Medical knowledge | Higher education » Z. Sekhniashvili - Concept Paper on Elimination of Iodine Deficiency Disorders in Georgia

Source: http://www.doksinet Z. SEKHNIASHVILI CONCEPT PAPER ON ELIMINATION OF IODINE DEFICIENCY DISORDERS IN GEORGIA 1 Source: http://www.doksinet Iodine Deficiency – Threat to the present and future generations of Georgia Iodine Deficiency Disorders (IDD) are one of the most widespread non-infectious diseases. 15 billion world population is under the risk of inadequate consumption of iodine, almost 655 million have enlarged thyroid gland (endemic goiter), while 43 million – mental retardation due to iodine deficiency. Over the last two decades studies revealed that iodine deficiency is not limited only to endemic goiter. Iodine deficiency causes relatively severe affect on the brain of young children, since induces development of unreversable changes. Even the modest deficiency of iodine can result in reduction of the intellectual potential of the population by 10% that represents a serious threat to intellectual and economic development of the nation. There are no

territories in Georgia where the population is not under the risk of developing iodine deficiency disorders. In the majority of regions screened up to date iodine deficiency in soil and water is reported. Development of goiter in the seaside regions of the country is suggested to be possibly influenced by the Chernobyl incident. In the latest years iodine deficiency was even more increased as a result of significant changes of the food content. Specifically, consumption of sea fish and seafood, rich in iodine has decreased by 3-4 fold. Food products taken by the urban population are mainly locally produced including products gained at household level, that due to the natural iodine deficiency contain low iodine content. The fact that over the recent years iodized salt import to Georgia was actually limited has also played an unfavourable role. What has been done for prevention and treatment of Iodine Deficiency Disorders in Georgia. Since 1921 throughout the Soviet Union, including

Georgia fight against endemic zones was initiated from a principally new position. Planned system for combating endemic goiter was established. At the initial stages the system studied medical-geographic, sanitary-hygienic and clinical aspects in complex with household conditions, drinking water status, nutrition behaviour and other factors contributing to development of the endemic goiter. Prevalence map of the endemic goiter was created, that has evaluated 40 administrative districts out of 72 as endemic zones. In 1935 republican dispensary for combating goiter was established in Tbilisi, followed by opening of the goiter prevention dispensaries in Adjara and Kutaisi. Since 30s implementation of iodine prophylactics represents a crucial aspect of the efforts for combating endemic goiter. In 1939 production of iodine salt was organized in Kutaisi, supplying Svaneti, Racha and Imereti population. The preventive measures significantly reduced goiter epidemic in Georgia. Studies of I

Aslanishvili in the regions revealed reduction of goiter incidence from 42.7% in 1038 to 14% in 1944 2 Source: http://www.doksinet The 37 endemic zones of Georgia were continuously supplied by iodized salt. In addition as a mandatory measure mass prophylactic through antistrumin was undertaken among children, pregnant and lactating women. The anti-goiter regional committees were actively involved in implementation of the above activities. The Georgian scientific literature of the period is rich in works dedicated to the various aspects of the endemic goiter. The bibliography manual “Medicine 1921-1947” lists over 80 articles, monographs and/or books dedicated to the theme. Since 1949 study of the environmental iodine balance was initiated by the research scientists. A correlation was determined between iodine content and goiter prevalence By early 1970s principal differences were achieved in efforts for combating endemic goiter in Georgia. Goiter incidence was substantially

reduced in the endemic areas The most severe manifestations of endemic goiter – endemic cretinism, severe forms of myxedema, etc. were practically eliminated The achieved results facilitated selfconfidence of the health care workers and the population and creation of the illusion for final elimination of the problem. A number of strategic mistakes were also followed, specifically reduction of the iodized salt import, canceling of the goiter dispensaries, etc. The logical reason was simple – we have no goiter, what do we need iodized salt and the goiter dispensaries for. The severe social-economic status of the country, increase of ecological, especially radioecological contamination, deterioration of the sanitaryhygienic conditions, population migration and other factors contributing to iodine deficiency aggravated the existing situation. The joint expeditions of Georgian and foreign scientists revealed really alarming results endemic goiter among the Georgian children comprised

32-87%. In 1997 stemmed from the alarming situation the Ministry of Health of Georgia developed a State Programme on Prevention of Iodine Deficiency Disorders. The goal of the programme is effective management of IDD through implementation of complex treatment-prophylactic measures resulting in reduction of the disorders and liquidation in future. Following activities were planned and implemented within the scope of the programme: 1. Specialized regional centers with appropriate technical facilities (ultrasound, urine iodine excretion testing equipment, etc.) for prevention of IDD were established in Tbilisi, Batumi, Kutaisi, Telavi and Zugdidi. 2. IDD prevention service was established providing free service to the relevant regional population for detection, prevention and treatment of endemic goiter. 3. Population monitoring system for IDD was established and is functioning, epidemiological studies of the diseases are performed, and epidemiological database is established. 4.

Consultation of the endocrinologist was provided to over 500,000 patients 5. Free treatment of the population affected by endemic goiter (II, III level, hypothyroisis, nodular). The charitable society “ ACTS Georgia” has imported 5 million tablets of Levoxil for supporting the programme, that is distributed to all medical 3 Source: http://www.doksinet institutions involved in the programme. The activity enabled to provide treatment not only to children but the total population. Operational (surgical) treatment was also performed among children with nodular goiter with a threat of malignant transformation of the nodule. 6. Training programme for IDD was developed reaching 124 physicians with a specialized training under coordination of the Programme Coordinator and the leading specialists. 7. Information support to the programme was strengthened, that has relevantly increased public demand on iodized salt. According to the relevant sectoral information import of iodized salt in

1999 comprised 1000 tones, while in 2001 – exceeded 10 000 tones. 8. Mass prophylactics by distribution of iodized oil capsules among children, pregnant and lactating women was performed trough joint efforts of the Ministry of Labour, Health and Social Affairs and the United Nations Children’s Fund. The activity representing one of the most important measures supporting the state programme has covered 10 regions of Georgia. 9. For assessment of effectiveness of the iodized oil capsules blood samples were collected from 25 patients per each district for testing on blood TSH and T4 levels as well as urine samples for urine iodine excretion determination. The revealed results (decrease of TSH, increase of T4 and increase of ioduria vs. initial levels) demonstrated the high effectiveness of the iodized oil capsules. 10. District IDD prevention committees were established in 71 areas of Georgia, water and soil iodine content has been measured, that in most cases correlates to the goiter

prevalence within the regions. Universal Salt Iodization – Way to Liquidation of Iodine Deficiency Disorders in Georgia The global coalition targets at actual elimination of IDD world wide for fulfilling the child rights for health, normal physical and mental development. For achievement of the goal the universal iodization of edible salt is supported. Since late 1999 70% of the produced edible salt worldwide is iodized. The success has been achieved by our neighbors in Azerbaijan, Armenia, Eastern Europe (Poland, Czech Republic, Slovakia, Hungary and Bulgaria) and in Asia (China, India and Iran). Currently 90% of the edible salt is iodized in Turkmenistan, while Kyrgyzstan has adopted a law on elimination of IDD through universal salt iodization. Considering the extremely negative impact of iodine deficiency on the present and future generations of Georgia and the international obligations of Georgia, further step for IDD elimination work should be developed and adopted according

to the Law of Georgia, envisaging: 1. Mandatory iodization of edible salt for the population living on the territory of Georgia in compliance to international standards; 2. Complex measures for control of production, import, storage and realization of iodized salt. 4 Source: http://www.doksinet Goal of the Global Commonwealth – Elimination of the Iodine Deficiency In 1999 at the WHO Assembly in Geneva, the WHO General Director, Dr. Gro Harlem Brundtland stated that iodine deficiency represents one of the major reasons for retardation of the mental and psychomotor development of children. IDD elimination will become the victory of the health care system as it was for smallpox and polio eradication. Universal salt iodization will ensure protection of the population from the threat of mental retardation. The world commonwealth targets at IDD elimination at the global scale as envisaged by the global declaration plan for “ensuring survival, protection and development of children”

signed by the President of Georgia along with the signatures of Heads of 90 States. Today IDD elimination is considered as a priority direction by the credible international organizations as the World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF). Georgia can enter the 21st century free from IDD burden and is obliged to do. It is difficult to estimate the cost of health, intellectual and physical capacities lost by the Georgian citizens due to the iodine deficiencies. Less complicated is to assess the gains from the IDD elimination. As per the World Bank estimates investment of 05% GDP into micronutrient malnutrition elimination efforts on average in a short term increases the GDP by 5%. It is difficult to find a more effective investment field with that low cost Global Commonwealth Committed for IDD Elimination by End 2005 1. Resolution of the WHO Assembly 2. Plan of Action endorsed at the world summit (1990, New York) of heads of states and governments,

envisaging IDD elimination by 2000 signed by heads of 159 states. The global efforts implemented over the last decade has changed the IDD geography. IDD prevention programmes resulted in complete elimination of IDD in a number of countries where natural deficiency of iodine is substantial (Sweden, Austria, Norway, Switzerland, Bulgaria, Slovenia, Czech). A number of other countries (Hungary, Yugoslavia, France, Great Britain, Baltic States) are on the way to IDD elimination. Among the ex Soviet Union countries IDD problem was sharply aggravated over the last years. The latter is related to disruption of the iodine prevention programmes and discontinuation of the iodized salt production. 5 Source: http://www.doksinet Iodine deficiency and its meaning Iodine is a crucial microelement for the human body. Iodine is essential in every age, however its deficiency is particularly dangerous for children in early ages, since every organ and tissue, brain, skeleton, as well as intellectual

and physiological potential is formulated from embryo to 3 years of age with participation of the micronutrient. If the iodine deficiency is not filled, subsequently the functional activity of the thyroid gland (t.g) decreases, blood thyroid hormone levels drop, metabolism slows down – hypothyroidism is developed. Thyroid hormone deficiency in fetus and newborns induces even more serious consequences – impairment of CNS development and formation of mental retardation. The level of mental retardation varies from mild (sub-clinical) to evident cretinism. Delarge and Glioroer studies in Belgium demonstrated that even slight reduction of iodine among pregnant women (50-75 mkg in 24 h, N – 150 mkg) results in reduction of free thyroxine level in blood and increase of thyrotropic hormone secretion. Hypothyroidism of the mother before initiation of the fetal t.g function (first 12 weeks) has a negative impact on embryogenesis process and CNS development. The experimental studies

revealed that receptors of the neuronal nucleus have capacity to join T3 before initiation of the fetal t.g function The latter indicates to the importance of the thyroid hormones for development and maturation of the brain. IDD deficient regions demonstrate correlation between the mother’s hypothyroidism and the level of CNS damage to the fetus, since the thyroid hormones influence the differentiation and myelination of neurons. Iodine deficiency results not only in brain damage but also visual, auditory and articulation impairments. Children grow up mentally and physically retarded Persons affected by IDD have lower learning capacities, undertake less complicated tasks, their work is less productive. Studies performed in China demonstrated that the development indices in IDD affected regions were 10-15% lower vs. regions with no IDD Consequences of iodine deficiency are as the iceberg: evident impairments (cretinism) reflect only a minor part of the pathology, while the major part

of the damage is hidden or carries sub-clinical nature. Iodine deficiency affects fertility and livelihood of future generations. Women living in IDD regions have impaired reproductive health, incidence of miscarriages and stillbirths become more frequent, perinatal and infant mortality increases. In order to interrelate all those conditions a term ‘Iodine Deficiency Disorders” was introduced in 1983. The latter envisages all those conditions induced by the impact of iodine deficiency on the growth and development of the organism. 6 Source: http://www.doksinet It is evident, that early stages of development carry far more consequences, starting from the intrauterine life to puberty period. At the same time implementation of iodine prevention programme enables not only to eliminate endemic goiter and cretinism, but also to increase in a short term productivity, human activity and as a result to improve the life quality and achieve public selfconfidence and better quality of

actualization. Spectrum of Iodine Deficiency (Khetzel, 1983) Fetus: - High perinatal mortality - Congenital malformations - Neurological cretinism: Mental retardation DDS, spastic diplegia, strabismus - Myxedematous cretinism: Hypothyroidism, dwarfism Newborn: - Congenital goiter - Congenital hypothyroidism - High mortality Child and Adolescent - Goiter - Juvenile (sub-clinical) hypothyroidism: IQ retardation Retardation of physical development Impairment of RH function development Adult - Goiter and its complications - Hypothyroidism: Reduction of physical work productivity Risk of Hypercholesterinemia and cardiovascular disorders Reduction of intellectual work productivity Women of Reproductive Age Goiter Anemia Reproductive health dysfunction Infertility Miscarriage Pre-term labour Risk of giving birth to child with endemic cretinism Hence, the IDD spectrum is rather wide and covers a range of disorders in the human body, starting from the antenatal period. Al Machavariani, the

Georgian scientist, even in 7 Source: http://www.doksinet early 1925 saw the deepness of the iodine deficiency. He wrote: “there are a range of diseases, that fairly could be considered as chronic epidemics, that eventually carry more victims but due to the slow progress, non-acute reflection does not cause the horrible feeling, as the typhus, cholera and other do.” Strategy for IDD Elimination in Georgia As noted above, majority of Georgian regions has IDD at various levels. As per the data from 1997-98, iodine consumption by the population in Georgia on average comprise 4080 mkg/day vs. the following requirements developed for the adequate development of children and normal functioning of the adult organisms: 1. 2. 3. 4. 90 mkg for children in early ages (2-6 years) 120 mkg for school age children (7-12 years) 150 mkg for adults (over 12 years) 200 mkg for pregnant and lactating women For this reason the preventive programmes should carry a mass nature and should ensure

the entire population of the country with adequate iodine levels. The most straightforward strategy for IDD elimination in Georgia is the USI, meaning that all types of salt consumed by the population should be iodized. Iodized salt is equally essential for livestock. Advantages of using iodized salt for mass prophylactics: 1. All persons consume equal quantity of salt annually; 2. Adding potassium iodate to salt does not changes its taste and smell; 3. Salt iodization technology is simple and accessible in low costs to almost all entrepreneurs. 4. Iodization increases salt’s price by no more than 5%; 5. Quality control of the iodized salt is simple at the production, wholesale and retail levels; Based on above the universal salt iodization is recommended by WHO and UNICEF as the universal and high cost-effective method for IDD elimination at the global scale. For achievement of the optimal iodine level (150 mkg/day) WHO recommends adding 20-40 mkg of iodine to 1 kg of salt. If

iodized salt is widely used in food production, less concentration of iodine is necessary. Iodized salt utilization in food production is not high in Georgia, and therefore 1-kg salt is iodized by 40 mkg iodine. On average consumption of 7-10 g of iodized salt per day within estimated 50% loss adequately ensures the human body with 150-mkg iodine/day. Over the last 2 years import of iodized salt to Georgia has increased almost 10-fold and has reached 10 000 tones per year, although the quantity meets only 70% of the 8 Source: http://www.doksinet requirements, that approximately amounts to 15 000 tones per year. Replacement of unstable potassium iodide by more stable potassium iodate, increase of iodine content in salt has significantly improved the salt quality. Storage/expiry dates increased from 3 to 9-12 months. It was already noted that iodization increases the salt’s price by 5% only Considering the low cost of the product, the consumer does not feel the price difference. As

per the estimates of economists, IDD prevention costs per person comprises less than 20 Tetri per year. At the same time the consumer himself covers prevention costs with no harm to the “pocket”, while bringing substantial benefit to health. The health care system has no other programme of the widespread non-infectious diseases having the same economic benefit. Thus, economic effectiveness, advantages and medical efficiency of the USI programme is clearly evident, although as opposed to infectious diseases (smallpox, polio) IDD could not be eliminated at once and forever. The underlying cause is the ecological deficiency of iodine in water and soil leading to deficiency of the micronutrient in the food products. Only systematic, continuous and controlled system of salt iodization ensures control of the situation over decades and guarantees elimination of the severe disease. Iodine prophylactics story in Georgia is the lesson of IDD return due to discontinuation of the salt

iodization process. On the other hand the prevention system through the salt iodization effectively continues to function since 1922 in Switzerland and USA. Mass and individual iodine prophylactics Iodized salt consumption is the basic method for IDD prevention and the mean for elimination of iodine deficiency. The world’s experience demonstrated that iodized salt has no alternatives, although in certain periods of life (adolescence, pregnancy, and lactation) demand on micronutrients increases and the organism requires regular intake of additional amount of iodine vs. physiological doses In this case individual or mass prophylactics are performed. Mass prophylactics is the prevention measure for specific target groups with increased risk: children, adolescents, pregnant and lactating women, women of reproductive age. Proceeded with regular intake of supplementation containing fixed physiological doses: 1. 2. 3. For children under 12 years – 50-100 mkg/day For adolescents and

adults – 100-200 mkg/day For pregnant and lactating women – 200 mkg/day Individual prophylactic is the prevention in individual persons through long-term intake of preparations containing physiological doses of iodine. One of the methods of mass prophylactics is the use of iodized oil capsules: Iodized oil. IDD prevention and treatment in the regions were due to various reasons (distance, no communication) distribution of iodized salt is complicated and even 9 Source: http://www.doksinet unfeasible, may be undertaken through medications, including oral or IM iodized oil administration. A more frequently used preparation is considered to be the iodized oil – Lipiodol, developed by the Guerbet’s laboratory in Paris. The latter is the oils of containing iodine as 38% of weight. The preparation is doped sub-cutaneously and later absorbed in blood. A capsule of lipiodol contains 200-mkg iodine Prophylactic doses of iodized oil (400 mg iodine) substantially increase urine iodine

excretion for the first 3 days of intake, also affecting the functional parameters of thyroid gland, its dimensions and level of microsomal antibodies. Signs of iodine induced thyrotoxicosis have not been revealed. IDD prevention among school children through the long-term lipiodol capsules (200 mg) ensures normal urine iodine excretion at least for 9 months and decreases goiter prevalence by 50%. At the same time does not affect substantially the autoimmune processes and thyroid gland function. Iodine preparations in Tablets (Potassium Iodide) Intake of 100 mkg Potassium Iodide guarantees normalization of Iodine metabolism in school age children, residing in the regions with moderate or mild iodine deficiency and does not cause any side effects despite receiving throughout the year. Regulation of the preperation intake influences the level of ioduria as well. Daily completion of iodine deficiency ensures sustainable liquidation of iodine deficiency. Discontinued treatment increases

the Iodine concentration in urine, though a median of Iodine renal excretion remains within the mild Iodine deficiency range. Various regimen of intake (daily or 5 days a week) does not impact substantially the quality of treatment: in both cases decreasing of thyroid gland enlargement rate by 1.5-2 fold is observed, as well as thyroid gland volume in majority of pupils. At the same time decrease in of the thyroid dimensions is more remarkable among children with the initial size of thyroid gland (P <0.01) Factors influencing the Iodine content in salt A number of factors influence the Iodine content in salt: 1. massive concentration of iodine in salt. Curerntly addition of 40+/- 10 mkg Iodine per 1kg salt is permissible (considering Iodine massive proportion, not iodate or potassium iodine proportion, which include 59.5% and 765% of Iodine, respectively) in Georgia. Early the State Standards 13893-91 envisaged addition of only 23+/-11 mg Iodine per 1 kg salt. Increasing of Iodine

proportion contributes to Iodine loss compensation in the process of its production, storage and consumption. 2. Iodized supplements. In terms of salt enrichment, Potassium Iodate is preferable, which is more stable than Potassium Iodide and is maintained in the salt much longer (if packed and stored adequately). Currently the national industry applies only Potassium Iodate for salt enrichment. 10 Source: http://www.doksinet Unequal distribution of iodine in salt during production. Salt iodization technology applied in Georgia ensures high homogeneity (25-55 mg/kg) of iodine in salt. Salt packaging and storage conditions. Currently iodized salt is released for retail sale mainly in small polyethylene, pasteboard or paper packages (1kg and less). For the food industry the iodized salt is released as 40kg polypropylene bags. In such bags the Iodine loss does not exceed 10-15% and iodized salt expiry is 9 months (actually the expire period lasts even longer). The salt is to be stored

in dry place, kept from direct sunlight At the household level iodized salt should be kept in a properly closed ware. Impact assessment of iodine deficiency on public health and monitoring of the Iodine Deficiency Disorders Prevention programme in Georgia Information collection and analysis is impossible without effective and reliable indicators. The indicators are necessary for evaluation of existing situation and control of the situation changes subsequently. Generally, there are quantitative indicators, though might be qualitative as well. Indicators are also direct or indirect Biological monitoring aims to assess demand on iodine and to reveal the biological effect of latter on the population level. For this purpose two types of indicators are used: clinical (thyroid gland dimensions) and biochemical (Iodine concentration in urine and TTH level in blood). Epidemiological survey for biological monitoring contributes to fulfillment of various objectives of IDD preventive programme

in specific countries. 1. At the initial stage epidemiological study enables to verify the evidence of Iodine deficiency in the country and its regions and assess the degree of its manifestation. 2. If IDD prevention programme is already implemented, the epidemiological studies will facilitate the evaluation of effectiveness of the implemented activities, and in particular, IDD liquidation will be determined as a public health challenge. 3. If IDD prevention programme is based on universal salt iodization, the outcomes of studies could indicate whether iodine content in the salt is adequate or needs corrections. Currently for assessment of the IDD burden and for utilization within the IDD elimination programme the recommendations of WHO, UNICEF and International Committee for Control of IDD control, issued in November 1992 and revised in September 1993, are in applied. 11 Source: http://www.doksinet EPIDEMIOLOGICAL CRITERIA FOR EVALUATION OF IDD BURDEN Criteria Goiter prevalence %

(palpation data) Goiter prevalence %, Thyroid gland enlargement (Ultrasound data) Urine iodine excretion (median, mkg/l) TTH rate > 5 µU/L during neonatal screening Population IDD burden frequency mild moderate School 5.0-199% 20.0-295% children School 5.0-199% 20.0-299% children severe >30.0% >30.0% School children 50-99 20-49 <20 newborns 3.0-199% 20.0-399% <40.0% Clinical indicator: Goiter prevalence in the population The examination of thyroid gland dimensions by palpation is performed as per the WHO classification (1994). 1. 0 degree – no evidence of Goiter. 2. 1st degree – Goiter is not visible, though it is palpable, and at the same time, each lobule is larger than the patients thumb distal phalange. 3. 2nd degree – Goiter is palpable and visible. The above classification is recommended for definition of thyroid gland dimensions both for clinical purposes and epidemiological survey. Though, the thyroid gland palpation does not give the reliable

results (especially in case of its moderate enlargement). Ultrasound investigation is the alternative method of thyroid gland examination. Evaluation of thyroid gland dimensions by Ultrasound examination. Ultrasound investigation is recommended to define precisely the thyroid gland volume and dimensions. The ultrasound investigation technology is relatively simple and requires determination of the three dimensions of the gland lobules. The volume of each lobule is calculated by means of width (W), length (L) and thickness (T) multiplication by ellipsoid coefficient (0.479) Volume = ((WR+LR+TR)+(WL+LL+TL)) x 0.479 12 Source: http://www.doksinet According to international standards, ultrasound investigation of adults (above 18 years) validates thyroid gland enlargement, if its volume exceeds 18ml in females and 25ml in males. In children the thyroid gland volume is compared with the standard index (by age and body surface indicator, accepted in the regions, where the median of

Iodine concentration in urine exceeds 100mkg/l). The thyroid gland volume depends not only on the child age, but on his/her height and weight as well. Therefore, it is more reasonable to apply the thyroid gland volume standards, calculated in correlation with body surface. The table bellow shows upper limits (97 percentage) of thyroid gland volume norms (ml) by body surface indices, accepted according to studies of Western and Eastern European countries, well-provided with Iodine. THYROID GLAND VOLUME STANDARDS FOR EPIDEMIOLOGICAL STUDIES Body surface square 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 boys 4.7 5.3 6.0 7.0 8.0 9.3 10.7 12.2 14.0 15.8 girls 4.8 5.9 7.1 8.3 9.5 10.7 11.9 13.1 14.3 15.6 Body surface square (BSS) is calculated by the following formula: BSS= B0.425 x P0725 x 7184 x 10-4 B – weight in kg, P – height in cm by special nomogram. Classification of Iodine Deficiency by Goiter prevalence in population Iodine deficiency degree

Goiter prevalence No evidence of Iodine deficiency <5% Mild Moderate Severe 5-19.9% 20.299% >30% 13 Source: http://www.doksinet Prevalence of Endemic Goiter in Georgia (percentage) 60 57.7 54 58.3 55 50 52 47.7 40 44.142 39.538 Georgian Population Child population 30 20 10 0 1997 1998 1999 2000 2001 We should bear in mind, that Goiter prevalence is indirect indicator of Iodine deficiency! Goiter prevalence in certain extent points to the previous, but not current Iodine deficiency. In Iodine deficiency conditions the Goiter distribution takes rather a long time. After the iodine needs normalization number of years are necessary until the Goiter prevalence among pupil declines by 5%. In this connection, Goiter prevalence should be considered as additional indicator of Iodine deficiency. Biochemical indicator: Iodine concentration in urine It is well-known, that more than 80% of Iodine is excreted by kidneys and consequently, Iodine concentration in urine

rather precisely points to the volume of its administration with food. Therefore, Iodine concentration in urine is quantitative, direct indicator Though, due to the Iodine wide-range individual variation in urine, this method cannot be used for assessment of Iodine consumption by particular individuals. And on the contrary, on population level the Iodine concentration in urine completely reflects the Iodine consumption for particular country or region. Currently there are number of laboratories in Georgia, measuring professionally the Iodine concentration in urine. For such kind of tests, it is necessary to equip those labs with appropriate equipment and reagents. When discussing the Iodine deficiency degree, generally, the average value of Iodine concentration in urine – median is applied due to the high variation amplitude of this indicator. Median is an average to which the distribution line is divided into two parts: the equal number of variational series members are distributed

on both sides of median. 14 Source: http://www.doksinet During assessment of Iodine deficiency level it is necessary to take into account not only median index, but Iodine distribution rate in urine with following Iodine concentration ranges: up to 20 mkg/l (severe), 20-49 mkg/l (moderate severity), 50-99 mkg/l (mild) and above 100 mkg/l (no deficiency). This enables provision of particular regions with Iodine. It should be mentioned, that assessment of Iodine concentration in urine during biological monitoring allows to take the situation "snap" reflecting the Iodine provision in particular place and in particular time. Classification of Iodine Deficiency by Iodine concentration in urine on population level Median of Iodine concentration in urine <20 20-49 50-99 100-200 201-299 >300 Degree of Iodine deficiency in urine Iodine severe deficiency Iodine moderate deficiency Iodine mild deficiency Iodine ideal level Moderate increase of Iodine need Increase of Iodine

need Epidemiological study planning During the biological monitoring it is necessary to plan, organize and conduct the epidemiological studies in proper way to assess the situation adequately. In epidemiological studies planning process it is necessary to consider in details the organizational aspect of this activity and involve in it all interested organizations and state bodies. It should be taken into account that usually the epidemiological studies are carried out among school age children and on the basis of schools, therefore the Ministry of Education and the schools authorities ought to issue the appropriate permission. Subsequently, all organizations engaged in the project should receive information on the study outcomes, as well as conclusions and recommendations. Representative group selection As well-known Iodine deficiency most adversely affects children of different age and women of fertility age, among which there is a high risk of having newborns with IDD. From

organizational and scientific points of view it is more reasonable to study school age children, determined by following factor: 1. Practically every child, despite their parents social and property status, goes to school. 2. The study of children may be carried out any time of the year, except of holidays. 3. The level of need in Iodine in pupil representatively manifests the same need in the whole population of considered region. 15 Source: http://www.doksinet Though, the Iodine concentration in urine amongst school age children reflects the need in Iodine for entire population, there are some exceptions from the rule: 1. While the Iodine Deficiency prevention programme envisages use of other methods along with salt general iodination (e.g distribution of Iodine tablets and Iodized oil capsules among children), the Iodine concentration in urine in children may substantially differ from total population data. 2. If children nutrition due to the various reasons is significantly

different from that of the rest of population (e.g children in schools are supplied by iodized bread at lunch), then the iodine indicator in urine will not reflect the "Iodine status" of the whole population. In this case, for more comprehensive evaluation of Iodine provision it seems more reasonable to include in the study the adults as well, first of all pregnant and reproductive age women. Concerning the epidemiological study, it is better to select the children of similar age; 810 year children are more optimal. If in the concerned schools a sufficient amount of those children is unavailable, the age range should be extended up to 6-12 year. Most important in terms of study is the age groups in all schools to be equal (8-10, or 6-12). In target groups the proportion of girls and boys ought to be similar, as well. The epidemiological study should be conducted in school itself. For children examination any facility can be used, though the urine samples collection and

analysis should not take place in medical cabinets to avoid urine steam subsistence into the sample and therefore distortion of results. Evaluation of study results Use of above-mentioned criteria (indicators) along with study results facilitates the unbiased evaluation of concerned territory. Regarding Iodine deficiency assessment usually both criteria are applied. Though, Iodine concentration in urine is a more valuable criterion. Hence, in study evaluation process the priority is given to this indicator. 1. Iodine concentration in urine is an optimal indicator for Iodine consumption through the food and water. From epidemiological point of view it is not necessary to investigate Iodine value in food, water and soil. 2. Iodine subsistence in urine reflects the level of Iodine consumption by population. Along with enhancement of Iodine consumption its concentration in urine is increasing several weeks later. Goiter prevalence in population reflects the Iodine consumption level in the

past (several years ago). Reduction of Goiter prevalence in correlation with Iodine consumption enhancement can be observed only in 2-3 years. 16 Source: http://www.doksinet 3. Iodine concentration in urine within 100-300 mkg/l on average is considered most optimal. The higher level of urine Iodine points to improvement of Iodine consumption Iodine excessive consumption is not hazardous (e.g in Japan median of Iodine concentration in urine exceeds 1000mkg/l), though the incidence of thyrotoxicosis induced by Iodine may increase. In terms of evaluation of IDD prevention programme effectiveness two following criteria are applied: Iodized salt consumption by population and Iodine concentration in urine. The programme is considered effective when more than 90% of population consumes the Iodized salt of high quality. If Iodine value in salt is optimal, the median of its concentration in urine should be within 100-300mkg/l ranges in case of Iodine massive consumption. CRITERIA OF IDD

PREVENTION PROGRAMME EFFICIENCY EVALUATION Indicator Iodine concentration in urine: median Number of samples with concentration < 100mkg/l Number of samples with concentration < 50mkg/l Iodized salt: Number of households consuming Iodized salts of high quality Objective 100-300 <50% <20% >90% Goal of the World Community - Complete liquidation of IDD The World Community aims to liquidate IDD in the whole world. Food general iodination is applied to achieve the goal. Since the end of 1999 the Salt industry provides only Iodized salt. Taking into account the negative effect of Iodine deficiency on contemporary and future generation, in Georgia the law on IDD liquidation should be adopted, which envisages the following: 1. Salt mandatory iodination, which will be consumed by Georgian population and will be in compliance with international standards. 2. Complex of activities concerning control of Iodized salt safety, production and realization. Implementation of biological

monitoring system, epidemiological studies carrying out on population level, medicaments supplying, improvement of education level in medical institutes, provision of large-scale educational activities on IDD among population are essential. The problem of Iodine deficiency, from our point of view, may be solved through the joint efforts of Health institutions, sanitary surveillance and salt manufacturers on the basis of appropriate legislation. 17