Total Goiter Rate Research Articles

Urinary Iodine Excretion Is the Most Appropriate Outcome Indicator for Iodine Deficiency at Field Conditions at District Level

To empower local authorities to plan and evaluate adequate interventions, appropriate iodine deficiency disorders (IDD) indicators need to be identified. The aim of this study was to describe the magnitude and severity of IDD with different outcome indicators and associate them with functional indicators. Schoolchildren (n = 544) aged 8–10 y were assessed in 11 villages within five subdistricts of Malang District, East Java, Indonesia. Outcome indicators of IDD were goiter size as measured by palpation and ultrasonography (USG), urinary iodine excretion (UIE) and serum thyroid stimulating hormone (TSH) concentration in blood as well as functional indicators such as intellectual performance (IQ: Catell’s Culture Fair Intelligence Test) and anthropometric indices. The total goiter rate (TGR) measured by palpation and USG were 35.7 and 54.4%, respectively. Based on UIE and TSH, the prevalence of iodine deficiency was 63.7 and 3.4%, respectively. In individuals, goiter, thyroid volume and UIE were associated significantly (r = −0.35; P < 0.001 and r = −0.30; P = 0.02 respectively). Among villages, TGR measured by palpation was significantly correlated with thyroid volume (r = 0.61; P = 0.045) and UIE (r = 0.68; P = 0.021), whereas TSH was not significantly associated with any of the observed indicators in individuals or groups. Multiple regression analysis showed that USG (β = −0.67; P < 0.001) and UIE (β = 4.39; P = 0.008) related significantly with cognitive performance (IQ). The associations between IDD indicators and cognitive performance and height-for-age Z scores suggest that socioeconomically advantaged children had better iodine status. We suggest that UIE is the best indicator for local authorities to assess iodine deficiency.

Iodine deficiency disorders in Bangladesh.

An extensive iodine deficiency disorders survey was conducted in Bangladesh in 1993 to assess the latest iodine nutriture status of the country. The clinical variables of the survey were goitre and cretinism, and the biochemical variable was urinary iodine. The "EPI-30 cluster" sampling methodology was followed for selecting the survey sites. In each survey site, the study population consisted of boys and girls, aged 5-11 years, and men and women, aged 15-44 years, in about equal populations. The total number of survey sites was 78 and the total number of respondents was 30,072. The total number of urine samples was 4512 (15% sub-sample). The current total goitre rate (grade 1 + grade 2) in Bangladesh is 47.1% (hilly, 44.4%; flood-prone, 50.7%; and plains, 45.6%). The prevalence of cretinism in the country is 0.5% (hilly, 0.8%; flood-prone, 0.5%; and plains, 0.3%). Nearly 69% of Bangladeshi population have biochemical iodine deficiency (urinary iodine excretion [UIE] < 10 mg/dl) (hilly, 84.4; flood-prone, 67.1%; and plains 60.4%). Women and children are more affected that men, in terms of both goitre prevalence and UIE. The widespread severe iodine deficiency in all ecological zones indicates that the country as a whole is an iodine-deficient region. Important recommendations of global interest are made from the experience of the survey.

Improved cassava-processing can help reduce iodine deficiency disorders in the Central African Republic

Cassava roots are the dominant staple food in the Central African Republic (CAR). A study on Iodine Deficiency Disorders (IDD) comparing two areas in the western and central parts of CAR revealed that cassava roots were consumed daily in all interviewed households. High-yielding potentially toxic “bitter” varieties dominated the cultivations in both areas. Iodine-excretion was equally low in both areas studied but total goitre rate was 28% in the central area and 50% in the western area. The thorough traditional processing-method strictly adhered to in the central study area effectively removed cyanogens as indicated by low urinary thiocyanate. Frequent shortcuts in processing in the western area resulted in cyanide exposure as indicated by urinary thiocyanate levels three times higher. We conclude that insufficiently processed cassava aggravates IDD in parts of CAR. However, the goitrogenic effect is due to shortcuts in traditional processing practices and not to the consumption per se of this high-yielding tropical staple crop. Since low iodine intake is the main cause of IDD and well-processed cassava is not goitrogenic, iodine supplementation should be the main preventive intervention but promotion of effective cassava processing can be complementary. Promotion of cassava varieties with low levels of cyanogenic glucosides should not be attempted until it has been demonstrated that such varieties perform well in the local farming and food system.

Prevalence of iodine deficiency disorders in adolescents.

In the present study the iodine status of 300 adolescent boys and girls was assessed by clinical examination and biochemical tests. The clinical examination revealed the total goitre rate (TGR) to be 65.2% among boys, and 69.6% among girls. The visible goitre rate (VGR) was 17.7% among boys and 21.1% among girls. Nutritional status of all adolescents was found to be poor as compared to their well-nourished counterparts. Using discriminant analysis it was found that age, height and weight of the adolescents were significantly related to goitre grade (p < 0.001), and they are important in prediction of goitre. Mild and moderate iodine deficiency were found to be prevalent among the adolescents. On the basis of urinary iodine/creatinine ratio, 38% of the adolescents were found to be suffering from mild iodine deficiency, i.e. average urinary iodine excretion between 50-100 mcg iodine/g creatinine. Moderate iodine deficiency (< 50 mcg iodine/g creatinine) was found to be prevalent among 12.4% of the adolescents. The results of this study indicate a high prevalence of mild and moderate IDD among the adolescents studied.

A High Prevalence of Hypothyroidism in Association with Endemic Goitre in Zimbabwean Schoolchildren

One-hundred-and-eighty-eight ostensibly normal, pubertal schoolchildren, aged 9-16 years, residing in Chinamora Communal Land, Zimbabwe, had blood taken to assess thyroid function. Total goitre rate in the area was 44 per cent in primary schoolchildren: 91 of the subjects tested were goitrous. Thyroid stimulating hormone levels (TSH) were above normal (5.0 mu/l) in 66 subjects overall, of whom 39 were goitrous. The 36 subjects with TSH levels above 7.0 mu/l also had total thyroxine (T4) estimations performed: of these, 19 were below 60 nmol/l. The results indicate a high prevalence of hypothyroidism in this at risk group. The implications of these results are discussed, notably the impairment of mental function that is likely to result.