Spot urine and 24-h diet recall estimates of dietary sodium intake from the 2008/09 New Zealand Adult Nutrition Survey: a comparison

Dietary Salt-Related Knowledge, Attitudes, and Behaviors of New Zealand Adults Aged 18-65 Years

OBJECTIVE

To explore dietary salt-related knowledge, attitudes, and behaviors of New Zealand (NZ) adults aged 18-65 years and assess differences by demographic subgroups.

DESIGN

Cross-sectional online survey conducted between June 1, 2018 and August 31, 2018.

SETTING

Participants were recruited in shopping malls, via social media, and a market research panel.

PARTICIPANTS

English-speaking adults residing in NZ.

VARIABLES MEASURED

An amended version of The Pan American and World Health Organization Knowledge, Attitudes, and Behaviors standardized survey tool was used. Demographic data (age, sex, ethnicity, and educational attainment) were also collected.

ANALYSIS

Descriptive statistics reported. Chi-square test for independence to assess differences by demographics.

RESULTS

The survey was completed by 1,131 adults (mean age 36 ± 15 years; n = 876 [78%] female; n = 661 [78%] NZ European/other; n = 210 [19%] Asian; n =164 [15%] Māori). In addition, 865 participants (83%) knew the primary dietary source of salt; 406 (40%) knew the recommended salt intake; 946 (95%) believed food manufacturers are responsible for sodium reduction; 563 (55%) supported government regulations; and 259 (26%) used food labels. Females and NZ European/other participants reported more favorable salt-reducing behaviors, such as avoiding fast-food and packaged, ready-to-eat foods (P < 0.001).

CONCLUSIONS AND IMPLICATIONS

Improving salt-related knowledge, attitudes, and behaviors in NZ is particularly important for men, underserved populations, and adults aged 45-65 years. A multicomponent, national NZ salt reduction program based on research addressing engagement and effectiveness for at-risk groups is warranted.

Role of high-salt diet in non-alcoholic fatty liver disease: a mini-review of the evidence

With the rising incidence of both obesity and diabetes, non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. However, lifestyle intervention remains to be an effective approach for NAFLD due to lack of therapeutic medication. Recently, salt, an essential micronutrient free of calories, has raised a global concern owing to its wide-range healthy relevance. Accumulated evidence has suggested that a long-term high-salt diet (HSD) independently increases the risk of NAFLD. In the past decades, a number of studies have been reported regarding the mechanism of much investigation concerning HSD-induced NAFLD. Here, we review the updates in epidemiology and molecular mechanism of HSD-induced NAFLD and provide a novel insight into the role of HSD in the regulation of lipid metabolism.

Association of dietary patterns with gut microbiota in kidney stone and non-kidney stone individuals

The dietary patterns are closely associated with gut microbiota, which has been proved associated with kidney stones. To assess the association among the dietary patterns, gut microbiota, and kidney stones, patients with calcium oxalate stones and participants without kidney stones were recruited in West China Hospital and were divided into the low nephrolithiasis risk (LNR) and high nephrolithiasis risk (HNR) dietary pattern group based on the results of food frequency questionnaires. The genomic DNA of the fecal samples were extracted for 16S ribosomal RNA gene sequencing. The non-kidney stone (NS) group comprised 39 LNR and 45 HNR individuals, while the kidney stone (KS) group consisted of 19 LNR and 50 HNR individuals. The distribution of oxalate in urine (p < 0.01) but not calcium (p = 0.741) was significantly varied among the four groups. Significant difference was found in the dietary patterns of people with KS and NS controls (X² = 5.744, p = 0.017). Forty-six discriminative bacteria were found among different dietary patterns groups in KS patients and NS controls. Not only gut bacteria such as Pseudomonas, Sphingomonas, Hydrogenoanaerobacterium, Faecalitalea, etc., but also metabolic pathways associated with inflammation, lipid, and mineral metabolism were found more abundant in KS patients with HNR dietary pattern. It is noteworthy that g__Prevotellaceae_UCG_001, g__hgcI_clade, and g__Bradyrhizobium were negatively related to water intake but instead had a positive correlation with salt and meat intake. Our study revealed that gut microbiota with significantly different abundance existed in the HNR dietary patterns compared to the LNR counterparts in both calcium oxalate KS and NS individuals. The dietary patterns may affect the prevention and management of calcium oxalate stones by regulating the homeostasis of gut microbiota.

Dietary sodium estimation methods: accuracy and limitations of old and new methods in individuals at high cardiovascular risk

OBJECTIVE

Accurate and easy to use methods for dietary Na intake estimation in population level are lacking. We aimed at (i) estimating the mean Na intake in the group level using a variety of dietary methods (DM) and urinary methods (UM) and correlating them with 24-h urine collection (24UCol) and (ii) improving the accuracy of the existing DM.

DESIGN

The most common DM (three 24-h dietary recalls (24DR) and FFQ) and UM (24UCol and spot urine collection using common equations) were applied. To improve the existing: (i) 24DR, discretionary Na was quantified using salt-related questions or adding extra 15 % in total Na intake and (ii) FFQ, food items rich in Na and salt-related questions were added in the standard questionnaire (NaFFQ).

SETTING

National and Kapodistrian University of Athens, Greece.

PARTICIPANTS

Totally, 122 high cardiovascular risk subjects (56·0 ± 12·6 years; 55·7 % males).

RESULTS

Mean 24 h Na excretion (24UNa) was 2810 ± 1304 mg/d. Spot urine methods overestimated the 24UNa (bias range: -1781 to -492 mg) and were moderately correlated to 24UCol (r = 0·469-0·596, P ≤ 0·01). DM underestimated the 24UNa (bias range: 877 to 1212 mg) and were weakly correlated with 24UCol. The improved DM underestimated the 24UNa (bias range: 877 to 923 mg). The NaFFQ presented the smallest bias (-290 ± 1336 mg) and the strongest correlation with 24UCol (r = 0·497, P ≤ 0·01), but wide limits of agreement in Bland-Altman plots (-2909 mg; 2329 mg), like all the other methods did.

CONCLUSIONS

The existing methods exhibit poor accuracy. Further improvement of the newly developed NaFFQ could be promising for more accurate estimation of mean dietary Na intake in epidemiological studies. Additional validation studies are needed.

Sodium in the New Zealand diet: proposed voluntary food reformulation targets will not meet the WHO goal of a 30% reduction in total sodium intake

PURPOSE

To simulate the potential impact of the HeartSAFE 2020 programme, a food reformulation initiative by the New Zealand (NZ) Heart Foundation, on sodium intake in the NZ adult population.

METHODS

A representative sample of NZ adults aged 15 years and older completed a 24-h diet recall survey, with 25% of participants completing a second diet recall, in the 2008/09 New Zealand Adult Nutrition Survey (n = 4721). These data were used to estimate sodium intakes of participants. The effect of altering the sodium content of 840 foods in 17 categories and 35 sub-categories included in the NZ HeartSAFE 2020 programme was simulated. The simulated sodium intake reductions in each food sub-category for the entire sample were calculated. Using sampling weights, simulated reductions in population sodium intake and by sociodemographic subgroups were also analysed.

RESULTS

Sodium intake from foods included in the HeartSAFE 2020 programme was 1307 mg/day (95% CI 1279, 1336) at baseline. After applying the HeartSAFE 2020 targets, potential sodium intake was 1048 mg/day (95% CI 1024, 1027). The absolute sodium reduction was 260 mg/day (95% CI 252, 268), corresponding to 20% sodium reduction for the foods included in the NZ HeartSAFE programme.

CONCLUSION

Current sodium targets featured in the NZ HeartSAFE programme will not meet the 30% sodium intake reduction set out by the WHO Global Action Plan. A more comprehensive strategy consistent with the WHO SHAKE Technical Package is needed to advance the goal of sodium intake reduction.

Processed Food and Atopic Dermatitis: A Pooled Analysis of Three Cross-Sectional Studies in Chinese Adults

Objective: The effect of processed foods on atopic dermatitis (AD) in adults is unclear. This study was to evaluate the association between processed foods and AD in the Chinese adult population.

Design: This study included three population-based cross-sectional studies using cluster sampling by villages, institutions, or factories. Participants underwent dermatological examinations by certificated dermatologists and a food frequency questionnaire survey. A spot urine sample was collected to estimate the daily sodium intake. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were presented as the effect size.

Setting: Shiyan city of Hubei province, and Huayuan, Shimen, Hengyang, Zhuzhou, and Changsha of Hunan province.

Participants: Automobile manufacture workers from Shiyan of Hubei province, and rural residents and civil servants from Hunan.

Results: A total of 15,062 participants, including 3,781 rural residents, 5,111 civil servants, and 6,170 workers, completed all evaluations. Compared to those hardly consumed pickles, consumption of pickles 1–3 times per week was significantly associated with AD (aOR: 1.35; 95% CI: 1.06–1.70). The intake of processed meats 1–3 times per month (aOR: 1.29; 95% CI: 1.05–1.58) and 1–3 times per week (aOR: 1.44; 95% CI: 1.11–1.87) were associated with AD dose-dependently when compared with those who rarely ate processed meats. Compared with non-consumers, the consumption of any processed foods 1–3 times per week (aOR: 1.39; 95% CI: 1.08–1.80) and ≥4 times per week (aOR: 1.41; 95% CI: 1.05–1.89) showed increased risks of AD. A positive association of estimated sodium intake with AD was also observed.

Conclusion: Intake of processed foods is associated with AD in Chinese adults.

[Validity and limitations of methods to measure the intake and elimination of salt]

High blood pressure (HBP) is the main modifiable cardiovascular risk factor. HBP can be related to high salt intake. To measure intake, not all feeding surveys are comparable and valid. The reference procedure for assessing salt intake consists of measuring the urinary excretion of sodium in urine collected during 24hours, although alternative methods have been proposed, such as the collection of punctual and timed urine samples. In this review, we analyze which instruments allow the assessment of salt intake and which of them have provided greater validity and reliability through studies of concordance with the elimination of sodium in urine. Current food consumption surveys are inadequate because of their wide variability and relatively low correlation with the elimination of sodium in 24-hour urine. Its main limitation is the need for validation in different population groups. In primary care, salt intake should be assessed by using frequency-of-consumption questionnaires that collect foods with a high salt content, the consumption of preprepared dishes and questions that quantify the addition of salt in the preparation of food or at the table. For the validation of these questionnaires, the standard gold elimination of 24-hour urine sodium adjusted according to creatinine clearance should be used.