Monitoring salt and iodine intakes in Dutch adults between 2006 and 2010 using 24 h urinary sodium and iodine excretions

Association between salt intake and gastric atrophy by Helicobacter pylori infection: first results from the Epidemiological Investigation of Gastric Malignancy (ENIGMA)

PURPOSE

Gastric atrophy (GA), usually linked to chronic infection with Helicobacter pylori (H. pylori), may over time evolve into gastric malignancy. Besides H. pylori, high salt intake may play a role in GA development. This study evaluates cross sectionally the association between salt intake and GA in Chilean adults.

METHODS

Population-based samples were recruited from two sites, Antofagasta and Valdivia, partaking in the Epidemiological Investigation of Gastric Malignancies. At recruitment, participants answered questionnaires and provided biospecimens. Salt intake (g/day) was estimated from casual spot urine samples using the Tanaka equation. GA was determined by serum pepsinogen levels. Only participants ≥ 40 to 70 years of age were considered in this analysis, n = 565. For the association between salt intake (as sex-specific quartiles) and GA, odds ratios (ORs) and the corresponding 95% confidence intervals (CI) were estimated through multivariable logistic regression.

RESULTS

In women, the multivariable-adjusted OR for GA comparing quartile 4 of the estimated salt intake (12.8 g/day) to quartile 1 (6.6 g/day) was 1.18 (95% CI 0.52-2.68, P-trend = 0.87). The corresponding OR in men was 0.49 (95% CI 0.19-1.27, P-trend = 0.17) with salt intakes of 12.8 g/day and 7.1 g/day for quartiles 4 and 1, respectively.

CONCLUSION

There was little evidence for an association between salt intake estimated from spot urine and GA risk in our cross-sectional analysis of middle aged and older adults in Chile. Reverse causation bias cannot be ruled out and the sample size was limited to provide more precise estimates.

An Evaluation of Food and Nutrient Intake among Pregnant Women in The Netherlands: A Systematic Review

Nutritional deficiencies during pregnancy can have serious consequences for the health of the (unborn) child. This systematic review provides an updated overview of the available food and nutrient intake data for pregnant women in The Netherlands and an evaluation based on the current recommendations. Embase, MEDLINE, and national institute databases were used. Articles were selected if they had been published since 2008 and contained data on food consumption, nutrient intake, or the status of healthy pregnant women. A qualitative comparison was made with the 2021 Dutch Health Council recommendations and reference values. A total of 218 reports were included, representing 54 individual studies. Dietary assessments were primarily performed via food frequency questionnaires. Protein, vitamin A, thiamin, riboflavin, vitamin B₆, folate, vitamin B₁₂, vitamin C, iron, calcium, and magnesium intakes seemed to be adequate. For folate and vitamin D, supplements were needed to reach the recommended intake. The reasons for concern are the low intakes of fruits, vegetables, and (fatty) fish, and the intakes of alcohol, sugary drinks, and salt. For several foods and nutrients, no or limited intake data were found. High-quality, representative, and recent data are needed to evaluate the nutrient intake of pregnant women in order to make accurate assessments and evaluations, supporting scientific-based advice and national nutritional policies.

Wpływ suplementacji diety selenem na przebieg autoimmunologicznego zapalenia tarczycy – przegląd badań klinicznych przeprowadzonych w populacji europejskiej

Wiele obserwacji wskazuje na zależność między zmniejszonymi zasobami selenowymi organizmu a różnymi schorzeniami tarczycy, w tym także autoimmunologicznym zapaleniem tarczycy (AZT). W większości prac poświęconych temu zagadnieniu zmiana stężenia przeciwciał anty-TPO była główną miarą oceny skuteczności suplementacji selenem (Se) diety pacjentów z AZT. Stężenie przeciwciał anty-TPO ma wpływ na intensywność nacieków limfocytarnych w gruczole tarczowym i stopień jego uszkodzenia, dlatego zmniejszenie ich stężenia w wyniku zwiększonego spożycia Se może się przyczynić do skuteczniejszego leczenia AZT. W części prac omówionych w artykule ewaluacja immunoregulacyjnego działania Se w przebiegu AZT została rozpatrzona w odniesieniu do szerszego zakresu parametrów biochemicznych i immunologicznych (głównie dotyczy to zmian w wytwarzaniu cytokin i chemokin). Wielu autorów potwierdziło wpływ Se na zmniejszanie stężenia przeciwciał anty-TPO, jednak wyniki wszystkich prac nie są jednoznaczne. Przyczyną rozbieżności może być odmienny stopień wysycenia tarczycy Se i jodem w różnych grupach pacjentów, różny stopień zaawansowania choroby, różne dawki Se podawanego pacjentom, stosowanie lub niestosowanie jednoczesnej terapii L-tyroksyną oraz polimorfizmy pojedynczych nukleotydów (SNP) występujące w genach kodujących poszczególne selenobiałka.

Na podstawie dostępnej literatury można wnioskować, iż zagadnienie dotyczące roli Se w AZT jest nadal słabo poznane. Istnieje potrzeba kontynuowania badań oceniających wpływ suplementacji diety Se na przebieg tej choroby, które powinny obejmować poza anty-TPO inne parametry kliniczne. Dopiero wyniki tak szeroko ujętych badań mogą być pomocne w formułowaniu nowych wytycznych dotyczących wspomagania leczenia przez odpowiednią modyfikację diety z uwzględnieniem suplementacji Se.

Neonatal heel prick screening TSH concentration in the Netherlands as indicator of iodine status

Background

Neonatal Thyroid Stimulating Hormone (nTSH) is proposed as indicator of iodine deficiency in a population. Population’s iodine sufficiency is indicated by a proportion of the newborns less than 3% having nTSH above 5 mIU/L. The aim of this study was to explore the Dutch neonatal heel prick screening TSH data to assess iodine status in the Netherlands and identify determinants and potential confounders of this assessment.

Methods

All newborns born in the Netherlands between 2007 and 2015 with a heel prick collection at day 3-7 were included (n = 1,435,600), except preterm neonates and baby’s with a low birth weight. Total T4 was measured for all children, nTSH was measured in the ~ 20% children with lowest total T4.

Results

The proportion with nTSH > 5mIU/L fluctuated between 0.6-1.3% in 2007-2015. nTSH was significantly associated with laboratory performing the nTSH assay and age of heel prick sampling. The overall increasing trend in proportion nTSH >1mIU/L was confounded by the laboratories with different and changed assays.

Conclusions

The low proportion neonates with high nTSH suggests a sufficient iodine status in the Netherlands. Whether the increased proportion nTSH>1mIU/L over the years is an early indicator of deterioration of the iodine status remains unclear, due to differences and changes in analytical assays. nTSH might be a valuable and inexpensive way to get crude insight in the (trend in) iodine status, but more research is needed on the validity and potential conditions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00722-4.

Sodium intake, health implications, and the role of population-level strategies

Evidence to date suggests that high sodium intake affects health adversely, yet the role of a population-level strategy to reduce sodium intake is often contested. This review focuses on current available evidence on regional sodium intake levels, health implications of sodium intake, and population-level strategies implemented worldwide. The limitations in evidence, the difficulties in implementing population-wide strategies to reduce sodium intake, and the need for such strategies are critically reviewed. Evidence clearly shows that sodium has an adverse effect on blood pressure, cardiovascular disease, and mortality. However, whether reduced sodium intake benefits all individuals or only hypertensive individuals is still unclear. Methodological issues and publication bias in current evidence are other matters of concern in sodium-related research. While it is essential to continue working toward the World Health Organization's target of 30% reduction in sodium intake, due consideration should be given to improving the quality of research, reducing bias in publications, and reviewing evidence more critically.

A Novel Urinary Biomarker Approach Reveals Widespread Exposure to Multiple Low-Calorie Sweeteners in Adults

BACKGROUND

Observational investigations into the health impacts of low-calorie sweeteners (LCSs) in humans fail to adequately identify or fully characterize LCS consumption.

OBJECTIVES

We aimed to utilize a novel biomarker approach to investigate exposure to 5 LCSs and to test whether reported low-calorie sweetened beverage (LCSB) consumption effectively identifies exposure to LCSs in adults.

METHODS

In this cross-sectional analysis, 2 population studies were conducted in adults. Urinary excretions of 5 LCSs, namely acesulfame-K, saccharin, cyclamate, sucralose, and steviol glycosides, were simultaneously determined using LC tandem-MS. In Study 1, previously collected 24-h urine samples (n = 357) were analyzed. In Study 2, previously collected 24-h urine samples (n = 79) were analyzed to compare urinary excretions of LCSs with self-reported LCSB consumption for identifying LCS exposure. Exposure to LCSs was characterized using descriptive statistics and chi-square tests were performed to assess associations between age-groups and LCS excretion, and to assess the proportion of individuals identified as LCS consumers using biomarker data or reported LCSB consumption.

RESULTS

A total of 341 adults (45% men) and 79 adults (39% men) were included in the final analysis of Studies 1 and 2, respectively. In Study 1, >96% of samples contained ≥1 LCS and almost 60% contained ≥3 LCSs. A greater proportion of younger adults (<40 y old) excreted ≥3 LCSs than older adults (>40 y old) (P < 0.001). In Study 2, a much higher prevalence of LCS consumption was observed using biomarker data (92%) than reported LCSB consumption (6%) (P < 0.001).

CONCLUSIONS

This work indicates widespread exposure to LCSs, suggesting that population-based research to date into LCS exposure and health may be flawed. Therefore, a urinary biomarker approach offers considerable potential for more robust investigations in this area.

Glucocorticoids affect metabolic but not muscle microvascular insulin sensitivity following high versus low salt intake

BACKGROUNDSalt-sensitive hypertension is often accompanied by insulin resistance in obese individuals, but the underlying mechanisms are obscure. Microvascular function is known to affect both salt sensitivity of blood pressure and metabolic insulin sensitivity. We hypothesized that excessive salt intake increases blood pressure and decreases insulin-mediated glucose disposal, at least in part by impairing insulin-mediated muscle microvascular recruitment (IMMR).METHODSIn 20 lean and 20 abdominally obese individuals, we assessed mean arterial pressure (MAP; 24-hour ambulatory blood pressure measurements), insulin-mediated whole-body glucose disposal (M/I value; hyperinsulinemic-euglycemic clamp technique), IMMR (contrast-enhanced ultrasound), osmolyte and water balance, and excretion of mineralocorticoids, glucocorticoids, and amino and organic acids after a low- and high-salt diet during 7 days in a randomized, double-blind, crossover design.RESULTSOn a low-, as compared with a high-salt, intake, MAP was lower, M/I value was lower, and IMMR was greater in both lean and abdominally obese individuals. In addition, natural logarithm IMMR was inversely associated with MAP in lean participants on a low-salt diet only. On a high-salt diet, free water clearance decreased, and excretion of glucocorticoids and of amino acids involved in the urea cycle increased.CONCLUSIONOur findings imply that hemodynamic and metabolic changes resulting from alterations in salt intake are not necessarily associated. Moreover, they are consistent with the concept that a high-salt intake increases muscle glucose uptake as a response to high salt-induced, glucocorticoid-driven muscle catabolism to stimulate urea production and thereby renal water conservation.TRIAL REGISTRATIONClinicalTrials.gov, NCT02068781.

Impact of Moderate Sodium Restriction and Hydrochlorothiazide on Iodine Excretion in Diabetic Kidney Disease: Data from a Randomized Cross-Over Trial

Sodium restriction may potentially reduce iodine intake. This study aimed to determine the effect of sodium restriction (dietary counseling) on 24-h urinary iodine excretion. Diuretics provide an alternative to sodium restriction and are frequently added to sodium restriction, so the effects of hydrochlorothiazide (50 mg daily) and combined therapy were also studied. We performed a post-hoc analysis of a Dutch multi-center, randomized cross-over trial in 45 patients with diabetic kidney disease with a mean age of 65 ± 9 years, mean eGFR of 65 ± 27 mL/min/1.73 m², median albuminuria of 648 [230–2008] mg/24 h and 84% were male. During regular sodium intake with placebo, mean 24 h urinary sodium and iodine excretion were 224 ± 76 mmol/24 h and 252 ± 94 ug/24 h, respectively (r = 0.52, p < 0.001). Mean iodine excretion did not change significantly if sodium restriction and hydrochlorothiazide were applied separately; mean difference −8 ug/day (95% CI −38, 22; p = 0.6) and 14 ug/day (95% CI −24, 52; p = 0.5), respectively. Combined therapy induced a significant decrease in mean iodine excretion (−37 ug/day; 95% CI −67, −7; p = 0.02), yet this was not seen to a clinically meaningful level. The number of patients with an estimated intake below recommended daily allowances did not differ significantly between the four treatment periods (p = 0.3). These findings show that sodium restriction is not a risk factor for iodine deficiency.

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.

Estimation of the salt intake distribution of Dutch kidney transplant recipients using 24-h urinary sodium excretion: the potential of external within-person variance

BACKGROUND

There is growing interest in assessing a population's prevalence of inadequate nutrient intake using biomarkers. However, within-person variation is generally ignored because repeated data collections are considered costly and burdensome.

OBJECTIVES

The study aimed to show the importance of estimating, from repeated 24-h urine collections, a population's habitual salt intake and to explore the potential of using the ratio of within-person variance to total variance from an external source (W:T variance) with single 24-h urine collection.

METHODS

Salt intake was predicted from data for 24-h urinary sodium excretion in adult kidney transplant recipients in 1992-1997 (n = 432) and 2006-2011 (n = 1159). The salt intake distribution of single-day measurements was compared with estimates from multiple 24-h urine collections, which were statistically corrected for within-person variance. Habitual salt intake was also estimated using single-day measurements and external variance estimates. From each distribution, the proportion below specified cut-off values was estimated.

RESULTS

In 2006-2011 the average habitual salt intake was 10.6 g/d (men) and 8.5 g/d (women); in 1992-1997 these values were 8.6 g/d and 7.5 g/d, respectively. The proportion with salt intake <6 g/d was 5% and 13% in 2006-2011 and 22% and 28% in 1992-1997, respectively, for men and women. Correction for within-person variance significantly narrowed the salt intake distribution-the proportion with salt intake <6 g/d was overestimated by 3-13 percentage points using single-day data. Sensitivity analyses showed the importance of a sufficient sample size for estimating variance components. Variation of the W:T variance showed up to 40 percentage points deviation in the proportion with intakes below a specified cut-off value.

CONCLUSIONS

To estimate a population's salt intake distribution, it is important to correct 24-h urinary sodium excretion for within-person variance. Predicting habitual salt intake distribution using single-day measurements with external variances is promising; a sensitivity analysis is recommended to show the effect of different external variances.

Food Consumption, Nutrient Intake and Status during the First 1000 days of Life in the Netherlands: a Systematic Review

Adequate nutrition is essential for growth and development in early life. Nutritional data serves as a basis for national nutritional guidelines and policies. Currently, there is no insight into the availability of such data during the first 1000 days of life. Therefore, a systematic review was performed, following the PRISMA reporting guideline, to identify studies on food consumption, nutrient intake or status in the Netherlands. Potential gaps were identified, and the quality of the studies is discussed. The databases Embase and Medline were used, as well as databases from national institutes. Articles published in 2008-2018 were screened by two independent reviewers. In total 601 articles were identified, of which 173 were included. For pregnant women, 32 studies were available with nutritional data, for young children 40 studies were identified. No studies were available for breastfeeding women. A large variety of foods and nutrients were assessed, however certain nutrients were lacking (e.g., vitamin K). Overall, the studies had methodological limitations, making the data unsuitable to assess nutrient inadequacies. There is a need for recent, high quality nutritional research to strengthen the understanding of the nutritional needs and deficiencies during early life, and is fundamental for national guidelines and policies.

Population-level interventions in government jurisdictions for dietary sodium reduction: a Cochrane Review

Background

Worldwide, excessive salt consumption is common and is a leading cause of high blood pressure. Our objectives were to assess the overall and differential impact (by social and economic indicators) of population-level interventions for dietary sodium reduction in government jurisdictions worldwide.

Methods

This is a Cochrane systematic review. We searched nine peer-reviewed databases, seven grey literature resources and contacted national programme leaders. We appraised studies using an adapted version of the Cochrane risk of bias tool. To assess impact, we computed the mean change in salt intake (g/day) from before to after intervention.

Results

Fifteen initiatives met the inclusion criteria and 10 provided sufficient data for quantitative analysis of impact. Of these, five showed a mean decrease in salt intake from before to after intervention including: China, Finland (Kuopio area), France, Ireland and the UK. When the sample was constrained to the seven initiatives that were multicomponent and incorporated activities of a structural nature (e.g. procurement policy), most (4/7) showed a mean decrease in salt intake. A reduction in salt intake was more apparent among men than women. There was insufficient information to assess differential impact by other social and economic axes. Although many initiatives had methodological strengths, all scored as having a high risk of bias reflecting the observational design. Study heterogeneity was high, reflecting different contexts and initiative characteristics.

Conclusions

Population-level dietary sodium reduction initiatives have the potential to reduce dietary salt intake, especially if they are multicomponent and incorporate intervention activities of a structural nature. It is important to consider data infrastructure to permit monitoring of these initiatives.

Aldosterone Is Not Associated With Metabolic and Microvascular Insulin Sensitivity in Abdominally Obese Men

CONTEXT

Impaired insulin-mediated muscle microvascular recruitment (IMMR) may add to the development of insulin resistance and hypertension. Increased aldosterone levels have been linked to these obesity-related complications in severely to morbidly obese individuals and to impaired microvascular function in experimental studies.

OBJECTIVES

To investigate whether aldosterone levels are associated with IMMR, insulin sensitivity, and blood pressure in lean and moderately abdominally obese men, and to study the effect of weight loss.

DESIGN, SETTING, PARTICIPANTS, INTERVENTION, MAIN OUTCOME MEASURES

In 25 lean and 53 abdominally obese men, 24-hour blood pressure measurement was performed, and aldosterone levels were measured using ultra-performance liquid chromatography tandem mass spectrometry. Insulin sensitivity was assessed by determining whole-body glucose disposal during a hyperinsulinemic clamp. IMMR in forearm skeletal muscle was measured with contrast-enhanced ultrasonography. These assessments were repeated in the abdominally obese men following an 8-week weight loss or weight stable period.

RESULTS

Sodium excretion and aldosterone levels were similar in lean and abdominally obese participants, but sodium excretion was inversely associated with aldosterone concentration only in the lean individuals [lean, β/100 mmol sodium excretion (adjusted for age and urinary potassium excretion) = -0.481 (95% confidence interval, -0.949 to -0.013); abdominally obese, β/100 mmol sodium excretion = -0.081 (95% confidence interval, -0.433 to 0.271); P for interaction = 0.02]. Aldosterone was not associated with IMMR, insulin sensitivity, or blood pressure and was unaffected by weight loss.

CONCLUSION

In moderately abdominally obese men, the inverse relationship between sodium excretion and aldosterone concentration is less than that in lean men but does not translate into higher aldosterone levels. The absolute aldosterone level does not explain differences in microvascular and metabolic insulin sensitivity and blood pressure between lean and moderately abdominally obese men.

Salt Reductions in Some Foods in The Netherlands: Monitoring of Food Composition and Salt Intake

BACKGROUND AND OBJECTIVES

High salt intake increases blood pressure and thereby the risk of chronic diseases. Food reformulation (or food product improvement) may lower the dietary intake of salt. This study describes the changes in salt contents of foods in the Dutch market over a five-year period (2011-2016) and differences in estimated salt intake over a 10-year period (2006-2015).

METHODS

To assess the salt contents of foods; we obtained recent data from chemical analyses and from food labels. Salt content of these foods in 2016 was compared to salt contents in the 2011 version Dutch Food Composition Database (NEVO, version 2011), and statistically tested with General Linear Models. To estimate the daily dietary salt intake in 2006, 2010, and 2015, men and women aged 19 to 70 years were recruited through random population sampling in Doetinchem, a small town located in a rural area in the eastern part of the Netherlands. The characteristics of the study population were in 2006: n = 317, mean age 49 years, 43% men, in 2010: n = 342, mean age 46 years, 45% men, and in 2015: n = 289, mean age 46 years, 47% men. Sodium and potassium excretion was measured in a single 24-h urine sample. All estimates were converted to a common metric: salt intake in grams per day by multiplication of sodium with a factor of 2.54.

RESULTS

In 2016 compared to 2011, the salt content in certain types of bread was on average 19 percent lower and certain types of sauce, soup, canned vegetables and legumes, and crisps had a 12 to 26 percent lower salt content. Salt content in other types of foods had not changed significantly. Between 2006, 2010 and 2015 the estimated salt intake among adults in Doetinchem remained unchanged. In 2015, the median estimated salt intake was 9.7 g per day for men and 7.4 g per day for women. As in 2006 and 2010, the estimated salt intake in 2015 exceeded the recommended maximum intake of 6 g per day set by the Dutch Health Council.

CONCLUSION

In the Netherlands, the salt content of bread, certain sauces, soups, potato crisps, and processed legumes and vegetables have been reduced over the period 2011-2016. However, median salt intake in 2006 and 2015 remained well above the recommended intake of 6 g.

Decreased, but still sufficient, iodine intake of children and adults in the Netherlands

Sufficient I intake is important for the synthesis of thyroid hormones, which play an important role in normal growth and development. Our aim was to estimate habitual I intake for the Dutch population and the risk of inadequate or excessive intakes. Further, we aimed to provide an insight into the dietary sources of I and the association with socio-demographic factors. Data from the Dutch National Food Consumption Survey 2007-2010 (n 3819; 7-69 years), and from the Dutch food and supplement composition tables were used to estimate habitual I intake with a calculation model. Contribution of food groups to I intake were computed and multiple linear regression was used to examine associations of intakes with socio-demographic factors. A total of ≤2 % of the population had an intake below the estimated average requirement or above the upper level. The main sources of I were bread containing iodised salt (39 %), dairy products (14 %) and non-alcoholic drinks (6 %). I intake (natural sources only, excluding iodised salt and supplements) was positively associated with (parental) education, which could at least partly be attributed to a higher consumption of dairy products. Among children, the consumption of bread, often containing iodised bakery salt, was positively associated with parental education. The I intake of the Dutch population (7-69 years) seems adequate, although it has decreased since the period before 2008. With the current effort to reduce salt intake and changing dietary patterns (i.e. less bread, more organic foods) it is important to keep a close track on the I status, important sources and potential risk groups.

TSH and fT4 during pregnancy: an observational study and a review of the literature

BACKGROUND

Trimester-specific reference intervals for TSH are recommended to assess thyroid function during pregnancy due to changes in thyroid physiology. Laboratories should verify reference intervals for their population and assay used. No consistent upper reference limit (URL) for TSH during pregnancy is reported in literature. We investigated the use of non-pregnant reference intervals for TSH, recommended during pregnancy by current Dutch guidelines, by deriving trimester-specific reference intervals in disease-free Dutch pregnant women as these are not available.

METHODS

Apparently healthy low risk pregnant women were recruited via midwifery practices. Exclusion criteria included current or past history of thyroid or other endocrine disease, multiple pregnancy, use of medication known to influence thyroid function and current pregnancy as a result of hormonal stimulation. Women who were TPO-antibody positive, miscarried, developed hyperemesis gravidarum, hypertension, pre-eclampsia, HELLP, diabetes or other disease, delivered prematurely or had a small for gestational age neonate were excluded. Blood samples were collected at 9-13 weeks (n=99), 27-29 weeks (n=96) and 36-39 weeks (n=96) of gestation and at 4-13 weeks post-partum (n=95). Sixty women had complete data during pregnancy and post-partum. All analyses were performed on a Roche Cobas e601 analyser.

RESULTS AND CONCLUSIONS

In contrast to current Dutch guidelines, the 97.5th percentiles of TSH in the first (3.39 mIU/L) and second trimesters (3.38 mIU/L) are well under the non-pregnant URL of 4.0 mIU/L. The higher TSH in the third trimester (97.5th percentile 3.85 mIU/L) is close to the current non-pregnant URL of 4.0 mIU/L. Absolute intra-individual TSH is relatively stable during pregnancy and post-partum as individuals tracked within the tertile assigned in trimester 1. Even small deviations within the population reference interval may indicate subtle thyroid dysfunction.

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.

Population-level interventions in government jurisdictions for dietary sodium reduction

BACKGROUND

Excess dietary sodium consumption is a risk factor for high blood pressure, stroke and cardiovascular disease. Currently, dietary sodium consumption in almost every country is too high. Excess sodium intake is associated with high blood pressure, which is common and costly and accounts for significant burden of disease. A large number of jurisdictions worldwide have implemented population-level dietary sodium reduction initiatives. No systematic review has examined the impact of these initiatives.

OBJECTIVES

• To assess the impact of population-level interventions for dietary sodium reduction in government jurisdictions worldwide.• To assess the differential impact of those initiatives by social and economic indicators.

SEARCH METHODS

We searched the following electronic databases from their start date to 5 January 2015: the Cochrane Central Register of Controlled Trials (CENTRAL); Cochrane Public Health Group Specialised Register; MEDLINE; MEDLINE In Process & Other Non-Indexed Citations; EMBASE; Effective Public Health Practice Project Database; Web of Science; Trials Register of Promoting Health Interventions (TRoPHI) databases; and Latin American Caribbean Health Sciences Literature (LILACS). We also searched grey literature, other national sources and references of included studies.This review was conducted in parallel with a comprehensive review of national sodium reduction efforts under way worldwide (Trieu 2015), through which we gained additional information directly from country contacts.We imposed no restrictions on language or publication status.

SELECTION CRITERIA

We included population-level initiatives (i.e. interventions that target whole populations, in this case, government jurisdictions, worldwide) for dietary sodium reduction, with at least one pre-intervention data point and at least one post-intervention data point of comparable jurisdiction. We included populations of all ages and the following types of study designs: cluster-randomised, controlled pre-post, interrupted time series and uncontrolled pre-post. We contacted study authors at different points in the review to ask for missing information.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data, and two review authors assessed risk of bias for each included initiative.We analysed the impact of initiatives by using estimates of sodium consumption from dietary surveys or urine samples. All estimates were converted to a common metric: salt intake in grams per day. We analysed impact by computing the mean change in salt intake (grams per day) from pre-intervention to post-intervention.

MAIN RESULTS

We reviewed a total of 881 full-text documents. From these, we identified 15 national initiatives, including more than 260,000 people, that met the inclusion criteria. None of the initiatives were provided in lower-middle-income or low-income countries. All initiatives except one used an uncontrolled pre-post study design.Because of high levels of study heterogeneity (I² > 90%), we focused on individual initiatives rather than on pooled results.Ten initiatives provided sufficient data for quantitative analysis of impact (64,798 participants). As required by the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) method, we graded the evidence as very low due to the risk of bias of the included studies, as well as variation in the direction and size of effect across the studies. Five of these showed mean decreases in average daily salt intake per person from pre-intervention to post-intervention, ranging from 1.15 grams/day less (Finland) to 0.35 grams/day less (Ireland). Two initiatives showed mean increase in salt intake from pre-intervention to post-intervention: Canada (1.66) and Switzerland (0.80 grams/day more per person. The remaining initiatives did not show a statistically significant mean change.Seven of the 10 initiatives were multi-component and incorporated intervention activities of a structural nature (e.g. food product reformulation, food procurement policy in specific settings). Of those seven initiatives, four showed a statistically significant mean decrease in salt intake from pre-intervention to post-intervention, ranging from Finland to Ireland (see above), and one showed a statistically significant mean increase in salt intake from pre-intervention to post-intervention (Switzerland; see above).Nine initiatives permitted quantitative analysis of differential impact by sex (men and women separately). For women, three initiatives (China, Finland, France) showed a statistically significant mean decrease, four (Austria, Netherlands, Switzerland, United Kingdom) showed no significant change and two (Canada, United States) showed a statistically significant mean increase in salt intake from pre-intervention to post-intervention. For men, five initiatives (Austria, China, Finland, France, United Kingdom) showed a statistically significant mean decrease, three (Netherlands, Switzerland, United States) showed no significant change and one (Canada) showed a statistically significant mean increase in salt intake from pre-intervention to post-intervention.Information was insufficient to indicate whether a differential change in mean salt intake occurred from pre-intervention to post-intervention by other axes of equity included in the PROGRESS framework (e.g. education, place of residence).We identified no adverse effects of these initiatives.The number of initiatives was insufficient to permit other subgroup analyses, including stratification by intervention type, economic status of country and duration (or start year) of the initiative.Many studies had methodological strengths, including large, nationally representative samples of the population and rigorous measurement of dietary sodium intake. However, all studies were scored as having high risk of bias, reflecting the observational nature of the research and the use of an uncontrolled study design. The quality of evidence for the main outcome was low. We could perform a sensitivity analysis only for impact.

AUTHORS' CONCLUSIONS

Population-level interventions in government jurisdictions for dietary sodium reduction have the potential to result in population-wide reductions in salt intake from pre-intervention to post-intervention, particularly if they are multi-component (more than one intervention activity) and incorporate intervention activities of a structural nature (e.g. food product reformulation), and particularly amongst men. Heterogeneity across studies was significant, reflecting different contexts (population and setting) and initiative characteristics. Implementation of future initiatives should embed more effective means of evaluation to help us better understand the variation in the effects.

High Iodine and Salt Intakes and Obesity do not Modify the Thyroid Function in Mexican Schoolchildren

Mexico is considered as a nutritional transition country with a high prevalence of overweight and obesity, and recent studies have reported a high iodine intake in children. Both high iodine intake and obesity have been associated with thyroid dysfunction. Our aim was to assess iodine and salt intake and thyroid function in Mexican schoolchildren with normal weight and obesity. A cross-sectional study was performed during 2012-2013 in schoolchildren from Queretaro, Mexico. Six hundred seventy-eight schoolchildren were evaluated to obtain nutrition status, urinary iodine concentration (UIC) and thyroid volume (TVol). The prevalence of overweight and obesity was 47.3 %, the median UIC was 428 μg/L and TVol was normal in all schoolchildren; however, obese girls had a higher TVol than normal weight at the age of 8, 10 and 12 years. A subsample of schoolchildren was divided in 6-8 and 9-12-year-old groups, in order to compare thyroid function (thyrotropin, free T4, and anti-thyroid antibodies); iodine and salt intake were estimated with 24-h urinary samples. No differences in thyroid function were observed in both age groups. In the 6-8-year-old group, obese schoolchildren had higher iodine intake than normal-weight children (415.5 vs. 269.1 μg/day, p < 0.05), but no differences in salt intake. In contrast, in the 9-12-year-old group, obese schoolchildren had higher salt intake than normal-weight children (6.2 vs. 3.8 g/day, p < 0.05), but no differences in iodine intake. Dietary patterns could explain the differences between both age groups. Further studies are needed to identify the main sources of iodine intake in Mexican populations.

Thyrotropin versus age relation as an indicator of historical iodine intake

BACKGROUND

In populations with mild iodine deficiency, the serum level of thyrotropin (TSH) is negatively and the serum free thyroxine (FT4) is positively associated with age. An ongoing decrease of TSH and increase of FT4 can be found after iodine supplementation. The aim of this study was to investigate whether there are current differences in the relation between thyroid function and age in relation to differences in iodine intake in the past.

METHODS

Eight medical laboratories in several regions of The Netherlands, which are all iodine sufficient at present but with a difference in iodine status in the past, provided the results of all TSH and FT4 measurements performed from 2006 until 2011, resulting in 330,802 TSH and 103,940 FT4 measurements.

RESULTS

The negative association between TSH and age in the elderly is only present in areas with a historical iodine deficiency (regression coefficients [RC] -0.008, 95% confidence interval [CI] -0.009; -0.007). In the historically iodine-sufficient population, TSH shows no obvious increase or decrease with age. In both the historically iodine-sufficient and iodine-deficient populations, FT4 levels were positively associated with age in the elderly (RC 0.009, 95% CI 0.008; 0.010 and RC 0.008, 95% CI 0.007; 0.010, respectively).

CONCLUSIONS

There are differences in relation between thyroid function and age between populations with differences in iodine intake in the past, despite an adequate iodine status at present. This raises the question whether the present but also historical iodine status of a population should be taken into account when establishing the reference limits of TSH and FT4.

Use of Urine Biomarkers to Assess Sodium Intake: Challenges and Opportunities

This article summarizes current data and approaches to assess sodium intake in individuals and populations. A review of the literature on sodium excretion and intake estimation supports the continued use of 24-h urine collections for assessing population and individual sodium intake. Since 2000, 29 studies used urine biomarkers to estimate population sodium intake, primarily among adults. More than half used 24-h urine; the rest used a spot/casual, overnight, or 12-h specimen. Associations between individual sodium intake and health outcomes were investigated in 13 prospective cohort studies published since 2000. Only three included an indicator of long-term individual sodium intake, i.e., multiple 24-h urine specimens collected several days apart. Although not insurmountable, logistic challenges of 24-h urine collection remain a barrier for research on the relationship of sodium intake and chronic disease. Newer approaches, including modeling based on shorter collections, offer promise for estimating population sodium intake in some groups.

Health gain by salt reduction in europe: a modelling study

Excessive salt intake is associated with hypertension and cardiovascular diseases. Salt intake exceeds the World Health Organization population nutrition goal of 5 grams per day in the European region. We assessed the health impact of salt reduction in nine European countries (Finland, France, Ireland, Italy, Netherlands, Poland, Spain, Sweden and United Kingdom). Through literature research we obtained current salt intake and systolic blood pressure levels of the nine countries. The population health modeling tool DYNAMO-HIA including country-specific disease data was used to predict the changes in prevalence of ischemic heart disease and stroke for each country estimating the effect of salt reduction through its effect on blood pressure levels. A 30% salt reduction would reduce the prevalence of stroke by 6.4% in Finland to 13.5% in Poland. Ischemic heart disease would be decreased by 4.1% in Finland to 8.9% in Poland. When salt intake is reduced to the WHO population nutrient goal, it would reduce the prevalence of stroke from 10.1% in Finland to 23.1% in Poland. Ischemic heart disease would decrease by 6.6% in Finland to 15.5% in Poland. The number of postponed deaths would be 102,100 (0.9%) in France, and 191,300 (2.3%) in Poland. A reduction of salt intake to 5 grams per day is expected to substantially reduce the burden of cardiovascular disease and mortality in several European countries.

Nutritional impact of sodium reduction strategies on sodium intake from processed foods

BACKGROUND/OBJECTIVES

Sodium intake in the Netherlands is substantially above the recommended intake of 2400 mg/day. This study aimed to estimate the effect of two sodium reduction strategies, that is, modification of the composition of industrially processed foods toward the technologically feasible minimum level or alteration of consumers' behavior on sodium intake in the Netherlands.

SUBJECTS/METHODS

Data from the Dutch National Food Consumption Survey (2007-2010) and the Food Composition Table (2011) were used to estimate the current sodium intake. In the first scenario, levels in processed foods were reduced toward their technologically feasible minimum level (sodium reduction in processed foods scenario). The minimum feasible levels were based on literature searches or expert judgment. In the second scenario, foods consumed were divided into similar food (sub)groups. Subsequently, foods were replaced by low-sodium alternatives (substitution of processed foods scenario). Sodium intake from foods was calculated based on the mean of two observation days for the current food consumption pattern and the scenarios.

RESULTS

Sodium levels of processed foods could be reduced in most food groups by 50%, and this may reduce median sodium intake from foods by 38% (from 3042 to 1886 mg/day in adult men). Substitution of foods may reduce sodium intake by 47% (from 3042 to 1627 mg/day in adult men), owing to many low-sodium alternatives within food groups.

CONCLUSIONS

In the Netherlands, reduction of sodium intake by modification of food composition or by alteration of behavior may substantially reduce the median sodium intake from foods below the recommended sodium intake.

Prevalence of iodine intake inadequacy in elderly Brazilian women. A cross-sectional study

BACKGROUND/OBJECTIVES

Inadequate iodine intake is still a problem in various regions of the world, and limited data exist regarding the ingestion of iodine in elderly people. We investigated the prevalence of iodine intake inadequacy in a group of elderly women living in a region of Brazil considered to be iodine-sufficient.

DESIGN AND SETTING

Cross-sectional study conducted in the public healthcare system of Bauru, São Paulo, Brazil.

METHODS

We evaluated 135 elderly women (average age of 68.2 years) who participated in a program of assistance to the elderly with respect to iodine intake through two 24-hour recalls using a nutritional computer program. The women were also evaluated with respect to serum levels of free thyroxin (FT4) and thyrotropin (TSH) and were classified as euthyroid, hypothyroid or hyperthyroid.

RESULTS

The average iodine intake of the group was 100.7 ± 39.2 μg. Twenty-nine patients (21.5%) presented thyroid dysfunction: 27 (20%) had hypothyroidism, and two (1.5%) had hyperthyroidism. The average iodine intake of the patients with hypothyroidism and euthyroidism was 92.7 μg and 101.7 μg, respectively. The prevalence of iodine intake inadequacy, considering the co-variables of age, race, income, body mass index, TSH, FT4 and arterial hypertension, was 51%, 48% and 66% in the general, euthyroid and hypothyroid patients, respectively.

CONCLUSION

We concluded that high prevalence of iodine intake inadequacy was present in this group of elderly women living in a region of Brazil considered to be iodine-sufficient.