Epidemiology of endemic cretinism in Sikkim, India.

A survey was conducted in Sikkim to determine the prevalence of endemic cretinism in the state. A household was the basic sampling unit. Villages were selected randomly in the state and from these households were selected randomly using the electoral lists. All members of the households were studied. Total of 17,837 individuals from 3,197 households from 249 villages were studied. There were 8,953 males and 8,884 females. A total of 617 endemic cretins were identified: 316 males and 301 females. The overall prevalence of endemic cretinism was 3.46%: (males 3.53% and females 3.39%). Endemic cretinism was observed in 194 (77.9%) villages studied. Neurological cretinism was the predominant form (98.7%). Deaf-mutism was the most salient neurological feature seen in 472 (76.5%) subjects. Motor system examination revealed proximal spasticity and brisk reflexes, both more marked in the lower limbs. Recording of daily life activities revealed 14.1% of the cretins to be totally dependent and another 23% to be requiring considerable assistance for their daily routine activities. The overall prevalence of goitre found in this survey was 54%. Urinary iodine concentration was estimated from a representative sample of the population; mean 4 micrograms/dl (SD 2.68). This survey shows the existence of severe iodine deficiency in Sikkim.

Thyroid function in a goitre endemia.

A study was conducted to determine the thyroid function in a goitre endemia. Sadam is small village in the south district of Sikkim. Severe iodine deficiency exist in this village (prevalence of goitre 73.5%, cretinism prevalence 4%; mean urinary iodine exeretion 4.13 ng/dl - SD 3.1). Total of 72 out pf 142 households were randomly selected. All the inmates of the households above 14 years of age were examined for goitre and blood samples were collected from them for estimation of concentration of thyroid stimulating hormones (triiodothyroine T-3, thyroixe T-4) and thyroid stimulating hormone (TSH). Total of 244 subjects were examined, (137 males and 107 females). Goitre was detected in 149 (61.1%) individuals. The mean T-3, T-4 and TSH concentrations in the non-goitrous groups were (SD in parenthesis) 110.13 ng/dl (26.19), 10.12 ug/dl (2.38) and 1.01 uu/ml (0.52). The corresponding values for the goitrous group were, 132.22 ng/dl (46.25), 9.06 ug/dl (2.04) and 1.33 uu/ml (1.19). The differences in the mean concentrations between the goitrous and non-goitrous groups were statistically significant. An inverse correlation between the goitre size and T-4 on the one hand, and TSH and T-4 on the other hand was noticed. The result of the study show that functional decompensation of the thyroid occur in the majority of goitrous subjects.

Iodine deficiency disorders in school children of Sikkim.

Sikkim is a small state in the eastern Himalayas. A survey was conducted to determine the prevalence of iodine deficiency disorders in the state. A two stage sampling procedure was adopted. In stage one, all villages in the state were listed and 249 were randomly selected for the survey. In stage two, households, were randomly selected from the selected villages using the electoral lists. The basic sampling unit was a household and all members of the households were studied. A total of 17,837 subjects were studied from 3,197 households of 249 villages. Overall prevalence of goitre and cretinism in the community as a whole, were 54.03% and 3.46% respectively. Of the population studied, 5939 were children in the age group of 5 to 16 years. There were 3,005 boys and 2,934 girls. Goitre was detected in 3,381 (56.9%). Goitre prevalence in the boys was 55.4% and in girls it was 58.5% (p = < 0.05). Grade I goitre was seen in 2,472 (73.1%), grade II in 888 (26.3%) and grade III in 21 (0.6%). Endemic cretinism was diagnosed in 175 subjects (2.9%). Cretinism prevalence in the boys was 3.1%, and in girls in was 2.8% and this difference was not significant. Neurological; cretinism was the predominant form (98.3%). Estimation of urinary iodine concentration in 167 subjects revealed the mean concentration to be 3.64 u/dl (SD 2.47). The median value was ug/dl indicating the skewed distribution of the urinary iodine concentration. The study shows the existence of severe iodine deficiency in the school-aged children of Sikkim.(ABSTRACT TRUNCATED AT 250 WORDS)

Intellectual and motor functions in school children from severely iodine deficient region in Sikkim.

High prevalence of endemic goitre (54%) and endemic cretinism (3.5%) exist in Sikkim. The level of intellectual functioning and motor performance were assessed in 90 school children in the age group of 10 to 12 years selected randomly from four severely iodine-deficient villages. Bender Visual Motor Gestalt Test, Binet-Kamat Test for mental ability and Raven's Coloured Progressive Matrices were the tests used. The results show an impairment in intellectual and other neuropsychological functions in a high percentage of the children. Visuomotor coordination was poor in 62 (69%). Binet-Kamat test results showed that 19 (21%) children were intellectually subnormal (IQ < 70). Majority of the children (> 80%) had significant impairment in language, meaningful memory, non-meaningful memory, conceptual thinking, numerical reasoning and motor skills. The children did better on non-verbal reasoning and social intelligence. Goitre was detected in 82 (91.1%). Urine samples for iodine estimations was collected from every second child examined. The mean urinary iodine concentration was 4.23 micrograms/dl (SD 2.16). Urinary iodine concentration was less than 2 micro gm/dl in 26.1% (11 children) and less than 5 micro gm/dl in 84.8% (39 children) indicating severe iodine deficiency. The test results show impairment of psychomotor development in children born and brought up in iodine-deficient environment.

Clinical study of endemic cretinism in south Sikkim.

One hundred individuals suffering from Endemic Cretinism were studied. There were 55 males and 45 females. 62% of the cretins had visible goitre. Thirty nine (62.9%) goitrous cretins had grade II goitre. Neurological cretinism was the predominant type encountered (99%) and Myxoedematous cretinism was seen in only one patient. The most salient neurological feature was deaf-mutism seen in 74%. Findings in the motor system were, apart from deaf-mutism, the most characteristic feature of the condition on clinical examination. 58% had exaggerated deep tendon reflexes and 31% had extensor plantar response. Squint was noticed in 29%. Familial aggregation was noticed and was striking. Endemic cretinism is a distinctive and easily identifiable clinical entity and is an important indicator of the severity of iodine deficiency in a community.