Prieto, Laura; Méndez, Virginia; Chiesa, Ana; Bengolea, Sonia; Gruñeiro-Papendieck, Laura.
La deficiencia de yodo es reconocida a nivel mundial como la primera causa de retardo mental evitable. El yodo es esencial para proveer una concentración adecuada de tiroxina necesaria para el buen desarrollo cerebral. La yoduria constituye el parámetro poblacional más preciso para determinar la suficiencia del aporte yodado. Objetivo: dada la vulnerabilidad de la población materno infantil a la carencia de yodo se propuso estudiar la yoduria en tres grupos etarios: G1: recién nacidos, G2: escolares de 6 a 12 años de vida y G3: embarazadas en el tercer trimestre de gesta de la zona urbana de la ciudad de Buenos Aires para determinar la suficiencia del aporte y el riesgo poblacional. Se calcularon mediana (M) y percentilo (P) de todos los grupos y se aplicó el criterio de suficiencia establecido por la OMS/ICCIDD Resultados: El Grupo 1: M: 232 ug/l P20: 120.66 ug/l; Grupo 2: M: 143.4 ug/l P20: 59.2 ug/l; Grupo 3: M: 137.5 ug/l P20: 99 ug/l. En nuestra población los valores obtenidos muestran que el umbral crítico de 100 ug/l como indicador de insuficiencia es superado por todos los grupos y que el porcentaje de población con yodurias menores de 50 ug/l es bajo, demostrando que en la ciudad de Buenos Aires el déficit de yodo se encuentra adecuadamente corregido en la población materno infantil.
Iodine deficiency has been well recognized as the world’s leading cause of preventable intellectual impairment. Iodine is essential to provide adequate levels of thyroid hormones necessary for pre and post natal brain development and urinary iodine (UI) concentration is the best indicator of the adequacy of iodine intake for the population. According to WHO/ICCIDD median urinary iodine concentrations in a iodine sufficient population should be > 100 ug/l and no more than 20 % of the population should have UI levels <50 ug/l. This supposes an opMuntimal intake of 150 ug of iodine per day. UI between 50 and 99 ug/l points out moderate d iodine deficiency while UI between 20 y 49 ug/l mild and < 20 ug/l severe insufficiency In regard of mother and child vulnerability to iodine deficiency UI was studied in three different groups, all residents of Buenos Aires City: Group 1 (G1): 109 newborn (3 to 7 days of life) studied at maternity discharge, Group 2 (G2): 101 scholars (6-12 years of age), Group 3 (G3): 32 healthy pregnant women without history of thyroid disorders , during their third trimester of pregnancy UI was determined in samples obtained at maternity discharge in G1 and in casual samples in G2 and 3. Sandell & Kolthof method with Pino’s modification was used. Concentrations in the range of 1.10 (DMD) to 250 ug/l were recognized . Results were analyzed according to their distribution in median (M) and percentiles (P) and WHO/ICCIDD criteria were applied to each group. Results Obtained results are shown in table 1and figures 1,2,3. For G1 median UI was 232 ug/l (range: 8.9 ug/l – 393.8 ug/l).20th percentile (P20) 120.66 ug/l. Only 8.25 % of newborn had a UI < 50 ug/l ( table 1, Fig 1) In G2 (figure 2) median was 143.4 ug/l (range 8.9 ug/l-381.5 ug/l). P20: 59.2 ug/l. 15.80 % of scholars showed UI levels< 50 ug/l. ( table 1,Fig 2) Figure 3 shows that G 3 had a median UI of 137.5 ug/l (range 37.8 ug/l-244.5 ug/l ) and P 20: 99 ug/l. Only 3.1 % of pregnant women had a UI < 50 ug/l (table 1, Fig 3). When applied to each population OMS /ICCIDD criteria showed that all of them were above the critical threshold of 100 ug/l and that people with UI levels <50 ug/l represented al low percentage of our studied groups. So, it can be concluded that in Buenos Aires City iodine deficiency is adequately corrected, and mothers and children who are more vulnerable to deficiency are not prone to have thyroid disorders for this reason. Nevertheless, monitoring of iodine population status should be performed periodically.