explore the bases of sex effects.

RESULTS

Our age-by-sex pattern of expression enriched for biological pathways involved hormone production, neuronal activation, and glial maturation. Additionally, we inferred a robust expansion of oligodendrocytes precursor cells into mature oligodendrocytes spanning the prepubertal (PD12) to peri-pubertal (PD27) timepoints. Using spatial transcriptomic data from postpubertal mice, we observed the lateral hypothalamic area and zona incerta were the most oligodendrocyte-rich regions and that these cells expressed genes known to be involved in pubertal regulation.

CONCLUSION

Together, by incorporating multiple biological timepoints and using sex as a variable, we identified gene and cell-type changes that may participate in orchestrating the pubertal transition and provided a resource for future studies of postnatal hypothalamic gene regulation.

Dietary Patterns and Association with Anemia in Children Aged 9-16 Years in Guangzhou, China: A Cross-Sectional Study

Anemia affects 1.8 billion people worldwide, and diet is one of the key modifiable factors for treating anemia in children. The dietary pattern has changed rapidly in recent decades, but its effect on childhood anemia has not been reported. This study aimed to identify dietary patterns among children in rural areas of Guangzhou, China, and explore their association with anemia. A total of 1476 children aged 9-16 years old were included in this study. Demographics, lifestyle, and anthropometric and dietary information were collected. Factor analysis was used to identify dietary patterns, and anemia was diagnosed based on hemoglobin levels. Robust Poisson regression and subgroup analysis were used to analyze the association between dietary patterns and anemia. The prevalence of anemia in children was 10.4%, with 6.1% in boys and 15.4% in girls. Four dietary patterns were identified, including a fast food pattern, a vegetarian pattern, a meat and egg pattern, and a rice and wheat pattern. A high score in the fast food pattern was positively associated with risk of anemia in children entering puberty (PR = 1.767, 95% CI: 1.026~3.043, p = 0.039), especially in girls after menarche, with marginal significance (PR = 1.740, 95% CI: 0.977~3.097, p = 0.059). A high score in the meat and egg pattern was negatively associated with risk of anemia in children entering puberty (PR = 0.498, 95% CI: 0.286~0.866, p = 0.013), especially in boys after spermatorrhea (PR = 0.237, 95% CI: 0.031~0.590, p = 0.007). The fast food pattern was a risk factor for anemia in children, and the meat and egg pattern was a protective factor for anemia in children entering puberty. The findings of this study could be used to guide the strategies of evidence-based preventive nutrition interventions to curb anemia in children.

Non-invasive methods for the assessment of biomarkers and their correlation with radiographic maturity indicators - a scoping review

BACKGROUND

Detection of skeletal maturity is vital in orthodontic treatment timing and planning. Traditional methods include hand-wrist radiography and cervical vertebral maturation index (CVMI). Though the radiographic methods are well established and routinely used to assess skeletal maturation, they carry the drawback of subjective perception and low reproducibility. With evolving concepts, skeletal maturation has been assessed quantitatively through biomarkers obtained from saliva, gingival crevicular fluid (GCF), and urine. The scoping review aims to explore the various biomarkers assessed through non-invasive methods and their correlation with radiographic skeletal maturity.

METHODOLOGY

The literature search was carried out on MEDLINE via Pubmed, Cochrane Library (Cochrane database of systematic reviews), Cochrane central register of controlled trials (CENTRAL), Google Scholar, Semantic Scholar, ScienceDirect, and Opengrey.eu for articles up to and including November 2020. Pertinent articles were selected based on inclusion and exclusion criteria. The results were tabulated based on the type of sample collected, the biomarker assessed, method of sample collection, and the radiographic method used.

RESULTS

The literature search resulted in 12 relevant articles. Among all the studies, 10 studies showed that the concentration of biomarkers increases during the pubertal growth peak. On the contrary, 2 articles showed no significant difference between the levels of biomarkers and pubertal growth peak.

CONCLUSION

It can be concluded that the level of biomarkers increases during the pubertal growth spurt and can provide a quantitative way of assessing skeletal maturity.

The critical roles of iron during the journey from fetus to adolescent: Developmental aspects of iron homeostasis

Iron is indispensable for human life. However, it is also potentially toxic, since it catalyzes the formation of harmful oxidative radicals in unbound form and may facilitate pathogen growth. Therefore, iron homeostasis needs to be tightly regulated. Rapid growth and development require large amounts of iron, while (especially young) children are vulnerable to infections with iron-dependent pathogens due to an immature immune system. Moreover, unbalanced iron status early in life may have effects on the nervous system, immune system and gut microbiota that persist into adulthood. In this narrative review, we assess the critical roles of iron for growth and development and elaborate how the body adapts to physiologically high iron demands during the journey from fetus to adolescent. As a first step towards the development of clinical guidelines for the management of iron disorders in children, we summarize the unmet needs regarding the developmental aspects of iron homeostasis.

Preliminary validation of serotransferrin and vitamin D binding protein in the gingival crevicular fluid as candidate biomarkers for pubertal growth peak in subjects with Class I and Class II malocclusion

INTRODUCTION

Identification of pubertal growth peak is of great importance for the orthopedic treatment of Class II malocclusion. Our previous work demonstrated that vitamin D binding protein (DBP) and serotransferrin (TF) in gingival crevicular fluid (GCF) could be candidate biomarkers of pubertal growth peak. This research aimed to preliminarily validate TF and DBP in subjects with Class I and Class II malocclusion, to compare their diagnostic accuracy, and to construct a statistic model to help the diagnosis of skeletal pubertal peak.

METHODS

Sixty-six circumpubertal subjects were recruited, including 32 subjects with Class I malocclusion and 34 subjects with Class II malocclusion. All subjects were divided into prepubertal, pubertal, and postpubertal groups according to their cervical vertebral maturation stages. GCF samples were collected, and the concentration of DBP and TF were detected by enzyme-linked immunosorbent assay.

RESULTS

Percentage of TF in GCF was significantly higher in pubertal than in prepubertal and postpubertal groups, in subjects with Class I and Class II malocclusion, whereas the difference observed in DBP was less significant. The diagnostic accuracy of TF was better than DBP and chronological age. The most optimal thresholds of maxillary and mandibular TF in distinguishing pubertal from nonpubertal subjects were 4.20% and 4.09%, respectively. The combination of TF and age exhibited the best diagnostic accuracy.

CONCLUSIONS

TF in GCF could be considered as a potential biomarker of pubertal peak and can assist the diagnosis of skeletal pubertal peak.

Proteomic analysis of gingival crevicular fluid for novel biomarkers of pubertal growth peak

Background

Detection of pubertal growth peak is vital in orthodontic treatment timing and planning. Gingival crevicular fluid (GCF) contains abundant proteins from different sources and is an ideal source of biomarkers. The aim of this research is to detect candidate GCF biomarkers of pubertal growth by tandem mass tags (TMT) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to help diagnosis and treatment planning of functional treatment.

Methods

Forty subjects were recruited and were divided into pubertal and post-pubertal groups according to cervical vertebral maturation method. GCF samples were collected by paper points. GCF proteome of pubertal and post-pubertal subjects was compared by TMT labelling coupled with LC-MS/MS.

Results

A total of 537 proteins were detected in GCF samples, with 183 proteins detected in GCF for the first time. These proteins were involved in processes of immune response, ion transport, and signal transduction. The GCF concentration of vitamin D binding protein (DBP) and seroserotransferrin (Tf) was significantly higher in pubertal than that in post-pubertal subjects. DBP and Tf, therefore, were considered to be candidate biomarkers of pubertal growth. This result was validated using GCF samples from new subjects (P < 0.05).

Conclusion

Our results indicate that TMT labelling coupled with LC-MS/MS were proved to be a useful method for proteomic analysis of GCF with high accuracy. The expression of DBP and Tf was increased in children at circumpubertal stage and can be considered candidate biomarkers of pubertal growth.

The Lack of Association of Iron Deficiency With Anemia in First Graders

Iron-deficiency anemia (IDA) is a disease with worldwide prevalence. The prevalence of IDA and iron deficiency (ID) was ascertained by serum ferritin and mean corpuscular volume (MCV) levels in first graders in Taibe. A total of 1132 first graders were tested for the iron status between the years 1999 and 2004. Serum ferritin, hemoglobin (Hb), hematocrit, MCV, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and red and white blood cell counts were checked. Hb<11.5 g/dL, serum ferritin<12 μg/L, and MCV<75 fL were the criteria we chose for establishing IDA, and serum ferritin<12 μg/L and MCV<75 fL for establishing ID. Non-IDA was ascertained by a low Hb value, coupled with normal serum ferritin. The mean value of serum ferritin was 26.6±16.8 μg/L. Eighty-two (11.8%) children had low serum ferritin (<12 μg/L). The mean value of Hb was 12.3±0.8, and 80 (11.5%) of the children had low Hb. A correlation was found between hematological parameters and Hb. The prevalence of IDA, ID, and non-IDA was 2.2%, 11.8%, and 9.4%, respectively. No correlation was found between indices of anemia and demographic characteristics. Non-IDA and ID are prevalent in 5 to 6-year-old Arab children; however, IDA is surprisingly low. We need to look for other causes of anemia in this age group of the population.

Iron status in elite young athletes: gender-dependent influences of diet and exercise

Iron depletion seems to occur more frequently among athletes than in the general population and may affect performance capacity. Only little information is available about the prevalence of iron status abnormalities in young elite athletes and whether iron depletion is associated with gender, sport, age or nutrition- and exercise-related factors in this group. Hence, diet, exercise and haematological data from 193 elite athletes (96 males, 97 females; 16.2 ± 2.7 years) from 24 different sports were analyzed retrospectively. Most female athletes failed to meet the recommended daily allowance for iron, even though dietary iron density was higher than in males (5.75 ± 0.78 vs. 6.17 ± 0.98 mg/1,000 kcal; P = 0.001). Iron depletion (serum ferritin < 35 μg/L) occurred in 31% of male and 57% of female athletes (P < 0.001). Low haemoglobin (males: <13 g/dL; females: <12 g/dL) and haematocrit (males: <40%; females: <36%) values were equally prevalent in both genders [haemoglobin: 7.3% (males), 6.2% (females); haematocrit: 13.5% (males); 15.5% (females)]. In females, reduced ferritin levels were associated with a lower dietary iron density (5.9 ± 0.8 vs. 6.6 ± 1.1 mg/1,000 kcal; P = 0.002). Males with iron depletion had a significantly higher estimated energy expenditure (48.7 ± 7.0 vs. 44.4 ± 7.6 kcal/kg/day; P = 0.009).

The beneficial effect of Mediterranean dietary patterns on dietary iron utilization in male adolescents aged 11-14 years

The effects of a diet based on Mediterranean patterns on iron bioavailability and iron status in adolescents were studied. The study was divided into two periods: basal period, in which 21 male adolescents consumed their habitual diet (basal diet); and nutritional intervention period, during which an experimental diet based on the Mediterranean model was consumed. Dietary iron utilization was studied by means of iron intake and iron output in faeces and urine, and iron status was analysed in fasting blood samples collected at the end of each period. No differences in total iron intake were found between diets, but consumption of the experimental diet increased iron absorption and retention compared with the basal diet. Biochemical parameters related to iron metabolism did not vary after the intervention period, although serum ferritin tended to increase. Therefore, a diet based on Mediterranean dietary patterns may improve dietary iron utilization during adolescence and may prevent iron deficiency.

Proporção de anemia de acordo com o estadiamento puberal, segundo dois critérios diagnósticos

OBJETIVO: Identificar a proporção de anemia ferropriva e sua distribuição por estadiamento puberal, em pacientes atendidos em ambulatório de adolescência, e comparar os valores de corte habitualmente utilizados na adolescência para esse diagnóstico. MÉTODOS: Estudo retrospectivo, por análise de 453 prontuários dos pacientes atendidos de janeiro a dezembro de 2003, no Centro de Atendimento e Apoio ao Adolescente do Departamento de Pediatria da Universidade Federal de São Paulo, Escola Paulista de Medicina. Destes, 215 (47,0%) rapazes e 238 (53,0%) moças. Utilizaram-se os testes de Kappa e McNemar para avaliar as concordâncias e discordâncias entre dois critérios distintos; teste "t" de Student para determinar as diferenças entre hemoglobina e índices hematimétricos nos grupos anêmico e não anêmico; e teste de Mann-Whitney para comparar os valores de hematócrito. RESULTADOS: A proporção de anemia, segundo os critérios adotados, foi de 7,50% (n=34) e 6,84% (n=31) na população; por estadiamento puberal encontrou-se, no sexo feminino, maior proporção nos estágios de mama 3 (30,00%) e 4 (50,00%) e no sexo masculino, em genitais 3 (40,00%), havendo concordância entre os dois critérios. CONCLUSÃO: Embora baixa, a proporção de anemia é relevante. A concordância obtida entre os valores propostos mostra que é possível usar qualquer um dos critérios. Há predomínio de anemia nas moças em estágio de mamas 3 e 4, justificado pela maior necessidade de ferro e perdas menstruais, que ocorrem nessas fases, respectivamente; nos rapazes, a proporção maior em estágio 3 (fase de aceleração de crescimento) pode sugerir que eles já estavam depletados antes de entrar na puberdade.

Severe malnutrition is associated with decreased levels of plasma transferrin receptor

Sixty children aged 1-3 years with protein malnutrition were involved in the present study. Measurements were made of plasma transferrin receptor (TfR), haemoglobin (Hb), ferritin, transferrin and Fe in comparison with twenty apparently healthy age- and sex-matched reference children in Nigeria. Plasma TfR was measured by an immunofluorometric assay. The mean plasma concentrations of both albumin (37 g/l) and transferrin (1·88 g/l) were within reference ranges in the ‘healthy’ children. The malnourished children had severe protein deficiency as indicated by their significantly lower mean plasma albumin (24·4-28·2 g/l; P < 0·0001) and transferrin (1·24-1·53 g/l; P < 0·0001) concentrations in comparison with the reference children. In the reference children, the traditional indicators of Fe nutrition (plasma Fe, transferrin Fe saturation and Hb) were within the reference ranges, but ferritin values were raised, indicating acute or chronic infection and/or inflammation. The mean concentrations of plasma TW (4·2-5-2 mg/l) in the malnourished group were significantly lower than the mean (6·1 mgn) of the reference children (P=0·0009). In the children with severe malnutrition, none of the indicators of Fe status except Hb (81·5-86·7 g/l; P<0·0001) showed Fe deficiency, including the serum concentration of TfR and the TfR : ferritin ratio, although the Fe status was lower than in the reference children (for Fe P = 0·009; and ferritin P=0·0004). In the absence of haemodilution, the low Hb values are a clear indication that the malnourished children were Fe deficient; none of the other indices was indicative of Fe deficiency. This is the first report of TfR levels in malnourished and healthy African children.

Effect of micronutrient supplement on health and nutritional status of schoolchildren: biochemical status

OBJECTIVE

We assessed the effect of a daily intake of a micronutrient-fortified beverage for 14 mo on indicators of biochemical status of important micronutrients in schoolchildren.

METHODS

A double-blind, placebo-controlled, matched-pair, cluster, randomization study design was used. Biochemical indicators of micronutrient status were evaluated at baseline and at the end of 14 mo on a subsample in nine matched pairs. Prevalence (percentage) of subclinical deficiency, mean, and mean increments of each indicator were compared between supplemented and placebo groups.

RESULTS

Extent of inadequacy at baseline was more or less 100% for folic acid, 65% for vitamins B2 and B6, and 55% for vitamins C and A. Prevalence of anemia among subjects was 55%, with inadequacy of vitamin B12 being 40% and that of vitamin D being 30%. No subject had inadequacy of iodine based on urinary iodine. Supplementation of a micronutrient-enriched beverage for 14 mo significantly improved the status of many of the nutrients. The effect was significant with respect to vitamins A, B2, and B12, folic acid, vitamin D, parathyroid hormone, and thyroid-stimulating hormone in children who received the supplement compared with those who received only placebo. Hemoglobin status improved only in children who had anemia in the supplemented group.

CONCLUSIONS

Prevalence of multiple subclinical micronutrient deficiencies are high in middle-income Indian school children. Daily consumption of a micronutrient-enriched beverage had positive effects that were confined to those nutrients that were inadequate at baseline.

Pubertal upregulation of erythropoiesis in boys is determined primarily by androgen

OBJECTIVES

To study the relative roles of androgens and the growth hormone-insulin-like growth factor I (GH-IGF-I) system in the regulation of erythropoiesis in boys during puberty.

STUDY DESIGN

We treated 23 boys with constitutional delay of puberty with low-dose testosterone (T), in combination with either a potent aromatase inhibitor, letrozole (Lz; 2.5 mg/d), or placebo (P). The study design was randomized, double-blinded, and placebo-controlled between the treated groups. Treatment with T + Lz was associated with high T and low IGF-I concentrations, whereas treatment with T + P resulted in moderately increased T and high IGF-I concentrations.

RESULTS

The blood hemoglobin concentration increased by 1.6 g/dL in T + Lz-treated boys, despite their low IGF-I concentrations. The estimated red blood cell volume increased more in T + Lz-treated than in T + P-treated boys (349 vs 174 mL, respectively, P = .01). Serum T concentrations during the treatment period correlated with the 12-month increments in hemoglobin and red blood cell volume. The changes in blood hemoglobin concentration and RBC in T + Lz-treated boys were similar to those we observed in a population of normal adolescent boys in the late stages of puberty.

CONCLUSIONS

The pubertal increase in hemoglobin concentration in boys is related to direct androgen effects.

Effectiveness of weekly vitamin A (10,000 IU) and iron (60 mg) supplementation for adolescent boys and girls through schools in rural and urban East Java, Indonesia

OBJECTIVE

High prevalences of vitamin A deficiency and anaemia among adolescents warrant interventions. This study evaluated the effectiveness of school-based supplementation to reduce anaemia and improve vitamin A status.

DESIGN

School-based, grade-randomized, intervention.

SUBJECTS AND SETTING

In all, 1757 girls and 1859 boys, aged 12-15 y, in 24 Junior High Schools.

INTERVENTIONS

Weekly supplementation for 14 weeks with 60 mg iron and 250 microg folate (Fe group; n=978), 10 000 IU vitamin A (VA group; n=970) or both (VAFe group; n=1042) to subjects in 15 schools, compared to subjects in nine other schools not receiving supplements (control; n=626).

RESULTS

The baseline anaemia prevalence (Hb <120 g/l) in girls was 20% (prepubertal) and 26% (pubertal), and in boys 24% (pre-pubertal) and 11% (pubertal). Serum retinol concentrations were low (<1.05 micromol/l) in 41% of boys and 45% of girls. The interventions did not increase haemoglobin concentrations. Serum retinol concentration of boys, but not girls, in the VA group increased (0.33 vs 0.07 micromol/l in controls; P<0.01). The risk factors for low serum retinol concentration were lower baseline serum retinol concentration (OR 0.02-0.03) with, for girls, nightblindness at baseline (OR 5.88), and for boys, not receiving vitamin A (OR control: 1.00; VA: 0.37; Fe: 0.77; VAFe: 0.34) and maternal illiteracy (OR mother never attended school 1.00, mother received any formal education 0.17-0.33).

CONCLUSIONS

Supplementation with vitamin A increased serum retinol concentration of boys. Iron supplementation did not change Hb. This appeared to be due to poor compliance, and partly related to side effects.

Iron metabolism in boys involved in intensive physical training

The purpose of the present study was to compare some haematological and iron-related parameters of prepubertal boys (10-12 years old) involved in intensive physical training program in preparation for the national championship with nontrained age-matched subjects. For this purpose, iron stores, haemoglobin, ferritin and serum transferrin receptor concentrations were taken into account. The athletes' dietary intakes were similar to the respective intakes in the control group. Mean ferritin concentration was similar in investigated groups of boys at the start of the study, but significant changes between those groups occurred during the 8 months of study. Compared with the control group, the trained ones have shown significantly higher serum transferrin receptor concentration during the competition period of the training season, just when they reached maximum performance capacity. Similarly, significant difference in total body iron, estimated as the sum of the individual's red blood cells iron and iron stores, between investigated groups occurred only during the competition period. The main finding of this study is that the endurance training in boys brings about significant decrease in serum ferritin, as well as iron stores in the body. Haematological parameters and iron status of trained children revealed latent anaemia (15%) or even manifest anaemia (9%). These findings indicate high prevalence of nonanaemic iron deficiency in young athletes and bear relationship to swimming training.

Socio-economic status and puberty are the main factors determining anaemia in adolescent girls and boys in East Java, Indonesia

OBJECTIVE

To determine prevalence and contributing factors of anaemia in adolescents.

DESIGN

Cross-sectional study of anaemia prevalence, socio-economic status and puberty.

SETTING

Schools in East Java, Indonesia.

SUBJECTS

Male and female adolescent pupils (age 12-15 y; n=6486).

RESULTS

Anaemia prevalence was 25.8% among girls (n=3486), 24.5% among pre-pubertal boys (n=821), and 12.1% among pubertal boys (n=2179). Socio-economic status, indicated by type of school attended, was an important factor determining the risk of anaemia. Girls had a higher risk when they attended a poor school (OR poorest school, 1.00; other schools, 0.67-0.87), had reached puberty (OR, 1.25), had lower retinol intake (OR 1st-4th quartiles-1.00, 0.97, 0.89, 0.77) and higher vitamin A intake from plant sources (OR 1st-4th quartiles-1.00, 1.10, 1.31, 1.04). Boys had a higher risk of anaemia when they attended a poor school (OR poorest school 1.00, other schools 0.54-0.63), were younger (OR per year=0.79), had not yet reached puberty (OR not yet, 1.00; already, 0.78), were shorter (OR per cm 0.95), had smaller mid-upper-arm circumference (MUAC) (OR per mm 0.99) and lower retinol intake (OR 1st-4th quartile 1.00, 0.67, 0.74, 0.68).

CONCLUSIONS

Anaemia in adolescents should be reported separately for pre-pubertal and pubertal subjects and for different ages, and the population's socio-economic status should be specified. The results of this survey call for treatment of anaemia in adolescents. Given Indonesia's current situation, micronutrient intake of adolescents should be increased using supplements for all girls and for pre-pubertal boys.

SPONSORSHIP

This survey was funded by USAID through the OMNI project.

Growth, dietary intake, and trace element status in pubescent athletes and schoolchildren

PURPOSE

To examine interactions between club-level sports training, dietary intake, and nutritional status during puberty.

METHODS

A 2-yr prospective study was undertaken with 64 boys (40 ice hockey players, 24 controls) and 71 girls (28 gymnasts, figure skaters, and runners, 43 controls). The boys' age in the beginning of the study was 12-13 yr, whereas the girls were 11-12 yr. The following variables were measured in the beginning, and after 1 and 2 yr: physical activity level (record), dietary intake (record), blood hemoglobin concentration, serum ferritin, zinc and copper concentration, anthropometric indices (height, weight, skinfolds, upper arm muscle girth), and biological maturation (self-report).

RESULTS AND CONCLUSIONS

The changes in the anthropometric variables throughout the study period were not different between the athletes and controls (P = 0.09). The athlete boys had higher mean energy, iron and zinc intakes, and higher mean serum zinc concentration than the controls (P < or = 0.003). The athlete and control girls' dietary intakes and biochemical indices of trace element status were not different from each other (P < or = 0.13). Moreover, sports participation was not associated with the longitudinal changes in trace element status (P > or = 0.08). These data suggest that club-level sports training does not affect growth, maturation or nutritional status during puberty.

Behavioral and hematologic consequences of marginal iron-zinc nutrition in adolescent monkeys and the effect of a powdered beef supplement

BACKGROUND

The adolescent growth spurt and menarche increase iron and zinc needs and could precipitate functional deficiencies if dietary sources are inadequate.

OBJECTIVE

The effects of mild, combined zinc and iron deprivation during the growth spurt and the ability of meat as a common dietary source of zinc and iron to reverse these effects was studied.

DESIGN

Pubertal female rhesus monkeys were fed control diets (n = 8) or diets marginally deficient in zinc (2 microg/g diet; n = 8) and iron (10 microg/g diet; n = 8) for 3 mo. A powdered beef supplement (104 microg Zn/g and 43 microg Fe/g, 11 +/- 2 g/d) was then fed daily to half of the deprived group for 3 additional months.

RESULTS

Growth and hematology were not affected significantly by iron-zinc deprivation, but plasma zinc and iron were somewhat lower in the deprived group than in the control group after 3 mo. The deprived monkeys reduced their participation in behavioral testing, responded more slowly and less frequently to test stimuli, and were less active. The beef supplement increased participation in testing and stabilized activity levels, but response times remained depressed. Plasma ferritin was lower in the nonsupplemented deprived monkeys than in the controls by the end of the experiment. Four of 8 of the deprived monkeys had iron deficiency anemia compared with none of the controls and 1 of 8 who received the beef supplement.

CONCLUSIONS

Marginal zinc and iron deprivation in early adolescence can lead to behavioral and hematologic dysfunction in nonhuman primates and dietary beef supplements can prevent and reverse some of these effects.

A longitudinal study of iron status in children at 12, 24 and 36 months

OBJECTIVES

To assess iron status in a sample of clinically well, Caucasian children and explore the complex factors which contribute to iron deficiency during infancy.

DESIGN

Infants recruited at birth and followed longitudinally at 1, 2, 3, 4, 5, 6, 9, 12, 24 and 36 months; feeding practices and socioeconomic data recorded. Iron status assessed using venous blood at 12, 24 and 36 months.

SETTING

Baseline data recorded in the maternity unit. Follow-up visits took place in the infants' homes and blood sampling in a paediatric hospital.

SUBJECTS

Subjects comprised a mixed socioeconomic group of healthy children (n = 121). Blood samples taken from 85, 72 and 67% at 12, 24 and 36 months, respectively.

RESULTS

Prevalence of anaemia (Hb < 110 g l(-1)) in the longitudinal sample (n = 76) increased from 2.6% at age 12 months to 9.2% at 24 months, and at age 36 months (n = 70) was 8%. The most significant finding was that at age 12 months, cows' milk consumption was negatively associated with iron status. Other variables also had an influence. At both 24 and 36 months the most significant predictor of iron status was earlier iron status.

CONCLUSIONS

Infants born to anaemic mothers or mothers who smoke and infants who consume cows' milk during infancy are at increased risk of developing anaemia. Breast milk is the ideal, but for the infant who is not breast fed an iron fortified formula should be used. Advice to mothers should focus on the importance of introducing nutrient dense complementary foods, such as meat, which contains readily absorbable iron.

Iron status of children with short stature during accelerated growth due to growth hormone treatment

We determined the influence of human growth hormone (hGH) treatment on blood soluble transferrin receptor (sTfR) in 35 children with short stature. Whereas the serum concentration of ferritin decreased from 29.6 micrograms/l to 19.7 micrograms/l, and that of transferrin increased from 2.9 g/l to 3.2 g/l during 6 months (p < 0.001), only a minimum rise in the sTfR concentration was observed (7.12 +/- 0.20 mg/l vs 7.51 +/- 0.19 mg/l, p = 0.025). The prevalence of anaemia or microcytosis did not increase. Most of the changes in serum ferritin and transferrin concentrations occurred during the first week. The study demonstrates that rapid body growth per se does not affect the sTfR concentration, but it may affect the serum transferrin and ferritin concentrations. Alternatively, GH may have a specific effect on serum ferritin and transferrin concentrations.