Sodium intake and blood pressure among US children and adolescents

Sodium intake and blood pressure in children

Elevation of blood pressure (BP) and the risk for progression to hypertension (HTN) is of increasing concern in children and adolescents. Indeed, it is increasingly recognized that target organ injury may begin with even low levels of BP elevation. Sodium intake has long been recognized as a modifiable risk factor for HTN. While it seems clear that sodium impacts BP in children, its effects may be enhanced by other factors including obesity and increasing age. Evidence from animal and human studies indicates that sodium may have adverse consequences on the cardiovascular system independent of HTN. Thus, moderation of sodium intake over a lifetime may reduce risk for cardiovascular morbidity in adulthood. An appetite for salt is acquired, and intake beyond our need is almost universal. Considering that eating habits in childhood have been shown to track into adulthood, modest sodium intake should be advocated as part of a healthy lifestyle.

Treatment Strategies to Prevent Renal Damage in Hypertensive Children

Hypertension secondary to chronic kidney disease prevails in earlier childhood and obesity-related primary hypertension in adolescence. Both are associated with a high risk of renal and cardiovascular morbidity. In children with chronic kidney disease, uncontrolled hypertension may accelerate progression to end-stage renal disease before adulthood is reached and increase a child’s risk of cardiac death a thousand-fold. Obesity-related hypertension is a slow and silent killer, and though early markers of renal damage are recognized during childhood, end-stage renal disease is a risk in later life. Renal damage will be a formidable multiplier of cardiovascular risk for adults in whom obesity and hypertension tracks from childhood. Management options to prevent renal damage will vary for these different target groups. This review provides a summary of the available renoprotective strategies in order to aid physicians involved in the care of this challenging group of children.

Dietary sodium, adiposity, and inflammation in healthy adolescents

OBJECTIVES

To determine the relationships of sodium intake with adiposity and inflammation in healthy adolescents.

METHODS

A cross-sectional study involved 766 healthy white and African American adolescents aged 14 to 18 years. Dietary sodium intake was estimated by 7-day 24-hour dietary recall. Percent body fat was measured by dual-energy x-ray absorptiometry. Subcutaneous abdominal adipose tissue and visceral adipose tissue were assessed using magnetic resonance imaging. Fasting blood samples were measured for leptin, adiponectin, C-reactive protein, tumor necrosis factor-α, and intercellular adhesion molecule-1.

RESULTS

The average sodium intake was 3280 mg/day. Ninety-seven percent of our adolescents exceeded the American Heart Association recommendation for sodium intake. Multiple linear regressions revealed that dietary sodium intake was independently associated with body weight (β = 0.23), BMI (β = 0.23), waist circumference (β = 0.23), percent body fat (β = 0.17), fat mass (β = 0.23), subcutaneous abdominal adipose tissue (β = 0.25), leptin (β = 0.20), and tumor necrosis factor-α (β = 0.61; all Ps < .05). No relation was found between dietary sodium intake and visceral adipose tissue, skinfold thickness, adiponectin, C-reactive protein, or intercellular adhesion molecule-1. All the significant associations persisted after correction for multiple testing (all false discovery rates < 0.05).

CONCLUSIONS

The mean sodium consumption of our adolescents is as high as that of adults and more than twice the daily intake recommended by the American Heart Association. High sodium intake is positively associated with adiposity and inflammation independent of total energy intake and sugar-sweetened soft drink consumption.

Lessons learned from community-based approaches to sodium reduction

PURPOSE

This article describes lessons from a Centers for Disease Control and Prevention initiative encompassing sodium reduction interventions in six communities.

DESIGN

A multiple case study design was used.

SETTING

This evaluation examined data from programs implemented in six communities located in New York (Broome County, Schenectady County, and New York City); California (Los Angeles County and Shasta County); and Kansas (Shawnee County).

SUBJECTS

Participants (n = 80) included program staff, program directors, state-level staff, and partners.

MEASURES

Measures for this evaluation included challenges, facilitators, and lessons learned from implementing sodium reduction strategies.

ANALYSIS

The project team conducted a document review of program materials and semistructured interviews 12 to 14 months after implementation. The team coded and analyzed data deductively and inductively.

RESULTS

Five lessons for implementing community-based sodium reduction approaches emerged: (1) build relationships with partners to understand their concerns, (2) involve individuals knowledgeable about specific venues early, (3) incorporate sodium reduction efforts and messaging into broader nutrition efforts, (4) design the program to reduce sodium gradually to take into account consumer preferences and taste transitions, and (5) identify ways to address the cost of lower-sodium products.

CONCLUSION

The experiences of the six communities may assist practitioners in planning community-based sodium reduction interventions. Addressing sodium reduction using a community-based approach can foster meaningful change in dietary sodium consumption.

Hypertension in the teenager

Over the last two decades, essential hypertension has become common in adolescents, yet remains under-diagnosed in absence of symptoms. Diagnosis is based on normative percentiles that factor in age, sex and height. Evaluation is more similar to adult essential hypertension than childhood secondary hypertension. Modifiable risk factors such as obesity, sodium consumption and low exercise should be addressed first. Many anti-hypertensive medications now have specific regulatory approval for children. Sports participation need not be limited in mild or well-controlled cases. Primary care physicians play an important role in reduction of cardiovascular mortality by early detection and referral when needed.

Use of environmental change strategies to facilitate sodium reduction: a case study in a rural California school district

CONTEXT

Excess sodium consumption increases the risk for hypertension, which is a leading risk factor for cardiovascular disease. For children and teenagers, school meals are a significant source of sodium consumption.

OBJECTIVE

To describe the environmental change strategies that were implemented to reduce sodium in the school meals of a rural California school district.

DESIGN

Descriptions of the environmental strategies, with an emphasis on staff training and infrastructure improvements.

SETTING

School district of approximately two thousand 9th- to 12th-grade students in rural, northern California.

PARTICIPANTS

School administration and food service staff at the 5 high schools in Anderson Union High School District.

INTERVENTION

Shasta County Public Health partnered with Anderson Union High School District to (1) facilitate changes to meal preparation practices, (2) improve cafeteria infrastructure, and (3) provide training and technical assistance to improve procurement strategies.

RESULTS

Environmental strategies to reduce sodium in school meals were implemented in 2011. Anderson Union High School District has continued to successfully implement scratch cooking and improve procurement strategies to reduce sodium in school meals.

CONCLUSION

Using an approach that includes environmental change strategies can lead to sodium reduction in a school setting.

Treatment of obesity-related hypertension in children and adolescents

The obesity epidemic has become a common concern among pediatricians, with an estimated 32 % of US children and adolescents classified as overweight and 18 % as obese. Along with the increase in obesity, a growing body of evidence demonstrates that chronic diseases, such as Type 2 diabetes, primary hypertension, and hyperlipidemia, once thought to be confined solely to adulthood, are commonly seen among the obese in childhood. Following a brief summary of the diagnosis and evaluation of hypertension in obese children and adolescents, this review will highlight recent research on the treatment of obesity-related hypertension. Pharmacologic and non-pharmacologic treatment will be discussed. Additionally, current and emerging therapies for the primary treatment of obesity in children and adolescents, which have been gaining in popularity, will be reviewed.

Food advertisements in two popular U.S. parenting magazines: results of a five-year analysis

Obesity rates among American youth have prompted an examination of food advertisements geared towards children. Research indicates children’s high exposure to these advertisements and their influence on food preferences. Less is known about the presence of these advertisements in parenting magazines. This study’s objective was to examine prevalence of food advertisements in popular parenting magazines and identify products by USDA food category. We analyzed 116 issues of two popular U.S. parenting magazines across five years. All food and beverage advertisements for USDA Food Category were coded. Breakfast cereals were coded for nutritional quality. The coding took place at varied libraries in New Jersey, in the United States. A total of 19,879 food and beverage products were analyzed. One-third of advertisements (32.5%) were for baked goods, snacks, and sweets -- products generally low in nutrient density. Two-thirds of the breakfast cereals were low in nutritional quality (64.6%). Beverages comprised 11% of the advertisements, fruit juices the highest proportion. Less than 3% of advertisements were for fruits and vegetables combined. No significant food product trends were evident across the five-year period. Food advertisements identified in parenting magazines were generally low in nutritional value. Additional research is necessary to determine the influence of food advertisements on parents’ purchasing habits.

Salt and public health: contested science and the challenge of evidence-based decision making

For more than four decades, starting in the late 1960s, a sometimes furious battle has raged among scientists over the extent to which elevated salt consumption has adverse implications for population health and contributes to deaths from stroke and cardiovascular disease. Various studies and trials have produced conflicting results. Despite this scientific controversy over the quality of the evidence implicating dietary salt in disease, public health leaders at local, national, and international levels have pressed the case for salt reduction at the population level. This article explores the development of this controversy. It concludes that the concealment of scientific uncertainty in this case has been a mistake that has served neither the ends of science nor good policy. The article poses questions that arise from this debate and frames the challenges of formulating evidence-based public health practice and policy, particularly when the evidence is contested.

A high school-based voluntary cardiovascular risk screening program: issues of feasibility and correlates of electrocardiographic outcomes

Risk factors for adult cardiovascular events can be identified from the prenatal period through childhood. We performed a cardiovascular risk-screening program in students from grades 9-12 in 7 high schools in Hillsborough County, FL. We obtained blood pressure (BP) measurements and calculated body mass index (BMI) as risk factors for future cardiovascular events as well as obtained an electrocardiogram (ECG) for the purposes of detecting possible life-threatening arrhythmias. Of ~14,000 students contacted, 600 (4 %) participated in the screening. Of these, 517 (86 %) were diagnosed with normal, 71 (12 %) with borderline, and 12 (1 %) with abnormal ECGs. Although no participant had any cardiac history, two of the abnormal ECGs indicated a cardiac diagnosis associated with the potential for sudden cardiac death. Both systolic and diastolic BP increased as the ECG diagnosis moved from normal (115.6/73.8) through borderline (121.0/75.9) to an abnormal (125.0/80.7) diagnosis (all P ≤ .0016). An increase in BMI was only observed when an ECG diagnosis was abnormal (P = .0180). Boys had a greater prevalence (18.97 %) of borderline or abnormal ECGs compared with girls (6.75 %), whereas no discernible differences were seen in ECG diagnosis between white and nonwhite individuals (15.09 and 12.26 %, respectively). Although participation rates were low, a high school-based cardiovascular risk-screening program including ECG is feasible. Although ECG diagnosis tended to be related to other known cardiovascular risk factors (BP, BMI), the utility of an abnormal ECG in adolescence as a predictor of future cardiovascular risk will require further evaluation in more controlled settings.

Sodium and potassium intakes among US infants and preschool children, 2003-2010

BACKGROUND

Data are limited on usual sodium and potassium intakes relative to age-specific recommendations and the sodium:potassium ratio in infants and preschoolers, especially among those aged <2 y, who are black or breastfed.

OBJECTIVE

The usual sodium intake above the Tolerable Upper Intake Levels (ULs), potassium intakes above Adequate Intakes (AIs), the sodium:potassium ratio, and sodium density (mg/kcal) among US infants and preschoolers by age group, as applicable, were estimated and compared by race-ethnicity and current breastfeeding status.

DESIGN

Data were analyzed among 3 groups of children (aged 7-11 mo, 1-3 y, and 4-5 y) from the NHANES 2003-2010 by using measurement error models.

RESULTS

Seventy-nine percent of children aged 1-3 y and 87% of those aged 4-5 y exceeded their sodium UL; among non-Hispanic black children, the estimates were 84% and 97%, respectively. For potassium, 97% of infants, 5% of children aged 1-3 y, and 0.4% aged 4-5 y met their AIs. Compared with non-Hispanic whites and Mexican Americans, non-Hispanic black infants and preschoolers had higher mean sodium density and sodium:potassium ratios. Currently breastfed infants and children consumed, on average, less sodium than those who were not breastfed (382 ± 53 compared with 538 ± 22 mg in those aged 7-11 mo and 1154 ± 88 compared with 1985 ± 24 mg in those aged 1-3 y, respectively), but the sodium:potassium ratio did not differ.

CONCLUSIONS

Most US preschoolers, particularly non-Hispanic blacks, consume too much sodium, and nearly all do not consume enough potassium. Data that suggest that currently breastfed infants consume less sodium than do those who are not breastfeeding merit further investigation.

Childhood blood pressure trends and risk factors for high blood pressure: the NHANES experience 1988-2008

The obesity epidemic in children makes it plausible that prevalence rates of elevated blood pressure (BP) are increasing over time. Yet, previous literature is inconsistent because of small sample sizes. Also, it is unclear whether adjusting for risk factors can explain longitudinal trends in prevalence of elevated BP. Thus, we analyzed a population-based sample of 3248 children in National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and 8388 children in continuous NHANES (1999-2008), aged 8 to 17 years. Our main outcome measure was elevated BP (systolic BP or diastolic BP ≥ 90th percentile or systolic BP/diastolic BP ≥ 120/80 mm Hg). We found that the prevalence of elevated BP increased from NHANES III to NHANES 1999-2008 (Boys: 15.8% to 19.2%, P=0.057; Girls: 8.2% to 12.6%, P=0.007). Body mass index (Q4 versus Q1; odds ratio=2.00; P<0.001), waist circumference (Q4 versus Q1; odds ratio=2.14; P<0.001), and sodium (Na) intake (≥ 3450 mg versus <2300 mg/2000 calories; odds ratio=1.36; P=0.024) were independently associated with prevalence of elevated BP. Also, mean systolic BP, but not diastolic BP, was associated with increased Na intake in children (quintile 5 [Q5] versus quintile 1 [Q1] of Na intake; β=1.25 ± 0.58; P=0.034). In conclusion, we demonstrate an association between high Na intake and elevated BP in children. After adjustment for age, sex, race/ethnicity, body mass index, waist circumference, and sodium intake, odds ratio for elevated BP in NHANES 1999-2008 versus NHANES III=1.27, P=0.069.

Salt intake and the association with blood pressure in young Iranian children: first report from the middle East and north Africa

BACKGROUND

This study aimed to assess the salt intake of Iranian children, and to assess the correlation of urinary electrolytes excretion with blood pressure.

METHODS

This cross-sectional study was conducted in 2011-2012 among 3-10-year-old children, selected by multi-stage cluster sampling from urban and rural areas of Isfahan, Iran. The sodium (Na), potassium (K), and creatinine (Cr) were measured in a random sample of the children's first morning fasting urine. Three-day averages of dietary intakes were analyzed by the Nutritionist-4 software.

RESULTS

The mean (SD) of urinary Na was 177.17 (28.68) mEq/day without significant difference according to gender and living area. The mean (SD) dietary intakes of Na and K were 2017.76 (117.94) and 1119.06 (76.03) mg/day, respectively. Children of urban and rural areas consumed similar sources of salty foods (bread, cheese, and snacks) and had low intake of vegetables. No significant association was documented between urinary electrolytes excretions and blood pressure.

CONCLUSIONS

This study, which to the best of our knowledge is the first of its kind in the Middle East and North Africa region, revealed that Iranian young children consume a large amount of sodium and small amount of potassium. The non-significant associations of electrolyte excretions with blood pressure may be because of the very young age group of participants. Given the development of preference to salt taste from early childhood, and the tracking of risk factors of chronic diseases from this age, reducing salt intake of young children should be emphasized.

USDA food and nutrient databases provide the infrastructure for food and nutrition research, policy, and practice

The USDA food and nutrient databases provide the basic infrastructure for food and nutrition research, nutrition monitoring, policy, and dietary practice. They have had a long history that goes back to 1892 and are unique, as they are the only databases available in the public domain that perform these functions. There are 4 major food and nutrient databases released by the Beltsville Human Nutrition Research Center (BHNRC), part of the USDA's Agricultural Research Service. These include the USDA National Nutrient Database for Standard Reference, the Dietary Supplement Ingredient Database, the Food and Nutrient Database for Dietary Studies, and the USDA Food Patterns Equivalents Database. The users of the databases are diverse and include federal agencies, the food industry, health professionals, restaurants, software application developers, academia and research organizations, international organizations, and foreign governments, among others. Many of these users have partnered with BHNRC to leverage funds and/or scientific expertise to work toward common goals. The use of the databases has increased tremendously in the past few years, especially the breadth of uses. These new uses of the data are bound to increase with the increased availability of technology and public health emphasis on diet-related measures such as sodium and energy reduction. Hence, continued improvement of the databases is important, so that they can better address these challenges and provide reliable and accurate data.