Population Survey of Iodine Deficiency and Environmental Disruptors of Thyroid Function in Young Children in Haiti.

Context: Iodine deficiency is the leading cause of preventable neurodevelopmental delay in children worldwide and a possible public health concern in Haiti. Objective: To determine the prevalence of iodine deficiency in Haitian young children and its influence by environmental factors. Design: Cross-sectional study, March through June 2015. Setting: Community churches in 3 geographical regions in Haiti. Participants: 299 healthy Haitian children aged 9 months to 6 years; one-third each enrolled in a coastal, mountainous, and urban region. Main Outcome Measures: Urinary iodide, serum thyrotropin (TSH), goiter assessment, and urinary perchlorate and thiocyanate. Results: Mean age was 3.3±1.6 years, with 51% female, median family income USD 30/week, and 16% malnutrition. Median urinary iodide levels were normal in coastal (145 µg/L, interquartile range [IQR] 97 to 241) and urban regions (187 µg/L, IQR 92 to 316), but revealed mild iodine deficiency in a mountainous region (89 µg/L, IQR 56 to 129), P < 0.0001. Grade 1 goiters were palpated in 2 children, but TSH values were normal. Urinary thiocyanate and perchlorate concentrations were not elevated. Predictors of higher urinary iodide included higher urinary thiocyanate and perchlorate, breastfeeding, and not living in a mountainous region. Conclusions: Areas of mild iodine deficiency persist in Haiti's mountainous regions. Exposure to two well-understood environmental thyroid function disruptors is limited.

Congenital hypothyroidism caused by excess prenatal maternal iodine ingestion.

We report the cases of 3 infants with congenital hypothyroidism detected with the use of our newborn screening program, with evidence supporting excess maternal iodine ingestion (12.5 mg/d) as the etiology. Levels of whole blood iodine extracted from their newborn screening specimens were 10 times above mean control levels. Excess iodine ingestion from nutritional supplements is often unrecognized.

Effect of environmental perchlorate on thyroid function in pregnant women from Córdoba, Argentina, and Los Angeles, California.

OBJECTIVE: To determine whether environmental perchlorate exposure adversely affects thyroid function in women in the first trimester of pregnancy. METHODS: First-trimester pregnant women were recruited from prenatal clinics in the Los Angeles County Hospital, Los Angeles, California, and in the Hospital Universitario de Maternidad dependent Universidad Nacional de Córdoba, Córdoba, Argentina, between 2004 and 2007. Spot urine and blood specimens were obtained during the clinic visit. Urinary perchlorate, iodine, and creatinine were measured, and thyroid function tests were performed. RESULTS: The study included 134 pregnant women from Los Angeles, California (mean gestational age ± SD = 9.1 ± 2.2 weeks), and 107 pregnant women from Córdoba, Argentina (mean gestational age = 10.0 ± 2.0 weeks). Median urinary iodine values were 144 µg/L in California and 130 µg/L in Argentina. Urinary perchlorate levels were detectable in all women (California: median, 7.8 µg/L [range, 0.4-284 µg/L] and Argentina: median, 13.5 µg/L [range, 1.1-676 µg/L]). Serum thyroperoxidase antibodies were detectable in 21 women from California (16%) and in 17 women from Argentina (16%). Using Spearman rank correlation analyses, there was no association between urinary perchlorate concentrations and serum thyrotropin, free thyroxine index, or total triiodothyronine values, including within the subset of women with urinary iodine values less than 100 µg/L. In multivariate analyses using the combined Argentina and California data sets and adjusting for urinary iodine concentrations, urinary creatinine, gestational age, and thyroperoxidase antibody status, urinary perchlorate was not a significant predictor of thyroid function. CONCLUSIONS: Low-level perchlorate exposure is ubiquitous, but is not associated with altered thyroid function among women in the first trimester of pregnancy.

Evidence of endemic goiter and iodine deficiency in a mountainous area of Haiti.

OBJECTIVE: To investigate reports of iodine-deficiency disorder in a specific area of Haiti. METHODS: In March 2008, this cross-sectional study was performed in an area 15 miles northeast of Jacmel, Haiti, within the Chaîne de la Selle Mountains. Before arrival of the study team, an announcement was made throughout local villages soliciting volunteers to meet at a central location. Of those who arrived, participants were selected in an attempt to sample individuals from all age groups, regardless of goiter status. After providing verbal informed consent, each participant was photographed and assigned a number to be used to protect privacy. An examiner performed palpation of the thyroid gland on each participant in accordance with World Health Organization criteria. Results of palpation were classified into 3 grades: grade 0, the thyroid gland was not palpable; grade 1, the thyroid gland was palpable but not visible; and grade 2, the thyroid gland was palpable and visible while the patient was in a normal position. Casual urine samples were collected from each participant and analyzed spectrophotometrically for urinary iodine concentration. RESULTS: Eighty-eight individuals aged 2 to 72 years participated in the study. Median urinary iodine concentration was 39 microg/L. Of the 88 participants, 82 (93%) were iodine deficient (18 [20%] were severely deficient), and 45 (51%) had goiter on physical examination, including 27 with grade 1 goiters and 18 with grade 2 goiters. CONCLUSIONS: We have documented iodine deficiency with associated endemic goiter in this previously uninvestigated Haitian population, for which world health agencies currently lack definitive data. These data have potential implications for both the local area and the country as a whole where further evaluation and treatment are needed for persons at high risk for iodine-deficiency disorder.