RESUMEN
OBJECTIVES: To examine sodium and potassium urinary excretion by socioeconomic status (SES), discretionary salt use habits and dietary sources of sodium and potassium in a sample of Australian schoolchildren. DESIGN: Cross-sectional study. SETTING: Primary schools located in Victoria, Australia. PARTICIPANTS: 666 of 780 children aged 4-12 years who participated in the Salt and Other Nutrients in Children study returned a complete 24-hour urine collection. PRIMARY AND SECONDARY OUTCOME MEASURES: 24-hour urine collection for the measurement of sodium and potassium excretion and 24-hour dietary recall for the assessment of food sources. Parent and child reported use of discretionary salt. SES defined by parental highest level of education. RESULTS: Participants were 9.3 years (95% CI 9.0 to 9.6) of age and 55% were boys. Mean urinary sodium and potassium excretion was 103 (95% CI 99 to 108) mmol/day (salt equivalent 6.1 g/day) and 47 (95% CI 45 to 49) mmol/day, respectively. Mean molar Na:K ratio was 2.4 (95% CI 2.3 to 2.5). 72% of children exceeded the age-specific upper level for sodium intake. After adjustment for age, sex and day of urine collection, children from a low socioeconomic background excreted 10.0 (95% CI 17.8 to 2.1) mmol/day more sodium than those of high socioeconomic background (p=0.04). The major sources of sodium were bread (14.8%), mixed cereal-based dishes (9.9%) and processed meat (8.5%). The major sources of potassium were dairy milk (11.5%), potatoes (7.1%) and fruit/vegetable juice (5.4%). Core foods provided 55.3% of dietary sodium and 75.5% of potassium while discretionary foods provided 44.7% and 24.5%, respectively. CONCLUSIONS: For most children, sodium intake exceeds dietary recommendations and there is some indication that children of lower socioeconomic background have the highest intakes. Children are consuming about two times more sodium than potassium. To improve sodium and potassium intakes in schoolchildren, product reformulation of lower salt core foods combined with strategies that seek to reduce the consumption of discretionary foods are required.
Asunto(s)
Salud Infantil , Dieta , Conducta Alimentaria , Estado Nutricional , Potasio/administración & dosificación , Cloruro de Sodio Dietético/administración & dosificación , Sodio/administración & dosificación , Australia , Niño , Preescolar , Estudios Transversales , Femenino , Alimentos , Humanos , Masculino , Política Nutricional , Necesidades Nutricionales , Padres , Potasio/orina , Clase Social , Sodio/orina , Cloruro de Sodio Dietético/orina , VictoriaRESUMEN
BACKGROUND: Dietary sodium and potassium are involved in the pathogenesis of cardiovascular disease. Data exploring the cardiovascular outcomes associated with these electrolytes within Australian children is sparse. Furthermore, an objective measure of sodium and potassium intake within this group is lacking. OBJECTIVE: The primary aim of the Salt and Other Nutrient Intakes in Children ("SONIC") study was to measure sodium and potassium intakes in a sample of primary schoolchildren located in Victoria, Australia, using 24-hour urine collections. Secondary aims were to identify the dietary sources of sodium and potassium, examine the association between these electrolytes and cardiovascular risk factors, and assess children's taste preferences and saltiness perception of manufactured foods. METHODS: A cross-sectional study was conducted in a convenience sample of schoolchildren attending primary schools in Victoria, Australia. Participants completed one 24-hour urine collection, which was analyzed for sodium, potassium, and creatinine. Completeness of collections was assessed using collection time, total volume, and urinary creatinine. One 24-hour dietary recall was completed to assess dietary intake. Other data collected included blood pressure, body weight, height, waist and hip circumference. Children were also presented with high and low sodium variants of food products and asked to discriminate salt level and choose their preferred variant. Parents provided demographic information and information on use of discretionary salt. Descriptive statistics will be used to describe sodium and potassium intakes. Linear and logistic regression models with clustered robust standard errors will be used to assess the association between electrolyte intake and health outcomes (blood pressure and body mass index/BMI z-score and waist circumference) and to assess differences in taste preference and discrimination between high and low sodium foods, and correlations between preference, sodium intake, and covariates. RESULTS: A total of 780 children across 43 schools participated. The results from this study are expected at the end of 2015. CONCLUSIONS: This study will provide the first objective measure of sodium and potassium intake in Australian schoolchildren and improve our understanding of the relationship of these electrolytes to cardiovascular risk factors. Furthermore, this study will provide insight into child taste preferences and explore related factors. Given the cardiovascular implications of consuming too much sodium and too little potassium, monitoring of these nutrients during childhood is an important public health initiative.
RESUMEN
OBJECTIVE: To investigate the iodine status of Melbourne adults in 1992-94 and 2007-08, and to assess dietary iodine intake to enable comparison with recommended Nutrient Reference Values. METHOD: A cross-sectional study utilising 24-hr urine samples collected at two time points in a random sample of the Melbourne Collaborative Cohort Study. Two hundred and fifty seven adults (128 males, 129 females) in 1992-94, with a mean age of 56 years, and 265 adults (132 males, 133 females) in 2007-08, with a mean age of 68 years, were assessed, all being Melbourne residents. Urinary iodine concentration (UIC) was determined and daily urinary iodine excretion and daily iodine intake were assessed. RESULTS: In 1992-94, the median UIC was 27 µg/L and 84% had UIC <50 µg/L. The median daily iodine intake was 51 µg/d, and 83% of participants had dietary iodine intakes below the Estimated Average Requirement of 100 µg/d. In 2007-08, the median UIC was 49 µg/L, 51% had UIC <50 µg/L and the median daily iodine intake was 98 µg/d, with 52% of intakes below the EAR. CONCLUSION: Melbourne adults were moderately iodine deficient in 1992-94, and borderline moderately deficient in 2007-08. IMPLICATIONS: While iodine status appears to have improved, it remains below an adequate level for much of the adult population of Victoria. Adequate monitoring is fundamental to assess whether the mandatory use of iodised salt in bread is effective in reducing iodine deficiency across all population groups.