A STRATIFIED CROSS-SECTIONAL CLUSTER MODEL SURVEY OF IODINE NUTRITION IN ARMENIA AFTER A DECADE OF UNIVERSAL SALT IODIZATION.

Objective: Iodine is a necessary nutrient for the synthesis of thyroid hormones and essential in human development. Being naturally deficient in iodine, Armenia launched a national universal salt iodization (USI) strategy in 2004. Although high rates of goiter continued to be reported, iodine status has not been studied since 2005. Therefore, this study sought to assess the current situation of population iodine nutrition in Armenia. Methods: We used a selective cross-sectional model to recruit three groups: school-age children (SAC), pregnant women (PW), and nonpregnant women of reproductive age (WRA) from each province. We collected casual urine and table salt samples from each participant, which were analyzed for iodine concentration. A repeat urine sample was collected in a subset of participants to adjust the results for within-person variation in iodine concentration. Group-wise urinary iodine concentrations (UICs) were compared with international reference criteria for iodine status. Results: Urine samples were collected from 1,125 participants from 13 different towns in Armenia; a total of 1,078 participants were included in the final analysis: 361 SAC (mean age, 10.5 years, 46.6% female), 356 PW (mean age, 26.1 years), and 361 WRA (mean age, 35.5 years). Population and geographically weighted median UIC were: SAC, 242 µg/L ([25th percentile] 203 to [75th percentile] 289 µg/L); PW, 226 µg/L (209 to 247 µg/L); WRA, 311 µg/L (244 to 371 µg/L). A total of 1,041 table salt samples were sufficient for laboratory analysis: 973 (93.4%) of the salt iodine measurements were within the national standard range of 40 ± 15 mg/kg. Conclusion: The results of household salt sampling indicated a successful USI strategy. While the present study did not achieve a truly representative sample of Armenia's population, the UIC results support the conclusion that iodine deficiency has not recurred and is not an underlying factor for any remaining high goiter prevalence in Armenia. Abbreviations: PW = pregnant women; SAC = school-age children; SI = salt iodine; UIC = urinary iodine concentration; USI = universal salt iodization; WHO = World Health Organization; WRA = women of reproductive age.

Constituent analysis of iodine intake in Armenia.

OBJECTIVE: We sought to assess the universal salt iodization (USI) strategy in Armenia by characterizing dietary iodine intake from naturally occurring iodine, salt-derived iodine in processed foods and salt-derived iodine in household-prepared foods. DESIGN: Using a cross-sectional cluster survey model, we collected urine samples which were analysed for iodine and sodium concentrations (UIC and UNaC) and household salt samples which were analysed for iodine concentration (SI). SI and UNaC data were used as explanatory variables in multiple linear regression analyses with UIC as dependent variable, and the regression parameters were used to estimate the iodine intake sources attributable to native iodine and iodine from salt in processed foods and household salt. SETTING: Armenia is naturally iodine deficient; in 2004, the government mandated a USI strategy. SUBJECTS: We recruited school-age children (SAC), pregnant women (PW) and non-pregnant women of reproductive age (WRA). RESULTS: From thirteen sites covering all provinces, sufficient urine and table salt samples were obtained from 312 SAC, 311 PW and 332 WRA. Findings revealed significant differences between groups: contribution of native iodine ranged from 81% in PW to 46% in SAC, while household salt-derived iodine contributed from 19% in SAC to 1% in PW. CONCLUSIONS: Differences between groups may reflect differences in diet. In all groups, household and processed food salt constituted a significant part of total iodine intake, highlighting the success and importance of USI in ensuring iodine sufficiency. There appears to be leeway to reduce salt intake without adversely affecting the iodine status of the population in Armenia.

New Statistical Approach to Apportion Dietary Sources of Iodine Intake: Findings from Kenya, Senegal and India.

Progress of national Universal Salt Iodization (USI) strategies is typically assessed by household coverage of adequately iodized salt and median urinary iodine concentration (UIC) in spot urine collections. However, household coverage does not inform on the iodized salt used in preparation of processed foods outside homes, nor does the total UIC reflect the portion of population iodine intake attributable to the USI strategy. This study used data from three population-representative surveys of women of reproductive age (WRA) in Kenya, Senegal and India to develop and illustrate a new approach to apportion the population UIC levels by the principal dietary sources of iodine intake, namely native iodine, iodine in processed food salt and iodine in household salt. The technique requires measurement of urinary sodium concentrations (UNaC) in the same spot urine samples collected for iodine status assessment. Taking into account the different complex survey designs of each survey, generalized linear regression (GLR) analyses were performed in which the UIC data of WRA was set as the outcome variable that depends on their UNaC and household salt iodine (SI) data as explanatory variables. Estimates of the UIC portions that correspond to iodine intake sources were calculated with use of the intercept and regression coefficients for the UNaC and SI variables in each country's regression equation. GLR coefficients for UNaC and SI were significant in all country-specific models. Rural location did not show a significant association in any country when controlled for other explanatory variables. The estimated UIC portion from native dietary iodine intake in each country fell below the minimum threshold for iodine sufficiency. The UIC portion arising from processed food salt in Kenya was substantially higher than in Senegal and India, while the UIC portions from household salt use varied in accordance with the mean level of household SI content in the country surveys. The UIC portions and all-salt-derived iodine intakes found in this study were illustrative of existing differences in national USI legislative frameworks and national salt supply situations between countries. The approach of apportioning the population UIC from spot urine collections may be useful for future monitoring of change in iodine nutrition from reduced salt use in processed foods and in households.

Iodine Intake through Processed Food: Case Studies from Egypt, Indonesia, the Philippines, the Russian Federation and Ukraine, 2010-2015.

The current performance indicator for universal salt iodisation (USI) is the percentage of households using adequately iodised salt. However, the proportion of dietary salt from household salt is decreasing with the increase in consumption of processed foods and condiments globally. This paper reports on case studies supported by the Global Alliance for Improved Nutrition (GAIN)-UNICEF USI Partnership Project to investigate processed food industry use of adequately iodised salt in contrasting national contexts. Studies were conducted in Egypt, Indonesia, the Philippines, the Russian Federation, and Ukraine. In all cases, the potential iodine intake from iodised salt in selected food products was modelled according to the formula: quantity of salt per unit of food product × minimum regulated iodine level of salt at production × average daily per capita consumption of the product. The percent of adult recommended nutrient intake for iodine potentially provided by the average daily intake of bread and frequently consumed foods and condiments was from 10% to 80% at the individual product level. The potential contribution to iodine intake from the use of iodised salt in the processed food industry is of growing significance. National USI strategies should encourage co-operative industry engagement and include regulatory monitoring of iodised salt use in the food industry in order to achieve optimal population iodine status.

The Use and Interpretation of Sodium Concentrations in Casual (Spot) Urine Collections for Population Surveillance and Partitioning of Dietary Iodine Intake Sources.

In 2013, the World Health Organization (WHO) called for joint surveillance of population salt and iodine intakes using urinary analysis. 24-h urine collection is considered the gold standard for salt intake assessment, but there is an emerging consensus that casual urine sampling can provide comparable information for population-level surveillance. Our review covers the use of the urinary sodium concentration (UNaC) and the urinary iodine concentration (UIC) from casual urine samples to estimate salt intakes and to partition the sources of iodine intakes. We reviewed literature on 24-h urinary sodium excretion (UNaE) and UNaC and documented the use of UNaC for national salt intake monitoring. We combined information from our review of urinary sodium with evidence on urinary iodine to assess the appropriateness of partitioning methods currently being adapted for cross-sectional survey analyses. At least nine countries are using casual urine collection for surveillance of population salt intakes; all these countries used single samples. Time trend analyses indicate that single UNaC can be used for monitoring changes in mean salt intakes. However; single UNaC suffers the same limitation as single UNaE; i.e., an estimate of the proportion excess salt intake can be biased due to high individual variability. There is evidence, albeit limited, that repeat UNaC sampling has good agreement at the population level with repeat UNaE collections; thus permitting an unbiased estimate of the proportion of excess salt intake. High variability of UIC and UNaC in single urine samples may also bias the estimates of dietary iodine intake sources. Our review concludes that repeated collection, in a sub-sample of individuals, of casual UNaC data would provide an immediate practical approach for routine monitoring of salt intake, because it overcomes the bias in estimates of excess salt intake. Thus we recommend more survey research to expand the evidence-base on predicted-UNaE from repeat casual UNaC sampling. We also conclude that the methodology for partitioning the sources of iodine intake based on the combination of UIC and UNaC measurements in casual urine samples can be improved by repeat collections of casual data; which helps to reduce regression dilution bias. We recommend more survey research to determine the effect of regression dilution bias and circadian rhythms on the partitioning of dietary iodine intake sources.

Performance of rapid test kits to assess household coverage of iodized salt.

OBJECTIVE: The main indicator adopted to track universal salt iodization has been the coverage of adequately iodized salt in households. Rapid test kits (RTK) have been included in household surveys to test the iodine content in salt. However, laboratory studies of their performance have concluded that RTK are reliable only to distinguish between the presence and absence of iodine in salt, but not to determine whether salt is adequately iodized. The aim of the current paper was to examine the performance of RTK under field conditions and to recommend their most appropriate use in household surveys. DESIGN: Standard performance characteristics of the ability of RTK to detect the iodine content in salt at 0 mg/kg (salt with no iodine), 5 mg/kg (salt with any added iodine) and 15 mg/kg ('adequately' iodized salt) were calculated. Our analysis employed the agreement rate (AR) as a preferred metric of RTK performance. Setting/Subjects Twenty-five data sets from eighteen population surveys which assessed household iodized salt by both the RTK and a quantitative method (i.e. titration or WYD Checker) were obtained from Asian (nineteen data sets), African (five) and European (one) countries. RESULTS: In detecting iodine in salt at 0 mg/kg, the RTK had an AR>90 % in eight of twenty-three surveys, while eight surveys had an AR90 %. CONCLUSIONS: The RTK is not suited for assessment of adequately iodized salt coverage. Quantitative assessment, such as by titration or WYD Checker, is necessary for estimates of adequately iodized salt coverage.

Estimation of the Prevalence of Inadequate and Excessive Iodine Intakes in School-Age Children from the Adjusted Distribution of Urinary Iodine Concentrations from Population Surveys.

BACKGROUND: The urinary iodine concentration (UIC), a biomarker of iodine intake, is used to assess population iodine status by deriving the median UIC, but this does not quantify the percentage of individuals with habitually deficient or excess iodine intakes. Individuals with a UIC <100 µg/L or ≥300 µg/L are often incorrectly classified as having deficient or excess intakes, but this likely overestimates the true prevalence. OBJECTIVE: Our aim was to estimate the prevalence of inadequate and excess iodine intake in children (aged 4-14 y) with the distribution of spot UIC from iodine surveys. METHODS: With the use of data from national iodine studies (Kuwait, Oman, Thailand, and Qatar) and a regional study (China) in children (n = 6117) in which a repeat UIC was obtained in a subsample (n = 1060), we calculated daily iodine intake from spot UICs from the relation between body weight and 24-h urine volume and within-person variation by using the repeat UIC. We also estimated pooled external within-person proportion of total variances by region. We used within-person variance proportions to obtain the prevalence of inadequate or excess usual iodine intake by using the Estimated Average Requirement (EAR)/Tolerable Upper Intake Level (UL) cutoff method. RESULTS: Median UICs in Kuwait, Oman, China, Thailand, and Qatar were 132, 192, 199, 262, and 333 µg/L, respectively. Internal within-person variance proportions ranged from 25.0% to 80.0%, and pooled regional external estimates ranged from 40.4% to 77.5%. The prevalence of inadequate and excess intakes as defined by the adjusted EAR/UL cutoff method was ∼45-99% lower than those defined by a spot UIC <100 µg/L or ≥300 µg/L (P < 0.01). CONCLUSIONS: Applying the EAR/UL cutoff method to iodine intakes from adjusted UIC distributions is a promising approach to estimate the number of individuals with deficient or excess iodine intakes.

Universal salt iodization in the Central and Eastern Europe, Commonwealth of Independent States (CEE/CIS) Region during the decade 2000-09: experiences, achievements, and lessons learned.

BACKGROUND: By 2000, the global track record on universal salt iodization (USI) indicated 26% access to adequately iodized salt in the Central and Eastern Europe, Commonwealth of Independent States (CEE/ CIS) Region. OBJECTIVE: Aimed at extracting lessons learned, this study examined experiences, achievements, and outcomes of USI strategies in CEE/CIS countries during the subsequent decade. METHODS: Information from the design, timing, execution, outputs, multi-sector management and results of actions by national stakeholders yielded 20 country summaries. Analysis across countries used a LogFrame Analysis typical for public nutrition development. RESULTS: By 2009, USI strategies had reached the target and population iodine nutrition shown adequate levels in 9 countries, while in 6 others, USI was close and/or population iodine status showed only minor imperfection. True USI, i.e., iodization of salt destined both for the food industry and the household, had been made mandatory in 13 of these 15 countries. In the Balkan area, USI and iodine nutrition advanced more than in CIS. Of the 20 sample countries, 17 (85%) had exceeded the mark of 50% adequate access, while the overall regional score reached 55% by 2010. CONCLUSIONS: Experience from this region suggests that strong partnership collaboration, a new concept in post-Soviet societies, was a major success factor. Voluntary iodization or focusing on household salt alone was less likely conducive for success. Achieving optimum iodine nutrition required the setting of proper iodine standard Weak political leadership insistence in the Russian Federation and Ukraine to embrace USI is the main factor why the region remains behind in the global progress.

The current salt iodization strategy in Kyrgyzstan ensures sufficient iodine nutrition among school-age children but not pregnant women.

OBJECTIVE: Although goitre and cretinism were brought under control in Kyrgyzstan during the 1960s by centrally directed iodized salt supplies, iodine-deficiency disorders (IDD) had made a comeback when the USSR broke up in 1991. Upon independence, Kyrgyzstan started developing its own salt processing industry and by 2001 the Government enacted a law on IDD elimination, mandating universal salt iodization (USI) at 25-55 mg/kg. The present study aimed to evaluate the effectiveness of the USI strategy on the iodine consumption, iodine status and burden of IDD in the population of Kyrgyzstan. DESIGN: A national, population-representative survey during autumn 2007 collected household salt and urine samples of school-age children and pregnant women for quantitative iodine measurements. Thyroid volume was measured by ultrasound. RESULTS: The median iodine content in household salt was 11.2 mg/kg; 97.9 % of salt samples were iodized, but only 39.5 % had >or=15 mg iodine/kg. The median urinary iodine concentration (UIC) of 114 microg/l in children did not differ from the UIC of 111 microg/l in pregnant women. Thyroid volume in pregnant women increased with the duration of pregnancy. Strong relationships existed between salt iodine levels and the UIC values in children and women. CONCLUSIONS: The iodine nutrition status of the Kyrgyz population is highly responsive to household salt iodization. Although the results in children suggest adequate iodine nutrition, the iodine consumption among pregnant women did not assure their dietary requirements. In-depth analysis of the survey data suggest that excess iodine intake is not likely to become a public health concern in Kyrgyzstan when the salt supply meets agreed standards.

An assessment of progress toward universal salt iodization in Rajasthan, India, using iodine nutrition indicators in school-aged children and pregnant women from the same households.

BACKGROUND: In Rajasthan, an Indian State with significant salt production, the sale of non-iodized salt for human consumption was banned in 1992. This study explored the relationships between the use of iodized salt in Rajasthan and the iodine status of children and pregnant women living in the area. METHODS: In a State-wide survey, 30 clusters were selected proportionate-to-population-size and 40 school children, 6-12 years old, were enrolled by random house-to-house visits in each cluster. Twelve pregnant women from the same households were also sampled. Salt used for cooking and a casual urine sample from each child and pregnant woman were collected. The salt iodine content was measured by titration and the urinary iodine concentration (UIC) by a quality-assured colorimetric method. RESULTS: Salt iodine content was >or=15 mg/kg in 41.9% of the households, and 23.0% used non-iodized salt. Median UIC was 139 microg/L in children and 127 microg/L in pregnant women. In households using non-iodized salt, the median UIC's were 96 microg/L and 100 microg/L in children and women, respectively. Dis-aggregating the UIC distributions by salt iodine levels revealed a consistent, step-wise pattern of UIC in children with increasing salt iodine content. A similar but less steep pattern was observed in pregnant women. The iodine status of both children and pregnant women attained the optimal range only when the salt iodine content was close to 30 mg/kg. CONCLUSION: For optimum iodine status in the population of Rajasthan, the iodization of household salt should be mandated at a higher level than what is practiced at present.

Monitoring and evaluation in flour fortification programs: design and implementation considerations.

Designing and implementing effective monitoring and evaluation (M&E) is an integral element of wheat flour fortification programs. This review provides practical guidance for designing a M&E system for a flour fortification program. The Centers for Disease Control and Prevention's Framework for Program Evaluation in Public Health has been adapted to identify key issues in the development of an integrated M&E system. A clear understanding of 1) the stakeholders in flour fortification and their needs, 2) the description and context of the fortification program, 3) the country's wheat flour and flour products market, and 4) the resources available for the M&E component are critical and should be considered early in a program's design.

Risk factors for vitamin A deficiency among preschool aged children in Pohnpei, Federated States of Micronesia.

In 1993, the Department of Health of the Federated States of Micronesia (FSM) conducted a population-based stratified random survey among 355 children aged 24-48 months in Pohnpei, one of the four FSM States. The objective was to determine the prevalence, and explore risk factors for vitamin A deficiency (VAD). Trained field workers collected data from a range of demographic, dietary and socioeconomic variables related to the children. The serum retinol concentration was 19.4 +/- 7.5 microg/dl (mean +/- SD), and the VAD prevalence (serum retinol <20 microg/dl) 53.1 per cent. The significant independent risk factors, determined by logistic regression, were: mother's work at home, sibling <2 years older, rural household located on the main island, early weaning, and child anemia, controlling for pipe water and electricity in the household. If compared with a reference of apparently healthy children of similar age in the USA, the distribution of serum retinol among young Pohnpei children was shifted entirely to low levels. We conclude that eliminating the pervasive VAD problem in Pohnpei would require a multi-pronged tactical approach that combines dietary improvement strategies with the ongoing supplementation effort.

Progress in salt iodization and improved iodine nutrition in China, 1995--99.

In 1993, the State Council of China announced the policy to virtually eliminate iodine-deficiency disorders (IDD) by 2000 and adopted universal salt iodization (USI) as the national strategy. Biennial province-based monitoring from 1995 onward aimed at capturing the use and iodine content of household salt, along with urinary iodine concentrations among schoolchildren from the same households. This paper reports on the progress made in China toward the goal of virtually eliminating iodine-deficiency disorders on the basis of 85 population-representative surveys in China's provinces during 1995--99. The percentage of households using adequately iodized salt (iodine > or = 20 mg/kg) increased from 43.1 % in 1995, to 82.2% in 1997, to 89.0% in 1999. In 1999, at least 90% of the households in 15 (48%) of the 31 provinces used adequately iodized salt, and a median urinary iodine concentration of less than 100 microg/L in children was reported in only one province. Across provinces, the median urinary iodine concentrations in children were positively correlated in each survey year with the median household salt iodine contents (combined r(s) = 0.74, p < .001) and with the proportions of households using adequately iodized salt (combined r(s) = 0.81, p <.001). Also in each survey year, the percentage of children with urinary iodine concentrations of at least 300 microg/L was correlated (combined r(s) = 0.69, p < .001) with the proportion of households using salt with iodine content of at least 40 mg/kg. The median urinary iodine concentration in children had reached 300 microg/L or more in 13 provinces (42%) by 1999. In a little more than five years, then, China has achieved outstanding progress toward the goal of virtual elimination of IDD through USI. Policy recommendations include improvement of quality assurance by salt manufacturers, along with a modest reduction in the mandated salt iodization levels.

Iodine deficiency: consequences and progress toward elimination.

While traditionally associated with cretinism and goiter, iodine deficiency has broad effects on central nervous system development that can occur in the absence of either condition. Any maternal iodine deficiency results in a range of intellectual, motor, and hearing deficits in offspring. This loss in intellectual capacity limits educational achievement of populations and the economic prowess of nations. Progress made since the historic World Summit for Children in 1990 has been outstanding. Approximately 70% of households in the world used iodized salt by 2000, compared with less than 20% in 1990. It is estimated that at least 85 million newborns out of 130 million annual births are protected from a loss in learning ability that would otherwise have occurred. The elimination of iodine deficiency, by expedient production, marketing, and universal consumption of iodized salt, represents a significant development effort in public nutrition. Although globally iodine nutrition has greatly improved, 20% to 30% of pregnancies and thus newborns still do not fully benefit from the use of iodized salt. Countries where success is in evidence could rapidly revert back to deficiency if vigilance is not maintained. Just as success came through concerted public-private-civic actions, making sure that this is expanded and will steadily go on requires continuous collaboration.

Dietary intake and nutritional status of young children in families practicing mixed home gardening in northeast Thailand.

One current initiative to assist rural Thai families to increase home food production and security is the implementation of home gardens that produce fish, small animals, and vegetables. This paper presents the results of an investigation comparing seasonal dietary intake and nutritional status among northeastern Thai children in mixed-gardening and nongardening families (n = 30 for each group). Assignment to the gardening group was based on the presence of a mixed garden, whereas nongardening subjects were randomly selected and matched for comparison. Statistical analysis (paired t-test) indicated that there was no significant difference in the observed biochemical variables (serum retinol, ferritin, hemoglobin) between groups at the p < or = .05 level. Nutritional status in regard to height-for-weight, weight-for-age, and weight-for-height Z scores was better among children of gardening families, although the differences were not significant. The small sample size and reported results indicate that the relationship between the practice of mixed home gardening and dietary intake and nutritional status needs further investigation.