High sodium and low potassium intake among Italian children: relationship with age, body mass and blood pressure

Sex- and gender-based medicine in pediatric nutrition

Consistent evidence increasingly highlights the significance of integrating sex and gender medicine to ensure a precision approach according to individual patient needs. Gender discrepancies emerge across various areas, even from pediatric age. The importance of recognizing these differences in pediatric nutrition is critical for the development of targeted nutritional strategies and interventions, particularly in cases of associated pathologies, including obesity, metabolic-associated fatty liver disease, eating disorders, and inflammatory bowel disease. The review highlights the biological and sociocultural factors that contribute to different nutritional needs and health outcomes in male and female children. By examining current evidence, we underscore the necessity for precision medicine approaches in pediatric care that consider these sex- and gender-based differences. Moreover, differences in dietary requirements and dietary patterns between males and females are evident, underscoring the need for precise nutrition strategies for a more accurate management of children and adolescents. This approach is essential for improving clinical outcomes and promoting equitable healthcare practices. This review aims to provide an overview of nutrition-related medical conditions exhibiting sex- and gender-specific discrepancies, which might lead to distinct outcomes requiring unique management and prevention strategies. Future research and public health initiatives should address these differences in designing effective lifestyle education programs and nutrition interventions targeting both children and adolescents.

Time to define food salt targets in Italy starting with cereal-based products: A safe and practical way to reduce the heavy burden of cardiovascular disease

BACKGROUND AND AIMS

Excess salt intake is the leading dietary risk factor for cardiovascular disease in most countries, including Italy. While the cost-effectiveness of interventions aimed to reduce salt intake has been proved, the WHO recommendation to reduce salt intake by 30 % at the global level by 2025 is far from being reached.

METHODS AND RESULTS

In Italy, two surveys of the general adult population have established that the average salt intake is still almost twice the WHO recommendation although it was reduced by 1.2 g/day between 2008-12 and 2018-19. Previous investigations had shown that non-discretionary salt added by the industry or by local craft producers represents at least 50 % of the total intake and indicated cereal-based products as the main source of non-discretionary salt. Two recent studies conducted by the Italian Society of Human Nutrition "Young Working Group" have provided updated information on the salt content of almost three thousand cereal-based products currently available on the Italian food market and shown that most of the items evaluated had a sodium content much higher than the sodium benchmarks recently proposed by WHO.

CONCLUSIONS

Italy has built the foundations of an effective population strategy for salt intake reduction: it is time however to proceed with full commitment to food reformulation if any substantial further progress has to be made. Salt benchmarks for Italy need to be defined for the food categories most relevant to population salt intake and their implementation should ideally be mandatory after consultation with food producers.

Initiatives to Reduce the Content of Sodium in Food Products and Meals and Improve the Population's Health

Table salt is the main source of sodium (Na) in the human diet. Excessive supply of Na in a diet is strongly linked to many non-communicable human diseases, such as hypertension, obesity and stomach cancer. The World Health Organization recommends that daily intake of salt in adult diets should be kept below 5 g/person/day, which corresponds to 2 g Na/person/day. However, on average, adults consume about 9-10 g/person/day, and children and young people about 7-8 g/person/day. Initiatives to reduce salt intake include modifications of food composition in collaboration with the food industry, education of consumers, salt marking on foodstuff labels and taxation of salt. A need also exists to educate society so that they choose low-sodium products. In view of the food technology and amount of salt intake, the most important and the easiest change to make is to reduce the content of salt in baked goods. This paper analyses the results of surveys regarding strategies to reduce salt content in food products and considers multifaceted initiatives to reduce salt intake as a possible efficient method of improving the population's health status.

Estimation of Salt Intake in Normotensive and Hypertensive Children: The Role of Body Weight

OBJECTIVE

The connection between increased dietary salt intake and arterial hypertension has been recognized for a long time, even in children. This study aimed to investigate salt consumption in normotensive and hypertensive children and evaluate their dietary habits.

MATERIALS AND METHODS

A total of fifty participants were included in this cross-sectional study: twenty-five normotensive children and 25 children of both sexes with essential arterial hypertension from 12-17 years old. Subjects' body mass index, waist-to-hip ratio, body composition and arterial blood pressure were measured, and their daily salt intake was calculated from 24-h urine samples. Using the food frequency questionnaire (FFQ), the data on the average daily total energy and food intakes were collected and analyzed using a suitable program.

RESULTS

Estimated daily salt intake was significantly higher in hypertensive compared to normotensive children, and this is positively associated with blood pressure and body mass index (BMI). Hypertensive children had significantly higher BMIs, which also positively correlated with blood pressure. Consistently, resting metabolic rate (kcal) is higher in hypertensive children compared to normotensive, and this is also associated with blood pressure. Reported energy intake is also enlarged in hypertensive compared to normotensive children and for both groups, levels are significantly higher than the recommended values.

CONCLUSIONS

Our study results confirm the relationship between daily salt consumption, blood pressure and body weight. Sodium consumption related to blood pressure and body weight among children. Cardiovascular disease prevention should start in early childhood by reducing salt intake and preventing overweight/obesity since these are two of the most important modifiable risk factors for hypertension.

The Severity of Obesity Promotes Greater Dehydration in Children: Preliminary Results

The state of hydration of the body depends on the balance between the amount of water and salt consumed and excreted (the urinary extraction of excess sodium requires water). Inappropriate nutrition, particularly consuming too much processed food, causes obesity in children and additionally causes excessive sodium consumption, thus increasing the risk of excessive water loss. The aim of this study was to assess the hydration status of children with obesity and the relation between hydration, body composition, urinary sodium extraction, and nutrient intake. The study group consisted of 27 patients with obesity, with a mean age of 12.89 ± SD 2.79. Each patient's height, weight, body composition (electrical bioimpedance (BIA)), diet (7-day record), and biochemical tests were assessed. The hydration status was assessed using 24-hour urine collection, 24-hour urine osmolality, and an ultrasound of the vena cava (IVC/Ao index). Overall, 55% of children (n = 15) had urine osmolality values above 800 mOsm/kgH2O, which indicates significant dehydration, and 53% (n = 14) were dehydrated, based on the IVC/Ao index. Children with obesity and dehydration had a significantly higher BMI (31.79 vs. 27.32; p = 0.0228), fat mass percentage (37.23% vs. 30.07% p = 0.0051), and fat mass in kg (30.89 vs. 20.55; p = 0.0158), and significantly higher sodium intake from their diet (3390.0 mg vs. 2921.0 mg; p = 0.0230), as well as their sodium/potassium ratio (2.4 vs. 2.0; p = 0.0043). The 24-hour urinary sodium excretion and osmolality values were directly related to fat-mass percentage and fat-mass (in kg) in a simple linear correlation analysis. Our preliminary results confirm that obesity is related to dehydration. The overall high sodium excretion in children with obesity indicates an excessive salt intake along with low potassium intake, which is a significant predictor of dehydration, regardless of the total water intake (TWI).

Changes of the CYP11B2 Expressing Zona Glomerulosa in Human Adrenals From Birth to 40 Years of Age

Background:

Aldosterone synthase (CYP11B2) antibodies for immunohistochemistry, enables to visualize aldosterone-producing zona glomerulosa (ZG), aldosterone-producing micronodules, and aldosterone-producing adenomas. The architecture of the ZG differs in old versus young age but the evolution of the changes is not well known. The pathogenesis of aldosterone-producing micronodules and aldosterone-producing adenomas is still unclear and research on the ZG in young populations is limited. In this study, we elucidate changes in human ZG with age by quantifying the CYP11B2 expression.

Methods:

We collected 83 human adrenal glands from 57 autopsy cases aged 0 to 40 years old. In 26 cases, both adrenals were available. We performed immunohistochemistry targeting CYP11B2 and quantified the relative CYP11B2 expressing area, CYP11B2 continuity, the mean gap length between CYP11B2-expressing areas and the maximum extension of CYP11B2 area (depth).

Results:

We found a negative correlation between age and the relative CYP11B2 expressing area, a negative correlation between age and CYP11B2 continuity, a positive correlation between age and mean gap length, and a positive correlation between age and maximum CYP11B2 depth. The changes in expression patterns of relative CYP11B2 expressing area, CYP11B2 continuity and mean gap length were seen in both adrenals of the same autopsy case.

Conclusions:

The decline of relative CYP11B2 expressing ZG area and continuity may indicate involution of the ZG, which is supported by an increase of gaps and maximum CYP11B2 depth indicating clustering, comparable to formation of aldosterone-producing micronodules. The similarities in both adrenals from the same case indicate that these changes occur bilaterally.

Isolated systolic hypertension in the young: a heterogeneous condition

Isolated systolic hypertension in the youth, is still a challenging problem. The prevalence of this hypertensive subtype may vary according to the different population study and is peculiar of male subjects among the youngest age classes. Several are the mechanisms reported as possible underlying causes of isolated systolic blood pressure elevation and again these differ according to the different study cohort and may vary from overweight and obesity status, linked to sympathetic overactivity, to increased and earlier arterial stiffness, hyperkinetic state, or exaggerated pulse pressure amplification form central to peripheral sites, due to enhanced arterial elasticity. Evidence is lacking regarding whether this condition is benign or associated to unfavorable cardiovascular events. The few long-term studies that followed isolated systolic hypertensives in the long-term, again reported conflicting results. Waiting for future studies, some clinical and hemodynamic characteristics of young isolated systolic hypertensives may help clinicians to better characterized patient's risk profile and decide whether to perform a strict follow-up with non-pharmacological measurements or to start drug treatment.

Importance of central BP assessment in ISH of the young. Which devices are best suited for practical use?

Isolated systolic hypertension (ISH), defined as brachial systolic blood pressure (bSBP) ≥140 mmHg and diastolic blood pressure (DBP) <90 mmHg, is highly prevalent among young subjects and in the elderly. The prognostic significance of ISH in young individuals remains the object of large debate which might be solved, at least in part, if considering the prognostic role of central BP. For any given value of pBP, the cardiovascular (CV) risk is better defined by central BP (cBP). Young individuals with ISH have long been considered at low CV risk, given the assumption that a "spurious hypertension" phenotype characterized by elevated peripheral (brachial) BP (pBP), normal cBP, and elevated BP amplification was often found in this population. However, this remains to be proven, because many other studies found no differences in BP amplification between ISH and sisto-diastolic hypertension. Despite numerous attempts, methodologies for cBP assessment by non-invasive devices are currently not standardized. As a result, different devices could provide different cBP values despite using the same biological signals. Devices providing accurate estimates of BP amplification as a dimensionless ratio between amplitudes of central and peripheral arterial waveforms might be well suited for clinical purposes in young individuals with ISH. There is urgent need of well-designed prospective studies aiming at longitudinally evaluating the amount of CV risk associated with elevated cBP in young subjects with ISH and their related incremental prognostic value.

Isolated systolic hypertension of the young and sodium intake

Isolated systolic hypertension is associated with higher risk of cardiovascular disease and all-cause mortality. Despite being the most common form of hypertension in the elderly, it is also detectable among young and middle-aged subjects. Dietary salt (sodium chloride) intake is an important determinant of blood pressure, and high salt intake is associated with greater risk of hypertension and cardiovascular events. In most countries, habitual salt intake at all age categories largely exceeds the international recommendations. Excess salt intake, often interacting with overweight and insulin resistance, may contribute to the development and maintenance of isolated systolic hypertension in young individuals by causing endothelial dysfunction and promoting arterial stiffness through a number of mechanisms, namely increase in the renin-angiotensin-aldosterone system activity, sympathetic tone and salt-sensitivity. This short review focused on the epidemiological and clinical evidence, the mechanistic pathways and the cluster of pathophysiological factors whereby excess salt intake may favor the development and maintenance of isolated systolic hypertension in young people.

Sodium and potassium intakes and adiposity among Iranian pre-adolescents and adolescents: a cross-sectional study

Background

High sodium and low potassium intakes are associated with the early development of chronic diseases (e.g., hypertension, obesity). Taking into account the limited data on sodium and potassium intakes by 24-h excretion in urine in pre-adolescents and adolescents, we wished to determine baseline salt intake in Iranian subjects aged 11–18 years.

Methods

This was an observational study involving 374 pre-adolescents and adolescents (154 boys and 220 girls). Sodium and potassium intakes were ascertained by measuring sodium and potassium excretion in urine over 24 h. Creatinine level was used to validate the completeness of the urine collections. The association between sodium and potassium intake and adiposity was determined based on body fat percentage.

Results

The mean 24-h urine sodium concentration was 3130 ± 2200 mg/day, equal to 7.961 ± 5.596 g/day salt intake. Approximately half of the study participants exceeded the upper limit of Na intake. The mean potassium intake was estimated 1480 ± 1050 mg/day. There was a positive association between urinary sodium excretion and adiposity in crude (OR 1.79; 95% CI: 1.08—2.74) and full adjusted model (OR: 3.15; 95% CI: 2.28–4.63). Also, in subsample analysis, there was a positive correlation between urinary sodium and adiposity in both pre-adolescents (OR: 2.71; 95% CI: 2.29—3.93) and adolescents (OR: 3.55; 95% CI: 2.17—4.74). However, no significant association was found between 24-h urinary potassium and adiposity.

Conclusion

Sodium intake, as estimated by 24-h urinary excretion, was higher than recommended and it was positively associated with adiposity. Also, this study reported low compliance of potassium intake recommendations in 11–18 years’ Iranian pre-adolescents and adolescents. Health promotion interventions are needed in order to broaden public awareness of high sodium intake and potassium inadequacy to reduce chronic diseases.

Assessing the Association of Sodium, Potassium Intake and Sodium/Potassium Ratio on Blood Pressure and Central Adiposity Measurements amongst Ellisras Undernourished, Rural Children Aged 5–13 Years: South Africa

Background: Numerous studies have shown how diet, such as sodium (Na) and potassium (K) intake, is an important risk factor for non-communicable diseases (NCDs). This study aimed to assess the relationship between sodium intake, potassium intake; and sodium/potassium ratio with blood pressure (BP) and abdominal obesity amongst Ellisras rural children. Method: In this cross-sectional study, data on dietary intake of sodium and potassium were collected using a 24-h recall questionnaire from a total of 765 participants, aged 5–13 years. Blood pressure and anthropometric measurements were also collected. Generalised linear models and Pearson correlation were conducted to assess the association of sodium intake, potassium intake; and their ratio with BP, waist circumference (WC), and waist-to-height ratio (WHtR). Results: In both age groups, less than 14.9% of males and 19.8% of females consumed above the recommended adequate intake (AI) of sodium. In addition, both age groups had more than 90% of males and females who consumed below the recommended AI of potassium. Moreover, the sodium/potassium ratio was above the WHO recommended level in more than 30% of males and females. The study found a significant, weak positive correlation of sodium intake with systolic BP (SBP), diastolic BP (DBP), and with WHtR. A significant, weak positive correlation was also found between sodium/potassium ratio and WHtR. In addition, a significant association was found between potassium intake and systolic BP. Conclusion: Although our study found a notable low average intake of sodium and potassium as compared to the recommended values. There was positive correlation found between sodium intake and BP. Furthermore, a positive correlation of sodium intake and sodium/potassium ratio with WHtR was also found.

Analysis of spot urine biomarkers and association with body weight in Japanese elementary schoolchildren

Childhood obesity is rapidly increasing worldwide and is largely the consequence of adoption of unhealthy diets excessive in calories and salt (NaCl) as well as devoid in pivotal micronutrients such as potassium (K) and magnesium (Mg). Education-based programs aiming to encourage healthy food knowledge and behaviors are crucial at a young age, and for this purpose, convenient ways to assess daily dietary intake are warranted. We therefore attempted to evaluate the dietary intake of Okinawan schoolchildren in Japan by analyzing a series of biomarkers in morning spot urine samples and explore whether these biomarkers correlate with body weight and a series of metabolic parameters. We enrolled 98 third-grade elementary schoolchildren in Okinawa, Japan. Morning spot urine samples were collected and analyzed using high-performance liquid chromatography (HPLC) to assess dietary intake. We found that estimated daily NaCl intake was higher in obese/overweight children as compared to healthy-weight children (p = 0.0001). There was also a significant positive correlation between body mass index (BMI) and NaCl intake (Spearman) (ρ = 0.45, p < 0.0001) and a negative correlation between BMI and Mg/Cr (ρ =  -0.27, p = 0.01). Furthermore, Na/K ratio was higher in samples collected on Monday (weekend) as compared to samples collected on Thursday or Friday (weekday) (p < 0.0001).

CONCLUSION

Via the use of morning spot urine analyses, our results show that NaCl intake was associated with obesity, and Mg excretion negatively correlated with BMI in Japanese schoolchildren, highlighting the potential role of these micronutrients in maintaining a healthy body weight.

WHAT IS KNOWN

•Overweight and obesity are largely due to excessive consumption of calories and positively correlated with salt (NaCl) intake. •Spot urine methods are convenient for assessing the nutritional needs and targeting prevention programs in children.

WHAT IS NEW

•Utilizing morning spot urine analyses, estimated NaCl intake is positively correlated and Mg/Cr negatively correlated with BMI in Okinawan schoolchildren. •As estimated via morning spot urine samples, a greater proportion of children likely exceeds the recommended NaCl intake on the weekend as compared to weekday.

Obesity, Sodium Homeostasis, and Arterial Hypertension in Children and Adolescents

BACKGROUND

The relationship between obesity, arterial hypertension, and excessive salt intake has been known for a long time; however, the mechanism of this relationship remains not clear.

METHODS

The paper presents a current literature review on the relationship between salt consumption and the development of arterial hypertension in children and adolescents with obesity.

RESULTS

In addition to the traditional theory of hypertension development due to the increase in intravascular volume and disturbances of sodium excretion, recent studies indicate the existence of a complex mechanism related to excessive, pathological secretory activity of adipocytes, insulin resistance, and impaired function of the renin-angiotensin-aldosterone axis. That makes obese children and adolescents particularly vulnerable to the development of salt-sensitive arterial hypertension. Studies performed in many countries have shown that children and adolescents consume more sodium than recommended. It is worth noting, however, that the basis for these recommendations was the extrapolation of data from studies conducted on adults. Moreover, more important than sodium intake is the Na/K ratio and water consumption.

CONCLUSION

Regardless of the population-wide recommendations on reducing salt intake in children, specific recommendations for overweight and obese patients should be developed.

Association between 24 h Urinary Sodium and Potassium Excretion and Dietary Intake in Japanese Male Adolescent Football Players

High urinary sodium-to-potassium ratio is considered a strong risk factor for hypertension. This study aimed to evaluate urinary excretion of sodium and potassium, and we analyzed these levels associated with dietary intake in Japanese adolescent football players. This cross-sectional study included 120 Japanese male adolescent football players. Over 24 h, urine was collected and measured for creatinine, sodium, and potassium levels. A dietary assessment was performed using a self-administered diet history questionnaire. The study analyzed 79 participants. The mean urinary sodium was 143.2 mmol/day, urinary potassium was 42.8 mmol/day, and the mean urinary sodium-to-potassium ratio was 3.6. Compared with the Japanese Dietary Reference Intakes, the estimated salt intake was 73.4% for the participants who exceeded the sodium intake, and the estimated potassium intake was 73.4% for the participants who did not satisfy it. Multiple regression analysis revealed that milk and dairy product intake was independently and positively associated with urinary potassium (β = 0.252) and independently and negatively associated with the urinary sodium-to-potassium ratio (β = −0.254). Adolescent football players had a high-sodium and low-potassium diet, well above the Japanese Dietary Reference Intakes recommendations. Milk and dairy products could be effective for increasing urinary potassium and decreasing the urinary sodium-to-potassium ratio.

Association between Ideal Cardiovascular Health and aortic stiffness in Italian adolescents. The MACISTE study

BACKGROUND AND AIMS

Ideal Cardiovascular Health (ICH), defined as optimal levels of cardiovascular (CV) health factors and behaviors, has been reported to be very low in adults and children, with consequent several negative health outcomes and higher CV risk. The present study investigated the burden of ICH among Italian adolescents and its association with carotid-femoral pulse wave velocity (cf-PWV).

METHODS AND RESULTS

387 healthy adolescents (mean age 17.1 ± 1.4 years) attending the "G. Donatelli" High School in Terni, Italy, were evaluated. ICH was assessed through clinical evaluation, laboratory measures and interviewer-administered questionnaires. Cf-PWV was measured by arterial tonometry (SphygmoCor). For each ICH metric, a score of 2 was assigned for ideal levels, 1 for intermediate, and 0 for poor. All subjects showed at least one ICH metric, whereas none showed all ICH 7 metrics. The average number of ICH metrics was 4.3 ± 1.1. The highest rates were observed for fasting blood glucose (98%), whereas an ideal healthy diet was achieved only by 8% of subjects. The Cf-PWV was inversely and linearly associated with the sum of ICH metrics (p = 0.03) and the ICH score (p < 0.01). At the multivariate analysis, the association between ICH score and cf-PWV remained significant after adjustment for age, sex, heart rate, mean arterial pressure and other confounders (p = 0.04).

CONCLUSION

ICH is relatively uncommon among Italian adolescents and inversely related to cf-PWV. Our results showed a detrimental association between CV unhealthy factors and behaviors with increased aortic stiffness, which starts developing at an early stage of the lifespan.

Relationship between salt consumption and iodine intake in a pediatric population

PURPOSE

The World Health Organization recommends reduction of salt intake to < 5 g/day and the use of iodized salt to prevent iodine deficiency states. A high prevalence of excess salt consumption and an inadequate iodine intake has been previously shown in an Italian pediatric population. It was appropriate, therefore, to analyse in the same population the relationship occurring between salt consumption and iodine intake.

METHODS

The study population was made of 1270 children and adolescents. Estimates of salt consumption and iodine intake were obtained by measuring 24 h urinary sodium and iodine excretion.

RESULTS

The iodine intake increased gradually across quartiles of salt consumption independently of sex, age and body weight (p < 0.001). Median iodine intake met the European Food Safety Authority adequacy level only in teenagers in the highest quartile of salt consumption (salt intake > 10.2 g/day). We estimated that approximately 65-73% of the total iodine intake was derived from food and 27-35% from iodized salt and that iodized salt made actually only 20% of the total salt intake.

CONCLUSION

In this pediatric population, in face of an elevated average salt consumption, the use of iodized salt was still insufficient to ensure an adequate iodine intake, in particular among teenagers. In the perspective of a progressive reduction of total salt intake, the health institutions should continue to support iodoprophylaxis, in the context of the national strategies for salt reduction. In order for these policies to be successful, in addition to educational campaigns, it is needed that the prescriptions contained in the current legislation on iodoprophylaxis are made compelling through specific enforcement measures for all the involved stakeholders.

Salt and Sugar: Two Enemies of Healthy Blood Pressure in Children

The prevalence of essential arterial hypertension in children and adolescents has grown considerably in the last few decades, making this disease a major clinical problem in the pediatric age. The pathogenesis of arterial hypertension is multifactorial, with one of the components being represented by incorrect eating habits. In particular, excessive salt and sugar intake can contribute to the onset of hypertension in children, particularly in subjects with excess weight. Babies have an innate predisposition for sweet taste, while that for salty taste manifests after a few weeks. The recent modification of dietary styles and the current very wide availability of salt and sugar has led to an exponential increase in the consumption of these two nutrients. The dietary intake of salt and sugar in children is in fact much higher than that recommended by health agencies. The purpose of this review is to explore the mechanisms via which an excessive dietary intake of salt and sugar can contribute to the onset of arterial hypertension in children and to show the most important clinical studies that demonstrate the association between these two nutrients and arterial hypertension in pediatric age. Correct eating habits are essential for the prevention and nondrug treatment of essential hypertension in children and adolescents.

Salt intake and blood pressure in Iranian children and adolescents: a population-based study

BACKGROUND

Previous studies have reported a high prevalence of hypertension in Iranian students, especially in rural areas. The aim of this study was to investigate the daily intake of salt in students and its association with high blood pressure.

METHODS

A random sub-sample was selected from the participants of the second phase of Shahroud schoolchildren eye cohort study and then a random urine sample was tested for sodium, potassium and creatinine. Urine electrolyte esexcretion and daily salt intake were calculated by Tanaka et al.'s formula.

RESULTS

Among 1455 participants (including 230 participants from rural area and 472 girls), the mean age was 12.9 ± 1.7 year and the mean daily salt intake was 9.7 ± 2.6 g (95% CI 9.5-9.8). The mean salt consumption in rural areas [10.8 (95% CI 10.4-11.2)] was higher than urban areas [9.4 (95% CI 9.3-9.6)], in people with hypertension [10.8 (95% CI 10.3-11.3)] was more than people with normal blood pressure [9.4 (95% CI 9.3-9.6)], and in boys [9.8 (95% CI 9.7-10.0)] was more than girls [9.3 (95% CI 9.1-9.6)]. Higher age, BMI z-score, male sex and rural life, were associated with increased daily salt intake. Increased salt intake was associated with increased systolic and diastolic blood pressure.

CONCLUSION

Daily salt intake in Iranian adolescents was about 2 times the recommended amount of the World Health Organization, was higher in rural areas and was associated with blood pressure. Reducing salt intake should be considered as an important intervention, especially in rural areas.

Idiopathic Osteoporosis and Nephrolithiasis: Two Sides of the Same Coin?

Idiopathic osteoporosis and nephrolithiasis are formidable health problems showing a progressive increase in their incidence and prevalence in the last decades. These temporal trends were observed in both pediatric and adult populations worldwide. Epidemiological and experimental studies indicate that both disorders show several common pathogenic environmental and genetic factors. In this review, we analyzed the clinical characteristics common to the two disorders and the state-of-the-art knowledge regarding the genetic predisposition and the environmental factors recognized as triggers in adult and pediatric ages. As a result of this work, we propose to consider idiopathic nephrolithiasis and osteoporosis as two possible expressions of a unique clinical syndrome. Accordingly, the clinical approach to both disorders should be modified in order to program an efficient primary and secondary prevention strategy.

The association between dietary sodium intake, adiposity and sugar-sweetened beverages in children and adults: a systematic review and meta-analysis

Higher intakes of Na may contribute to weight gain. The primary aim of this systematic review and meta-analysis was to examine the relationship between dietary Na intake and measures of adiposity in children and adults. Given the previous link between Na intake and the consumption of sugar-sweetened beverages (SSB), which are a known risk factor for obesity, a secondary aim examining the relationship between Na intake and SSB consumption was assessed. A systematic literature search identified cross-sectional and longitudinal studies and randomised controlled trials (RCT) which reduced dietary Na (≥3 months). Meta-analysis was performed for outcomes with ≥3 studies. Cross-sectionally higher Na intakes were associated with overweight/obesity in adults (five studies; n 11 067; OR 1·74; 95 % CI 1·43, 2·13) and in children (three studies; n 3625, OR 3·29; 95 % CI 2·25, 4·80), and abdominal obesity (five studies; n 19 744; OR 2·04; 95 % CI 1·72, 2·42) in adults. Overall, associations remained in sensitivity analyses which adjusted for energy. Findings from longitudinal studies were inconsistent. RCT in adults indicated a trend for lower body weight on reduced-Na compared with control diets (fifteen studies; n 5274; -0·29 kg; 95 % CI -0·59, 0·01; P = 0·06); however, it is unclear if energy intakes were also altered on reduced-Na diets. Among children higher Na intakes were associated with higher intake of SSB (four studies, n 10 329, b = 22, 16 and 26 g/d); no studies were retrieved for adults. Overall, there was a lack of high-quality studies retrieved. While cross-sectional evidence indicates Na intake was positively associated with adiposity, these findings have not been clearly confirmed by longitudinal studies or RCT.

A systematic review and meta-analysis of 24-h urinary output of children and adolescents: impact on the assessment of iodine status using urinary biomarkers

PURPOSE

Urinary iodine concentration (UIC (μg/ml) from spot urine samples collected from school-aged children is used to determine the iodine status of populations. Some studies further extrapolate UIC to represent daily iodine intake, based on the assumption that children pass approximately 1 L urine over 24-h, but this has never been assessed in population studies. Therefore, the present review aimed to collate and produce an estimate of the average 24-h urine volume of children and adolescents (> 1 year and < 19 years) from published studies.

METHODS

EBSCOHOST and EMBASE databases were searched to identify studies which reported the mean 24-h urinary volume of healthy children (> 1 year and < 19 years). The overall mean (95% CI) estimate of 24-h urine volume was determined using a random effects model, broken down by age group.

RESULTS

Of the 44 studies identified, a meta-analysis of 27 studies, with at least one criterion for assessing the completeness of urine collections, indicated that the mean urine volume of 2-19 year olds was 773 (654, 893) (95% CI) mL/24-h. When broken down by age group, mean (95% CI) 24-h urine volume was 531 mL/day (454, 607) for 2-5 year olds, 771 mL/day (734, 808) for 6-12 year olds, and 1067 mL/day (855, 1279) for 13-19 year olds.

CONCLUSIONS

These results demonstrate that the average urine volume of children aged 2-12 years is less than 1 L, therefore, misclassification of iodine intakes may occur when urine volumes fall below or above 1 L. Future studies utilizing spot urine samples to assess iodine status should consider this when extrapolating UIC to represent iodine intakes of a population.

Physical Activity and Physical Competence in Overweight and Obese Children: An Intervention Study

With the current obesity epidemic and the decline of fitness among school-aged children, the importance of obesity interventions to promote physical activity and healthy habits has become indisputable. The purpose of this study was to assess the efficacy of a school-based multicomponent intervention in increasing physical activity (PA) levels, actual physical abilities, and perceived physical abilities in clinical and nonclinical samples of overweight/obese boys and girls aged 10-12 years. The clinical intervention group (n = 35) participated in a 7-month after-school program in addition to curricular physical education lessons, while the nonclinical control group (n = 29) received usual curricular lessons. Measures included levels of PA and fitness and individual's perceptions of physical ability. After treatment, the intervention group showed improved PA levels, perceived physical ability, and throwing and jumping task performances compared to the control group. Results indicate that a multicomponent program can improve levels of PA, fitness, and perceived competence of overweight participants. Findings highlight the importance of a comprehensive healthy lifestyle program that includes physical, psychosocial, and behavioral factors and suggest practical implications for educators, trainers, and teachers in identifying best practices targeting childhood obesity.

Dietary Sodium Intake and Health Indicators: A Systematic Review of Published Literature between January 2015 and December 2019

As the science surrounding population sodium reduction evolves, monitoring and evaluating new studies on intake and health can help increase our understanding of the associated benefits and risks. Here we describe a systematic review of recent studies on sodium intake and health, examine the risk of bias (ROB) of selected studies, and provide direction for future research. Seven online databases were searched monthly from January 2015 to December 2019. We selected human studies that met specified population, intervention, comparison, outcome, time, setting/study design (PICOTS) criteria and abstracted attributes related to the study population, design, intervention, exposure, and outcomes, and evaluated ROB for the subset of studies on sodium intake and cardiovascular disease risks or indicators. Of 41,601 abstracts reviewed, 231 studies were identified that met the PICOTS criteria and ROB was assessed for 54 studies. One hundred and fifty-seven (68%) studies were observational and 161 (70%) focused on the general population. Five types of sodium interventions and a variety of urinary and dietary measurement methods were used to establish and quantify sodium intake. Five observational studies used multiple 24-h urine collections to assess sodium intake. Evidence mainly focused on cardiovascular-related indicators (48%) but encompassed an assortment of outcomes. Studies varied in ROB domains and 87% of studies evaluated were missing information on ≥1 domains. Two or more studies on each of 12 outcomes (e.g., cognition) not previously included in systematic reviews and 9 new studies at low ROB suggest the need for ongoing or updated systematic reviews of evidence on sodium intake and health. Summarizing evidence from assessments on sodium and health outcomes was limited by the various methods used to measure sodium intake and outcomes, as well as lack of details related to study design and conduct. In line with research recommendations identified by the National Academies of Science, future research is needed to identify and standardize methods for measuring sodium intake.

Sodium and potassium excretion predict increased depression in urban adolescents

This study examined the prospective role of urinary sodium and potassium excretion in depressive symptoms among urban, low-income adolescents, and whether these relationships vary by gender. A total of 84 urban adolescents (mean age 13.36 years; 50% male; 95% African American) self-reported on their depressive symptoms at baseline and 1.5 years later. At baseline, the youth also completed a 12-h (overnight) urine collection at home which was used to measure sodium and potassium excretion. After adjusting for baseline depressive symptoms, age, BMI percentile, and pubertal development, greater sodium excretion and lower potassium excretion predicted more severe depressive symptoms at follow-up, with no significant gender differences. The results suggest that consumption of foods high in sodium and low in potassium contributes to the development of depressive symptoms in early adolescence, and that diet is a modifiable risk factor for adolescent depression. Interventions focusing on diet may improve mental health in urban adolescents.

Development of Durum Wheat Breads Low in Sodium Using a Natural Low-Sodium Sea Salt

Durum wheat is widespread in the Mediterranean area, mainly in southern Italy, where traditional durum wheat breadmaking is consolidated. Bread is often prepared by adding a lot of salt to the dough. However, evidence suggests that excessive salt in a diet is a disease risk factor. The aim of this work is to study the effect of a natural low-sodium sea salt (Saltwell^®) on bread-quality parameters and shelf-life. Bread samples were prepared using different levels of traditional sea salt and Saltwell^®. The loaves were packaged in modified atmosphere conditions (MAPs) and monitored over 90 days of storage. No significant differences (p ≤ 0.05) were found in specific volumes and bread yield between the breads and over storage times, regardless of the type and quantity of salt used. Textural data, however, showed some significant differences (p ≤ 0.01) between the breads and storage times. 5-hydroxymethylfurfural (HMF) is considered, nowadays, as an emerging ubiquitous processing contaminant; bread with the lowest level of Saltwell^® had the lowest HMF content, and during storage, a decrease content was highlighted. Sensory data showed that the loaves had a similar rating (p ≤ 0.05) and differed only in salt content before storage. This study has found that durum wheat bread can make a nutritional claim of being "low in sodium" and "very low in sodium".

Novel Insights into the Pathogenesis and Management of the Metabolic Syndrome

The metabolic syndrome, by definition, is not a disease but is a clustering of individual metabolic risk factors including abdominal obesity, hyperglycemia, hypertriglyceridemia, hypertension, and low high-density lipoprotein cholesterol levels. These risk factors could dramatically increase the prevalence of type 2 diabetes and cardiovascular disease. The reported prevalence of the metabolic syndrome varies, greatly depending on the definition used, gender, age, socioeconomic status, and the ethnic background of study cohorts. Clinical and epidemiological studies have clearly demonstrated that the metabolic syndrome starts with central obesity. Because the prevalence of obesity has doubly increased worldwide over the past 30 years, the prevalence of the metabolic syndrome has markedly boosted in parallel. Therefore, obesity has been recognized as the leading cause for the metabolic syndrome since it is strongly associated with all metabolic risk factors. High prevalence of the metabolic syndrome is not unique to the USA and Europe and it is also increasing in most Asian countries. Insulin resistance has elucidated most, if not all, of the pathophysiology of the metabolic syndrome because it contributes to hyperglycemia. Furthermore, a major contributor to the development of insulin resistance is an overabundance of circulating fatty acids. Plasma fatty acids are derived mainly from the triglycerides stored in adipose tissues, which are released through the action of the cyclic AMP-dependent enzyme, hormone sensitive lipase. This review summarizes the latest concepts in the definition, pathogenesis, pathophysiology, and diagnosis of the metabolic syndrome, as well as its preventive measures and therapeutic strategies in children and adolescents.

Comprehensive dietary evaluation of Italian primary school children: food consumption and intake of energy, nutrients and phenolic compounds

Information on children's diet including bioactive compounds is quite scarce. This observational study investigated the composition of the diet of children living in Parma (Italy; n = 172, 8-10 years) using 3-day food records completed in winter and spring. Mean daily intakes of food groups, energy and nutrients were obtained using the national food database, while (poly)phenol contents were estimated from Phenol-Explorer or by specific literature searches. Food consumption, energy and nutrient intakes decreased in spring and were partially in line with national data. Adherence to the nutritional recommendations was not satisfied for the majority of nutrients. Main contributors to the phenolic intake were flavonoids (flavan-3-ols) and phenolic acids (hydroxycinnamic acids), while main dietary sources were fruit, chocolate-based products, vegetables, and tea & coffee (decaffeinated). This study provided the first comprehensive analysis of the nutritional composition of children's diet. Future research should look at the health implications of dietary choices in children.

Should we eat more potassium to better control blood pressure in hypertension?

Changes in lifestyle and nutrition are recommended as the first-step approach to the management of hypertension by all national and international guidelines. Today, when considering nutritional factors in hypertension, almost all the attention is focused on the reduction of salt intake to improve blood pressure (BP) control. Changes in potassium intake are only briefly evoked in guidelines. Few physicians actually think about proposing to eat more foods that are high in potassium (fruits, vegetables, nuts) to better control BP. Yet, during the last 40 years, increasing evidence has accumulated demonstrating that increasing potassium intake, either with food products or with supplements, is associated with significant reductions of both systolic and diastolic BP. The hypotensive effect of potassium is particularly marked in patients with hypertension and in subjects with a very high sodium intake, suggesting that potassium counterbalances the effects of sodium. In addition, several meta-analyses have now confirmed that high potassium intake reduces the risk of stroke by ∼ 25%. Finally, increasing potassium in the diet may perhaps be beneficial for some renal patients, as post hoc analyses have suggested that a high potassium intake may retard the decline of renal function in patients with early chronic kidney disease (CKD) stages. However, high potassium intake may be risky and sometimes even dangerous in hypertensive patients with CKD stages 3-5, specifically diabetics. In this context, however, as the level of evidence remains low, more prospective clinical studies are needed. The goal of this review is to discuss the actual evidence that supports the recommendation to eat more potassium in order to better control BP in essential hypertension and to review the restrictions in CKD patients with hypertension.

Salt and Health: Survey on Knowledge and Salt Intake Related Behaviour in Italy

BACKGROUND AND AIM

Excess sodium intake is a recognised causal factor of hypertension and its cardiovascular complications; there is however a lack of practical instruments to assess and monitor the level of knowledge and behaviour about dietary salt intake and to relate these factors to the population general dietary habits.

METHODS AND RESULTS

A self-administered questionnaire was developed to assess the salt and health related knowledge and behaviour of the Italian population through an online survey. A sample of 11,618 Italian participants completed the questionnaire. The degree of knowledge and the reported behaviour about salt intake were both found to be related to age, gender, home region, level of education and occupation. There was a significant interrelation between salt knowledge and behaviour and both were significantly and directly related to the degree of adherence to a Mediterranean-like dietary pattern. A hierarchical evaluation was also made of the relevance of any single question to the overall assessment of knowledge and behaviour about salt intake.

CONCLUSIONS

The study population overall appeared to have a decent level of knowledge about salt, but a less satisfactory behaviour. Our findings point to social inequalities and young age as the main factors having a negative impact on knowledge and behaviour about salt intake as part of generally inadequate dietary habits. The degrees of knowledge and behaviour were significantly and directly interrelated, confirming that improving knowledge is a key step for behavioural changes, and suggesting that educational campaigns are crucial for the implementation of good practices in nutrition.

The association of parents' behaviors related to salt with 24 h urinary sodium excretion of their children: A Spanish cross-sectional study

BACKGROUND

Sodium intake is excessive among Spanish children, but the salt use behaviors of parents and children are unknown. This study aims to determine behaviors related to salt intake in both schoolchildren and parents and the relationship between parental behaviors and 24 h urinary sodium excretion (UNa-24h) in children.

SUBJECTS AND METHODS

A convenience sample was taken from a cross-sectional analysis. Parents completed a self-reported questionnaire about their behaviors related to salt, and their responses were compared with the UNa-24h of their own children. The median test was used to identify differences in UNa-24h according to behaviors. Logistic regression was used to assess the relationship between the behaviors of parents and high sodium excretion in the children and the risk of children's use of table salt, adjusting for age, sex, and BMI. Multinomial logistic regression models, adjusted by the covariates, were used to study the children's salt preferences.

RESULTS

A total of 329 schoolchildren from different Spanish provinces were included in the study (mean age: 9.0 ± 1.2 years, 157 girls). The majority of families (parents mean age: 42.0 ± 5.2 years) reported adding salt to food during cooking (92%), and 59% of them never looked at the sodium content on food labels. However, none of these behaviors were related to UNa-24h (p > 0.05). The use of iodized salt (53%), the presence of a salt shaker on the table (6%), and the use of table salt by fathers (57%), mothers (52%) or children (17%) increased the odds (p < 0.05) of children having a higher UNa-24h. Checking sodium content on food labels and the use of table salt by the children or father was associated with a lower preference for salty foods (p < 0.05).

CONCLUSIONS

It is important to make parents aware of the relationship between their behaviors regarding the use of discretionary salt and their children's sodium intake. Our data suggest that salt-specific education programs on how to reduce salt both in-home and outside the home should be implemented to improve behavior skills related to salt consumption in parents and children.

Central blood pressure and pulse wave velocity in young and middle-aged Japanese adults with isolated systolic hypertension

Isolated systolic hypertension (ISH), defined as systolic blood pressure (SBP) ≥140 mmHg and diastolic BP (DBP) <90 mmHg, is a common type of hypertension among young men. This study aimed to investigate the clinical characteristics, central blood pressure, and arterial stiffness of young and middle-aged Japanese individuals with ISH. A total of 432 male participants, aged 18-49 years, were classified into six subgroups: optimal BP (SBP <120 mmHg and DBP <80 mmHg), high-normal BP (SBP 120-129 mmHg and DBP <80 mmHg), high-BP (SBP 130-139 mmHg and/or DBP 80-89 mmHg), ISH (SBP ≥140 mmHg and DBP <90 mmHg), isolated diastolic hypertension (IDH) (SBP <140 mmHg and DBP ≥90 mmHg), and systolic and diastolic hypertension (SDH) (SBP ≥140 mmHg and DBP ≥90 mmHg). Participants with ISH had a greater body mass index (BMI) and waist circumference than the optimal BP participants but were more likely to be physically active than the IDH and SDH participants. The central SBP of the ISH subgroup was higher than that of the optimal/high-normal/high-BP subgroups and lower than that of the SDH subgroup. The carotid-femoral pulse wave velocity (cfPWV) of the ISH subgroup was higher than that of the optimal and high-normal BP subgroups and lower than that of the SDH subgroup after adjusting for age, heart rate, BMI, and physical activity. These differences disappeared after further adjustment for central mean arterial pressure. In conclusion, the central SBP of Japanese men with ISH was greater than that of Japanese men with optimal/high-normal/high-BP, but the progression of arterial stiffness was unclear.

Dietary reference values for sodium

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) derived dietary reference values (DRVs) for sodium. Evidence from balance studies on sodium and on the relationship between sodium intake and health outcomes, in particular cardiovascular disease (CVD)-related endpoints and bone health, was reviewed. The data were not sufficient to enable an average requirement (AR) or population reference intake (PRI) to be derived. However, by integrating the available evidence and associated uncertainties, the Panel considers that a sodium intake of 2.0 g/day represents a level of sodium for which there is sufficient confidence in a reduced risk of CVD in the general adult population. In addition, a sodium intake of 2.0 g/day is likely to allow most of the general adult population to maintain sodium balance. Therefore, the Panel considers that 2.0 g sodium/day is a safe and adequate intake for the general EU population of adults. The same value applies to pregnant and lactating women. Sodium intakes that are considered safe and adequate for children are extrapolated from the value for adults, adjusting for their respective energy requirement and including a growth factor, and are as follows: 1.1 g/day for children aged 1-3 years, 1.3 g/day for children aged 4-6 years, 1.7 g/day for children aged 7-10 years and 2.0 g/day for children aged 11-17 years, respectively. For infants aged 7-11 months, an Adequate Intake (AI) of 0.2 g/day is proposed based on upwards extrapolation of the estimated sodium intake in exclusively breast-fed infants aged 0-6 months.

Lifestyles and Cardiovascular Prevention in Childhood and Adolescence

Pathology studies demonstrated that coronary fatty streaks develop early in life and that even more advanced fibrous plaques are present in a proportion of adolescents. The presence and extent of atherosclerosis in children and adolescents can be correlated with the same risk factors present in adults; as well as, childhood levels of these risk factors predict adult cardiovascular diseases. Children are born with ideal cardiovascular health but, unfortunately, most of them develop over time modifiable behavioral risk factors. Achieving sustained lifestyle changes initiated too late in adults is difficult, and pharmacologic risk factor control cannot fully restore a low-risk state. Therefore, it seems eminently reasonable to initiate healthful lifestyle training as early in life, decreasing the prevalence of cardiovascular risk factors to retard atherogenic processes and reduce the future burden of cardiovascular diseases. Many guideline recommendations encourage universal adoption of healthier lifestyles, identification of children with cardiovascular risk factors, and their treatment using targeted lifestyle modification and, rarely, pharmacotherapy. Major gains will likely accrue from public health strategies targeting incorrect diet, physical activity, and cigarette smoking. Individualized strategies, however, will initially focus on the highest risk children such as those with familial hyperlipidaemia, diabetes, hypertension, and obesity. The primary purpose of this article is to provide a broad overview on the long-term cardiovascular effects of risk factors in children and youth and to outline various lines of evidence for the efficacy of primordial and primary prevention in young people, as well as recommendations for population- and individual-level strategies and evidence-based interventions.

Low sleep time is associated with higher levels of blood pressure and fat mass in Amerindian schoolchildren

OBJECTIVES

While altered sleep patterns (ie, low sleep time) have been studied and reported in adults as a new cardiometabolic risk factor, less information is available on how sleep patterns impact children of different ethnicities. The aim of this study was to compare the levels of blood pressure and other cardiometabolic risk factors in relation to different levels of sleep time in schoolchildren of Amerindian Mapuche or European-ancestry of Southern Chile.

METHODS

In a cross-sectional study, 540 Chilean schoolchildren (6-13 years) were divided into two ethnic groups (n = 119 Mapuche Amerindians and n = 421 European-ancestry). Groups were analyzed according to sleep time per day as registered by parents' report and distributed into quartile categories of sleep time: Mapuche (quartile 1 [Q1] ≥10.0 h, n = 34; Q2 9.5-10.0 h, n = 29; Q3 8.5-9.0 h, n = 31; and Q4 ≤ 8.5 h, n = 25), and European (Q1, n = 99; Q2, n = 77; Q3, n = 144; Q4, n = 101). The main cardiovascular parameters (systolic [SBP] and diastolic blood pressure) were complemented with anthropometric/body composition (body mass, body mass index [BMI], waist circumference, fat mass, muscle mass, lean mass), cardiorespiratory (heart rate rest, oxygen saturation), and muscle strength (handgrip of dominant and non-dominant arm) outcomes.

RESULTS

From Q1 and across Q2, Q3, and Q4, there was an increase in delta mean SBP in both Mapuche (Δ +17.6 mm Hg) and European (Δ +7.3 mm Hg) schoolchildren with 30-90 min of decreased sleep time (using ≥10 h as reference in Q1). The tendency for worsening of other cardiometabolic risk factors was maintained for delta mean BMI (Δ +2.6 kg/m² ), waist circumference (Δ +12 cm), and fat mass (Δ +8.3%) in Mapuches, whereas European peers showed only worsened waist circumference (Δ +6 cm) across Q2, Q3, and Q4 in comparison with reference Q1. There was also a higher prevalence of hypertension in Mapuche (31.1%) compared to in European schoolchildren (17.6%).

CONCLUSIONS

Mapuche and European schoolchildren show higher levels of SBP with a decrease in sleep time of 30 min; however, there is a higher prevalence of hypertension and obesity in ethnic Mapuches than in European schoolchildren. These findings indicate that more studies should be applied at early school ages for preventing low sleep time and their related cardiometabolic risk factors for hypertension development in different ethnic groups.

Isolated systolic hypertension in the young: a position paper endorsed by the European Society of Hypertension

: Whether isolated systolic hypertension in the young (ISHY) implies a worse outcome and needs antihypertensive treatment is still a matter for dispute. ISHY is thought to have different mechanisms than systolic hypertension in the elderly. However, findings from previous studies have provided inconsistent results. From the analysis of the literature, two main lines of research and conceptualization have emerged. Simultaneous assessment of peripheral and central blood pressure led to the identification of a condition called pseudo or spurious hypertension, which was considered an innocent condition. However, an increase in pulse wave velocity has been found by some authors in about 20% of the individuals with ISHY. In addition, obesity and metabolic disturbances have often been documented to be associated with ISHY both in children and young adults. The first aspect to consider whenever evaluating a person with ISHY is the possible presence of white-coat hypertension, which has been frequently found in this condition. In addition, assessment of central blood pressure is useful for identifying ISHY patients whose central blood pressure is normal. ISHY is infrequently mentioned in the guidelines on diagnosis and treatment of hypertension. According to the 2013 European Guidelines on the management of hypertension, people with ISHY should be followed carefully, modifying risk factors by lifestyle changes and avoiding antihypertensive drugs. Only future clinical trials will elucidate if a benefit can be achieved with pharmacological treatment in some subgroups of ISHY patients with associated risk factors and/or high central blood pressure.

Sodium intake and blood pressure in children and adolescents: a systematic review and meta-analysis of experimental and observational studies

Background

High sodium intake is a cause of elevated blood pressure in adults. In children and adolescents, less evidence is available and findings are equivocal. We systematically reviewed the evidence from experimental and observational studies on the association between sodium intake and blood pressure in children and adolescents.

Methods

A systematic search of the Medline, Embase, CINAHL and CENTRAL databases up to March 2017 was conducted and supplemented by a manual search of bibliographies and unpublished studies. Experimental and observational studies involving children or adolescents between 0 and 18 years of age were included. Random-effects meta-analyses were performed by pooling data across all studies, separately for experimental and observational studies, and restricting to studies with sodium intake and blood pressure measurement methods of high quality. Subgroup meta-analyses, sensitivity analyses and meta-regressions were conducted to investigate sources of heterogeneity and confounding. The dose-response relationship was also investigated.

Results

Of the 6572 publications identified, 85 studies (14 experimental; 71 observational, including 60 cross-sectional, 6 cohort and 5 case-control studies) with 58 531 participants were included. In experimental studies, sodium reduction interventions decreased systolic blood pressure by 0.6 mm Hg [95% confidence interval (CI): 0.5, 0.8] and diastolic blood pressure by 1.2 mm Hg (95% CI: 0.4, 1.9). The meta-analysis of 18 experimental and observational studies (including 3406 participants) with sodium intake and blood pressure measurement methods of high quality showed that, for every additional gram of sodium intake per day, systolic blood pressure increased by 0.8 mm Hg (95% CI: 0.4, 1.3) and diastolic blood pressure by 0.7 mm Hg (95% CI: 0.0, 1.4). The association was stronger among children with overweight and with low potassium intake. A quasi-linear relationship was found between sodium intake and blood pressure.

Conclusions

Sodium intake is positively associated with blood pressure in children and adolescents, with consistent findings in experimental and observational studies. Since blood pressure tracks across the life course, our findings support the reduction of sodium intake during childhood and adolescence to lower blood pressure and prevent the development of hypertension.

Dietary habits of adolescents living in North America, Europe or Oceania: A review on fruit, vegetable and legume consumption, sodium intake, and adherence to the Mediterranean Diet

AIMS

This review aimed at investigating fruit, vegetable and legume consumption, salt/sodium intake, and the adherence to the Mediterranean dietary pattern in adolescents, three key aspects towards the adoption of a healthy diet.

DATA SYNTHESIS

Three separate searches were carried out on PubMed and Scopus, using the same procedure, searching for studies published in the previous decade with data on fruit and/or vegetable or legume consumption, salt or sodium intake, and adherence to the Mediterranean Diet assessed using the KIDMED questionnaire. The review included a total of 58 papers, which describe original investigations on healthy adolescents (10-19 years old) living in North America, Europe or Oceania, with a sample size >150 participants. The average fruit and vegetable consumption has been found strongly below the recommended values of 400 grams or 5 portions per day in almost all the examined populations. Very little is known about adolescents' legume consumption. Few available data have been found also for sodium intake and, for the majority of the screened populations, levels were far above the recommended 5 grams per day. Lastly, a medium-low adherence to the Mediterranean Diet has been found for adolescents living in Mediterranean Countries.

CONCLUSIONS

Adolescents living in North America, Europe or Oceania are far from being compliant with the nutritional recommendations for fruit, vegetables, legumes, and sodium, and they do not follow the principles of the Mediterranean Diet. Educational and behavioural interventions are required to improve adolescents' dietary patterns.

Highlighting of Urinary Sodium and Potassium among Indonesian Schoolchildren Aged 9-12 Years: The Contribution of School Food

Background

Sodium (Na) and potassium (K), the essential nutrients, have vital role in promoting cellular growth including growth and development of children. Excessive Na intake and inadequate K consumption, which consequently increases the risk of cardiovascular disease, have been reported. Spot electrolyte urine was highly correlated and validated with gold standard to estimate electrolyte dietary intake. This study aimed at predicting sodium and potassium intake using morning spot urine among Indonesian schoolchildren.

Methods

A cross-sectional study was carried out in 155 healthy elementary students aged 9–12 years. Spot urine samples were collected and analyzed for Na, K, and creatinine. Predicted 24 h Na and K excretions were compared to the Indonesian recommendation dietary allowances. The Na and K contribution from school food was reported by observing directly and the dietary recall method.

Results

A total of 80 boys and 75 girls recruited as samples in this study demonstrated that their estimated urinary Na and K were 105.42 ± 66.05 mmol/day and 16.39 ± 12.57 mmol/day, respectively. Na intake was on average higher than recommended; meanwhile, almost all subjects showed very low compliance of K intake recommendation. Furthermore, food intake at school contributed to those conditions. Na and K content of school food contributed 33% and 29% of the daily intake of each nutrient and contributed 125% and 25% higher than the Na and K school standard, respectively.

Conclusions

Indonesian schoolchildren aged 9–12 years are categorized by excessive Na intake and very deficient K intake. The present study highlights the need for policies in the environmental school setting to reduce Na intake and K intake.

Iodine deficiency among Italian children and adolescents assessed through 24-hour urinary iodine excretion

BACKGROUND

Iodine is an essential micronutrient for intellectual development in children. Information on iodine intakes based on 24-h urinary iodine excretion (UIE) is scant, because iodine status is only assessed by the measurement of urinary iodine concentration (UIC) in spot urine samples.

OBJECTIVES

The aim of our study was to evaluate the iodine intake of school-age children and adolescents, using UIE measurement in 24-h urine collections.

METHODS

The study population included 1270 healthy subjects (677 boys, 593 girls) aged 6-18 y (mean age ± SD: 10.3 ± 2.9) from 10 Italian regions. Daily iodine intake was estimated as UIE/0.92, based on the notion that $\sim$92% of the dietary iodine intake is absorbed. The adequacy of intakes was assessed according to the Dietary Reference Values for iodine of the European Food Safety Authority (EFSA). Body mass index (BMI) and UIC were also measured for each subject.

RESULTS

Based on the scientific opinion of EFSA, 600 of 1270 subjects (47.2%) had a lower than adequate iodine intake, with a higher prevalence among girls (54.6%) compared with boys (40.2%) (P < 0.001). Although UIE and 24-h urinary volumes increased with age (P < 0.001), a progressive decrease in the percentage of subjects with iodine excretion <100 µg/24 h (P < 0.001) was observed, without any significant difference in the percentage of subjects with UIC <100 µg/L. No significant association was detected between BMI z-score and UIE (P = 0.603) or UIC (P = 0.869).

CONCLUSIONS

A sizable proportion of our population, especially girls, appeared to be at risk of iodine inadequacy. The simple measurement of UIC could lead to underestimation of the occurrence of iodine deficiency in younger children, because of the age-related smaller urine volumes producing spuriously higher iodine concentrations.

Cardiometabolic risk factors differ among adolescents with obesity in three European countries - a cross-sectional study

Aim

We aimed to compare modifiable cardiometabolic risk factors among treatment‐seeking adolescents with obesity in Italy, Germany and Norway.

Methods

This retrospective, registry‐based, cross‐sectional cohort study included 2,327 (59% girls) 12–18 year‐old adolescents with obesity from three tertiary care outpatient clinics in Europe, between 1999 and 2015. The prevalence of cardiometabolic risk factors was compared between clinics, and multivariate logistic regression models including gender, age, waist circumference and body mass index were used to assess the associations between population and cardiometabolic risk.

Results

In total, 1,396 adolescents (60% girls) from Italy, 654 (58% girls) from Germany and 277 (51% girls) from Norway were included. The mean ± SD age was 15.2 ± 1.6 years, body mass index 38.8 ± 6.5 kg/m² and body mass index standard deviation score 3.21 ± 0.43. The prevalence of elevated nonhigh‐density lipoprotein‐cholesterol in Norway, Germany and Italy was 60%, 54% and 45%, while the prevalence of high systolic or diastolic blood pressure (≥130 or ≥85 mmHg) were 15%, 46% and 66%, respectively.

Conclusion

Cardiometabolic risk factors among treatment‐seeking adolescents with obesity from Italy, Germany and Norway differed across the populations in this study, which might imply that preventive clinical work should reflect such differences.

Sources of Dietary Sodium in Food and Beverages Consumed by Spanish Schoolchildren between 7 and 11 Years Old by the Degree of Processing and the Nutritional Profile

Excessive salt intake has negative effects on health and persists as a dietary problem in Spanish children. However, the analysis of dietary sodium sources has not been extensively studied. A group of 321 children between 7 and 11 years old from five Spanish regional communities was studied. A three-day dietary record was used to determine the contribution of food and beverages to dietary sodium intake. The food consumed was classified based on the level of processing (NOVA classification) and the nutritional profile. Boys consumed more dietary sodium and sodium from ultra-processed food (UPF) than girls (p < 0.05). The main sources of dietary sodium from discretionary food were meat and meat products (25.1%), some ready-to-eat and pre-cooked dishes (7.4%) and sugars and sweets (6.3%). More than 4/5 of the total dietary sodium consumed came from processed foods (PF) and UPF. Ready-to-eat and pre-cooked dishes (14.4%), meat and meat products (10.6%), and cereals (10.2%) were the most relevant UPF. These results demonstrate that a key point for Spanish children is a reduction in the sodium content in PF and UPF, whether these foods are for basic or discretionary consumption. Furthermore, a decrease in the frequency and the quantity of discretionary food consumption should be encouraged.

Estimation of salt intake and excretion in children in one region of Switzerland: a cross-sectional study

PURPOSE

Salt intake among children in Switzerland is unknown. The objectives of this study were to determine salt excretion and to identify the main dietary sources of salt intake among children in one region of Switzerland.

METHODS

We conducted a cross-sectional study using a convenient sample of children 6-16 years of age in Valais, Switzerland, between 2016 and 2018. All children visiting several regional health care providers and without any clinical condition that could affect sodium intake or excretion were eligible. Each child completed a 24-h urine collection to assess salt excretion and two dietary questionnaires to assess dietary sources of salt intake. Weight and height were measured.

RESULTS

Data were available on 94 children (55 boys and 39 girls; mean age 10.5 years; age range 6-16 years). The mean 24-h salt urinary excretion was 5.9 g [SD 2.8; range 0.8-16.0; 95% confidence interval (CI) 5.3-6.5]. Two-thirds (62%) of the children had salt excretions above recommendations of maximum intake (i.e., ≥ 2 g per day for children up to 6 years of age and ≥ 5 g per day for children 7-16 years of age). The salt excretion tended to be higher during the week-end (6.0 g, 95% CI 5.4-6.6) than during the week (5.4 g, 95% CI 4.3-6.7). The main sources of salt intake were pastas, potatoes, and rice (23% of total salt intake), pastries (16%), bread (16%), and cured meats (10%). One child out of three (34%) added salt to their plate at the table.

CONCLUSIONS

Salt intake in children in one region of Switzerland was high. Our findings suggest that salt intake in children could be reduced by lowering salt content in commonly eaten foods.

TRIAL REGISTRATION NUMBER

NCT02900261.

Effects of Lifestyle Modifications on Elevated Blood Pressure and Excess Weight in a Population of Italian Children and Adolescents

BACKGROUND

Children's excess weight is a common problem due to low-quality diet and poor physical activity and is a risk factor associated with hypertension. Aim of this study was to assess the effect of a nonpharmacological multidisciplinary intervention on blood pressure (BP) and body weight in a population of children with excess weight and/or elevated BP.

METHODS

Children consecutively referred to a Prevention of Cardiovascular Risk Clinic by the primary care pediatrician from 2009 to 2015 were assessed at baseline and followed up over time.

RESULTS

Out of 273 children (median age 11.4 years, 55% male), 61% were excess weight only, 7% had elevated BP only, and 32% showed both conditions. The probability of reaching the clinical target (normal weight and BP values) at 1 year of follow-up was 19% (confidence interval [CI]: 14%; 24%) and increased up to 38% (CI: 28%; 47%) at 3 years. At 1 year of follow-up, in the overall population both body mass index (BMI) and systolic BP z-scores decreased significantly from 1.77 to 1.47 and from 0.99 to 0.52, respectively (P < 0.0001). BP was significantly reduced in both children with elevated BP only (reduction = 0.91, P = 0.0157) and subjects with excess weight and elevated BP (reduction = 0.89, P < 0.0001). Variables significantly related with systolic BP z-score at 1 year of follow-up were baseline systolic BP z-score and BMI z-score reduction during follow-up (P < 0.001 and P = 0.0003, respectively).

CONCLUSION

Our data demonstrate the efficacy of lifestyles modification on weight and BP in children, both when elevated BP and excess weight were present as distinct clinical problems and in the case of their association.

Measuring Children's Sodium and Potassium Intakes in NZ: A Pilot Study

Low sodium and high potassium intakes in childhood protect against rises in blood pressure (BP) and risk of cardiovascular disease (CVD) later in life. Our aim was to pilot methods for collection of 24-h urine samples (gold standard) and diet recalls to assess sodium and potassium intakes and their food sources in 30 children aged 8–11 years at one New Zealand primary school. A diverse sample (n = 27) was recruited over a two-week period. All children provided a urine sample (71% complete) and interviewer-assisted 24-h diet recall (Intake24 software). Median (range) sodium intake was 2191 (1087 to 4786) mg/day (salt equivalent 5.5 g), potassium intake was 1776 (800–2981) mg/day, BP was 105 (84–129)/62 (53–89) mmHg, and sodium to potassium molar ratio was 2.0 (1.1–4.8). Frequent use of discretionary salt was uncommon. Major food sources of sodium were bread, pies and pastries, and bread and pasta-based dishes, and potassium were sauces and condiments, dairy products, and non-alcoholic beverages. Most participants provided adequate data and enjoyed taking part. A larger survey is warranted to confirm findings and inform a potential intervention(s). Small improvements to study procedures and resources should improve completeness of urine samples and quality of 24-h diet recall data.

Assessment of Sodium and Potassium Intakes in Children Aged 6 to 18 Years by 24 h Urinary Excretion in City of Rabat, Morocco

Background

The incidence of noncommunicable diseases (NCDs) has greatly increased, mainly due to high level of dietary sodium. Thus, reduction of sodium intake in population has been recognized as one of the most cost-effective strategies to reduce NCDs. The aim of this study was to estimate sodium and potassium consumption in a sample of Moroccan children as a baseline study to implement national strategy for salt intake reduction.

Methods

The study was conducted on 131 children aged 6-18 years recruited from Rabat and its region. Sodium excretion and potassium excretion were measured on 24 h urinary collection, and the creatinine excretion was used to validate completeness of urine collections.

Results

The average of urinary sodium was 2235.3 ± 823.2 mg/day, and 50% of children consume more than 2 g/d of sodium (equivalent to 5 g/day of salt), recommended by the WHO. However, daily urinary excretion of potassium was 1431 ± 636.5 mg/day, and 75% of children consume less than adequate intake. Sodium consumption increased significantly with age. Of particular interest, 46.7% of children aged 6-8 years and 49.3% of children aged 9-13 years consume more than the corresponding upper limits.

Conclusions

Children have high sodium and low potassium status. There is evidence of the urgent need to implement a strategy for reduction of dietary sodium intake in Morocco.

Comparison of sodium, potassium, calcium, magnesium, zinc, copper and iron concentrations of elements in 24-h urine and spot urine in hypertensive patients with healthy renal function

Sodium, potassium, calcium, magnesium, zinc, copper and iron are associated with the sequela of hypertension. The most reliable method for testing those elements is by collecting 24-h urine samples. However, this is cumbersome and collection of spot urine is more convenient in some circumstance. The aim of this study was to compare the concentrations of different elements in 24-h urine and spot urine.

METHODS

Data was collected from a sub-study of China Salt Substitute and Stroke Study. 240 participants were recruited randomly from 12 villages in two counties in Ningxia, China. Both spot and 24-h urine specimens were collected from each patient. Routine urine test was conducted, and concentration of elements was measured using microwave digestion and Inductively Coupled Plasma-Optical Emission Spectrometry. Partial correlation analysis and Spearman correlation analysis were used to investigate the concentration of different elements and the relationship between 24- h urine and spot urine.

RESULTS

A partial correlation in sodium, potassium, calcium, magnesium and iron was found between paired 24-h urine and spot urine samples except copper and zinc: 0.430, 0.426, 0.550, 0.221 and 0.191 respectively.

CONCLUSIONS

Spot urine can replace 24-h urine for estimating some of the elements in hypertensive patients with normal renal function.

Dietary intake and sources of sodium and potassium among Australian schoolchildren: results from the cross-sectional Salt and Other Nutrients in Children (SONIC) study

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.