Sodium and Potassium Intakes and Their Ratio in Adults (18-90 y): Findings from the Irish National Adult Nutrition Survey.

An individual's sodium to potassium intake ratio (Na:K) has been shown to be an important predictor of hypertension. The aim of this study was to estimate the mean 24 h urinary Na, K and Na:K of Irish adults and to identify the foods that determine Na:K in a nationally representative sample of Irish adults. This study was based on data from the Irish National Adult Nutrition Survey (2008-2010) (NANS), which collected spot urine samples and dietary data in a nationally representative sample of Irish adults aged 18+ years. The mean urinary molar Na:K of Irish men and women was 1.90 and 2.15, respectively, which exceed target molar ratios of ≤1.0 and ≤2.0. The mean estimated 24-h urinary excretion of Na was 4631 mg for men and 3525 mg for women, which exceed target maximum population intakes for all gender and age groups. The mean estimated 24-h urinary excretion of K was 3894 mg for men and 2686 mg for women, with intakes in women of all ages and older men (65+ years) below current recommendations. The key foods positively associated with a lower Na:K were fruits, vegetables, potatoes, breakfast cereals, milk, yogurt and fresh meat, while the foods negatively associated with a lower Na:K were breads, cured and processed meats and butters and fat spreads. Strategies to reduce sodium and increase potassium intakes are necessary to lower population Na:K, which may help to reduce the burden of hypertension-related diseases in the Irish population.

Validity of Absolute Intake and Nutrient Density of Protein, Potassium, and Sodium Assessed by Various Dietary Assessment Methods: An Exploratory Study.

It is suggested that nutrient densities are less affected by measurement errors than absolute intake estimates of dietary exposure. We compared the validity of absolute intakes and densities of protein (kJ from protein/total energy (kJ)), potassium, and sodium (potassium or sodium (in mg)/total energy (kJ)) assessed by different dietary assessment methods. For 69 Dutch subjects, two duplicate portions (DPs), five to fifteen 24-h dietary recalls (24 hRs, telephone-based and web-based) and two food frequency questionnaires (FFQs) were collected and compared to duplicate urinary biomarkers and one or two doubly labelled water measurements. Multivariate measurement error models were used to estimate validity coefficients (VCs) and attenuation factors (AFs). This research showed that group bias diminished for protein and sodium densities assessed by all methods as compared to the respective absolute intakes, but not for those of potassium. However, the VCs and AFs for the nutrient densities did not improve compared to absolute intakes for all four methods; except for the AF of sodium density (0.71) or the FFQ which was better than that of the absolute sodium intake (0.51). Thus, using nutrient densities rather than absolute intakes does not necessarily improve the performance of the DP, FFQ, or 24 hR.

Socioeconomic Status Associated With Urinary Sodium and Potassium Excretion in Japan: NIPPON DATA2010.

BACKGROUND: Although socioeconomic status (SES) may affect food and nutrient intakes, few studies have reported on sodium (Na) and potassium (K) intakes among individuals with various SESs in Japan. We investigated associations of SES with Na and K intake levels using urinary specimens in a representative Japanese population. METHODS: This was a cross-sectional study of 2,560 men and women (the NIPPON DATA2010 cohort) who participated in the National Health and Nutrition Survey Japan in 2010. Casual urine was used to calculate estimated excretion in 24-hour urinary Na (E24hr-Na) and K (E24hr-K). The urinary sodium-to-potassium (Na/K) ratio was calculated from casual urinary electrolyte values. An analysis of covariance was performed to investigate associations of aspects of SES, including equivalent household expenditure (EHE), educational attainment, and job category, with E24hr-Na, E24hr-K, and the Na/K ratio for men and women separately. A stratified analysis was performed on educational attainment and the job category for younger (<65 years) and older (≥65 years) participants. RESULTS: In men and women, average E24hr-Na was 176.2 mmol/day and 172.3, average E24hr-K was 42.5 and 41.3, and the average Na/K ratio was 3.61 and 3.68, respectively. Lower EHE was associated with a higher Na/K ratio in women and lower E24hr-K in men and women. A shorter education was associated with a higher Na/K ratio in women and younger men, and lower E24hr-K in older men and women. CONCLUSION: Lower EHE and a shorter education were associated with a lower K intake and higher Na/K ratio estimated from casual urine specimens in Japanese men and women.

Assessment of a Salt Reduction Intervention on Adult Population Salt Intake in Fiji.

Reducing population salt intake is a global public health priority due to the potential to save lives and reduce the burden on the healthcare system through decreased blood pressure. This implementation science research project set out to measure salt consumption patterns and to assess the impact of a complex, multi-faceted intervention to reduce population salt intake in Fiji between 2012 and 2016. The intervention combined initiatives to engage food businesses to reduce salt in foods and meals with targeted consumer behavior change programs. There were 169 participants at baseline (response rate 28.2%) and 272 at 20 months (response rate 22.4%). The mean salt intake from 24-h urine samples was estimated to be 11.7 grams per day (g/d) at baseline and 10.3 g/d after 20 months (difference: -1.4 g/day, 95% CI -3.1 to 0.3, p = 0.115). Sub-analysis showed a statistically significant reduction in female salt intake in the Central Division but no differential impact in relation to age or ethnicity. Whilst the low response rate means it is not possible to draw firm conclusions about these changes, the population salt intake in Fiji, at 10.3 g/day, is still twice the World Health Organization's (WHO) recommended maximum intake. This project also assessed iodine intake levels in women of child-bearing age and found that they were within recommended guidelines. Existing policies and programs to reduce salt intake and prevent iodine deficiency need to be maintained or strengthened. Monitoring to assess changes in salt intake and to ensure that iodine levels remain adequate should be built into future surveys.

Assessment of dietary sodium intake using a food frequency questionnaire and 24-hour urinary sodium excretion: a systematic literature review.

Food frequency questionnaires (FFQs) are often used to assess dietary sodium intake, although 24-hour urinary excretion is the most accurate measure of intake. The authors conducted a systematic review to investigate whether FFQs are a reliable and valid way of measuring usual dietary sodium intake. Results from 18 studies are described in this review, including 16 validation studies. The methods of study design and analysis varied widely with respect to FFQ instrument, number of 24-hour urine collections collected per participant, methods used to assess completeness of urine collections, and statistical analysis. Overall, there was poor agreement between estimates from FFQ and 24-hour urine. The authors suggest a framework for validation and reporting based on a consensus statement (2004), and recommend that all FFQs used to estimate dietary sodium intake undergo validation against multiple 24-hour urine collections.

Simple questions in salt intake behavior assessment: comparison with urinary sodium excretion in Japanese adults.

BACKGROUND AND OBJECTIVES: To clarify whether six conventional 'high-risk' behaviors toward excess salt intake captured by simple questions such as frequency of salty food consumption are related to actual salt intake. Also, to examine the relationship of nutrition knowledge, food label use, and food preparation with actual salt intake. METHODS AND STUDY DESIGN: Study participants were 742 subjects (370 men and 372 women) aged 20-69 years from 20 areas of Japan. Salt intake and dietary knowledge/behavior were evaluated with two 24-hour urine collections and a questionnaire, respectively. Multivariable linear regression analyses by sex included sodium excretion as a dependent variable, each knowledge/behavior item as an independent variable, and with age, body mass index, education, and smoking as covariates. RESULTS: Four 'high-risk' behaviors (frequency of miso soup and salty foods consumption, proportion of consumed noodle soup, and amount of seasoning/condiment use) were associated with higher sodium excretion in men (p for trend <=0.04) and were marginally associated in women (p for trend <=0.06). Combination of these behaviors elevated the odds ratios for excess salt intake (sodium excretion: >136 mmol/day). Most of the other nine dietary factors were not associated with sodium excretion. Interestingly, women who decided to purchase foods after referring to the salt/sodium content information on food label, had significant lower sodium excretion than other women (p for trend=0.03). CONCLUSIONS: High-risk behaviors toward excess salt intake captured by simple questions were actually related to excess salt intake. Specific and practical advice based on answers to these questions might contribute to salt reduction in Japanese population.

Neighbourhood socioeconomic status and cross-sectional associations with obesity and urinary biomarkers of diet among New York City adults: the heart follow-up study.

OBJECTIVE: To determine whether neighbourhood socioeconomic status (SES) is associated with body mass index (BMI), waist circumference (WC) and biomarkers of diet (urinary sodium and potassium excretion). DESIGN: A cross-sectional study. SETTING: The data reported were from the 2010 Heart Follow-up Study, a population-based representative survey of 1645 adults. PARTICIPANTS: Community-dwelling diverse residents of New York City nested within 128 neighbourhoods (zip codes). PRIMARY AND SECONDARY OUTCOME MEASURES: BMI (kg/m2) and WC (inches) were measured during in-home visits, and 24-hour urine sample was collected to measure biomarkers of diet: sodium (mg/day) and potassium (mg/day), with high sodium and low potassium indicative of worse diet quality. RESULTS: After adjusting for individual-level characteristics using multilevel linear regressions, low versus high neighbourhood SES tertile was associated with 1.83 kg/m2 higher BMI (95% CI 0.41 to 3.98) and 251 mg/day lower potassium excretion (95% CI -409 to 93) among women only, with no associations among men (P values for neighbourhood SES by sex interactions <0.05). CONCLUSION: Our results suggest that women may be particularly vulnerable to the effects of a socioeconomically disadvantaged neighbourhood. Future neighbourhood research should explore sex differences, as these can inform tailored interventions. TRIAL REGISTRATION NUMBER: NCT01889589; Results.

Validation of Simplified Tools for Assessment of Sodium Intake in Iranian Population: Rationale, Design and Initial Findings.

BACKGROUND: The 24-hour urine sodium excretion is considered the gold standard method to estimate salt intake. However, since this method is not easy to perform, this study developed two instruments, including a semi-quantitative food frequency questionnaire (FFQ) and one spot urine sodium excretion, to assess sodium intake. These two methods were then compared with 24-h urine sodium excretion and twelve 24-h recalls during a year. METHODS: This study was performed on 219 healthy subjects aged ≥ 6 years in 2014-2015. The FFQ was completed twice, at baseline and one year thereafter, to examine the reproducibility of the FFQ. The validity of three spot urine sodium excretions in the morning, afternoon, and evening and FFQ for the assessment of sodium intake were compared against the 24-h urine sodium excretion method. Moreover, the validity of FFQ was examined against 24-h dietary recalls for the assessment of total sodium consumption and contribution of food groups to sodium intake. The content validity of the FFQ was estimated by an expert panel including 10 nutritionists. RESULTS: Based on their nutrients, the final food items were categorized into 11 groups including: 1) dairy products, 2) fruits, 3) vegetables, 4) meat and egg, 5) grains and legumes, 6) mixed dishes, prepared foods, and restaurant foods, 8) nuts and seeds, 8) oils and fats, 9) sauces and desserts, 10) drinks, and 11) others. CONCLUSIONS: Spot urine and a specific FFQ comprising 136 items were used to develop a method for the assessment of sodium intake and contribution of foods to its intake among the Iranian population. This method can be used in large-scale population studies at the national level.

Usefulness and Pitfalls in Sodium Intake Estimation: Comparison of Dietary Assessment and Urinary Excretion in Chilean Children and Adults.

BACKGROUND: High sodium intake has been associated with various noncommunicable disease like hypertension, cardiovascular disease, or stroke. To estimate accurately sodium intake is challenging in clinical practice. We investigate the usefulness and limitations of assessing sodium intake simultaneously by dietary assessment and urinary samples in both children and adults. METHODS: We used a cross-sectional study design inviting 298 Chilean subjects (74 children and 222 adults) aged between 9 and 66 years of both genders. Sodium intake by dietary assessment was obtained from Chilean food composition data, based on FAO tables. Sodium and creatinine excretion were measured in 24-hour urine samples, in all participants. RESULTS: Adequate urinary collection was obtained in 81% of children (59/74) and 61% of adults (135/222). The mean sodium intake by dietary assessment was similar to the sodium excretion in 24 hours (3,121±1,153mg/d vs. 3,114±1,353mg/24h, P = nonsignificant) in children but was significantly lower (3,208±1,284mg/d vs. 4,160±1,651mg/24h, P < 0.001) in adults. In both children and adults, sodium intake correlated with urinary sodium excretion (r = 0.456, P < 0.003 and r = 0.390, P < 0.001, respectively). Secondary analyses also suggested that the dietary assessment was more inaccurate in overweight adult subjects. CONCLUSIONS: Our results showed that average sodium intake was higher than recommended in both children and adults (WHO ≤2,000mg/d). The sodium intake estimated by dietary assessment correlated with urinary excretion in all subjects, but in obese adults was more inaccurate than in children. Future studies to validate the appropriate test to assess sodium intake by age and nutritional status are warranted.

Factors Associated With High Sodium Intake Based on Estimated 24-Hour Urinary Sodium Excretion: The 2009-2011 Korea National Health and Nutrition Examination Survey.

Although reducing dietary salt consumption is the most cost-effective strategy for preventing progression of cardiovascular and renal disease, policy-based approaches to monitor sodium intake accurately and the understanding factors associated with excessive sodium intake for the improvement of public health are lacking. We investigated factors associated with high sodium intake based on the estimated 24-hour urinary sodium excretion, using data from the 2009 to 2011 Korea National Health and Nutrition Examination Survey (KNHANES). Among 21,199 adults (≥19 years of age) who participated in the 2009 to 2011 KNHANES, 18,000 participants (weighted n = 33,969,783) who completed urinary sodium and creatinine evaluations were analyzed in this study. The 24-hour urinary sodium excretion was estimated using Tanaka equation. The mean estimated 24-hour urinary sodium excretion level was 4349 (4286-4413) mg per day. Only 18.5% (weighted n = 6,298,481/3,396,973, unweighted n = 2898/18,000) of the study participants consumed less the 2000 mg sodium per day. Female gender (P < 0.001), older age (P < 0.001), total energy intake ≥50 percentile (P < 0.005), and obesity (P < 0.001) were associated with high sodium intake, even after adjusting for potential confounders. Senior high school/college graduation in education and managers/professionals in occupation were associated with lower sodium intake (P < 0.001). According to hypertension management status, those who had hypertension without medication consumed more sodium than those who were normotensive. However, those who receiving treatment for hypertension consumed less sodium than those who were normotensive (P < 0.001). The number of family members, household income, and alcohol drinking did not affect 24-hour urinary sodium excretion. The logistic regression analysis for the highest estimated 24-hour urinary sodium excretion quartile (>6033 mg/day) using the abovementioned variables as covariates yielded identical results. Our data suggest that age, sex, education level, occupation, total energy intake, obesity, and hypertension management status are associated with excessive sodium intake in Korean adults using nationally representative data. Factors associated with high sodium intake should be considered in policy-based interventions to reduce dietary salt consumption and prevent cardiovascular disease as a public health target.

Daytime cold exposure and salt intake based on nocturnal urinary sodium excretion: A cross-sectional analysis of the HEIJO-KYO study.

Increased cardiovascular incidence in winter is partly explained by higher blood pressure due to cold exposure. Although higher salt intake induced by cold exposure has been reported in mice, the association remains unclear in humans. To investigate the association between salt intake and cold exposure in winter, a cross-sectional study was conducted among 860 elderly subjects (mean ± standard deviation: 72.0 ± 7.1 years). We determined ambient temperature at every 10 min according to indoor temperature measured in the subjects' home, outdoor temperature, and self-administered diary logging time spent outdoors. Salt intake was estimated by nocturnal sodium excretion rate of overnight urine collection. A 1°C lower daytime ambient temperature was significantly associated with a higher urinary sodium excretion rate by 0.07 mmol/h in the subsequent night independent of age, sex, body weight, alcohol intake, calcium channel blocker use, diabetes, household income, estimated glomerular filtration rate, daytime physical activity (p=0.02). After further adjustment for outdoor temperature and day length, the lowest tertile groups of ambient daytime temperature (10.1 ± 2.3°C) showed the nocturnal urinary sodium excretion rate was higher by 14.2% (7.62 vs. 6.54 mmol/h) compared with the highest tertile group (19.3 ± 1.8°C). Higher sodium excretion rate was associated with higher nighttime ambulatory blood pressure (p<0.01) and its lower nocturnal dipping (p<0.01). Significant association between higher salt intake and daytime cold exposure partly explain the mechanism of higher blood pressure in winter, and suggest that a reduction of cold exposure might be effective to decrease salt intake.

Effects of a behavioral intervention that emphasizes spices and herbs on adherence to recommended sodium intake: results of the SPICE randomized clinical trial.

BACKGROUND: For decades, dietary sodium intake in the United States has remained high, and few studies have examined strategies for maintaining recommended intakes. OBJECTIVE: We examined the effects of a behavioral intervention, which emphasized spices and herbs, on the maintenance of sodium intake at the recommended intake of 1500 mg/d in individuals to whom the US Dietary Guidelines for Americans apply. DESIGN: We conducted a 2-phase study that included adults ≥18 y of age for whom Dietary Guidelines for Americans recommends 1500 mg Na/d. The study was conducted in Baltimore, Maryland, from 2012 to 2014. In phase 1, 55 individuals consumed a low-sodium diet for 4 wk. Participants were provided all foods, snacks, and calorie-containing drinks. In phase 2, 40 participants from phase 1 were randomly assigned to either a behavioral intervention to reduce sodium intake (n = 20) or a self-directed control group (n = 20) for 20 wk. The primary study outcome was the change in mean 24-h urinary sodium excretion during phase 2. Linear regression analyses were used to determine intervention effects on urinary sodium excretion. RESULTS: Participant characteristics were as follows: women: 65%; African American: 88%; hypertension: 63%; diabetes: 18%; mean age: 61 y; and mean body mass index (in kg/m(2)): 30. At the end of phase 2, mean 24-h sodium excretion was lower in the behavioral intervention than in the self-directed group (mean difference: -956.8 mg/d; 95% CI: -1538.7, -374.9 mg/d) after sodium intake at screening was controlled for (P = 0.002). These findings persisted in sensitivity analyses that excluded potentially incomplete urine collections [Mage's equation mean difference: -1090 mg/d (P = 0.001); Joosens' equation mean difference: -796 mg/d (P = 0.04)]. CONCLUSIONS: A multifactorial behavioral intervention emphasizing spices and herbs significantly reduced sodium intake. Because of the ubiquity of sodium in the US food supply, multilevel strategies addressing individual behaviors and the food supply are needed to improve adherence to recommendations. This trial was registered at clinicaltrials.gov as NCT01615159.

Racial/ethnic residential segregation, neighborhood poverty and urinary biomarkers of diet in New York City adults.

Consuming less sodium and more potassium are components of a healthy diet and reduced cardiovascular disease risk. Racial/ethnic segregation and poverty are both associated with dietary habits, but data linking dietary intake to neighborhood characteristics are limited, particularly in Hispanic and Asian American ethnic enclaves. This study presents relationships between neighborhood-level segregation, poverty and biologic indicators of sodium and potassium consumption. Data were from the 2010 Heart Follow-Up Study, a cross-sectional health survey, which included 24-h urine collections and self-reported health status (n = 1656). Black, Hispanic, and Asian segregated areas and neighborhood poverty were defined for aggregated zip-code areas. Multivariable models assessed the association between neighborhood segregation and poverty and sodium and potassium intake, after adjustment for individual-level covariates. In unadjusted models, potassium intake (a marker of fruit and vegetable consumption) was lower in high-versus low-Hispanic segregated neighborhoods, and the sodium-potassium ratio was higher in high-versus low black and Hispanic segregated neighborhoods, and in high-versus low-poverty neighborhoods; the sodium-potassium ratio was lower in high-versus low Asian segregated neighborhoods. Segregation and poverty were not independently associated with nutrition biomarkers after adjustment for demographics and for each other; however, practical consideration of neighborhood race/ethnic composition may be useful to understand differences in consumption.

[Assessment of dietary intake and urinary excretion of sodium and potassium in adults]. / Evaluación de la ingesta dietética y excreción urinaria de sodio y potasio en adultos.

BACKGROUND: Hypertension is associated with elevated sodium and low potassium intakes. The determination of sodium and potassium intake by dietary records is inaccurate, being its measurement from 24-h urine collection the reference method. AIM: To determine urinary sodium and potassium excretion in adults. To compare dietary sodium and potassium intake and their excretion from an isolated urine sample against the reference method. MATERIAL AND METHODS: Seventy healthy adults aged 35 ± 8 years with a body mass index 25 ± 2 kg/m² (36 women) were studied. Urine was collected over 24 h, including an isolated urine sample taken in fasting conditions. Additionally, three 24-h dietary records were performed. RESULTS: Reported sodium and potassium intake was 2,720 ± 567 and 1,068 ± 433 mg/day, respectively. In turn, urinary excretion of sodium and potassium was 4,770 ± 1,532 and 1,852 ± 559 mg/day, respectively. These latter values were significantly higher than those obtained by dietary records. Furthermore, the urinary sodium and potassium excretion estimated from an isolated urine sample was 4,839 ± 1,355 and 1,845 ± 494 mg/day, respectively. These values were similar to those obtained with a 24 h urine collection. CONCLUSIONS: Dietary records underestimated electrolyte intake when compared with the reference method. Using an isolated urine sample to estimate electrolyte intake may be a reliable alternative.

Evaluación de la ingesta dietética y excreción urinaria de sodio y potasio en adultos / Assessment of dietary intake and urinary excretion of sodium and potassium in adults

Background: Hypertension is associated with elevated sodium and low potassium intakes. The determination of sodium and potassium intake by dietary records is inaccurate, being its measurement from 24-h urine collection the reference method. Aim: To determine urinary sodium and potassium excretion in adults. To compare dietary sodium and potassium intake and their excretion from an isolated urine sample against the reference method. Material and Methods: Seventy healthy adults aged 35 ± 8 years with a body mass index 25 ± 2 kg/m² (36 women) were studied. Urine was collected over 24 h, including an isolated urine sample taken in fasting conditions. Additionally, three 24-h dietary records were performed. Results: Reported sodium and potassium intake was 2,720 ± 567 and 1,068 ± 433 mg/day, respectively. In turn, urinary excretion of sodium and potassium was 4,770 ± 1,532 and 1,852 ± 559 mg/day, respectively. These latter values were significantly higher than those obtained by dietary records. Furthermore, the urinary sodium and potassium excretion estimated from an isolated urine sample was 4,839 ± 1,355 and 1,845 ± 494 mg/day, respectively. These values were similar to those obtained with a 24 h urine collection. Conclusions: Dietary records underestimated electrolyte intake when compared with the reference method. Using an isolated urine sample to estimate electrolyte intake may be a reliable alternative.

The body composition and excretory burden of lean, obese, and severely obese individuals has implications for the assessment of chronic kidney disease.

Obesity could affect associations between creatinine generation, estimated body surface area, and excretory burden, with effects on chronic kidney disease assessment. We therefore examined the impact of obesity on the performances of estimated glomerular filtration rate (eGFR), the urine albumin:creatinine ratio (ACR), and excretory burden in 3611 participants of the Chronic Renal Insufficiency Cohort. Urine creatinine excretion significantly increased with body mass index (BMI) (34 and 31% greater at 40 kg/m(2) or more versus the normal of 18.5-25 kg/m(2)) in men and women, respectively, such that patients with a normal BMI and an ACR of 30 mg/g had the same 24-h albuminuria as severely obese patients with ACR 23 mg/g. The bias of eGFR (referenced to body surface area-indexed iothalamate (i-)GFR) had a U-shaped relationship to obesity in men but progressively increased in women. Nevertheless, obesity-associated body surface area increases were accompanied by a greater absolute (non-indexed) iGFR for a given eGFR, particularly in men. Two men with eGFRs of 45 ml/min per 1.73 m(2), height 1.76 m, and BMI 22 or 45 kg/m(2) had absolute iGFRs of 46 and 62 ml/min, respectively. The excretory burden, assessed as urine urea nitrogen and estimated dietary phosphorus, sodium, and potassium intakes, also increased in obesity. However, obese men had lower odds of anemia, hyperkalemia, and hyperphosphatemia. Thus, for a given ACR and eGFR, obese individuals have greater albuminuria, absolute GFR, and excretory burden. This has implications for chronic kidney disease management, screening, and research.

Healthy dietary habits score as an indicator of diet quality in New Zealand adolescents.

Adoption of optimal dietary habits during adolescence is associated with better health outcomes later in life. However, the associations between a pattern of healthy dietary habits encapsulated in an index and sociodemographic and nutrient intake have not been examined among adolescents. This study aimed to develop a behavior-based diet index and examine its validity in relation to sociodemographic factors, nutrient intakes, and biomarkers in a representative sample of New Zealand (NZ) adolescents aged 15-18 y (n = 694). A 17-item Healthy Dietary Habits Score for Adolescents (HDHS-A) was developed based on dietary habits information from the 2008/2009 NZ Adult Nutrition Survey. Post hoc trend analyses were used to identify the associations between HDHS-A score and nutrient intakes estimated by single 24-h diet recalls and selected nutritional biomarkers. Being female, not of Maori or Pacific ethnicity, and living in the least-deprived socioeconomic quintile were associated with a higher HDHS-A score (all P < 0.001). HDHS-A tertile was associated positively with intake of protein, dietary fiber, polyunsaturated fatty acid, and lactose and negatively with sucrose. Associations in the expected directions were also found with most micronutrients (P < 0.05), urinary sodium (P < 0.001), whole blood (P < 0.05), serum (P < 0.01), and RBC folate (P < 0.05) concentrations. This suggests that the HDHS-A is a valid indicator of diet quality among NZ adolescents.

Neighborhood socioeconomic disadvantage is associated with higher ratio of 24-hour urinary sodium to potassium in young Japanese women.

Information on the relationship of neighborhood characteristics to objective indicators of dietary intake is extremely limited. The aim of this observational cross-sectional study was to examine the association between neighborhood socioeconomic status (SES) and 24-hour urinary excretion of sodium and potassium in a population with a high ratio of urinary sodium to potassium. Subjects were 1,032 female Japanese dietetics students aged 18 to 22 years, residing in 293 municipalities in Japan. Neighborhood SES index was defined by seven municipal-level variables, namely unemployment, household overcrowding, poverty, education, income, home ownership, and vulnerable groups, with an increasing index signifying increasing neighborhood socioeconomic disadvantage. Urinary excretion of sodium and potassium was estimated from a single 24-hour urine sample. Neighborhood SES index was not significantly associated with 24-hour urinary excretion of sodium (mean value for each quartile of neighborhood SES: 133.5, 135.2, 126.5, and 141.7 mmol/day, respectively; P for trend 0.10) or potassium (mean value for each quartile: 43.5, 42.2, 38.4, and 42.5 mmol/day, respectively; P for trend 0.44). However, neighborhood SES index was significantly positively associated with the ratio of 24-hour urinary sodium to potassium (mean value for each quartile: 3.14, 3.28, 3.37, and 3.41, respectively; P for trend 0.03). This significant association remained after adjustment for household SES variables (mean value for each quartile: 3.15, 3.35, 3.29, and 3.41, respectively; P for trend 0.04). Neighborhood socioeconomic disadvantage was associated with higher ratio of 24-hour urinary sodium to potassium in young Japanese women.

Validity of reported energy expenditure and reported intake of energy, protein, sodium and potassium in rheumatoid arthritis patients in a dietary intervention study.

OBJECTIVES: The aim of the study was to validate a diet history interview (DHI) method and a 3-day activity registration (AR) with biological markers. SUBJECTS AND STUDY DESIGN: The reported dietary intake of 33 rheumatoid arthritis patients (17 patients on a Mediterranean-type diet and 16 patients on a control diet) participating in a dietary intervention study was assessed using the DHI method. The total energy expenditure (TEE), estimated by a 3-day AR, was used to validate the energy intake (EI). For nine subjects the activity registration was also validated by means of the doubly labelled water (DLW) method. The excretion of nitrogen, sodium and potassium in 24-h urine samples was used to validate the intake of protein, sodium and potassium. RESULTS: There was no significant difference between the EI and the TEE estimated by the activity registration or between the intake of protein, sodium and potassium and their respective biological markers. However, in general, the AR underestimated the TEE compared to the DLW method. No significant differences were found between the subjects in the Mediterranean diet group and the control diet group regarding the relationship between the reported intakes and the biological markers. CONCLUSION: The DHI could capture the dietary intake fairly well, and the dietary assessment was not biased by the dietary intervention. The AR showed a bias towards underestimation when compared to the DLW method. This illustrates the importance of valid biological markers.

Sodium economy in white-tailed deer (Odocoileus virginianus).

Sodium is considered the mineral most limiting to growth and reproduction of mammalian herbivores worldwide. Notwithstanding the large database on physiological adaptations to low sodium intake, information on maintenance sodium requirements and sodium dynamics of mammals is depauperate. We measured sodium intake and output in adult, nonreproductive white-tailed deer (n = 15) over four seasons to estimate daily requirements for sodium on a seasonal and an annual basis. Dietary sodium content was based on best available predictions of sodium requirements. With regression techniques, we estimated metabolic fecal excretion and endogenous urinary losses of sodium. Average daily sodium requirement, defined as the minimum sodium intake at which intake equaled excretion, was estimated to be 3.27 mg kg-1 body mass d-1. Seasonal estimates did not vary. We propose that sodium requirements for maintenance in mammalian herbivores scale to body mass at an exponent that is similar to that for metabolic rate and forage intake (0.71-0.75). Development of an allometric relationship between sodium need and body mass would permit stronger inference regarding the role of sodium in population regulation, foraging decisions, or distribution and movements of mammalian herbivores.