Micronutrient-fortified rice can be a significant source of dietary bioavailable iron in schoolchildren from rural Ghana.

Iron deficiency and anemia are prominent contributors to the preventable disease burden worldwide. A substantial proportion of people with inadequate dietary iron rely on rice as a staple food, but fortification efforts are limited by low iron bioavailability. Furthermore, using high iron fortification dosages may not always be prudent in tropical regions. To identify alternative fortification formulations with enhanced absorption, we screened different iron compounds for their suitability as rice fortificants, measured in vitro gastric solubility, and assessed dietary iron bioavailability using stable isotopic labels in rural Ghanaian children. Isotopic incorporation in red blood cells indicates that in the two age groups of children investigated (4 to 6 and 7 to 10 years), formulations provided 36 and 51% of the median daily requirement in absorbed iron, respectively. We describe approaches to enhancing iron bioavailability from fortified rice, which can substantially contribute to the prevention of iron deficiency in rice-eating populations.

Overweight impairs efficacy of iron supplementation in iron-deficient South African children: a randomized controlled intervention.

BACKGROUND: Many countries in the nutrition transition have high rates of iron deficiency (ID) and overweight (OW). ID is more common in OW children; this may be due to adiposity-related inflammation reducing iron absorption. OBJECTIVE: We investigated whether weight status predicts response to oral iron supplementation in ID South African children. DESIGN: A placebo-controlled trial of oral iron supplementation (50 mg, 4 × weeks for 8.5 months) was done in ID 6- to 11-year-old children (n=321); 28% were OW or obese. BMI-for-age z-scores (BAZ), hepcidin (in a sub-sample), hemoglobin, serum ferritin (SF), transferrin receptor (TfR), zinc protoporphyrin (ZnPP) and C-reactive protein (CRP) were measured; body iron was calculated from the SF to TfR ratio. RESULTS: At baseline, BAZ correlated with CRP (r=0.201, P<0.001) and CRP correlated with hepcidin (r=0.384, P<0.001). Normal weight children supplemented with iron had significantly lower TfR concentrations at endpoint than the OW children supplemented with iron and the children receiving placebo. Higher BAZ predicted higher TfR (ß=0.232, P<0.001) and lower body iron (ß=-0.090, P=0.016) at endpoint, and increased the odds ratio (OR) for remaining ID at endpoint in both the iron and placebo groups (iron: OR 2.31, 95% CI: 1.13, 4.73; placebo: OR 1.78, 95% CI: 1.09, 2.91). In the children supplemented with iron, baseline hepcidin and BAZ were significant predictors of endpoint TfR, with a trend towards a hepcidin × BAZ interaction (P=0.058). CONCLUSION: South African children with high BAZ have a two-fold higher risk of remaining ID after iron supplementation. This may be due to their higher hepcidin concentrations reducing iron absorption. Thus, the current surge in OW in rapidly developing countries may undercut efforts to control anemia in vulnerable groups. The trial is registered at clinicaltrials.gov as NCT01092377.

A composite score combining waist circumference and body mass index more accurately predicts body fat percentage in 6- to 13-year-old children.

PURPOSE: Body mass index (BMI) and waist circumference (WC) are widely used to predict % body fat (BF) and classify degrees of pediatric adiposity. However, both measures have limitations. The aim of this study was to evaluate whether a combination of WC and BMI would more accurately predict %BF than either alone. METHODS: In a nationally representative sample of 2,303 6- to 13-year-old Swiss children, weight, height, and WC were measured, and %BF was determined from multiple skinfold thicknesses. Regression and receiver operating characteristic (ROC) curves were used to evaluate the combination of WC and BMI in predicting %BF against WC or BMI alone. An optimized composite score (CS) was generated. RESULTS: A quadratic polynomial combination of WC and BMI led to a better prediction of %BF (r (2) = 0.68) compared with the two measures alone (r (2) = 0.58-0.62). The areas under the ROC curve for the CS [0.6 * WC-SDS + 0.4 * BMI-SDS] ranged from 0.962 ± 0.0053 (overweight girls) to 0.982 ± 0.0046 (obese boys) and were somewhat greater than the AUCs for either BMI or WC alone. At a given specificity, the sensitivity of the prediction of overweight and obesity based on the CS was higher than that based on either WC or BMI alone, although the improvement was small. CONCLUSION: Both BMI and WC are good predictors of %BF in primary school children. However, a composite score incorporating both measures increased sensitivity at a constant specificity as compared to the individual measures. It may therefore be a useful tool for clinical and epidemiological studies of pediatric adiposity.

Prevalence of iodine deficiency in Europe in 2010.

The adverse effects of iodine deficiency (ID) intellectual impairment, damaged reproduction, goiter and hypo- and hyperthyroidism are well known and easily corrected with salt iodization, but they continue to impair health and socioeconomic development, with more than two billion people at risk worldwide. During the major global expansion of salt iodization over the past four decades, much of Europe has remained iodine deficient. Although every European country endorsed the goal of eliminating iodine deficiency at the 1992 World Health Assembly, control of iodine deficiency has received low priority in much of Europe. However, there has been recent progress in the region and the number of children with low iodine intakes has decreased by ca. 30% since 2003. This paper presents an estimate of the prevalence of iodine deficiency in Europe in 2010, based on a systematic review to update the WHO Vitamin and Mineral Nutrition Information System (VMNIS) database.

A comparison of the bioavailability of ferrous fumarate and ferrous sulfate in non-anemic Mexican women and children consuming a sweetened maize and milk drink.

BACKGROUND/OBJECTIVES: Ferrous fumarate is recommended for the fortification of complementary foods based on similar iron absorption to ferrous sulfate in adults. Two recent studies in young children have reported that it is only 30% as well absorbed as ferrous sulfate. The objective of this study was to compare iron absorption from ferrous fumarate and ferrous sulfate in infants, young children and mothers. SUBJECTS/METHODS: Non-anemic Mexican infants (6-24 months), young children (2-5 years) and adult women were randomly assigned to receive either 4 mg Fe (women) or 2.5 mg Fe (infants and young children) as either [(57)Fe]-ferrous fumarate or [(58)Fe]-ferrous sulfate added to a sweetened drink based on degermed maize flour and milk powder. Iron absorption was calculated based on incorporation of isotopes into erythrocytes after 14 days. RESULTS: Within each population group, no significant differences (P > 0.05) in iron absorption were found between ferrous fumarate and ferrous sulfate. Mean iron absorption from ferrous fumarate vs ferrous sulfate was 17.5 vs 20.5% in women (relative bioavailability (RBV) =86), 7.0 vs 7.2% in infants (RBV = 97) and 6.3 vs 5.9% in young children (RBV = 106). CONCLUSIONS: Ferrous fumarate is as well absorbed as ferrous sulfate in non-anemic, iron sufficient infants and young children, and can be recommended as a useful fortification compound for complementary foods designed to prevent iron deficiency. Further studies are needed to clarify its usefulness in foods designed to treat iron deficiency.

Iron excess in recreational marathon runners.

BACKGROUND/OBJECTIVES: Iron deficiency and anemia may impair athletic performance, and iron supplements are commonly consumed by athletes. However, iron overload should be avoided because of the possible long-term adverse health effects. METHODS: We investigated the iron status of 170 male and female recreational runners participating in the Zürich marathon. Iron deficiency was defined either as a plasma ferritin (PF) concentration <15 microg/l (iron depletion) or as the ratio of the concentrations of transferrin receptor (sTfR) to PF (sTfR:log(PF) index) of > or =4.5 (functional iron deficiency). RESULTS: After excluding subjects with elevated C-reactive protein concentrations, iron overload was defined as PF >200 microg/l. Iron depletion was found in only 2 out of 127 men (1.6% of the male study population) and in 12 out of 43 (28.0%) women. Functional iron deficiency was found in 5 (3.9%) and 11 (25.5%) male and female athletes, respectively. Body iron stores, calculated from the sTfR/PF ratio, were significantly higher (P<0.001) among male compared with female marathon runners. Median PF among males was 104 microg/l, and the upper limit of the PF distribution in males was 628 microg/l. Iron overload was found in 19 out of 127 (15.0%) men but only 2 out of 43 in women (4.7%). Gender (male sex), but not age, was a predictor of higher PF (P<0.001). CONCLUSIONS: Iron depletion was present in 28% of female runners but in <2% of males, whereas one in six male runners had signs of iron overload. Although iron supplements are widely used by athletes in an effort to increase performance, our findings indicate excess body iron may be common in male recreational runners and suggest supplements should only be used if tests of iron status indicate deficiency.

Development and optimization of iron- and zinc-containing nanostructured powders for nutritional applications.

Reducing the size of low-solubility iron (Fe)-containing compounds to nanoscale has the potential to improve their bioavailability. Because Fe and zinc (Zn) deficiencies often coexist in populations, combined Fe/Zn-containing nanostructured compounds may be useful for nutritional applications. Such compounds are developed here and their solubility in dilute acid, a reliable indicator of iron bioavailability in humans, and sensory qualities in sensitive food matrices are investigated. Phosphates and oxides of Fe and atomically mixed Fe/Zn-containing (primarily ZnFe2O4) nanostructured powders were produced by flame spray pyrolysis (FSP). Chemical composition and surface area were systematically controlled by varying precursor concentration and feed rate during powder synthesis to increase solubility to the level of ferrous sulfate at maximum Fe and Zn content. Solubility of the nanostructured compounds was dependent on their particle size and crystallinity. The new nanostructured powders produced minimal color changes when added to dairy products containing chocolate or fruit compared to the changes produced when ferrous sulfate or ferrous fumarate were added to these foods. Flame-made Fe- and Fe/Zn-containing nanostructured powders have solubilities comparable to ferrous and Zn sulfate but may produce fewer color changes when added to difficult-to-fortify foods. Thus, these powders are promising for food fortification and other nutritional applications.

Overweight children have higher circulating hepcidin concentrations and lower iron status but have dietary iron intakes and bioavailability comparable with normal weight children.

BACKGROUND: Obesity increases the risk for iron deficiency, but the underlying mechanism is unclear. It is possible that overweight individuals may have lower dietary iron intake and/or bioavailability. Alternatively, obesity-related inflammation may increase hepcidin concentrations and reduce iron availability. Circulating hepcidin levels have not been compared in normal weight vs overweight individuals. OBJECTIVE: The objective of this study was to compare iron status, dietary iron intake and bioavailability, as well as circulating levels of hepcidin, leptin and interleukin-6 (IL-6), in overweight vs normal weight children. DESIGN: In 6-14-year-old normal and overweight children (n=121), we measured dietary iron intake, estimated iron bioavailability and determined body mass index s.d. scores (BMI-SDS). In all children (n=121), we measured fasting serum ferritin, soluble transferrin receptor (sTfR), C-reactive protein (CRP) and leptin; in a subsample, we measured IL-6 (n=68) and serum hepcidin (n=30). RESULTS: There were no significant differences in dietary iron intake or bioavailability comparing normal and overweight children. The prevalence of iron-deficient erythropoiesis (an increased sTfR concentration) was significantly higher in the overweight than in the normal weight children (20 vs 6%, P=0.022, with sTfR concentrations of 4.40+/-0.77 and 3.94+/-0.88 mg l(-1), respectively, P=0.010). Serum hepcidin levels were significantly higher in the overweight children (P=0.001). BMI-SDS significantly correlated with sTfR (P=0.009), serum hepcidin (P=0.005) and the three measures of subclinical inflammation, namely CRP (P<0.001), IL-6 (P<0.001) and leptin (P<0.001). In a multiple regression model, serum hepcidin was correlated with BMI-SDS (P=0.020) and body iron (P=0.029), but not with the inflammatory markers. CONCLUSION: Our findings indicate that there is reduced iron availability for erythropoiesis in overweight children and that this is unlikely due to low dietary iron supply but rather due to hepcidin-mediated reduced iron absorption and/or increased iron sequestration.

Dietary determinants of subclinical inflammation, dyslipidemia and components of the metabolic syndrome in overweight children: a review.

OBJECTIVE: To review and summarize the dietary determinants of the metabolic syndrome, subclinical inflammation and dyslipidemia in overweight children. DESIGN: Review of the current literature, focusing on pediatric studies. PARTICIPANTS: Normal weight, overweight, or obese children and adolescents. RESULTS: There is a growing literature on the metabolic effects of excess body fat during childhood. However, few pediatric studies have examined the dietary determinants of obesity-related metabolic disturbances. From the available data, it appears that dietary factors are not only important environmental determinants of adiposity, but also may affect components of the metabolic syndrome and modulate the actions of adipokines. Dietary total fat and saturated fat are associated with insulin resistance and high blood pressure, as well as obesity-related inflammation. In contrast to studies in adults, resistin and adiponectin do not appear to be closely linked to insulin resistance or dyslipidemia in childhood. However, circulating leptin and retinol-binding protein (RBP) 4 correlate well with obesity, central obesity and the metabolic syndrome in children. Intakes of antioxidant vitamins tend to be low in obese children and may be predictors of subclinical inflammation. Higher fructose intake from sweets and sweetened drinks in overweight children has been linked to decreased low-density lipoprotein (LDL) particle size. CONCLUSIONS: Dietary interventions aimed at reducing intakes of total fat, saturated fat and free fructose, whereas increasing antioxidant vitamin intake may be beneficial in overweight children. More research on the relationships between dietary factors and the metabolic changes of pediatric obesity may help to identify the dietary changes to reduce health risks.

The increase of fatty acid-binding protein aP2 in overweight and obese children: interactions with dietary fat and impact on measures of subclinical inflammation.

BACKGROUND: In adults, circulating aP2 may link obesity, inflammation and the metabolic syndrome, but there are few data in children. Experimental models support that dietary factors, particularly dietary fat, may be major determinants of phenotype. OBJECTIVE: The aim of this study was to investigate, in normal, overweight and obese children, the relationships among aP2, the metabolic syndrome, inflammation and diet. DESIGN: This was a cross-sectional study conducted in Northern Switzerland. SUBJECTS: Subjects for this study were 6- to 14-year-old, prepubertal and early pubertal, normal weight, overweight and obese children (n=124). MAIN OUTCOME MEASURES: Body mass index (BMI), body fat percent, waist-to-hip ratio, blood pressure, circulating aP2, fasting insulin, C-reactive protein (CRP), plasma lipids and dietary intakes of macro- and micronutrients were determined. RESULTS: Circulating aP2 markedly increased with increasing central and total adiposity, and predicted measures of insulin resistance. Independent of BMI standard deviation scores and puberty, aP2 correlated with intake of the antioxidant vitamins A, C and E as well as circulating concentrations of CRP, leptin and low-density lipoprotein cholesterol. Children with lower aP2 concentrations consuming high-fat diets did not show an increase in fasting insulin or CRP, whereas those with higher aP2 concentrations showed marked increases in these measures with high intakes of fat or saturated fat. CONCLUSIONS: Increased central and overall adiposity in children are associated with higher circulating aP2 concentrations. In children with high dietary intakes of total fat and saturated fat, but not those with low intakes, higher aP2 concentrations are associated with measures of insulin resistance and inflammation.

Adiposity in women and children from transition countries predicts decreased iron absorption, iron deficiency and a reduced response to iron fortification.

BACKGROUND: Overweight is increasing in transition countries, while iron deficiency remains common. In industrialized countries, greater adiposity increases risk of iron deficiency. Higher hepcidin levels in obesity may reduce dietary iron absorption. Therefore, we investigated the association between body mass index (BMI) and iron absorption, iron status and the response to iron fortification in populations from three transition countries (Thailand, Morocco and India). METHODS: In Thai women (n=92), we examined the relationship between BMI and iron absorption from a reference meal containing approximately 4 mg of isotopically labeled fortification iron. We analyzed data from baseline (n=1688) and intervention (n=727) studies in children in Morocco and India to look for associations between BMI Z-scores and baseline hemoglobin, serum ferritin and transferrin receptor, whole blood zinc protoporphyrin and body iron stores, and changes in these measures after provision of iron. RESULTS: In the Thai women, 20% were iron deficient and 22% were overweight. Independent of iron status, a higher BMI Z-score was associated with decreased iron absorption (P=0.030). In the Indian and Moroccan children, 42% were iron deficient and 6.3% were overweight. A higher BMI Z-score predicted poorer iron status at baseline (P<0.001) and less improvement in iron status during the interventions (P<0.001). CONCLUSIONS: Adiposity in young women predicts lower iron absorption, and pediatric adiposity predicts iron deficiency and a reduced response to iron fortification. These data suggest the current surge in overweight in transition countries may impair efforts to control iron deficiency in these target groups. Interactions of the 'double burden' of malnutrition during the nutrition transition may have adverse consequences.

Low anemia prevalence in school-aged children in Bangalore, South India: possible effect of school health initiatives.

OBJECTIVE: Anemia is a serious public health problem in Indian school children. Since 2003, simple health intervention programs such as antihelminthic treatment and vitamin A supplementation have been implemented in primary schools in the Bangalore region, Karnataka, India. This study examines the prevalence of anemia in school children who are beneficiaries of this program. DESIGN: Cross-sectional survey. SETTING: Bangalore district, South India. SUBJECTS: A total of 2,030 boys and girls, aged 5-15 years, attending schools in the Bangalore district. INTERVENTIONS: School-based, twice yearly intervention: deworming (albendazole 400 mg, single oral dose) and vitamin A supplementation (200,000 IU, single oral dose). MAIN OUTCOME MEASURES: Anemia prevalence based on measure of blood hemoglobin (Hb). RESULTS: Mean age and blood Hb concentration of all children were 9.5+/-2.6 years and 12.6+/-1.1 g/dl (range 5.6-16.7), respectively. The overall anemia prevalence in this group was 13.6%. Anemia prevalence was lower in boys than girls (12.0%; n=1037 vs 15.3%; n=993 respectively, P<0.05). There was no significant difference in anemia prevalence between children in urban and rural locations (14.6 and 12.3%, respectively). CONCLUSIONS: The current low anemia prevalence in Bangalore could be due to the impact of school-based intervention programs that have been in place since 2003. The beneficial interactions of deworming and vitamin A supplementation could have widespread implications for current preventive public health initiatives. There is now need for the development of clear policy guidelines based on these simple and integrated interventions.

Urinary excretion of an intravenous 26Mg dose as an indicator of marginal magnesium deficiency in adults.

BACKGROUND: Measurement of magnesium (Mg) status is problematic because tissue Mg deficiency can be present without low serum Mg concentrations. OBJECTIVE: To evaluate a modified version of the Mg retention test using stable isotopes for the assessment of Mg status in general, and the detection of marginal Mg deficiency in particular. DESIGN: A modified version of the Mg retention test using a small dose of (26)Mg was evaluated for assessment of Mg status in 22 healthy subjects. Muscle Mg concentration was used as reference for Mg status. A muscle biopsy was taken from the lateral portion of the quadriceps muscle from each subject. After 2 to 4 weeks, 11 mg of (26)Mg (as MgCl(2) in 14 ml water) were injected i.v. over a period of 10 min and all urine was collected for the following 24 h. Excretion of the isotopic label was expressed as percentage of the administered dose excreted in urine within 24 h. RESULTS: Mean +/- s.d. Mg concentration in muscle was 3.85 +/- 0.17 mmol/100 g fat-free dried solids. Mean +/- s.d. excretion of the injected dose within 24 h was 7.9 +/- 2.1%. No correlation was found between muscle Mg concentration and excretion of the isotopic label (r (2 ) = 0.061, P = 0.27). CONCLUSIONS: In this study, urinary excretion of an intravenous Mg tracer was not influenced by muscle Mg concentration and its usefulness for the detection of marginal Mg deficiency could therefore not be demonstrated. SPONSORSHIP: Swiss Foundation for Nutrition Research and Swiss Federal Institute of Technology, Zurich, Switzerland.

Dietary magnesium intake in type 2 diabetes.

BACKGROUND: Magnesium deficiency is common in type 2 diabetes and may have a negative impact on glucose homeostasis and insulin resistance, as well as on the evolution of complications such as retinopathy, thrombosis and hypertension. OBJECTIVE: To assess the dietary magnesium intake of patients with type 2 diabetes in Zurich, Switzerland and to compare the magnesium intake of diabetic and non-diabetic subjects. DESIGN: The magnesium intake of 97 randomly selected patients with type 2 diabetes and 100 healthy, non-diabetic controls matched for age and sex was estimated using a diet history method. During winter and summer periods, mean daily magnesium intakes were calculated from detailed information given by the test subjects about their eating habits over the previous 2 months. The calculations were performed using EBIS, a computer program based on a German nutrient data base (BLS 2.3), with food items specific to Switzerland added or directly analysed when necessary. RESULTS: The mean+/-s.d. daily magnesium intake of the male diabetic and male control subjects was 423.2+/-103.1 and 421.1+/-111.0 mg, respectively. The mean daily magnesium intake of the female diabetic and female control subjects was 419.1+/-109.7 and 383.5+/-109.7 mg, respectively. There were no significant differences in daily magnesium intake between the diabetic and the non-diabetic subjects and mean intakes in both groups exceeded Swiss recommended dietary intakes. CONCLUSIONS: Dietary intake of magnesium appears sufficient in Swiss adults with type 2 diabetes and is unlikely to contribute to the aetiology of magnesium deficiency. SPONSORSHIP: The Swiss Federal Institute of Technology, Zurich, Switzerland.

A national survey of iron and folate status in pregnant women in Switzerland.

Women often do not meet the increased iron and folate needs of pregnancy. Maternal iron-deficiency anemia is associated with poor maternal and infant outcomes, including preterm delivery and low birth weight. Poor folate status increases risk for maternal anemia, spontaneous abortion, and congenital defects. Because of this, supplemental iron and folate are often recommended during pregnancy. There are few data on iron and folate status in pregnant women in Switzerland. We measured iron and folate status in a national sample of Swiss pregnant women, estimated the prevalence of anemia, and determined if supplement use is associated with iron and/or folate status in this group. A 3-stage probability to size cluster sampling method was used to obtain a representative national sample of pregnant women (n = 381) in the second and third trimester. We measured hemoglobin, hematocrit, mean corpuscular volume, and serum folate and ferritin concentrations. Serum transferrin receptor concentration was determined in anemic subjects. The use of iron and folate supplements was evaluated by questionnaire. Mean hemoglobin (+/- SD) in the sample was 123 g/L (+/- 1.0). The prevalence of anemia was 6%. Of the 21 anemic women, 11 were iron-deficient, giving an iron-deficiency anemia prevalence of 3%. Nineteen percent of women had low serum ferritin concentrations (< 12 micrograms/L) and 4% had low serum folate concentration (< 2.5 micrograms/L). Supplements containing iron were taken by 65% of women, and 63% were taking folate-containing supplements. Women in the second and third trimester taking folate-containing supplements had significantly higher serum folate concentrations compared to those not taking a folate supplement (p < 0.001). In the third trimester, women taking iron-containing supplements had significantly higher serum ferritin concentrations compared to those not taking an iron-containing supplement (p < 0.01). Our findings indicate that iron and folate status appears to be adequate in the majority of pregnant women in Switzerland, and that use of iron and folate supplements may have a positive impact on status.

Monitoring the adequacy of salt iodization in Switzerland: a national study of school children and pregnant women.

BACKGROUND: Several countries with long-standing salt iodization programs, including Switzerland, have recently reported declining and/or low urinary iodine (UI) levels in their populations. In Switzerland, in response to studies indicating low UI levels in children and pregnant women, the salt iodine level was increased in 1998 from 15 to 20 mg/kg. OBJECTIVE: Our objective was to evaluate iodine nutrition in a national sample of Swiss school children and pregnant women 8 16 months after the increase in the salt iodine level. DESIGN: A 3-stage probability proportionate to size cluster sampling method was used to obtain a representative national sample of 600 children aged 6-12 y and 600 pregnant women. We then measured UI in both groups, thyrotropin (TSH) in pregnant women and thyroid volume by ultrasound to determine goiter prevalence in school children. RESULTS: The median UI (range) of the children and pregnant women was 115 microg/l (5-413) and 138 microg/l (5-1881), respectively. The median blood TSH concentration (range) of pregnant women was 0.6 mU/l (0.2-2.1). Based on the current WHO/ICCIDD normative data for thyroid volume, none of the children were goitrous, using either age/sex-specific or BSA/sex-specific cutoffs. CONCLUSIONS: The iodine status of the Swiss population is once again adequate, illustrating the value of periodic monitoring and prudent adjustments to the iodine level in salt. This approach could serve as a model for countries struggling to maintain dietary iodine intake in the face of shifting dietary habits and changes in the food supply.

Toward a consensus on reference values for thyroid volume in iodine-replete schoolchildren: results of a workshop on inter-observer and inter-equipment variation in sonographic measurement of thyroid volume.

OBJECTIVE: Interpretation of thyroid ultrasonography for assessing goiter prevalence requires valid reference criteria from iodine-sufficient populations. Reports have suggested the current reference criteria for thyroid volume (T(vol)) of WHO/ICCIDD (International Council for the Control of Iodine Deficiency Disorders) may be too high. Our objective was to determine if inter-observer and/or inter-equipment variability contributes to the disagreement in sonographic T(vol) in children reported from iodine-sufficient areas. DESIGN: A 2-day workshop in which four experienced ultrasound examiners from around Europe measured T(vol) in 45 6--12-year-old Swiss schoolchildren using four different portable ultrasound machines. One of the participating examiners (observer A) had generated the T(vol) data in European children that are the basis for the WHO/ICCIDD reference criteria. METHODS: Sonographic T(vol) was measured in each child by all four examiners on all four machines. Six hundred and eighty-four examinations were completed, with examiners having no knowledge of one another's results. Inter-observer and inter-equipment variation was calculated. RESULTS: Mean inter-equipment variation in T(vol) was 15.2% (95% CI: 14.1, 16.3%). There were no significant differences in T(vol) between equipment (P=0.51). For all observers, the mean inter-observer variation in T(vol) was 25.6% (95% CI: 23.9, 27.2%). At all ages and all body surface areas, there was a large systematic measurement bias (+30% volume) between the mean T(vol) of observer A and the mean Tvol of observers B, C and D. Reanalysis using data from observers B, C and D reduced the mean inter-observer variation in T(vol) to 13.3% (95% CI: 11.9, 14.7%). A correction factor for the systematic difference of operator A for the P50 and P97 of T(vol) was estimated using analysis of covariance. When applied to the WHO/ICCIDD reference data, it sharply reduced the discrepancy between the WHO/ICCIDD criteria and those from other iodine-sufficient children around the world. CONCLUSIONS: Inter-equipment error contributes minimally to reported differences in sonographic T(vol). Even among experienced examiners, inter-observer variation in sonographic T(vol) in children can be high, and probably contributes to the current disagreement on normative values in iodine-sufficient children. A systematic bias at least partially explains why the WHO/ICCIDD reference data differ from those reported from other iodine-sufficient children around the world. The findings argue strongly for the standardization of methods used for sonographic measurement of T(vol) in children.

A national study of the prevalence of overweight and obesity in 6-12 y-old Swiss children: body mass index, body-weight perceptions and goals.

OBJECTIVES: To estimate the prevalence of overweight and obesity in Swiss children and to obtain information on weight perceptions and weight control practices in this population. DESIGN: Cross-sectional, three-stage, probability-proportionate-to-size cluster sampling. SETTING: Middle schools throughout Switzerland. SUBJECTS: A representative national sample of 595 6-12 y-old schoolchildren. INTERVENTION: Measurement of weight and height; interview on weight perceptions and weight control practices. RESULTS: Body mass index (BMI) was calculated and used as an indicator of overweight. The BMIs of the Swiss children were compared with US, UK, French and Swiss reference data. Depending on which reference data were used, the prevalence of obesity varied between 9.7 and 16.1% and the prevalence of overweight varied between 21.7 and 34.2%. Girls were significantly more likely to consider themselves too fat (26% and 15%, respectively) and to report currently trying to lose weight (30% and 18%, respectively) compared to boys (P<0.05). CONCLUSIONS: The prevalence of overweight in Swiss children, and its attendant health and social consequences, are important public health concerns. SPONSORSHIP: The Swiss Foundation for Nutrition Research, Zürich, Switzerland.

Thyroid volumes in a national sample of iodine-sufficient swiss school children: comparison with the World Health Organization/International Council for the control of iodine deficiency disorders normative thyroid volume criteria.

OBJECTIVE: The determination of goiter prevalence in children by thyroid ultrasound is an important tool for assessing iodine deficiency disorders. The current World Health Organization/International Council for the Control of Iodine Deficiency Disorders (WHO/ICCIDD) normative values, based on thyroid volume in iodine-sufficient European children, have recently been questioned, as thyroid volumes in iodine-sufficient children from the USA and Malaysia are smaller than the WHO/ICCIDD reference data. Our objective was to describe ultrasonographic thyroid volumes in a representative national sample of iodine-sufficient Swiss school children, and to compare these with the current reference data for thyroid volume. DESIGN AND METHODS: A 3-stage, probability proportionate-to-size cluster sampling method was used to obtain a representative national sample of 600 Swiss children aged 6-12 years. The following data were collected: thyroid size by ultrasound, urinary iodine concentration, weight, height, sex and age. RESULTS: The median urinary iodine concentration (range) of the children was 115 microgram/l (5-413). Application of the WHO/ICCIDD thyroid volume references to the Swiss children resulted in a prevalence of 0%, using either age/sex-specific or body surface area (BSA)/sex-specific cut-off values. Upper limits of normal (97th percentile) of thyroid volume from Swiss children calculated using BSA, sex and age were similar to those reported in iodine-sufficient children in the USA, but were 20-56% lower than the corresponding WHO/ICCIDD references. CONCLUSIONS: Swiss children had smaller thyroids than the European children on which the WHO/ICCIDD references are based, perhaps due to a residual effect of a recent past history of iodine deficiency in many European regions. However, there were sharp differences between our data and a recent set of thyroid volume data in Swiss children produced by the operator and equipment that generated the WHO/ICCIDD reference data. This suggests that interobserver and/or interequipment variability may contribute to the current disagreement on normative values for thyroid size by ultrasound in iodine-sufficient children.

Effect of oral iodized oil on thyroid size and thyroid hormone metabolism in children with concurrent selenium and iodine deficiency.

OBJECTIVES: To determine the efficacy of oral iodized oil in goitrous children who are both selenium (Se) and iodine deficient; to investigate if Se status modifies the response of iodine deficient, goitrous children to oral supplementation with iodized oil. DESIGN: A longitudinal intervention trial. SETTING: Two rural villages in the western Côte d'Ivoire. SUBJECTS: 51 goitrous non-anemic schoolchildren with both iodine and Se deficiency. INTERVENTION: Each child received an oral dose of 0.4 ml iodized poppyseed oil containing 200 mg of iodine. They were followed for 1 y with measurements of urinary iodine (UI), thyrotropin (TSH), thyroxine (T4), and thyroid volume by ultrasound. RESULTS: At baseline all children were goitrous and Se deficient; median UI was 29 microg/l and mean serum Se (s.d.) was 14.8 (10.7) microg/l. After receiving iodized oil, thyroid volume decreased significantly vs baseline at 10, 15, 30 and 50 weeks (P<0.001). At 50 weeks mean percentage change in thyroid volume from baseline was-46.6% and only five children remained goitrous. Median TSH values at 5, 10, 15, 30 and 50 weeks were reduced significantly (P<0.001) compared to baseline. Among individual children the severity of Se deficiency predicted the degree of response to iodized oil. Baseline serum Se and percentage change in thyroid volume from baseline at 50 weeks were strongly correlated (r2=0.554). Baseline Se and percentage decrease in TSH from baseline at 30 weeks were also well-correlated (r2=0.467). CONCLUSION: Although more severe Se deficiency partially blunts the thyroid response to iodine supplementation, oral iodized oil is an effective method for iodine repletion in goitrous children who are Se deficient. SPONSORSHIP: The Swiss Federal Institute of Technology, Zürich, the Foundation for Micronutrients in Medicine, Rapperswil, Switzerland, and the Thrasher Research Fund, Salt Lake City, USA.