Dietary iodine supplements not only have no harmful effect on the neurodevelopment of the children, they may even be beneficial. Given the possible presence of confounding variables not controlled for in this study, these findings should be considered as preliminary.

Glucokinase (GK) is a glycolytic key enzyme that functions as a glucose sensor in the pancreatic ␤-cell, where it governs glucose-stimulated insulin secretion (GSIS). Heterozygous inactivating mutations in the glucokinase gene (GCK) cause a mild form of diabetes (maturityonset diabetes of the young [MODY]2), and activating mutations have been associated with a mild form of familial hyperinsulinemic hypoglycemia. We describe the first case of severe persistent hyperinsulinemic hypoglycemia due to a "de novo" mutation in GCK (Y214C). A baby girl presented with hypoglycemic seizures since the first postnatal day as well as with inappropriate hyperinsulinemia. Severe hypoglycemia persisted even after treatment with diazoxide and subtotal pancreatectomy, leading to irreversible brain damage. Pancreatic histology revealed abnormally large and hyperfunctional islets. The mutation is located in the putative allosteric activator domain of the protein. Functional studies of purified recombinant glutathionyl Stransferase fusion protein of GK-Y214C showed a sixfold increase in its affinity for glucose, a lowered cooperativity, and increased k cat . The relative activity index of GK-Y214C was 130, and the threshold for GSIS predicted by mathematical modeling was 0.8 mmol/l, compared with 5 mmol/l in the wild-type enzyme. In conclusion, we have identified a de novo GCK activating mutation that causes hyperinsulinemic hypoglycemia of exceptional severity. These findings demonstrate that the range of the clinical phenotype caused by GCK mutations varies from complete insulin deficiency to extreme hyperinsulinemia. Diabetes

The benefits of iodine supplements during pregnancy remain controversial in areas with a mild-to-moderate iodine deficiency. The aim of the present study was to determine the effect of improving iodine intakes, with iodised salt (IS) or iodine supplements, in pregnant Spanish women. A total of 131 pregnant women in their first trimester were randomly assigned to three groups: (1) IS in cooking and at the table, (2) 200 mg potassium iodide (KI)/d or (3) 300 mg KI/d. No differences were found in thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3) or thyroid volume (TV) between the three groups. Regardless of the group in which women were included, those who had been taking IS for at least 1 year before becoming pregnant had a significantly lower TV in the third trimester (P¼0·01) and a significantly higher urinary iodine in the first (173·7 (SD 81·8) v. 113·8 (SD 79·6) mg/l, P¼0·001) and third trimesters (206·3 (SD 91·2) v. 160·4 (SD 87·7) mg/l, P¼0·03). Also, no differences were seen in TSH, FT4 or FT3. Children's neurological development was not significantly associated with the consumption of IS for at least 1 year before becoming pregnant and no differences were found according to the treatment group. In conclusion, in pregnant women with insufficient iodine intake, the intake of IS before becoming pregnant was associated with a better maternal thyroid function. The form of iodide intake was not associated with maternal thyroid function or children's neurological development.

The association between iodine deficiency and poor mental and psychomotor development is known. However, most studies were undertaken in areas of very low iodine intake. We investigated whether a similar association is found in schoolchildren from southern Europe with a median urinary iodine output of 90 microg/liter. Urinary iodine levels were measured in 1221 children who also completed a questionnaire about their usual dietary habits. Intelligence quotient (IQ) was measured by Cattell's g factor test. IQ was significantly higher in children with urinary iodine levels above 100 microg/liter. The risk of having an IQ below the 25th percentile was significantly related to the intake of noniodized salt and drinking milk less than once a day. As expected, the risk of having an IQ below 70 was greater in children with urinary iodine levels less than 100 microg/liter. In conclusion, this study demonstrates that the IQ of schoolchildren in a developed country can be influenced by iodine intake. The results support the possibility of improving the IQ of many children from areas with mild iodine deficiency by ensuring an iodine intake sufficient to achieve a urinary iodine concentration greater than 100 microg/liter.

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The aim of this study was to determine the relationship between auditory capacity and urinary iodine, taking into account thyroid volume and function, in a population of school-age children. Audiometry was carried out in 150 children (ages 6-14 years), together with measurements of thyroid volume, thyrotropin (TSH), free T3, free T4, thyroglobulin, antiperoxidase and anti-TSH receptor antibodies, as well as iodine in a casual urine sample. Children with a TSH >5 microU/mL were excluded from the study. In the children with palpable goiter, there was an inverse relation between the auditory threshold at all frequencies and ioduria. Children with thyroglobulin values >10 ng/mL had a higher auditory threshold at all frequencies. In the children with palpable goiter and ioduria <100 microg/L, the levels of thyroglobulin and ioduria and the age accounted for 75% of the decibel (dB) variance at 2000 (Hertz), with similar results at other frequencies. The children with a thyroid sized at the >95th percentile had an odds ratio of 3.86 (95% confidence interval: 2.59-5.10) of having a threshold >20 dB. The results warn that iodine prophylaxis is needed to prevent not only goiter but also other iodine-deficiency disorders, such as involvement of the auditory threshold in school-age children.

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Hypoglycemia is the most common adverse event associated with insulin treatment in diabetes. The consequences of hypoglycemia can be quite aversive and potentially life threatening. The physical sequelae provide ample reason for patients to fear hypoglycemia and avoid episodes. For these reasons, our purpose in this study was to develop a new measure that explores specific fear of hypoglycemia (FH) in adult patients with type 1 diabetes and to examine its psychometric properties. The instrument developed to assess FH was initially made up of 20 items, of which 18 were negative and 2 were positive, assessed on a 5-point Likert scale (1-5). This scale was completed by 229 patients with type 1 diabetes. Additionally, a structured interview and a closed question called subjective fear of hypoglycemia were included as diagnostic criteria. A factor analysis employing the principal-components method and promax rotation was carried out, resulting in a new scale composed of 15 items. Three factors (fear, avoidance, and interference) were obtained and explained 58.27% of the variance. The scale showed good internal consistency (Cronbach's α = .891) and test-retest reliability (r = .908, p < .001), as well as adequate concurrent and predictive validity. The cutoff score that provided the highest overall sensitivity and specificity was set at 28 points. The Fear of Hypoglycemia 15-item scale (FH-15) demonstrated good reliability and validity. This study suggests that the new instrument may serve as a valuable measure of specific FH for use in research and clinical practice.