Iodine status in a Sherpa community in a village of the Khumbu region of Nepal

Abstract

Objective: To assess the iodine status of Sherpa residents living in Kunde village, Khumbu region, Nepal. Design: Prevalence of goitre was determined by palpation. Urinary iodine concentrations (UIC) were determined in casual morning samples, and thyroid-stimulating hormone (TSH) in finger-prick blood samples on filter paper. Dietary and demographic data were obtained via questionnaire, and selected foods analysed for iodine. Setting: Khumbu region is an area of low soil iodine in Nepal, where the prevalence of goitre was greater than 90 % in the 1960s prior to iodine intervention. Subjects: Two hundred and fifteen of 219 permanent residents of Kunde were studied. Results: Overall prevalence of goitre was 31 % (Grade 1 goitre, 27.0 %; Grade 2, 4.2 %). When adjusted to a world population, goitre prevalence was 27 % (95 % CI 23, 32 %); Grade 2 goitre prevalence was 2.8 % (95 % CI 1.0, 4.6 %). Median UIC was 97 μg/l, but only 75 μg/l in women of childbearing age. Thirty per cent had UIC < 50 μg/l and 52 % had UIC < 100 μg/l, while 31 % of children aged <14 years had UIC > 300 μg/l. Ten per cent of participants had TSH concentrations >5 μU/ml. Conclusions: The prevalence of severe iodine deficiency has decreased since the 1960s, but mild iodine deficiency persists, particularly in women of childbearing age. The consumption of high-iodine uncooked instant noodles and flavour sachets by school-aged children contributed to their low prevalence of goitre and excessive UIC values. This finding may obscure a more severe iodine deficiency in the population, while increasing the risk of iodine-induced hyperthyroidism in children. Ongoing monitoring is essential. © The Authors 2008.